Letter: Cleaner cars

Sir: Electric vehicles should not be dismissed out of hand by Barrie Phillips and Dr Tim Dennis (letters, 25, 30 October).

In cities, the ability of the internal combustion engine to deliver power efficiently is appalling. Most of the time the engine is either at idle or pulling the vehicle along at less than 20mph. You would be lucky to achieve an overall efficiency of 20 per cent.

A conventional coal-fired power station has a generating efficiency of around 35 per cent. Transmission, distribution, battery charging and motor efficiency losses reduce this to around the same figure of 20 per cent for the overall efficiency of an electric vehicle. But if our electric vehicle is charged overnight, the chances are its energy needs will be met by one of the newer and more efficient combined cycle gas turbine stations which operate at around 55 per cent efficiency. This translates to a figure of about 33 per cent for our electric car.

Air pollution would be moved away from the city to the power station, where it can more easily be controlled. The urban environment would be greatly improved and would encourage people to walk and cycle without breathing in traffic fumes.

The electric vehicle may not be a panacea, but it has an important contribution to make in improving our urban areas.

NIGEL FOX

Reading