towards nearly zero-energy buildings

Dr. Andreas Hermelink

23/01/2014

TOWARDS NEARLY ZERO-ENERGY BUILDINGS

Webinar

© ECOFYS | |

Content

> Introduction

> Nearly Zero-Energy Buildings (nZEB)

> Reporting template and analytical framework for Member States

> Specific issues around the nZEB definition

> Benchmarks for nZEB

> Convergence between cost-optimality and nZEB?

> Conclusions and Recommendations

23/01/2014 Dr. Andreas Hermelink 2

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Introduction – What‘s the issue?

> Emissions gap report Cancún:

Scenarios that give the world a

chance to stay below 2 °C have:

> World GHG Emissions peak before

2020

> World GHG Emissions in 2050

50-60% below 1990 level

> Due to the high share of

industrialized countries in GHG

emissions, Europe has a target of

80%-95% GHG reductions.


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A roadmap for moving to a low carbon economy

in 2050, EC 2011, Minimum Reduction vs. 1990


-20%

-54%

-37%

-80%

-93% -88%

-100%

-90%

-80%

-70%

-60%

-50%

-40%

-30%

-20%

-10%

0%

Cross sectoral Power Buildings

2020

2030

2050

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A roadmap for moving to a low carbon economy

in 2050, EC 2011, Maximum Reduction vs. 1990


-30%

-68%

-53%

-95% -99%

-91%

-100%

-90%

-80%

-70%

-60%

-50%

-40%

-30%

-20%

-10%

0%

Cross sectoral Power Buildings

2020

2030

2050

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Content

> Introduction








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Definition of Nearly Zero-Energy Buildings

> Energy Performance of Buildings Directive’s (EPBD), Article 9:

– [A nearly Zero-Energy Building is a] “building that has a very high

energy performance… [ ]. The nearly zero or very low amount of

energy required should to a very significant extent be covered by

energy from renewable sources, including renewable energy

produced on-site or nearby.”


2019/2021 today building stock

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Nearly Zero-Energy Buildings: Key Questions


2019/2021 today building stock

> Burning questions

– Options to achieve nearly zero-energy buildings?

– What about the share of renewables?

– What is “nearly zero”?

– Do nZEB need to be cost-optimal?

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Nearly Zero-Energy Buildings: Close Up

> Residential & non-residential buildings

> All NEW buildings

> Included services: heating, domestic hot

water, cooling, ventilation, lighting

(commercial buildings) and auxiliary

energy => NOT: plug-loads, appliances

> First, reduce energy needs for these

services to cost-optimal levels

> Second, cover the nearly zero rest (very

significantly) from renewable sources

> Annual GHG emissions 2050:

appr. 3 kg CO2 / m2a in building stock

> => nZEB also means nearly zero

emission building!

> Today there is no more specific definition

in Europe which is common sense!


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Content

> Introduction


> Reporting template and analytical framework for Member

States






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Request for National nZEB Plans

> Member States shall draw up national plans for increasing the number of

nearly zero-energy buildings (EPBD Article 9 paragraph 1).

> The National plans shall include:

– Application in practice of the national definition of nearly zero

energy buildings

– Intermediate targets

– Policies and financial or other measures for the promotion of

nZEB

> “The Commission shall evaluate the national plans … notably the adequacy

of the measures envisaged by the Member States… .” (EPBD Article 9,

paragraph 4).

> After having received the national plan the Commission “… may request

further specific information regarding the requirements set out in

paragraphs 1,2 and 3”

=> common reporting format on nZEB is helpful


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Template for National Plans

> Reporting template

– provided by the European Commission to MS; developed by Ecofys

– Also serves the Commission as an analytical framework.

> Categories included

– Starting point

– Application of the definition of nearly zero-energy building

– Intermediate targets (qualitative and quantitative)

– Intermediate targets also for new buildings occupied and owned by

public authorities (by 31 December 2018)

– Policies and measures for the promotion of all new buildings being

nearly zero-energy buildings after 31 December 2018 resp.

– Additional information

– Possible improvements (self-assessment and possible improvements)


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Template for nZEB definition

> How do member states define the nearly

zero-energy buildings? Do they fulfill the

EPBD/RED requirements?

