It should be noted that this recommendation is not to heat with electricity, but to heat using an electric heat pump. Direct electric heating is inefficient and should not be considered as the main heating system in a building.
So the question is in fact: Why are we told to heat with an electric heat pump?
An electric heat pump consumes less energy than traditional heating (natural gas, oil, wood). Indeed, due to its higher efficiency, a heat pump consumes 3 to 5 times less energy than a traditional boiler (e.g. 5’000 kWh of electricity instead of 20’000 kWh (2’000 m3) of natural gas). So there are huge energy savings!
However, electricity must be produced to power the heat pump.
As the burning of fossil fuels harms the climate (carbon dioxide emissions), it is important to get stop using these fuels.
The technologies to produce renewable, non-carbon electricity are available and are being deployed on an industrial scale around the world. These include wind power plants, photovoltaic plants, hydroelectric plants and biogas or biomass plants. Some people even consider nuclear power plants to be ‘sustainable’ because of their low carbon emissions.
If we can heat by replacing fossil fuel burning systems with heat pumps running on renewable electricity, this avoids carbon emissions which impact the climate and reduces energy consumption due to the higher efficiency of the heat pumps. Obviously, the massive deployment of heat pumps must be accompanied by an increase in renewable electricity production and, where necessary, the reinforcement of electricity networks.
In order to decarbonise combustion heating systems by using renewable combustion fuels, it should be recognised that the production of biofuels requires huge areas of monocultures of energy-providing plants. To return to the example at the beginning, the production of 5,000 kWh of electricity from photovoltaic panels requires an area of 22m2, whereas it takes about 4,000m2 of energy-providing plants to produce 20,000 kWh of biogas. As a source of renewable energy, electricity is therefore not only efficient in terms of use, but also in terms of production.