Electric cars are widely excepted as a ‘green’ alternative to fossil fuelled vehicles as they emit no tailpipe emissions and because their carbon footprint can be largely determined by the electricity mix from which they recharge.
However what has not been fully analysed and understood is just how green the manufacture, operation and disposal of the rechargeable batteries are. It is well known that modern electric cars are reliant largely on lithium ion batteries which require the extraction of rare lithium to produce. Critics of electric cars have claimed that this much undermines the environmental argument for electric cars, but now, new analysis from Swiss scientists has shown that electric cars perform better than expected after the ecological footprint of their batteries is accounted for.
Research institute, Empa has for the first time calculated the environmental impact of lithium-ion batteries and concluded that, with this taken into account, a conventional car with a petrol engine would need to achieve around 70mpg in order to be as environmentally friendly as an electric car.
That’s a tall order, average mpg for a petrol car is around 40mpg, while even the greenest petrol car currently available on the market-the Toyota iQ achieves just 65.7mpg on a combined cycle.
The investigation shows that the environmental impact of producing the batteries is only a fraction of an electric car’s impact. Using a standard European electricity mix, an electric car the size on a VW Golf was compared to a new petrol-engine car meeting Euro 5 emissions regulations.
The research concluded that, at mos,t only 15 per cent of the electric car’s total burden could be ascribed to the battery (including its manufacture, maintenance and disposal). Half of this figure, that is about 7.5 per cent of the total environmental burden, occurs during the refining and manufacture of the battery’s raw materials, copper and aluminium. The production of the lithium, in the other hand, is responsible for only 2.3 per cent of the total.
“Lithium-ion rechargeable batteries are not as bad as previously assumed,” Dominic Notter, co-author of the ‘Contribution of Li-Ion Batteries to the Environmental Impact of Electric Vehicles’ study said.
In fact, the refuelling of an electric car over a 150,000 mile lifetime, by far accounted for the greatest share of the car’s environmental impact. “Refueling” with electricity sourced from a mixture of atomic, coal-fired and hydroelectric power stations, as is usual in Europe, results in three times as much pollution as from the Li-ion battery alone.
