Building

Solutions

Automotive

Industry

www.rehau.co.uk

INTRODUCTION TO RENEWABLE HEAT

TECHNOLOGIES CPDCPD PRESENTATION

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REHAU

LEARNING OBJECTIVESCPD AGENDA

- Introduction to REHAU

- DECC heat strategy & Renewable Heat Incentive

(RHI)

- Ground source heat pumps

- Biomass boilers (incl. district heating)

- Biogas / anaerobic digestion

- Solar thermal & Underground Thermal Energy

Storage

- Case studies

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REHAU

REHAU COMPANY HISTORY

Private Company

- 1948 Founded in the Bavarian town of

REHAU

- 1962 First UK Sales Office and

Warehouse

opened in Slough

- 1975 First Manufacturing Plant was

opened in

Amlwch

- 1995 Opening of the new headquarters

in

Ross-on-Wye

- 2012 REHAU celebrated its 50th

anniversary

trading in the UK

UK LOCATIONS

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REHAU

REHAU WORLDWIDE

6 CONTINENTS 175 LOCATIONS OVER 17,000

EMPLOYEES

THINK GLOBALLY – ACT LOCALLY

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REHAU

REHAU DIVISIONS

FURNITURE, HOUSEHOLD

APPLIANCES, HOSES AND

INDUSTRIAL DEVELOPEMENTS

EXTERIOR, WATER MANAGEMENT,

AIR MANAGEMENT & SEALING

WINDOW AND CURTAIN WALLING

TECHNOLOGY, BUILDING

TECHNOLOGY, CIVIL ENGINEERING

UNLIMITED POLYMER SOLUTIONS

Building

Solutions

Automotive

Industry

©

REHAU

GOVERNMENT STRATEGY ON RENEWABLE HEATDEPARTMENT OF ENERGY & CLIMATE CHANGE (DECC) HEAT STRATEGY – MARCH 2013

Covers 4 areas:

- Industrial heat

- Heat networks (district heating)

- Heating & Cooling for buildings

- Grids & Infrastructure

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REHAU

DEPLOYMENT OF RENEWABLE HEAT OVER TIMEDECC HEAT STRATEGY

Source: DECC Nov 2012

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REHAU

WHAT IS THE RENEWABLE HEAT INCENTIVE (RHI)?INTRODUCTION

Government created incentives schemes to end users to increase uptake of renewable

technologies to meet EU legally binding 2020 carbon reduction targets.

2 types:

Feed in Tariffs (FiT) –

ELECTRICITY

Renewable Heat Incentive -

HEAT

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REHAU

INCENTIVES FOR RENEWABLE HEATRENEWABLE HEAT INCENTIVE (RHI)

- RHI provides client an income for every kWh of

renewable heat produced.

- Only commercial buildings in Phase 1 - domestic

properties will be included in Phase 2 (Summer

2014)

- District heating eligible for Phase 1 (multiple

buildings) but only if heat generated from biomass

or biogas

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REHAU

RHI PHASE 1 – NON-DOMESTICKEY CRITERIA

- Payments are paid over 20 years to the client (quarterly payments)

- Tariffs are fixed once application is accredited

- Heat must be metered

- OFGEM administer the scheme

- Tariffs are index-linked to inflation

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REHAU

Tariff Eligible Sizes Tier Tariff (p/kWhth)

from 1st Oct 2014

Small biomass < 200 kW Tier 1* 7.6

Tier 2 2.0

Medium biomass 200-1,000 kW Tier 1* 5.1

Tier 2 2.2

Large biomass > 1,000 kW 2.0

Biomass CHP All 4.1

Small biogas < 200 kW 7.5

Medium biogas 200-600kW 5.9

Large biogas > 600kW 2.2

TARIFF LEVELS – 1 of 2RENEWABLE HEAT INCENTIVE (RHI) – NON-DOMESTIC

*Tier 1 is for the first 15% hours of the year (1314 hours). All additional hours

come under Tier 2

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REHAU

Tariff Eligible Sizes Tier Tariff (p/kWhth)

from 1st July 2014

GSHP All Tier 1* 8.7

Tier 2 2.6

Deep Geothermal

(>500m)

5.0

ASHP 2.5

Solar Thermal < 200kWth 10.0

TARIFF LEVELS – 2 of 2RENEWABLE HEAT INCENTIVE (RHI) – NON-DOMESTIC

*Tier 1 is for the first 15% hours of the year (1314 hours). All additional hours

come under Tier 2

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REHAU

RENEWABLE HEAT INCENTIVEHEAT METERS

Heat meters are required for RHI compliance as

the payments are based on eligible heat used,

not heat generated.

