Are Electric Cars Really Green?

I've been seeing several commentators point out that to deliver power for an electric car, it has to go through several conversion phases, each of which add substantially to the inefficiency of the process.  This is absolutely true.  For example: burning natural gas to produce electricity produces at best about 60% of the theoretical conversion efficiency.  Realistically it's closer to 40%.  Line drops add 5-20% further loss, and charging/discharging the battery adds another 5-20%.     Burning coal or petroleum is even worse--30%.  Meanwhile, a Prius is able to turn gasoline into motion at about 30%.    So: picking relatively favorable numbers for natural gas, we get .4 * .9 * .85 = 30.6% conversion efficiency from the carbon in the natural gas to the motion.  The commentators are right: there's no efficiency advantage in a pure electric.

But this omits the really big point, which is that it's possible to power a pure electric car from completely carbon free resources: Hydroelectric, Wind, Solar, Geothermal, etc.  This is not true for a Hybrid, like the Prius.

Another complaint: There are a lot more batteries and they're harder to recycle.  This is true too.  Lithium and NiMH batteries are harder to recycle than lead acid batteries.  (Lead car batteries are over 99% recycled).   But several companies (including Toyota) are doing it fairly successfully.   There's another win too: even if a lithium battery does get into the landfill, it's far less toxic than a lead battery, and nowhere near as bad as the Cadmium from a NiCd, which can poison a compost heap at extremely low concentrations.

Another: the glass, brass and tungsten from incandescent light bulbs is worth recycling, but the largest component, the glass, is close to chemically inert.   CFCs (and other fluorescent bulbs) have about the same amount of glass, but they have a bunch of other stuff, all of which is easily recycled.   The most important, by far, is the small amount of Mercury, which is nearly as harmful as Cadmium. (The amount of Mercury in a Fluorescent bulb is tiny though, compared to the amount in a NiCd battery).  Home Depot and many others will recycle these.  I keep a box for this purpose in my garage.