Why should direct electric heating be banned?
Direct electric (or “resistance”) heaters for heating buildings or for hot water production are very inefficient compared to other options. They are therefore an energy aberration that should be avoided.
Not all forms of energy are equal. Electricity is a high-value form of energy, in the sense that it makes it possible to provide unique energy services: supply of electrical and electronic equipment, production of very high-temperature heat for specific applications, production of high-quality light for lighting, etc. Conversely, low-temperature heat (typically below 50°C) is a low-value form of energy that can be produced by many means other than electricity.
In addition, direct electric heating is characterised by poor performance in terms of energy efficiency. It is true that direct electric heating is, in itself, 100% energy-efficient (all the electricity is dissipated as heat in the room). However, it does consume a lot of valuable electricity, even though there is a much more energy-efficient solution: the heat pump! For the same amount of electricity consumed, the heat pump can provide between 2.5 and 4 times more heat than direct electric heating. Replacing direct electric heating with an electric heat pump can therefore save between 60 and 75% of electricity without changing the comfort of the building [→ Q98]. Just as the incandescent light bulb has been banned because of its low energy efficiency compared to other models of much more efficient lamps [→ Q42], electric resistance heating should also give way.
Furthermore, the apparent 100% energy efficiency of resistance heaters hides the fact that electricity had to be generated. This production generated losses, the extent of which depends on the method of production. For example, if electricity is produced by a modern natural gas-fired power plant, the overall electrical efficiency of resistance heating is close to 55%. This represents a very significant waste of energy, which is why the installation of these systems is prohibited in an increasing number of cantons. In comparison, a modern boiler, whether gas or wood chip, offers energy efficiency of around 90% in terms of final energy.
Today, direct electric heating accounts for just under 8% of annual energy consumption for heating buildings and more than 20% for domestic hot water heating. More importantly, direct electric heating accounts for an average of 11% of our total electricity consumption in winter! This consumption coincides with the time of the year when Switzerland does not produce enough electricity to cover its own needs [→ Q11]. In winter, we import an average of 6.7 TWh of electricity to cover our demand. Over a year, approximately 5.1 TWh is used for electric heating and 2.7 TWh for domestic hot water. By doing away with direct electric heating and electric water heaters, Switzerland could significantly reduce its external dependence on electricity supply.
- Favrat, Maréchal & Epelly (2008)
- Favrat, D., Maréchal, F. & Epelly, O. (2008). The challenge of introducing an exergy indicator in a local law on energy. Energy, 33(2). 130–136.
- Kemmler, A and Koziel, S and Wüthrich, P and Notter, B and Keller, M and Jakob, M and Catenazzi, G (2017)
- Kemmler, A and Koziel, S and Wüthrich, P and Notter, B and Keller, M and Jakob, M and Catenazzi, G (2017). Analyse des schweizerischen Energieverbrauchs 2000-2016 nach Verwendungszwecken. Office fédéral de l'énergie (OFEN).