Sunday, November 28, 2010
The Longest Tailpipe
EV's are zero emission vehicles. The cars themselves emit nothing when driving. Of course that power in the battery had to come from somewhere, and depending on how it's produced there will be some emissions. Detractors call this the "Long Tailpipe" argument. It's usually based on the viscerally unpleasant image of "Plugging in to a lump of Coal". Coal looks dirty, it's dark and dusty, coal mining is ugly, coal plants have stuff coming out of the stacks, all around nasty. However, these same people rarely if ever address the fact that the gasoline in your tank has large energy inputs, and therefore emissions, before it even gets into your tank. Oil drilling isn't any better than coal mining, (BP oil spill anyone?), and the refining process takes vast amounts of energy, including electricity. Depending on the base stock refining a gallon of gasoline can take around 7 killowatt hours of energy to produce. That means an EV with an average use of 200 watt hours per mile can drive 35 miles on the same amount of energy used to create a gallon of gas. Then it has to be pumped, trucked, and pumped again to get into your tank, all using energy and all creating emissions. Exact numbers are hard to pin down, but generally the worst numbers for a coal powered EV are still better than the best numbers from a conventional car when the full supply chain is taken into account. It's also much easier to control and monitor the emissions from a single power plant than millions of unregulated vehicles in various states of repair. The reality is that the average grid mix is around
48% 45% 40% coal powered so the real world numbers are much better for EVs, and as we improve our grid they will get even better. EV's also allow you to create your own power at home through solar, wind, and micro hydro, all truly zero emissions. Try refining your own gasoline at home with zero emissions. The longest, dirtiest tailpipe still belongs to ICE vehicles. Besides, which vehicles would you rather be surrounded by when stuck in traffic?