My recent column for The Times on the arithmetic behind electric cars:
The British government is under pressure to follow France and Volvo in promising to set a date by which to ban diesel and petrol engines in cars and replace them with electric motors. It should resist the temptation, not because the ambition is wrong but because coercion could backfire.
The electric motor is older than the internal combustion engine by about half a century. Since taking over factories from the steam piston engine at the end of the 19th century, it has become ubiquitous. Twinned with its opposite number, the turbine (which turns work into electricity, rather than vice versa), it drives machines in factories, opens doors, raises lifts, prepares food, brushes teeth and washes plates.
These are fantastic motors and we should be using even more of them, especially in personal transport. They are quiet and clean at the point of use, so could have transformative effects on the quality of life of those living near roads and in urban areas. In the future they could even fly planes.
But if it is to be cordless, an electric drive must carry a heavy battery. Using lithium atoms, among the lightest there are, has helped to make batteries lighter, but they are still bulky, slow to charge and liable to explode if charged too fast. Imagine the congestion at charging stations if every car was electric.
Building an electric car generates considerably more carbon dioxide than creating a comparable petrol model because so much energy is required for the mining and processing of lithium, nickel and other materials for the battery. The battery accounts for more than half the cradle-to-grave emissions created by an electric car. Fuelling that car from a coal-fired grid like China’s or India’s makes the emissions even worse.
With Europe’s mix of generating capacity — less coal, more gas, more wind and more nuclear — an electric vehicle does emit less carbon dioxide over its lifetime than a comparable petrol or diesel vehicle, but not by a large margin. As one study concluded: “We find that electric vehicles powered by the European electricity mix reduce [global warming potential] by 26 per cent to 30 per cent relative to gasoline . . . and 17 per cent to 21 per cent relative to diesel.”
Then there is the question of where the extra electricity is to come from. In recent years we have struggled to build enough power stations for existing users, let alone adding all cars and heating too, for that is the plan. Britain’s cars travel about 250 billion miles a year. Assuming the use of very small Nissan Leaf-style vehicles, that mileage would add an extra 16 per cent of demand to our existing electricity grid.
If we want the new capacity to be low carbon — and since we cannot seem to get our act together on nuclear, and solar works poorly at this latitude, especially in winter — then how many wind turbines would be needed to generate that much extra electricity? Roughly 10,000 onshore or 5,000 offshore, requiring a subsidy of at least £2 billion, more than double the size of our existing windfarm estate. Yikes.
Meanwhile, the idea of using electric vehicles to balance the grid, allowing us to dump spare juice into them when the wind blows and take it out when it does not, is, according to Ofgem, pie in the sky, at least until autonomous vehicles arrive and cars can go scurrying off to central charging points after dropping you at home, which is some way off.
Finally, remember that — globally at least — 40 per cent of road transport fuel is used by lorries, not cars, so electrifying all cars still leaves a big chunk to tackle. In short, electric cars are a great technology but almost trivial as a climate policy. They’re attractive for other reasons.
To achieve a major transition in the economy, such as to electric transport, you could force the issue with a legal deadline, challenging the engineers to solve the practical problems and incentivising businesses to leave their comfort zone and abandon existing technologies.
Without a government ban it might never happen. But that sort of hothouse growth risks entrenching an immature technology, preventing a better one from coming along.
Here is a cautionary tale illustrating the latter point. Ten years ago Gordon Brown, then chancellor, and Hilary Benn, environment secretary, announced that ahead of an EU timetable Britain would forcibly phase out incandescent light bulbs in favour of compact fluorescent (CFL) ones, promising that this would “help tackle climate change, and also cut household bills”. By sending free CFL bulbs to most households and requiring retailers to sell only the new bulbs, this cost the country almost £3 billion.
Slow to warm up, tending to flicker, with a much shorter lifetime than expected and dangerous to dispose of, CFL bulbs were less popular with consumers than with manufacturers, who tooled up to produce them. Now, just ten years later, nobody wants CFL bulbs, thanks to the dramatic fall in price of the next technology: more efficient, better quality and safer LED lights. The government backed the wrong technology. Fortunately, in that case, changing course won’t be very hard, though the waste of £3 billion is a miserable thought. It would be much worse if we picked the wrong battery technology for electric vehicles.
Tesla’s decision to build a “Gigafactory” to make lithium-ion batteries may establish a new standard for battery technology for a generation, at the risk of pinching off research into potentially better designs for batteries. Or Tesla may find itself with an obsolete system if one of those other technologies suddenly achieves a breakthrough.
Perhaps we should leave this to the market. The great merit of private enterprise is that it reduces the cost of learning by putting a limit to the extent of the hazard of any particular adventure. One company gambles, and takes a hit, but the harm is limited and the lesson is learnt by everyone.
A ministerially mandated nationwide failure would be costly in itself and could delay the wider use of a genuinely promising development in personal transport. Don’t let the state screw this up.
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