MID Class 2 compliant is minimum standard.

2 types of systems:

- Complex (more than 1 meter)

- Simple (1 meter)

The system owner provides OFGEM with meter

readings on a quarterly basis.

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REHAU

RENEWABLE HEAT CARBON SAVINGSENERGY SAVINGS FOR A TYPICAL DOMESTIC PROPERTY

Technology Cost

(£/MWh)

Carbon Savings (kg/a)

over baseline

Baseline gas boiler 70 0

Air-source heat pump 110 -100

Ground-source heat

pump

130 500

Small scale DH

network

120 3,500

Large scale DH

network

100 4,200

Anaerobic digestion

CHP

215 5,900

Source: Powry / AECOM – Report for DECC

April 2009

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REHAU

“When replacing a heating appliance, consideration

should be given to connecting to any existing local heat

networks. If the work involves pipework changes,

consideration should be given to providing capped off

connections to facilitate subsequent connection to a

planned local heat network.”

L1B & L2B

“Providing appropriate facilities at the construction stage can make

subsequent enhancements much easier and cheaper, e.g.

providing capped off connections that can link into a planned

community heating scheme.”

L1A

Source: Conservation of Fuel & Power, L1A Domestic New Build, L1B

Existing dwellings, L2A New Build other than Dwellings, L2B Exisiting

Buildings other than Dwellings

PART L BUILDING REGULATIONSRENEWABLE HEAT IS MENTIONED

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REHAU

If thermal energy is supplied from a district or

community heating or cooling system, emission

factors should be determined by considering the

particular details of the scheme.

Calculations should take account of the annual

average performance of the whole system (i.e. the

distribution circuits and all the heat generating plant,

including any Combined Heat and Power (CHP), and

any waste heat recovery or heat dumping).

L2A

Grid electricity for heat pumps TER is calculated by

with a fuel factor of 1.47

L1A

PART L BUILDING REGULATIONSRENEWABLE HEAT IS MENTIONED

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REHAU

Both documents contain

important design and

installation guidance for both

Heat Pump and District

Heating Schemes and must

be considered as part of a

design.

PART L BUILDING REGULATIONSBUILDING SERVICES COMPLIANCE GUIDE (NON-DOMESTIC AND DOMESTIC)

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REHAU

GROUND SOURCE HEATING & COOLING

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REHAU

Deep geothermal (energy from the earth’s core) (>

400m)

- Hydrothermal systems (using water stores)

- Petrothermal systems (artificially pumping water deep

underground)

- Deep geothermal probes (using a closed loop system)

Ground-source (from the sun) (< 400m)

- Ground-source collectors (sub-surface, at a depth of

1.5m)

- Ground-source probes (using boreholes at depths of

ca.100m)

- Ground-source spiral probes (spiral probes buried up

to 5m deep)

- Ground-source energy piles (using the building

foundations)

- Ground water bore holes (open loop systems using

ground water)

INTRODUCTIONDIFFERENCE BETWEEN GEOTHERMAL AND GROUND SOURCE

Rain 13 W/m² Solar radiation

up to 600 W/m²

0,06 W/m² Geothermal heat flow

20°

300m

10m

0 m

summerwinte

r

0° 10°

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REHAU

SEASONAL VARIATIONS OF GROUND TEMPERATURE

INTRODUCTION TO GROUND SOURCE ENERGY

February

May

August

November

Temperature °C

Depth

(m)

Increase of ca.

3K per 100m

depth

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REHAU

INTRODUCTION TO GROUND SOURCE ENERGYWHAT ARE THE ADVANTAGES OF GROUND-SOURCE ENERGY?

- Renewable and sustainable energy source

- Year round usage – independent from climate & season

- Reduced carbon emissions for both heating and cooling

- Can provide space heating, hot water and cooling

- No fuel deliveries required

- Hidden from view

- Low running costs

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REHAU

INTRODUCTION TO GROUND SOURCE ENERGYHOW DOES A GROUND SOURCE HEAT PUMP WORK?

