A team of Swiss researchers compares the total life-time impact of a gas car and an electric car to put to rest some lingering questions.
The conventional wisdom is that electric cars are the more environmentally-friendly option, because they don't burn fossil fuels. But for the informed skeptic there are usually two lingering questions. First, doesn't that electricity come from dirty coal anyway? And second, what's the environmental impact of producing that big, costly battery in the electric car?
Well, the Swiss Federal Laboratories for Materials Science and Technology (EMPA) has completed a life-cycle comparison between an electric car and an internal combustion engine car to settle some of those nagging questions.
The researchers used an electric car "comparable to a Volkswagen Golf in size and power," with a lithium ion battery, a range of 125 miles, and an assumed lifespan of 93,000 miles. They compared it with a "new efficient gasoline car" of a similar technological level that gets 45 miles per gallon and has the same lifespan.
The results? As the researchers explain, they erred on the side of overaccounting for the environmental impact of the battery and the electric car still wins out. If you assume the electric car is powered entirely by electricity generated from coal, its cradle-to-grave environmental impact is equivalent to that of a gasoline car that gets 45 miles per gallon (roughly what a Prius gets). If you assume the electric car is powered by the current typical mix of European power, it's equivalent to a gas-powered car that gets 58.8 miles per gallon. And if the electric car is powered entirely by renewable energy, an equivalent gas powered car would need to get 117 miles per gallon.
In general, the environmental impact of producing the battery is a much smaller factor in the overall environmental impact of the car than the actual driving of the car. As the paper puts it:
...the environmental burdens of mobility are dominated by the operation phase regardless of whether a gasoline-fueled [internal combustion engine car] or a European electricity fueled [battery electric vehicle] is used. The share of the total environmental impact ... caused by the battery ... is 15%. The impact caused by the extraction of lithium for the components of the Li-ion battery is less than 2.3%.
So there you have it. If you're buying a new car, an electric car is better, environmentally speaking.
Here's the exception though: If you were to compare buying a used gas car to a new electric car, and you assume that the seller doesn't replace the gas car, and that your decision prevents a potential electric car from ever being produced, it would probably be better to buy the used gas car.