Guest blog: Electricity demand for electric cars

This is the work of Leon Zippel, be sure to follow him on Twitter. If German is your native language, the original story was published here. I translated the article with permission. The blog is based on facts & figures from Germany.

Many people are asking themselves these days where we will get the electricity for electric cars in the future. How much electricity do we need for 100% electric cars, and where will it come from in the end? I would like to discuss this in the following.

The country needs new technologies

As a society, we have set ourselves the goal of decarbonising all sectors. To achieve this, of course, we need new technologies in many areas. So in transport, too, we need new ways of powering vehicles without fossil fuels in the future.

In road transport, the majority of the industry here has opted for the electric car, even before the EU Parliament's recent decision.

There is a good reason for this: the electric car with battery is by far the most efficient form of propulsion available.

Of course, in principle there are other ways of powering vehicles with liquid fuels that are CO2-neutral, at least in balance sheet terms, but these have one problem: efficiency.

The drive efficiency of the e-car is about 3-4 times as high as that of the fossil combustion engine. The overall efficiency of a combustion engine with eFuels is more like a factor of 5-6.

This means that if I want to run a combustion engine with synthetic fuels, I need about 6 times as much energy (in this case electricity) as for an electric car (see graph from T&E).

There is no more efficient (i.e. energy-saving) drive than the battery-electric one. From a purely physical point of view, any solution with a liquid or gaseous fuel cannot possibly beat the electric car, because the production of these fuels is enormously lossy.

This must be made clear as a basis before we talk about where the electricity for electric cars should come from. Now that the basics are clear, let's move on to the actual topic.

Where does the electricity come from and how much do we need?

To power a fleet of 100% electric cars (assuming the identical fleet size as today), we need about 132 TWh of electricity.

Annual electricity production in Germany is currently around 520-550 TWh. That means we need about 24-25% more electricity to power all cars electrically.

Ideally, of course, this electricity will come from renewable sources, although of course it will be out of the electricity mix for the next few years.

This is made up of wind power, coal, gas, solar/PV, hydropower, biomass, etc. and was 51% renewable in the first half of 2022!

Incidentally, the fact that the electricity mix still includes fossil energy is not a contradiction. Even with today's electricity mix, the electric car is about 50% lower in CO2 emissions over its life cycle than the combustion engine (including production, of course).

But let's take a concrete example. The “ampel coalition” government has set itself the target of 15 million electric cars on the roads by 2030. In 2030, these will require about 41 TWh of electricity, which is about 8% more than today.

This shows quite clearly that this is of course a challenge, but not an impossibility. By comparison, the same CO2 savings from eFuels would require about 35% more electricity by 2030, instead of 8%.

So we need to produce about 1% more electricity for electric cars per year (and build up renewable energy capacity).

Conclusion

Of all the options, the electric car has by far the lowest electricity demand, and is therefore the "smallest" challenge in terms of securing the electricity supply.

The ramp-up of renewable energies goes hand in hand with the ramp-up of e-mobility. The vehicles are becoming CO2-poorer every year in parallel with the electricity mix!

Text: Léon Zippel, on Twitter.