Just how good are electric cars from the climate viewpoint?

Use of the electric car, allied to the fact that the family are avoiding air travel, has helped cut transport-related emissions by a total of 93 % compared with before project start. The reason for this big decrease is that the car runs on renewable electricity, so emissions are very low. However, if everyone was to buy an electric car, would it be reasonable to claim that all the electric cars were running on hydropower?

Some people say that if we increase electricity consumption a little in Sweden, that will require us to buy in a little more coal-powered electricity from Denmark. Even if Sweden exports electricity, the effect will be the same. If we use more electricity and export less, this would mean that the Danes would have to rely more on coal-fired power stations instead of hydropower that they could otherwise have purchased from Sweden. This means that coal is a marginal power source. And if you recharge your electric car with coal power, from the climate viewpoint it is pretty much the same as running a petrol car.

There are several things that are rather tricky in this perspective. One is that the EU has a trading system for emissions rights whereby the permitted level of emissions from the electricity and industrial sectors in the EU is a political decision. Therefore, if we use a little more electricity in Sweden, this does not mean that emissions increase but that someone else in the EU will either have to reduce their electricity consumption or invest in coal-less power production. This means that net emissions from the electric car will in practice be zero, although the emissions rights will be somewhat more expensive in the EU. However, one might counter that we can also let petrol-powered cars be part of the EU’s trading system, in which case the contribution from yet another petrol car would in practice also be zero.

A trading system is a control mechanism for ensuring that emissions reductions take place where they are cheapest to implement. However, it is nonetheless important to be able to evaluate technologies in advance. So the question returns to whether or not electric cars are better than petrol cars bearing in mind today’s electricity production. It is true that if we increase electricity consumption in Sweden by a little, then a little more coal power will be used this year. But an electric car has a life-span of around ten to fifteen years. Will coal remain a marginal power source throughout that time? What is more, if we were to go for electric cars in Sweden, new power stations would have to be built. What will be decisive is which new energy sources will be driven by the introduction of electric cars. Additional coal power, or renewable energy sources? This issue will be decided not so much by electric car customers but more by political decisions about which control mechanisms there are for the electricity generating sector.

The climate impact of electric cars therefore cannot be evaluated solely on the basis of the car, but must instead be viewed in a larger context. If a political decision is taken not to redirect electricity production, the electric car will not be a good climate alternative. But if resources are invested in redirecting power production, electric cars may well become a good solution for the future transport system.

Another two points to make about electric cars. One is that we would actually only need about 6 % more electricity production in Sweden to replace all passenger cars with electric cars. The second is production of the cars themselves. We estimate that the Lindell family’s car generates 100 kg CO2/person per year, which in itself is not a whole lot. But that figure can be a lot less if the electricity generating system were changed. In other words in a future in which power for electric cars is only a minor climate-related problem, actual manufacture of the cars will also only be a minor climate-related problem.

Fredrik Hedenus, Chalmers