Ground loop (vertical /

horizontal)

Space heating circuit

(ideally underfloor heating)

0°C

4°C

30°

C

35°

C

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REHAU

COEFFICIENT OF PERFORMANCE OF HEAT PUMP

INTRODUCTION TO GROUND SOURCE ENERGY

0

1

2

3

4

5

6

7

-5 0 5 10 15

Heating Water temp in °C

En

erg

y u

se

ε (

CO

P) T = 35°C

T = 45°C

T = 55°C

C.O.P

Return temperature of ground-source circuit

°C

Flow

temperature of

heating circuit

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REHAU

Domestic applications:

- Vertical probes

- Spiral / helix probes

- Coaxial probes for radial drilling

- Horizontal collectors

- Energy/thermal piles

Commercial applications:

- Vertical probes

- Energy piles

- HPR probes (up to 800m)

FOR EVERY DEMAND AN INDIVIDUAL GROUND-SOURCE SOLUTION

METHODS TO EXTRACT GROUND SOURCE ENERGY

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REHAU

PE 100:

- Standard pipe material in UK market

- Should be manufactured to SKZ HR 3.26 test

regulations

- Lower pressure losses due to flow-enhancing

bend (coefficient of pressure loss = 0,34 )

GROUND-SOURCE PROBESPE 100 PROBES & NEW GENERATION PE-RC

Point load standing times

comparison between PE 100 and

PE-RC

New generation is PE 100-

RC:

- Polyethylene Resistant to

Crack

- Improved point load

resistance over PE 100

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REHAU

GROUND-SOURCE THERMAL PILES

Pipework can be integrated into structural piles to

exploit ground-source energy.

PE-Xa is more suited to thermal piles due to its

improved bending radii (no joints needed in pile).

Thermal piles have to be used for heating and

cooling.

EXPLOITING THE BUILDING‘S FOUNDATIONS

Helical pipes can be used to

reduce installation times and

increase heat transfer over

meander thermal piles.

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REHAU

In most projects, multiple ground

loops are managed using an

external manifold.

This is typically housed in an

external chamber (either pre-

fabricated or built on site).

Benefits:

• Reduced condensation risk

• Ease of access

• Less pipes entering plant room

GROUND-SOURCE LAYOUTEXAMPLE LAYOUT & PIPEWORK REQUIRED

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REHAU

Modular manifolds:

- Offer flexibility on-site due to modular design

- Up to 12 ports per manifold

- Low pressure losses due to 2 ½ internal

diameter

Manifold chambers:

• Made of PE with an integrated polymer manifold

• Up to 20 port chambers possible

• Can be pre-assembled in factory or holes drilled

on site

• Watertight and walkable cover

GROUND-SOURCE ACCESSORIESMANIFOLD & CHAMBERS

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REHAU

Moseley Hall Hospital, Birmingham

Ground-source heating using 28 RAUGEO

probes PE-Xa at 152m deep

CASE STUDIES – VERTICAL BOREHOLES

GROUND-SOURCE SYSTEMS

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REHAU

ASKAP Telescope – Western Australia

- Fully off-grid installation – GSHP used 100% for

cooling

- 98 x 32mm PE-Xa probes, each 125m long

(48°C estimated flow temp)

- 7,800m of RAUGEO pipe to connect boreholes

- 12 manifold chambers

GROUND-SOURCE SYSTEMSCASE STUDIES – VERTICAL BOREHOLES

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REHAU

Kinsale Lifeboat Station, Ireland

Ground-source heating using 1200m of PE-Xa

pipe integrated into structural concrete caissons,

which support the building. Uses tidal flow to

extract ground-source energy.

CASE STUDIES – THERMAL PILES

GROUND-SOURCE SYSTEMS

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REHAU

Suffolk One College, Ipswich

Used ICAX interseasonal heat transfer system

for 20,000m² building.

Absorber: 1,560m² bus turning area, using 14km

of 25mm RAUGEO PE-Xa

Underground storage: 18 x 100m PE-Xa probes

CASE STUDIES – INTERSEASONAL HEAT TRANSFER

GROUND-SOURCE SYSTEMS

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REHAU

Jenbach Tunnel, Austria

Test project conducted on new high-speed rail tunnel

passing below town on Jenbach.

