Efficiency and sufficiency

The success of the energy transition depends not only on what sort of energy we use but also on how we use it. Economical use of energy plays a major part in reducing CO2 emissions and combating climate change. The potential for cutting energy use is often particularly high in well-off households. At the same time, efficiency and sufficiency measures help to reduce the costs of electricity and heating incurred by private households. This benefits low-income households for whom higher energy costs are a particular burden.

“Despite the major price hikes, the energy consumption of private households in Germany has remained very stable,” explains Dr Corinna Fischer, a researcher in the Sustainable Products & Material Flows Division. “For example, their energy consumption in 2016 amounted to 665 billion kilowatt-hours, which was actually 0.4 per cent higher than in 1990.” This meant that private households accounted for just over a quarter of Germany’s total final energy consumption. “By far the largest proportion is used for heating; some way behind is energy use for hot water and household tasks such as cooking, washing and chilling,” says Fischer.

The German government aims to reduce total energy consumption by 50 per cent between 2008 and 2050. “Policy measures such as the Ecodesign Directive and the EU energy label ensure that efficient products are available and easy to identify,” says Fischer. “However, we also need concrete measures to actually enable consumers to replace old appliances.” Changing consumption patterns so that people adopt sufficiency behaviours is an important means of reducing energy demand and costs. “It means, for example, not accumulating too many appliances and also thinking about their size,” explains Fischer. “For instance, doubling the screen diagonal of a TV may quadruple its energy consumption.” The Oeko-Institut has explored the issue of sufficiency in detail in two working papers under the catchphrase “When less is more”.

“By adopting efficiency and sufficiency measures households can in theory halve their electricity consumption,” says the researcher, “but sadly almost none of this potential is currently being realised.” Ways of using energy more sustainably are being highlighted in the project “Electricity efficiency classes for households”. As part of this project the Oeko-Institut and the Institute for Social-Ecological Research (ISOE) have developed various tools to help private households save electricity. Funding from the Federal Ministry of Education and Research has enabled these tools to be tested in a field trial. “We divided households into efficiency classes on the basis of factors such as the number of people in the household and the type of hot water heating,” the researcher explains. “This means that similar households can be compared with each other.” The field trial also included personal advice on saving electricity and monthly documentation of participants’ electricity consumption. “As a result of the individual measures – such as buying more economical refrigerators and freezers or using the tumble dryer less often – the participating households cut their electricity consumption by an average of about five per cent,” says Fischer. “For those who used a lot of electricity the savings potential was in fact nearly ten per cent.” The Oeko-Institut’s researcher believes that sufficiency measures that lead to changed consumption patterns are particularly promising here: “The people who use a lot of electricity are often affluent. They use the electricity for their numerous appliances and devices – in this project we came across households that are using four refrigerators and freezers, although they don’t really need so many.”

New living spaces

One of the main reasons why average electricity consumption for heating, lighting and many other purposes remains high is that housing space per person is also high: living space per person increased from 46.1 m2 in 2011 to 46.5 m2 in 2016, partly as a result of an increase in the proportion of single-person households and the proportion of older people who are owner-occupiers. The average living space for pensioners is 88 m2. The current project “Opportunities for instrumenting energy consumption reduction through behaviour change” for the Federal Environment Agency pinpoints a number of obstacles to reducing living space, including lack of awareness of the issue and emotional ties to a property. However, with the Institut für Energie- und Umweltforschung (ifeu), the Oeko-Institut is also highlighting the opportunities of instruments such as financial subsidies for dividing detached and semi-detached houses, thereby creating additional accommodation units. “If only a fraction of the pensioners who own their detached homes were to reduce their living space, this could cut energy consumption by about 250 gigawatt-hours and greenhouse gas emissions by 59,300 tonnes annually,” explains Tanja Kenkmann, a researcher in the Energy and Climate Division. “Reducing living space is therefore a very worthwhile sufficiency measure.”

The “LebensRäume” (“Living Spaces”) project, which will run until 2020, is also addressing the issue of over-large living spaces: with the Steinfurt district authority, the “energieland 2050 – Haus im Glück” association and the ISOE, the Oeko-Institut is exploring how the use of living space can be optimised and made compatible with the requirements of generation-appropriate living. “In this project the first step involves analysing the background – factors such as the ownership structure and the needs of residents,” says Kenkmann. “The aims include setting up an advice point that will help people find accommodation of a size appropriate to their needs.” With funding from the Federal Ministry of Education and Research the project team is also monitoring a trial of the accommodation-finding service.

Measure and impact

Specific ways in which people in different income groups can cut their energy usage have also been explored by the Oeko-Institut in the project “Concept for an absolute reduction in the demand for energy: Potentials, conditions and instruments for achieving the energy consumption goals of the energy action plan” conducted for the Federal Environment Agency. “We analysed the possible effects of various measures in the periods to 2020 and 2030, focusing in particular on sufficiency measures such as reducing hot water consumption, lowering room temperatures and cutting down on living space,” says Fischer. In all income brackets the biggest potential savings arose from reducing people’s living space. “Other measures were also considered, including in connection with mobility a shift from driving to cycling and in connection with electronics a reduction in television viewing.” The analysis shows that each measure can result in cost savings of between 0.03 and 0.25 per cent of household income; for an average household this is equivalent to about 10-100 euros per measure. Various sufficiency measures can therefore result in significant savings in total – without the need for any investment. This is of particular relevance to low-income households and it can make a substantial contribution to the success of the energy transition

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Dr Corinna Fischer specialises in sustainable consumption and sustainable products. She is a Senior Researcher in the Sustainable Products & Material Flows Division, where she works on issues such as the consumer perspective, consumer behaviour and energy-efficient products. The work of Tanja Kenkmann, a Senior Researcher in the Energy & Climate Division, includes developing and evaluating instruments to increase the energy efficiency of the building stock. She also specialises in municipal climate change mitigation.