> Table for reporting the detailed

application of the definition of nearly

zero-energy buildings in practice.


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Template for nZEB definition


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Content

> Introduction








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off-site nearby

Different Physical Boundaries for Supplying

Energy from Renewable Sources, 1

> “the nearly zero or very low amount of energy required should be covered to a

very significant extent by energy from renewable sources, including [but

not saying: “being” or “limited to”] energy from renewable sources

produced on-site or nearby”.

> Main arguments to include off-site: provide sufficient number of choices for

building owner, ensure equal chances, reflect reality of renewable supply


on-site

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Single Building and Off-Site Supply

> Two different physical boundaries for demand and supply

> Balancing import and export

> Balance gets easier when focus switches to building owner as „legal system“

=> high share of RE possible without any on-site renewables


off-site nearby

on-site

import

export

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Metric and Period of the Balance

> EPBD requires national nZEB definition to

include a numerical indicator for the energy

performance. Which metric to use?

– Delivered energy => primary energy factors

(PEF) => Primary energy

– PEF sometimes intransparent, for electricity

steep decrease forecasted

– Switch to CO2 might happen in the future

> Period of the balance

– EPBD: Net balance over one year (include

heating & cooling)

– Question of length of sub-intervals

– The shorter the sub-interval, the more

ambitious it is to achieve (nearly)

zero-energy balances => aim: less stress

for (electricity) grids


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Period of the Balance – „Load Match Index“

> Result: The net ZEB can only “live” without importing energy for 25% of a

year’s hours; e.g. all nocturnal hours need energy imports.

> Annual sub-interval over-estimates renewable share

> Currently monthly balances seem to be a viable solution.


source: Koch et al. 2011

> Different sub-intervals

for a 1 year period:

– 1 year

– 1 month

– 1 day

– 1 hour

> Balancing „PV on the

roof“-export with

import from grid;

> PV system sized for

annual „net 0“

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Variations in nZEB definitions

> 71 nZEB definitions from 17 EU and 2 countries beyond have been analysed

> graph shows which boundary is explicitly allowed/forbidden/not mentioned

for renewable energy (heat & electricity)


0

10

20

30

40

50

60

70

80

option1:footprint option2:on-site option3:off-site generation

option4:off-site green electricity

Nu

mb

er o

f avail

ab

le

defi

nit

ions/la

bels

not defined

no

yes

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Content

> Introduction


> Reporting template and analytical framework for Member States incl.

specific issues around the nZEB definition





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Approach for deriving benchmarks

> Cost-optimality methodology

> Dynamic simulation of multiple variants (office, single, 4 climate

zones/cities, new/retrofit, 2010/2020, private/societal

perspective) => clouds of variants

> Defining primary energy benchmark area

> Calculation of renewable share within benchmark area

> Classification of energy needs within benchmark area

> Feedback-loop with global cost


© ECOFYS | | 23/01/2014 Dr. Andreas Hermelink 24

Cost-optimality: Definition of “global costs”

> Global cost calculations (EN 15459) result in a net present

value of costs incurred during a defined calculation period

> initial investment

> annual costs for every year (running costs)

> final (residual) value

> disposal costs

> Two different perspectives to be taken

> macroeconomic perspective (excl. taxes and subsidies, including

carbon costs etc., macroeconomic discount rate)

> financial perspective (incl. taxes and subsidies, excluding carbon costs

etc., market interest rate)

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Economic

optimum

kWh/m2a

€/m2

1

6 5 4 3

2

„Cost optimal

range“

Derivation of cost optimal level

Dr. Andreas Hermelink 25 23/01/2014

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Financial and environmental gap today

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Defining the primary energy benchmark area


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Defining the primary energy benchmark area


The “benchmark area” is determined in the following way:

• Determine the variant with minimum net primary energy,

• Consider an increase of 15 to 25 kWh/m2y,

• At this new level of net primary determine the variant with minimum global cost,

• Increase global cost by 15-25%

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Results net primary energy ranges

Simulated net primary energy ranges in different European

regions and building categories


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Results energy needs

Simulated energy needs for heating and cooling in different

European regions and building categories


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Results onsite share renewables