Tunnel was 12m diameter. Estimated outputs ca. 10-

15W/m²

Heat extracted was used to heat the buildings above

the tunnel.

CASE STUDY – GEOTHERMAL TUNNEL LINING

GROUND-SOURCE SYSTEMS

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REHAU

BIOMASS / DISTRICT HEATING

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REHAU

HEAT SOURCE OPTIONS FOR DISTRICT HEATINGTECHNOLOGY AGNOSTIC

Sources include:

- Biomass (wood chip /

pellet)

- Gas boiler

- Gas fired CHP

- Biomass CHP

- Anaerobic digestion CHP

- Deep geothermal

- Waste heat from power

stations

- Energy from Waste

- Industrial waste heat

- Solar thermal

©

REHAU

Typically use wood chip or wood pellets for heating.

Most systems installed today are heat only.

Biomass CHP (gasification / pyrolysis) coming to market

slowly.

BIOMASSINTRODUCTION

Wood pellets

Wood chip

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REHAU

Biomass district heating schemes work well

because:

• Biomass boilers are often bulkier than traditional

boilers, hence typically located in external plant

room, not individual houses

• Require regular wood chip or pellet deliveries to

only one central plant

• Can be located discreetly on site extremes

• Qualifies for Renewable Heat Incentive

BIOMASSBIOMASS DISTRICT HEATING

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REHAU

Hot water or steam is centrally produced

- Transported via an insulated pipe network

- Connected to individual properties via a heat

interface unit

- Heat metered

- Heat delivered via conventional heating systems

DISTRICT HEATINGDEFINITION

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REHAU

Large carbon savings possible

Economies of scale – increase efficiency

Ideal for technologies not feasible on individual

properties (e.g. biomass / energy from waste)

Future proof – easy to change fuel source

Minimise maintenance using one central plant –

no individual gas checks required

DISTRICT HEATINGBENEFITS

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REHAU

DISTRICT HEATINGNATIONAL HEAT MAP

- Launched in March 2012 by DECC

- Covers all 388 LA’s in England

- Consistent format, can zoom in on

individual street level

- Assist in developing cross-LA border

district heating schemes

- Ideal for feasibility studies

http://ceo.decc.gov.uk/nationalheatmap

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REHAU

PRE-INSULATED STEEL PIPEWORKRIGID STEEL PIPEWORK

Advantages:

- Strong material – resistant to impact damage

- Larger diameter sizes available

- Capable of withstanding higher flow temperatures / pressure

Disadvantages:

- Only straight lengths possible

- Joints required every 6-12m

- High installation costs

- Corrosion problems (therefore warning systems are required)

- Specialist welding required

λ ≈ 0.024 W/mK

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REHAU

Bonded insulation:

Advantages:

- Excellent thermal insulation

- No water ingress if outer jacket punctured

- No thermal expansion (self-compensating)

- More flexible compared to steel

- Long coil lengths possible (less joints)

Disadvantages:

- Less flexible compared to open cell

λ = 0.022 W/mK

PRE-INSULATED POLYMER PIPEWORKTWO TYPES OF PIPE INSULATION – BONDED INSULATION

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REHAU

PRE-INSULATED POLYMER PIPEWORKTWO TYPES OF PIPE INSULATION – NON-BONDED INSULATION

Non-bonded insulation:

Advantages:

- Greater flexibility

- Simpler jointing / installation (foam easily

removed)

- Ideal for confined spaces

- Long coil lengths possible (less joints)

Disadvantages:

- PU closed cell pipes have improved thermal

insulation

λ = 0.043 W/mK

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REHAU

PRE-INSULATED PIPEWORKPE-Xa COMPRESSION SLEEVES

- Only two components: fitting and sleeve

- Ideal for below ground applications

- Can be used in all weather conditions

- Minimal bore reduction

- Totally secure, permanent fitting

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REHAU

Most flow temperatures are ca. 80°C:

- Extends pipe lifespan

- Makes a safer network (no steam)

Ensure return temperature is as low as

possible (high ΔT):

- Reduces pipe size - > reduce capital

costs

- Reduces heat losses (improves

efficiency)

