Energy-saving heating systems, energy-efficient household appliances and yet the savings are not as great as expected. This is often due to the so-called rebound effect. For example, residents of apartments that have undergone an energy-efficient refurbishment are more generous with their heating energy than before. If you know this, you have a chance to counteract it.
The road to hell is paved with good intentions: we stick rigidly to our New Year's resolutions, lose two kilos... and reward ourselves for our success with a piece of cake at the weekend. Many people recognise this behaviour from dieting. But you can also see it in other contexts. The energy sector, for example, is highly prone to such reactions, as ista points out in a white paper on the rebound effect.
The rebound effect reduces success
The rebound effect describes how consumers use the gains from energy efficiency at least partly for higher consumption. In recent decades, for example, the number of (single) households has steadily increased, as has living space per person, which in turn has a negative effect on energy demand. What’s more, people tend to reward themselves for their efforts in such a way that success suffers: it starts with a reward meal after a successful diet and ends with spending money as soon as a bonus or tax refund lands in their account.
Housing is the major concern for our carbon footprint
This phenomenon is particularly damaging in the residential building sector, which is one of the biggest CO₂ emitters in Germany anyway. There are programmes and subsidies to make buildings more energy-efficient, replace heating systems with more effective ones or get away from fossil fuels altogether. However, so far these offers have not been taken up as much as originally hoped: according to the DIW heat monitor (2019), the climate-adjusted heat energy consumption of an apartment building only fell by 2.6 per cent between 2010 and 2019. One reason is the low annual refurbishment rate of about one per cent of buildings. Another reason why the reduction in CO₂ emissions is too low is the rebound effect.
How the rebound effect works
One example: people who invest in a more effective heating system save energy and money. In everyday life, however, this tempts them to set a higher temperature for their heating ("It doesn't cost anything!") or consume more ("Let's treat ourselves!"). This is to the detriment of their carbon footprint.
A research project conducted by BINE Information Service in cooperation with the E.ON Research Center and RWTH Aachen University took a closer look. For the purpose of a study, 90 apartments were renovated, in a standard version, as a “3-litre house” or as a passive house with different energy-efficient measures. The surprising finding: in all buildings, actual consumption was higher than the calculated consumption. And the more energy-efficiently the building was renovated, the greater the rebound effect.
Does consumption transparency help?
So what is the answer to the rebound effect? First of all, we should accept that this connection exists - and then act. Environmental organisations and government institutions have long been considering how to reduce the rebound effect through incentives or regulations. Each one of us can also do our bit. For example, transparent and regular information about their consumption helps people use energy more sparingly. Regular information on consumption can therefore help to fully exploit the potential of energy-efficient refurbishments.
Saving energy: how to achieve the greatest effect
- Consciously save energy: more than two-thirds of the energy used by private households goes into heating their homes. So the biggest savings are to be expected when a household changes its heating behaviour. Unfortunately, this is when the risk of a rebound effect is also particularly high. Always be conscious of how much you are saving and put the money you save in your bank account - or invest it in further energy-saving measures.
- Make carefully considered investments: the rebound effect decreases if measures to improve energy efficiency only pay off over a long period of time. Keep reminding yourself that you are investing time, money and effort in these measures. Then you are more likely to see the energy savings you make as hard-earned profit that you want to keep.
- Practise habits: once we have got into the habit of economising, energy consumption will automatically remain at a low level. Incorporate as many energy-saving tips as possible into your daily life and keep it up. On average, it takes 66 days to establish a new habit.
- Put the environment before your finances: if financial motives predominate, the rebound effect increases as soon as prices fall slightly. People who are primarily environmentally conscious are more likely to change their behaviour permanently. Take pleasure from the fact that your consumption behaviour is not only helping your own wallet, but also the environment.
- Analyse data and facts: only people who know their consumption can plan sensibly. Check and compare your heating bills. That way you can identify potential savings or see whether a measure has been worthwhile.