Simulated shares of onsite renewables on total primary energy

demand in different European regions and building categories


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Feedback loop with global cost


0

500

1000

1500

2000

2500

3000

3500

0%

20%

40%

60%

80%

100%

EN < 15kWh/m2

15 < EN < 30kWh/m2

30 < EN < 45kWh/m2

45 < EN < 60kWh/m2

60 < EN < 75kWh/m2

EN > 75kWh/m2

Glo

bal

Co

st -

30 y

ears

[€/

m2]

% o

f B

uild

ing

Var

ian

ts w

ith

in c

lass

es o

f En

ergy

Nee

ds

for

Hea

tin

g an

d C

oo

ling

Paris - Office - New Building - 2010Financial Persp. (RIR = 4%, Tax included)

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Summary results energy needs

Energy needs (being the sum of heating and cooling) turned out to

be in the following low ranges for the following climate zones:

> Zone 1: Catania (others: Athens, Larnaca, Luga, Seville, Palermo):

15-45 kWh/m2a (new office), 15-30 kWh/m2a (new SFH)

> Zone 2: Budapest (others: Bratislava, Ljubjana, Milan, Vienna):

15-45 kWh/m2a (new office), <15 kWh/m2a (new SFH)

> Zone 3: Paris (others: Amsterdam, Berlin, Brussels, Copenhagen,

Dublin, London, Macon, Nancy, Prague, Warszawa): 30-45

kWh/m2a (new office), here variants having the same average

global cost were found in the classes <15 kWh/m2a and 15-30

kWh/m2a as well; <15 kWh/m2a (new SFH)

> Zone 4: Stockholm (Helsinki, Riga, Stockholm, Gdansk, Tovarene):

15-30 kWh/m2a (office), <25 kWh/m2a (SFH)


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Cost-opt vs. nZEB – The Commission‘s view

> After 2013, all new buildings and renovations shall be based on

cost optimal requirements.

> How is it with cost optimality of nZEB after 2020? Do they have

to be cost optimal as well? (i.e. what if the technologies

necessary for reaching nZEB will not be cost optimal?)


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Cost-opt vs. nZEB – The Commission‘s answer

> Basically cost optimality and nearly zero energy buildings are two

different concepts. Nevertheless, the minimum energy performance

requirements for new buildings after 2020 (i.e. NZEB) will have to

be cost optimal as well. In best case (depending on circumstances, like

investment costs and energy prices and depending on the exact definition

of nearly zero energy buildings by the respective Member State) the

technical requirements derived from the two systems get close to

each other around 2020 to allow a smooth transition.


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Gap in life cycle costs


Financial and environmental gaps between nearly zero-energy building,

cost optimality and current requirements in 2011

Financial and environmental gap between nearly zero-energy building

and cost optimality in 2021

2010 2020

Changes of system costs, energy prices and primary energy factors expected

Cost optimum clearly moves to lower net primary energy between 2010 and 2020

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Conclusions and Recommendations

> nZEB usually are correlated with very low energy needs (close

or equal to Passive House)

> Buildings constructed with very low energy needs have global

costs over 30 years lower or comparable to buildings with high

energy needs

> These results seem relatively robust towards changes in various

economic parameters, e.g. the assumed interest rates

> The economic attractiveness of low energy need buildings

grows when considering the scenario of constructing a building

in 2020

> The cost optimum in all cases moves towards zero

> This result is reinforced in case energy prices would rise more

significantly than assumed


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Conclusions and Recommendations

> It is likely to be a good economic investment to continue

support for innovation and to completely close the gap between

cost-optimal and zero energy

> Not to forget: Buildings with low energy needs have

supplementary benefits like higher thermal and visual comfort

> nZEB as a cornerstone for EU 2050 climate targets

> On-site RE currently in the focus, but

> Off-site RE must get a viable nZEB option as well

– Equality, even chances, avoid discrimination

– Community and large scale production

> Only demand reduction and RE will succeed


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Please contact us for more information

Dr. Andreas Hermelink

Ecofys Germany GmbH

Am Karlsbad 11

10785 Berlin

Germany

T: +49 30 297 735 79-50

E: [email protected]

I: www.ecofys.com


mailto:[email protected]

http://ecofys.com/

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