Electric vehicles (EV) deliver net emissions reductions when compared to conventional vehicles and can save motorists over $1,200 in fuel costs, according to a landmark US study from the Union of Concerned Scientists (UCS).

The report is the most comprehensive assessment to date of the lifetime emissions of electric and conventional vehicles and will answer critics of electric cars who have argued that their reliance on fossil fuel-generated electricity undermines their green credentials.

The study, entitled ‘State of Charge: Electric Vehicles’ Global Warming Emissions and Fuel Cost Savings Across the United States’, looked at EV’s total emissions and running costs based on the varying energy mixes and tariffs adopted by different US states.

It concluded that in all US states emissions related to EVs were lower than average emissions from conventional vehicles, while 45 per cent of Americans lived in areas where relatively low carbon energy supplies meant that EVs delivered emissions levels that are lower than those of the best performing 50 miles per gallon conventional car.

“This report shows drivers should feel confident that owning an electric vehicle is a good choice for reducing global warming pollution, cutting fuel costs, and slashing oil consumption,” said Don Anair, the report’s author and senior engineer for UCS’s Clean Vehicles Program. “Those in the market for a new car may have been uncertain how the global warming emissions and fuel costs of EVs stack up to gasoline-powered vehicles. Now, drivers can for the first time see just how much driving an electric vehicle in their hometown will lower global warming emissions and save them money on fuel costs.”

He added that with 26 states currently boasting renewable electricity standards that require increased investment in clean energy, emissions relating to EVs are likely to fall further over time.

“The good news is that as the nation’s electric grids get cleaner, consumers who buy an EV today can expect to see their car’s emissions go down over the lifetime of the vehicle,” he said.

The report also looked at the cost of charging electric vehicles compared to the cost of purchasing gasoline for a conventional vehicles and again concluded that while costs varied by state all electric vehicle drivers could expect to see significant savings.

Based on electricity rates in 50 US cities, average levels of driving, and gasoline costs of $3.50 a gallon, motorists could expect to save between $750 to $1,200 a year in fuel costs.

The report added that with fuel prices rising, EV savings would also climb, calculating that with each 50 cent increase in fuel prices EV drivers would save a further $200 a year.

The report did not compare costs based on the full lifetime of the vehicle, on the grounds that the purchase price of EVs varies significantly.

However, with typical EVs costing between $5,000 and $10,000 more than comparable conventional cars, the report’s findings suggests that some EV drivers could enjoy savings over the full lifetime of the vehicle.

The study will represent a major boost to the fledgling EV industry, which has long maintained that as up-front costs fall the lower running costs associated with EVs will make them a compelling proposition, particularly for fleet operators.

In addition, supporters of EVs will note that with the US boasting a relatively carbon-intensive energy grid, electric cars in Europe and regions with low carbon energy grids are likely to enjoy even greater emissions savings.