Three offshore wind projects won contracts from the government in the latest subsidy auction for 'less established technologies' © Alamy

Sir, Further to “ National Grid says charging electric cars could blow a home’s fuse” (August 21): users of electric vehicles who use rapid chargers can expect to pay about 20p per kilowatt hour, the Tesla UK supercharging rate for electricity. For those users who travel an average of 50km (30 miles) a day this way, it works out at about £2 per day, plus the road charges that EV users can expect to pay eventually. That is the same as the £2 daily access charge rate for a Boris bike in London, plus the further bike journey time charges.

The London Array of offshore wind turbines produces enough electricity for 1m electric cars to travel about 12,500km (8,000 miles) each per year and the car majors should be getting together to fund many more of these offshore wind farms, which are increasingly proving to be very good value for money. Users who charge up at home will be paid to connect their cars to the grid for long periods. As 1m cars will store the equivalent of about 10 days of the average continuous output from the London Array, this will help stabilise the grid to allow peak charging for other rapid charger users, balancing overall supply and demand.

Leon Di Marco

FSK Technology Research,

London W9, UK

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