PIPE SIZINGIMPORTANCE OF OPTIMISING THE FLOW / RETURN TEMPERATURES

Flow / return

temperatures

(C)

Heat

load

(kW)

Pipe size

required

82-71 450 110mm

80-60 450 90mm

80-50 450 75mm

Flow / return

temperatures (C)

Pipe size (mm) Heat losses

RAUTHERMEX

(F&R)

% heat loss saving

82-71 110 4.1 kW -

80-60 90 2.5 kW 38%

80-50 75 1.8 kW 56%

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REHAU

East Holme, Dorset

- 16 houses connected to community district

heating network

- 25, 32, 40 and 50mm RAUVITHERM DUO pipes

used, some in trenches up to 400m long

- 120 tonnes of waste timber on site to be used to

feed biomass boiler

BIOMASS & HEAT NETWORKS CASE STUDIES

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REHAU

Lochaber School, Fort William

- Remote energy centre using a 540kW

wood pellet biomass boiler

- 400m of RAUTHERMEX, including 160mm

UNO

BIOMASS & HEAT NETWORKSCASE STUDIES

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REHAU

HMP Grampian: Petershead, Scotland

- Originally a steel pipe specification

- Centralised biomass boiler

- Worked with consultant to optimise pipe size

and reduce capital costs

- 2,200m of pipework (RAUTHERMEX 40-

125mm)

- Large installation time & cost savings

(compared to 12m steel lengths)

BIOMASS & HEAT NETWORKS CASE STUDIES

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REHAU

BIOGAS / ANAEROBIC DIGESTION

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REHAU

BIOGAS / ANAEROBIC DIGESTIONPOSSIBLE FEEDSTOCKS

Organic substances which can be used in

anaerobic digestion systems:

- Animal waste (e.g. cow / pig manure)

- Unused crops (leaves, stalks) & grass

cuttings

- Abattoir / slaughterhouse waste

- Food waste

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REHAU

BIOGAS / ANAEROBIC DIGESTION INTRODUCTION

CHP supplies

electricity to grid

Fermenter Biogas powered

CHP

District heating

Solid waste

for fertilizer

Liquid

animal

waste

• Cow manure is heated to

produce methane

• Methane generated sent

to CHP unit for electrical

generation.

• Excess heat from CHP fed

back into fermenter and

used for district heating

• Solid waste reused as

fertiliser

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REHAU

BIOGAS / ANAEROBIC DIGESTIONFORMATION OF BIOGAS

Fermentation of organic substances

occurs when:

- Air-tight conditions

- In a damp environment

- Methanogenic bacterium are

present

- Between 0 and 70°C

The fermentation produces

combustable methane gas. Apart

from that, carbon dioxide and water

are produced.

©

REHAU

Much Fawley Farm AD plant, Herefordshire

- AD plant fed by slurry, maize & silage

- RAUVITHERM pipework connects hot water from

CHP to chicken sheds

- 2,500m of pipework in total (75 UNO & 32 DUO)

ANAEROBIC DIGESTION CASE STUDIES

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REHAU

Bioenergy village, Effelter, Germany

- 160 kW Biogas plant

- Uses CHP unit to deliver heat to 36 houses,

fire station and restaurant

- Additional wood chip biomass boiler for peak

demands

- System produces 1.1 million kWh/a

- CO2 saving of 370,000 kg/a

ANAEROBIC DIGESTION CASE STUDIES

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REHAU

SOLAR THERMAL / UNDERGROUND THERMAL

ENERGY STORAGE (UTES)

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REHAU

COMBINING DISTRICT HEATING WITH UTESUNDERGROUND THERMAL ENERGY STORAGE

Using underground thermal energy storage with intelligent controls, optimum use of all

energy sources can be achieved.

The excess solar heat in summer can then be efficiently stored and then utilised in winter

with an increased efficiency.

0

100

200

300

400

500

600

700

800

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

He

at

req

uir

em

en

t M

Wh

/mo

nth

Heat requirement Available solar energy

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REHAU

Due to the high temperature resistance of PE-Xa (-40°C to 95°C), PE-Xa probes are ideal

for storing excess solar thermal heat in the summer.

