An electric car consumes less energy than a car with a combustion engine (diesel, petrol, etc.) because of the low efficiency of combustion cars (15 to 30%, the rest being lost as heat). Driving a combustion car with a fuel consumption of 6 litres per 100 km uses about 60 kWh, while the consumption of an electric car is easily below 20 kWh. So there are huge energy savings!
However, the electricity to power the car still has to be produced. This brings us to a slightly longer answer.
Given the climatic effects of all fossil fuel combustion, we need to reduce our dependency on it.
Electricity is the easiest energy carrier to decarbonise. This is not to say that it is easy, but for other carriers (liquid or gaseous fuel) it is even more difficult.
The technologies to generate renewable 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.
So if we manage to get around by replacing our combustion cars with electric cars running on renewable electricity, we avoid climate-impacting emissions and reduce energy consumption. Of course, the massive deployment of electric cars must be accompanied by an increase in renewable electricity production and, where necessary, the reinforcement of electricity networks. Note, however, that national electricity consumption would not even increase by 20% if all cars were electric. If we consider a 20-year transition, this represents less than 1% growth in electricity consumption per year, which does not seem to be inordinate.
In order to decarbonise our mobility by using renewable combustible fuels, it should be recognised that the production of biofuels requires huge areas of monocultures of energy-providing plants. To drive 15,000 km in an electric car you need 3,000 kWh, which can be produced with photovoltaic panels on a surface of 15m2. To produce biofuel from rapeseed, 7,500m2 would be needed to drive the same distance in a combustion engine car. Even switching to green hydrogen, given the poor yield of its production by electrolysis, would still require three times the surface area of using electricity directly in an electric car.
As a source of renewable energy, electricity is therefore not only efficient in terms of use, but also in terms of production.