Electric vehicle sales in the US have doubled in the first six months of 2013 compared to the same period last year.

Plug-in electric vehicle (PEV) sales tripled from around 17,000 in 2011 to 52,000 in 2012 whilst more than 40,000 have already been bought in the first six months this year – more than twice as many sold during the same period in 2012.

Statistics from the US Energy Department showed the price of fuelling electric vehicles increased slightly to $1.18 (£0.77) from $1.14 (£0.74) in the latest monthly numbers, however, it remains far below the $3.49 (£2.27) cost of a gallon of fuel.

Energy Secretary Ernest Moniz said: “More and more Americans are taking advantage of the low and stable price of electricity as a transportation fuel and that’s very good news for our economy as well as the environment. As the market continues to grow, electric vehicles will play a key role in our effort to reduce air pollution and slow the effects of climate change.”

The cost of a battery for PEVs has dropped by nearly 50% in the last four years and is expected to fall to $10,000 (£6,515) by 2015.

New research last month predicted hybrid electric car sales across the globe to double by 2020 and a report last year forecast EVs powered by fuel cells could account for a third of all cars on the road by 2050.