-> Increased COP & excellent ground recharging

UNDERGROUND THERMAL ENERGY STORAGETEMPERATURE OF RESISTANCE OF PE-XA vs PE 100

Durability (safety factor SF=1,25)

Pipe SDR 11(25x2,3 and 32x2,9)

PE–Xa PE 100

20 °C100 year / 15

bar20 °C

100 year / 15.7

bar

30 °C100 year / 13.3

bar30 °C

50 year / 13.5

bar

40 °C100 year / 11.8

bar40 °C

50 year / 11.6

bar

50 °C100 year / 10.5

bar50 °C

15 year / 10.4

bar

60 °C 50 year / 9.5 bar 60 °C 5 year / 7.7 bar

70 °C 50 year / 8.5 bar 70 °C 2 year / 6.2 bar

80 °C 25 year / 7.6 bar 80 °C -

90 °C 15 year / 6.9 bar 90 °C -

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REHAU

UNDERGROUND THERMAL ENERGY STORAGEEXAMPLE SCHEMATIC

Heat source

(e.g. solar

thermal)

CHP plant and short-term buffer storage

Borehole

thermal energy

storage (BTES)

District heating

pipework to

transport heat to

local buildings

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REHAU

CASE STUDY

UNDERGROUND THERMAL ENERGY STORAGE

Drakes Landing Solar Community, Okotoks,

Canada

System description

- 52 house community

Heat sources:

- 800 solar thermal collectors (ca. 2300m2 area)

Heat storage:

- Borehole thermal energy storage of 144 x

25mm PE-Xa probes at 35m depth

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REHAU

CASE STUDIES – UTES - LIVE DATA AT WWW.DLSC.CA

UNDERGROUND THERMAL ENERGY STORAGE

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REHAU

Solar Storage Crailsheim, Germany

CASE STUDY

UNDERGROUND THERMAL ENERGY STORAGE

System description

- 260 dwellings, school, sports hall

- 4100 MWh/a with network temperatures

flow/return 65/35°C

Heat sources:

- 7,300m² solar collectors with 5,1MW peak

output

- 750 kW heat pump

- Supplementary heating through district

heating network

Heat storage:

- 100m³ high temperature peak load storage

(hot water)

- 480m³ buffer storage (hot water)

- 43,200m³ ground-source probe underground

storage (80 PE-Xa probes)

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REHAU

Braedstrup District Heating & Solar Park,

Denmark

CASE STUDY

UNDERGROUND THERMAL ENERGY STORAGE

System description

-1,400 homes

- DH network owned by community

- 6MW system (3,800 MWh/a)

Heat sources:

- 16,000m² solar collectors

- Heat pump

- Peak heating through district heating

network

Heat storage:

- 2,500m³ buffer tank(hot water)

- 50 PE-Xa probes at 50m deep

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REHAU

CPD SUMMARY OUTCOMES

At the End of this CPD You should now:

- Understand the basics principles of the Renewable Heat Incentive (RHI)

- Understand the benefits of GSHPs and different methods of heat extraction

- Be aware of different biomass fuels and the benefits of district heating, including

district heating pipework sizing and optimisation

- Understand what feedstocks can be used for anaerobic digestion

- Be aware how large solar thermal farms can be combined with district heating in

Underground Thermal Energy Storage systems to improve system efficiencies

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REHAU

Bibliography

Here are the information sources used in this CPD and potential further reading:

- https://www.gov.uk/government/publications/the-future-of-heating-a-strategic-

framework-for-low-carbon-heat

• Part L Documents

:http://www.planningportal.gov.uk/buildingregulations/approveddocuments/downlo

ads

• And associated documents:

http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partl/bc

associateddocuments9/

- Ground Source Standards: http://www.gshp.org.uk/Standards.html

- District Heating information: http://www.chpa.co.uk/

- Part L Explained The Bre guide, BRE Press ISBN 1-86081-910-9

©

REHAU

Low energy

windows / curtain

walling

Ground-air heat

exchanger

Ground-source

probes/collectors

Stormwater

management

District

heating

pipework

Underfloor

heating/cooling

RENEWABLE ENERGY SOLUTIONSRELIABILITY FOR GENERATIONS

Outdoor de-icing

Building

Solutions

Automotive

Industry

www.rehau.co.uk

THANK YOU FOR YOUR ATTENTIONANY QUESTIONS?