Cool Roofing Technologies

Hashem Akbari Heat Island Group

Ernest Orlando Lawrence Berkeley National Laboratory

Tel 510-486-4287 E_mail H_AkbariLBLgov

httpHeatIslandLBLgov

STEAB Visit to LBNL August 14 2007

2

Orthophoto of Sacramento

3

Under the Canopy Fabric of Sacramento CA

0

10

20

30

40

50

60

70

80

Downtown Industrial Industrial Office Com Com Res

o

f sur

face

are

a

Grass Roofs Pavements Others

Cooling roofs by increasing solar reflectance

bull A conventional dark roof absorbs most sunlight

bull Increasing solar reflectance frac34 reduces solar heat gain frac34 lowers roof temperature

bull High thermal emittance frac34 facilitates radiative cooling frac34 helps keep roof temperature low

bull Lowering roof temperature can reduce frac34 building cooling electricity use frac34 peak power demand

4

frac34 ambient air temperature

Environmental impacts of cooling roofs

bull Benefits frac34 increased human comfort frac34 slowed smog formation frac34 mitigation of urban heat islands in summer frac34 decreased waste from disposal of roofs

bull Penalties frac34 slightly higher wintertime heating energy use frac34 degraded wintertime urban air quality

5

Direct and Indirect Effects of Light-Colored Surfaces

bullDirect Effect - Light-colored roofs reflect solar radiation reduce air-

conditioning use

bullIndirect Effect - Light-colored surfaces in a neighborhood alter surface

energy balance result in lower ambient temperature

6

7

Methodology Energy and Air-Quality Analysis

Slows Reaction

Rates

Cooler Roofs

Cooler Pavements

All Vegetation

Cooler Roofs

Shade Trees

Reduces Outdoor Temps

Lower CO2 NOx and

VOC Levels

Reduces AC Use

Less Energy

Consumed

Reduces Demand at

Power Plants

Area Sources

Emit Less

Direct

Lower Ozone Levels

Indi

rect

Strategies Processes Results

White Roofs Measured Cooling Savings

bull Sacramento 80 in a house 35 in two school bungalows

bull Florida 10-43 in several houses average 19

bull California and Florida 5ndash20 in several commercial buildings

8

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

3

Under the Canopy Fabric of Sacramento CA

0

10

20

30

40

50

60

70

80

Downtown Industrial Industrial Office Com Com Res

o

f sur

face

are

a

Grass Roofs Pavements Others

Cooling roofs by increasing solar reflectance

bull A conventional dark roof absorbs most sunlight

bull Increasing solar reflectance frac34 reduces solar heat gain frac34 lowers roof temperature

bull High thermal emittance frac34 facilitates radiative cooling frac34 helps keep roof temperature low

bull Lowering roof temperature can reduce frac34 building cooling electricity use frac34 peak power demand

4

frac34 ambient air temperature

Environmental impacts of cooling roofs

bull Benefits frac34 increased human comfort frac34 slowed smog formation frac34 mitigation of urban heat islands in summer frac34 decreased waste from disposal of roofs

bull Penalties frac34 slightly higher wintertime heating energy use frac34 degraded wintertime urban air quality

5

Direct and Indirect Effects of Light-Colored Surfaces

bullDirect Effect - Light-colored roofs reflect solar radiation reduce air-

conditioning use

bullIndirect Effect - Light-colored surfaces in a neighborhood alter surface

energy balance result in lower ambient temperature

6

7

Methodology Energy and Air-Quality Analysis

Slows Reaction

Rates

Cooler Roofs

Cooler Pavements

All Vegetation

Cooler Roofs

Shade Trees

Reduces Outdoor Temps

Lower CO2 NOx and

VOC Levels

Reduces AC Use

Less Energy

Consumed

Reduces Demand at

Power Plants

Area Sources

Emit Less

Direct

Lower Ozone Levels

Indi

rect

Strategies Processes Results

White Roofs Measured Cooling Savings

bull Sacramento 80 in a house 35 in two school bungalows

bull Florida 10-43 in several houses average 19

bull California and Florida 5ndash20 in several commercial buildings

8

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cooling roofs by increasing solar reflectance

bull A conventional dark roof absorbs most sunlight

bull Increasing solar reflectance frac34 reduces solar heat gain frac34 lowers roof temperature

bull High thermal emittance frac34 facilitates radiative cooling frac34 helps keep roof temperature low

bull Lowering roof temperature can reduce frac34 building cooling electricity use frac34 peak power demand

