Electric Vehicles – A Dream Turning Real?

Electric vehicles are stimulating our fantasy. Are they the magic solution helping us reducing our dependency from oil and paving the way for a greener mobility?  Or is it just wishful thinking making us believe that all road transport one day may be switched to electricity whereas, in fact, we do not even have sufficient production capacities to power an entire fleet of electric vehicles?

Phillip Muller has performed some interesting research on that issue. Have a look at his arguments here.

Electromobility – How Much Extra Capacity Do We Need?

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Let us imagine a world where all fossil-fuel driven cars have been replaced by electrical ones.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.

Paving the Way for Electromobility?

Electric cars are considered carbon-free. Although, strictly speaking, this is not correct, since their production requires a substantial amount of CO2, we may nevertheless consider them a more carbon-friendly alternative to the classical motor vehicle.

One of the key issues with electricity-driven vehicles is their competitiveness with regard to conventional cars. And here the prospects are not too shiny, at least for the time being. Clearly, there is room, plenty indeed, for development. The Achilles´ heel of the electric car is its battery which is heavy, takes a lot of space in the trunk and enables the driver to go about 150 km before recharging again. The latter process takes several hours, but may be speeded up to something like 20 minutes or so. Comparing this to the respective data for a classical vehicle is no incentive for excessive optimism. A gasoline or diesel driven car may go easily up to 1000 km without refuelling, and stopping at the gas station would normally take not more than 5 minutes.

Obviously, with these performance data the electric vehicle is no serious competitor to the conventional one. How to overcome these difficulties? Apparently, everything depends on the battery, its weight, its capacity and the time needed to recharge it.  One may, however, question if it ever will be possible to go 1000 km before approaching the next plug? Surely, nobody knows what will be the state-of-the-art in 10 or 20 years from now. Or has anybody thought about the performance of an iPhone ten years ago? So there is indeed room for surprises, but also for disappointments. An example for the latter is the continuous research effort on nuclear fusion which, although ambitiously driven for several decades, has not led to any viable economic output so far.

One possibility to get rid of the drawbacks of excessive battery weights is changing the supply mode altogether. Instead of carrying a heavy battery on board one might think of electrifying the road network. Via a special transmission mechanism the cars could get their power directly from a built-in electricity grid. For the time being it seems, however, exaggerated to electrify the entire road network. But what about having only the motorways with a built-in recharging facility?

In Europe, more than 85% of the population live within less than 50 km from a motorway. Thus, drivers would need the battery just for getting to the next motorway and then could connect to a specially designed supply system. This, in turn, could reduce the size (and weight) of vehicle batteries, thereby leaving more space for transporting items or people.

But what about costs? Implementing such a system would essentially mean rebuilding the entire motorway grid. And building motorways is expensive. A (very) conservative estimate says that each km would cost a minimum of 6 M€. Thus, electrifying the complete motorway infrastructure in Europe with a total length of 65 000 km would, according to our approach, amount to some 390 billion €. The real costs, however, might be significantly higher. In addition, due to its higher complexity, the new motorway network would certainly require higher maintenance costs, putting additional burden on public finances.  In 2000 the World Bank estimated the average maintenance costs for paved roads to be somewhere between 20 000 and 200 000 USD per km. This figure is bound to rise for an electrified roadwork.

Is it worth the effort or might it be more sensible to use biofuels or fuel cells instead?