TU / e Eindhoven University of Technology Wim Heijs

Exploring energy rebound effects

Wim HeijsRichard Adrians

contact: w.j.m.heijs@tue.nlDepartment of Architecture, Building and Planning

ERES 2011 Eindhoven

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TU / e Eindhoven University of Technology Wim Heijs

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Contents

• Backgrounds

• Rebound effects

• Exploratory research

• Conclusions

TU / e Eindhoven University of Technology Wim Heijs

Backgrounds: world energy productionBackgrounds: world energy production

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TU / e Eindhoven University of Technology Wim Heijs

Backgrounds: world electricity productionBackgrounds: world electricity production

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TU / e Eindhoven University of Technology Wim Heijs

Backgrounds: household energy use Neth.Backgrounds: household energy use Neth.

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household energy use

Gj per person

other sources

natural gas(temp. corrected)

electricity

apparent stagnation despite technologicaland psychologicalefforts ...

TU / e Eindhoven University of Technology Wim Heijs

Backgrounds: reasons for stagnation

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Real estate, e.g.:- quality of existing stock- investment, pay back time

Occupants, e.g.:- knowledge- motivation, bad examples (industry, city)- strong habits, behavioral patterns

rebound effects (or take back effects)

TU / e Eindhoven University of Technology Wim Heijs

Rebound effect in general

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- energy efficiency measures

- monetary savings

- increased consumption (direct or indirect through production)

- backfire: total elimination of saving (or worse)

TU / e Eindhoven University of Technology Wim Heijs

Rebound effect: types

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- direct rebound effects: increased use when costs are lower e.g. higher room temperature, leave lights on,

Wonderful, this new boiler!

Now it takes twice as long

before Norman gets angry...

or take longer showers

TU / e Eindhoven University of Technology Wim Heijs

Rebound effect: types

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- indirect rebound effects: opportunity to purchase new goods/services e.g. dryer, waterbed, more illumination indoors

or in the garden...

Don’t worry, dear.

It’s energy efficient lighting!

TU / e Eindhoven University of Technology Wim Heijs

Rebound effect: types

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- reinforced by marketing / technology push (especially electric appliances)

Finally, you CAN afford

the dryer you never had,

AND save energy!!!

TU / e Eindhoven University of Technology Wim Heijs

Exploratory research: existing studies

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- contradictory: estimated 1 - 80% (max. 170%)

- large diversity of relevant behaviors many intervening factors

- changes over time: longitudinal approach

- problems concerning reliability

TU / e Eindhoven University of Technology Wim Heijs

Exploratory research: design

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- limited time, opportunity (MSc R. Adrians)

- to find indications while maximizing chance: most noticeable after significant change in energy use, move to a low energy dwelling

- survey N=451, list of possible direct (30) and indirect (10) rebound effects controls: - no income change, drop energy costs

- equal dwelling / household size - different energy-related features, etc.

TU / e Eindhoven University of Technology Wim Heijs

Exploratory research: results

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- return rate 12% (N=54, holidays)

- some controls unusable (hh / energy costs) unreliable answers, change of provider, no or dissimilar bills (no more natural gas, additional costs electricity heat pump, etc.)

- others usable (income, situation) removed: changed household size (22), dwelling size, other intervening effects (11) - remaining for analyses: 21 cases

TU / e Eindhoven University of Technology Wim Heijs

Exploratory research: main indicators

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- higher living room temperature night/day* 15/5 d- more rooms heated simultaneously* 12 d- higher temperatures when absent* 10 d- computer / tv on longer 10/5 d- increased number of lights indoors 7 d/i- new freezer (not a replacement) 7 i- more frequent use of dishwasher 6 d- garden lighting on longer 6 d- new garden lighting (not a replacement) 5 i- more lights left on for security 5 d- more frequent / longer showers 4/4 d

* to some extent natural / recommended

TU / e Eindhoven University of Technology Wim Heijs

Conclusions

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- provisional indications (in)direct rebound effects to some extent mitigated by ‘normal usage’- low energy houses, energy-conscious people: more frequent in ‘normal’ population?

- main lessons learned: > control intervening factors very difficult > statistical correction of situational differences using large samples > longitudinal design, objective measures

TU / e Eindhoven University of Technology Wim Heijs

Conclusions

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- rebound effects plausible, inevitable- partly responsible for slow progress- disregard: transformation of problems instead of solution

- difficult to prevent, inherent to economy - awareness necessary first step- research on prevalence, strategies- what about larger users (industry, government)?- renewable sources the only real way out?

TU / e Eindhoven University of Technology Wim Heijs

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Thank you forThank you foryour attentionyour attention

Questions andQuestions anddiscussion...discussion...