4

frac34 ambient air temperature

Environmental impacts of cooling roofs

bull Benefits frac34 increased human comfort frac34 slowed smog formation frac34 mitigation of urban heat islands in summer frac34 decreased waste from disposal of roofs

bull Penalties frac34 slightly higher wintertime heating energy use frac34 degraded wintertime urban air quality

5

Direct and Indirect Effects of Light-Colored Surfaces

bullDirect Effect - Light-colored roofs reflect solar radiation reduce air-

conditioning use

bullIndirect Effect - Light-colored surfaces in a neighborhood alter surface

energy balance result in lower ambient temperature

6

7

Methodology Energy and Air-Quality Analysis

Slows Reaction

Rates

Cooler Roofs

Cooler Pavements

All Vegetation

Cooler Roofs

Shade Trees

Reduces Outdoor Temps

Lower CO2 NOx and

VOC Levels

Reduces AC Use

Less Energy

Consumed

Reduces Demand at

Power Plants

Area Sources

Emit Less

Direct

Lower Ozone Levels

Indi

rect

Strategies Processes Results

White Roofs Measured Cooling Savings

bull Sacramento 80 in a house 35 in two school bungalows

bull Florida 10-43 in several houses average 19

bull California and Florida 5ndash20 in several commercial buildings

8

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Environmental impacts of cooling roofs

bull Benefits frac34 increased human comfort frac34 slowed smog formation frac34 mitigation of urban heat islands in summer frac34 decreased waste from disposal of roofs

bull Penalties frac34 slightly higher wintertime heating energy use frac34 degraded wintertime urban air quality

5

Direct and Indirect Effects of Light-Colored Surfaces

bullDirect Effect - Light-colored roofs reflect solar radiation reduce air-

conditioning use

bullIndirect Effect - Light-colored surfaces in a neighborhood alter surface

energy balance result in lower ambient temperature

6

7

Methodology Energy and Air-Quality Analysis

Slows Reaction

Rates

Cooler Roofs

Cooler Pavements

All Vegetation

Cooler Roofs

Shade Trees

Reduces Outdoor Temps

Lower CO2 NOx and

VOC Levels

Reduces AC Use

Less Energy

Consumed

Reduces Demand at

Power Plants

Area Sources

Emit Less

Direct

Lower Ozone Levels

Indi

rect

Strategies Processes Results

White Roofs Measured Cooling Savings

bull Sacramento 80 in a house 35 in two school bungalows

bull Florida 10-43 in several houses average 19

bull California and Florida 5ndash20 in several commercial buildings

8

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Direct and Indirect Effects of Light-Colored Surfaces

bullDirect Effect - Light-colored roofs reflect solar radiation reduce air-

conditioning use

bullIndirect Effect - Light-colored surfaces in a neighborhood alter surface

energy balance result in lower ambient temperature

6

7

Methodology Energy and Air-Quality Analysis

Slows Reaction

Rates

Cooler Roofs

Cooler Pavements

All Vegetation

Cooler Roofs

Shade Trees

Reduces Outdoor Temps

Lower CO2 NOx and

VOC Levels

Reduces AC Use

Less Energy

Consumed

Reduces Demand at

Power Plants

Area Sources

Emit Less

Direct

Lower Ozone Levels

Indi

rect

Strategies Processes Results

White Roofs Measured Cooling Savings

bull Sacramento 80 in a house 35 in two school bungalows

bull Florida 10-43 in several houses average 19

bull California and Florida 5ndash20 in several commercial buildings

8

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

7

Methodology Energy and Air-Quality Analysis

Slows Reaction

Rates

Cooler Roofs

Cooler Pavements

All Vegetation

Cooler Roofs

Shade Trees

Reduces Outdoor Temps

Lower CO2 NOx and

VOC Levels

Reduces AC Use

Less Energy

Consumed

Reduces Demand at

Power Plants

Area Sources

Emit Less

Direct

Lower Ozone Levels

Indi

rect

Strategies Processes Results

White Roofs Measured Cooling Savings

bull Sacramento 80 in a house 35 in two school bungalows

bull Florida 10-43 in several houses average 19

bull California and Florida 5ndash20 in several commercial buildings

8

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

White Roofs Measured Cooling Savings

bull Sacramento 80 in a house 35 in two school bungalows

bull Florida 10-43 in several houses average 19

bull California and Florida 5ndash20 in several commercial buildings

8

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Potential National Savings from Changing Roof Reflectivity

Peak Demand Savings in All US $37M

$35M

$16M

$27M $10M $20M $8M

$3M New York $9M $20M

Chicago

$9M

Philadelphia DCBaltimore

Los Angeles

Phoenix DallasFt Worth

Atlanta

Houston Miami New Orleans FtLauderdale

9

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

ldquoCoolrdquo products for low-sloped roofs

bull Many materials available frac34 coating (white) frac34 single-ply membrane (white) frac34 painted metal (white cool colored)

bull Products are rated by the Cool Roof Rating Council (CRRC) frac34 labels solar reflectance thermal emittance

