There are plans to electrify the transport system. Electric cars will, according to some futuristic scenarios, soon populate our roads. Car makers are quickly developing the needed technology which so far has not left its infancy stage. Nevertheless, there is room for improvements and technological progress. Perhaps we will see a significant number of electric autos on the road withing a decade or two. Germany wants to have have 1 million electric cars by 2020.
Let us imagine a world where all fossil-fuel driven cars have been replaced by electrical ones. In addition, we may suppose that people have not changed their driving habits, i.e. the number of km driven per car is not lower than it was during the gasoline and diesel era. Thus, the energy needed for transport purposes is more or less the same for electrical or conventional cars.
From this we may estimate of how much extra capacity we need in order to generate the electricity that is supposed to power the vehicle fleet. Given the current structure of the energy grid it is pretty obvious that the existing generation capactiy for electricity will not be sufficient to supply the required energy for an entirely electrified auto world.
Let´s look at the European figures first. In 2007, road traffic accounted for a final energy consumption of 309 Mtoe. This is equivalent to 3600 TWh. Taking into account efficiency gains, since electric engines are more efficient than combustion engines, we may estimate the final consumption in the electric world to 1800 TWh. This corresponds to 63% of total EU final electricity consumption in 2007. Thus, production capacity must be upgraded accordingly if we want to have electric cars only on the road. But how much extra capacity is needed?
A top-performing nuclear power plant may produce some 10 TWh per year. From this we may conclude that about 180 extra nuclear plants may fill the energy gap. It goes without saying that this is not a very likely scenario, given that countries like Germany and Belgium are planning to abandon nuclear altogether. For other countries like Austria, nuclear is not an option in the first place. There may be plans to build new capacities in some European countries, like in Finland. However, nowhere do we get near the requested capacity. Likewise coal-fired power plants are not an option due to their greenhouse gas emissions.
So what about renewable energies? Let us take the Desertec initiative as a reference point. It is a gigantic proposal supposed to transmit in 2020 some 60 TWh of electrical energy from the north African desert to Europe. This amount of energy, however, is about a factor 60 short of what is needed (1800 TWh). Even the anticipated transmission volume of 700 TWh in 2050 falls short of the electricity needs for full electromobility. Thus the challenge is much bigger than we may think of in our most optimistic dreams. Even a full-scalce Desertec facility will not be able to provide sufficient energy for an electrified transport scheme.
Traffic requires even more energy resources in the US. According to the US Energy Information Administration (EIA) in 2007 about 27 763 Trillion Btu were used for transport purposes only. Correcting for non-road traffic (mainly air transport, water transport and rail) about 20 000 trillion Btu went into vehicle transport. Translating this into electrical units and accounting for efficiency gains as above leaves us with some 2900 TWh which would be needed in order to put the entire US vehicle park on an electrical basis.
Not surprisingly, the respective requirements are even more challenging than in the European case. It goes without saying that similar arguments apply for Asia, Latin America and Africa. The effort to embark into electromobility is tremendous. In any case, a massive extension of electricity generation capacity is unavoidable.