A study conducted by the Union of Concerned Scientists finds that electric cars have significantly lower emissions over their lifetime than their gasoline powered counterparts.
The study looked at the Nissan LEAF and the Tesla Model S. Both have higher emissions during manufacture than conventional cars. The LEAF’s emissions were 15% higher than those of a comparable car getting 29 mpg. The Model S emissions were 68% higher than a comparable car getting 21 mpg. Much of those higher numbers are attributable to the battery manufacturing process.
But the proof of the pudding occurs when the cars hit the road. Assuming an average useful life of 179,000 miles, both the LEAF and the Model S were found to have 51% lower emissions overall than their internal combustion powered rivals. The LEAF only needed 6 months of driving to offset its higher emissions during manufacture. The Model S needed 16 months of actual driving to do so.
Of course, any study of electric cars has to take into account the emissions that come from producing electricity. In places like West Virginia, where the vast majority of electricity comes from burning coal, the results are different than they would be in California, which has the greenest electrical grid in the US.
No matter how the figures are sliced and diced, however, electric cars still emit far fewer carbon emissions during their lifetimes than cars that burn fossil fuels.
Note: The Tesla Gigafactory under construction in Nevada, which will build all the batteries used by Tesla automobiles, is designed to have no carbon emissions at all. That is an industry first.