10

frac34 website wwwcoolroofsorg

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cool Roofing Materials Availability High-Sloped Roofs

bull Limited but expanding material availability frac34 Tile (several maufacturers) frac34 Coatings (one manufacturer) frac34 Metal (many manufacturers) frac34 Shake (only for custom application) frac34 Shingles (one manufacturer)

bull Over 70 of high-sloped roofs use hot asphalt shingles

11

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

12

ISPLBNL Shingle With Whiter Roofing Granules

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

13

White is lsquocoolrsquo in Bermuda

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

14

and in Santorini Greece

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

15

Cool Roof Technologies

flat white

pitched white

pitched cool amp colored

Old New

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

16

Cool Colors Reflect Invisible Near-Infrared Sunlight

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cool and Standard Brown Metal Roofing Panels

bull Solar reflectance ~ 02 higher bull Afternoon surface temperature ~ 10ordmC lower

17

Courtesy BASF

Coatings

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

18

Example Dioxazine Purple Over Various Undercoats

bull Two-layer system frac34 top coat thin layer of dioxazine purple (14-27 microm) frac34 undercoat or substrate

aluminum foil (~ 25 microm) opaque white paint (~1000 microm) non-opaque white paint (~ 25 microm) opaque black paint (~ 25 microm)

purple over

aluminum foil

purple over

opaque white paint

purple over

non-opaque white paint

purple over

opaque black paint

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

19

Dioxazine Purple Reflectances

over aluminum Rsolar = 041

over opaque white Rsolar = 042

over non-opaque white Rsolar = 030

over opaque black Rsolar = 005

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

20

National Labs and Industrial Partnership bull Program is sponsored by

CECPIER bull ORNL and LBNL are teaming

with industry bull Broad industrial partnership

bull Industry partners frac34 3M (ganules) frac34 American Roof Tile Coating frac34 BASF (metal) frac34 Custom-Bilt Metals frac34 Elk Manufacturing (shingles) frac34 Ferro frac34 GAF (shingles) frac34 Hanson Roof Tile frac34 ISP Minerals (ganules) frac34 MCA (tiles) frac34 Monier Lifetile (tile) frac34 Shepherd Color Company

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cool and Standard Color-Matched Concrete Tiles

cool Courtesy American Rooftile Coatings

standard

bull Can increase solar reflectance by up to 05 bull Gain greatest for dark colors

∆R=037 ∆R=026 ∆R=023 ∆R=015 ∆R=029 ∆R=029

21

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

22

Increasing solar reflectance of fiberglass asphalt shingles prototypes

cooler ρ=028

ρ = solar reflectance

ρ=036

warmer ρ=023 ρ=027 ρ=028

ρ=037

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

23

Increasing solar reflectance of fiberglass asphalt shingles Elk Prestiquereg Cool Color Series

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

24

Increasing solar reflectance of metal roofing BASF Ultra-Coolreg metal roof coatings

numbers denote solar reflectances cooler (warmer)

Courtesy BASF

Industrial Coatings

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

25

Cool Metal Roofs

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Increasing solar reflectance of clay tiles MCA Clay Tile cool colored tiles

26

Model Color Initial solar reflectance

Solar reflectance after 3 years

Weathered Green Blend

043 049

Natural Red 043 038

Brick Red 042 040

White Buff 068 056

Tobacco 043 041

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

27

Non-residential building energy and equipment savings15-year net present value of savings ($1000 ft2)

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

30-year net present value of savings ($1000 ft2) concrete tile roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 39 53 37 56 42 58 39 71 74 60 64 55 68 66 66 60

Energy 406 917 726 992 781 1593 1432 1822 1862 1390 1190 1109 1355 1477 1900 791 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

28

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

30-year net present value of savings ($1000 ft2) metal roofs

0

500

1000

1500

2000

2500

3000

California Climate Zone

Equip 41 57 41 61 47 57 48 83 88 65 71 60 73 72 71 65

Energy 495 1053 847 1128 919 1870 1692 2141 2181 1561 1330 1243 1507 1648 2093 918 $010ft2 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Tota

l Sav

ings

[Equ

ipm

ent +

30-

Year

NPV

Ene

rgy]

($1

000

ft2)

29

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cool Roofs Standards bull Building standards for reflective roofs

- American Society of Heating and Air-conditioning Engineers (ASHRAE) New commercial and residential buildings

