Mini revealed its electric Mini E costs less than 2p per mile to run, but a businessman from the Hebridean island of Islay has gone one better by being able to run an electric car for free.
Mark Reynier is managing director of the Bruichladdich whisky distillery. The distillery uses technology where waste products from the whisky-making process are turned into gas, which then powers a generator to produce electricity.
That electricity powers the whole distillery and also charges a Nissan Leaf that Mr Reynier has recently taken delivery of.
He explained: 'It was frustrating to make such strides in being self-sufficient when my car needed the most expensive diesel in the UK from the mainland, so the arrival of the Leaf has allowed me to be as self-sufficient as possible.
'Every day I drive eight miles along the Atlantic coast in total silence, on a single charge. It's glorious.'
Not every car buyer has a handy eco distillery to produce electricity for them, but domestic solar panels can produce enough electricity to charge electric cars.
DJ Mark Goodier recently had British Gas fit 12 solar panels fitted to his house to help charge his Nissan Leaf.
'It's not costing me or the environment anything, because the energy generated by the solar panels covers the cost of the electricity it uses,' he said.
Consumers would have to pay for a domestic car charging point and the solar panels, which wouldn't give much change from 10,000. The panels would provide a yearly income thanks to the Feed-in Tariff, however, where producers are paid by the UK's electricity suppliers.