Treehugger recently reported on a study from Switzerland’s EMPA (the Swiss Federal Laboratories for Materials Science and Technology) dealing with the relative environmental impacts of electric- and gas-powered vehicles. According to their study, electric vehicles come out on top, but not by as much as some may have hoped or imagined. While it is difficult to objectively compare the two technologies (because their environmental impacts can be of different types), the report attempts to tease out the effects through a sensitivity analysis. Environmental burdens for different types of Li-ion batteries appeared to be similar, while the production method of electricity used to charge the vehicle highly affected the environmental impact. Hard coal power plants increased the burden by 13.4% but hydropower decreased the burden by 40.2% (see p. 6554).
Treehugger reports some useful statistics for comparing the two technologies. If coal is used for electricity generation, an electric vehicle gets the rough equivalent of 45.2 miles per gallon (mpg). If a more typical European mix of power is used (renewable, nuclear, and combustion), the electric vehicle gets the rough equivalent of 58.8 to 78.4 mpg. If an electric car is charges with renewables only, it gets the equivalent of 117.6 mpg. So, even with “dirty electricity,” electric vehicles achieve a remarkably high fuel economy.
The report’s main conclusion is that “E-mobility” (electric mobility) provides environmental benefits over conventional mobility, and that the Li-ion battery plays a minor role in the vehicles’ environmental burden.