- Many state California Georgia Florida Hawaii hellip bull Air quality standards

- South Coast AQMD - SF Bay Area AQMD - EPArsquos SIP (State Implementation Plans)

30

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

White Roofs Programs in California

bull One Time CEC Incentive -- $20 Million frac34 at $015 to $020 per square foot

bull California utilities incentives bull 2001 to 2005-- credits white and cool colored

roofs bull 2005 requires cool flat roofs bull 2008 may require cool roofs for all buildings

31

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cool Roof Programs around the World

32

bull US bull Europe bull Asia bull Middle East

bull China bull India (Hyderabad

demos see graphs funded by USAID)

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cool Roofs to Save CO2

33

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Cool Surfaces also Cool the Globe

bull Cool roof standards are designed to reduce ac demand save money and save emissions In Los Angeles they will eventually save ~$100000 per hour

bull Annual savings in the US = $1-2B ~ 7 M tons CO2

bull Annual savings in the world = $10-15B ~ 100 M tons CO2

bull But higher albedo surfaces (roofs and pavements) directly cool the world (001 K) quite independent of avoided CO2 So we discuss the effect of cool surfaces for tropical temperate cities

34

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

35

100 Largest Cities have 670 M People

0

1000

2000

3000

4000

5000

0 10 20 30 40

Population (M)

Are

a D

ensi

ty(m

2 per

son)

Mean = 560 m2p Med = 430 m2p

Tokyo

Mexico City New York City Mumbai Satildeo Paulo

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Dense Urban Areas are 1 of Land

bull Area of the Earth = 511x1012 m2

bull Land Area (29) = 148x1012 m2 [1] bull Area of the 100 largest cities = 038x1012 m2 = 026

of Land Area for 670 M people bull Assuming 3B live in urban area urban areas =

[3000670] x 026 = 12 of land bull But smaller cities have lower population density

hence urban areas = 2 of land bull Dense developed urban areas only 1 of land [2]

36

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Potentials to Increase Urban Albdeo is 01

bull Typical urban area is 25 roof and 35 paved surfaces

bull Roof albedo can increase by 025 for a net change of 025x025=0063

bull Paved surfaces albedo can increase by 015 for a net change of 035x015=0052

bull Net urban area albedo change at least 010

37

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Effect of Increasing Urban Albedo by 01

bull Net Change in Global albedo = [CityLand]x[LandGlobe]x∆a = [2]x[1]x∆a = 001 x 029 x01 = 00003 [3]

bull The effect on global temperature frac34 Using three different calculations is about 001K

38

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Carbon Equivalency bull Modelers estimate a warming of 2K in 60 years so

003Kyear bull Change of 01 in urban albedo will result in 001K a delay

of ~03 years in global warming bull Worldrsquos current rate of CO2 emissions =

25 G tonsyear (41 tonsyear per person) bull Worldrsquos rate of CO2 emissions averaged over next 60

years = 40 G tonsyear bull Hence 03 years delay is worth 12 Gt CO2 ~ 200 Mt

CO2year

39

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Equivalent Value of Avoided CO2

bull CO2 currently trade at ~$10ton bull 12Gt worth $120 billion for changing albedo of roofs

and paved surface bull Cooler roofs alone worth $60B bull Cooler roofs also save air conditioning (and provide

comfort) worth over $600B - $900B over 60 years 100 Mt CO2year

bull We would like to start an international organization where the developed countries offer $1 million per large city in a developing country to trigger a cool roofpavement program in that city

40

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Market Deployment of Cool Color Cars

bull Toyota experiment (surface temperature 10 degC cooler with cool coatings) bull Ford is also working on a similar technology

41

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

42

Effect of AC on fuel consumption US Cal

No of Vehicles (106) 213 26 Milesyearcar (103) 12 12 Fuel Eff [mpg] 20 20 Annual fuel use [109gal] 130 15 Annual fuel expense at 25 $gal [$B] 230 38 Reduced efficiency due to AC 15 15 time AC runs 50 50 AC contribution to fuel use [109gal] 96 12 AC contribution to fuel expense [$B] 24 3

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

Benefits of 28K (5degF) reduction in soak temperature

US Cal Reduction in AC capacity 11 11 Improvement in mpg 18 18 Reduced NOx emission 45 45 Reduced fuel expense ($M) 2876 346 Reduced CO emission (tonneday) 978 1178 Reduced NOx emission (tonneday) 103 124 Reduced NMHC emission (tonneday) 18 22

43

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition

44

Practical Guidelines

bull EPA Guidebook (1992) bull Good practical information bull Greatest focus on trees

bull EPA is working on a new edition