HOW CLEAN IS AN EV? CLEAN!

What's the carbon footprint of an electric car?
Tom Fowler, February 5, 2010 (Houston Chronicle)

"…I've always assumed that one big coal-fired electric turbine would be cleaner and more efficient than a million individual internal combustion engines. At the very least it would be easier to try to monitor and scrub the emissions from that one big stack vs. all those scattered/mobile tailpipes….But having never crunched the numbers I asked…an Austin green energy and technology consultant…[to] calculate the carbon footprints of an electric vehicle and a gasoline vehicle…

"His rough estimate…Electric vehicle: 0.14 lbs of CO2 per mile…Gasoline vehicle: 0.71 lbs of CO2 per mile…[The calculation starts with] kilowatt hours. Very roughly, one pound of coal generates 1 kWh of electricity…"

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"The next question is, how much energy does [a battery electric vehicle] use to go, say, 100 miles on the highway and in the city? …The battery holds 24 kWh of charge and Nissan says it has a range of over 100 miles…That's 0.24 kWh per mile, or, roughly…four miles/pound of coal…[One pound of coal produces roughly 2.9 pounds of carbon]…that's 3/4 lb of carbon produced for every mile…[T]hat's roughly 3/4 lb of carbon produced by every one pound of coal burned, or roughly 1/5 lb of carbon produced for every 1 lb of coal burned.

"For gasoline, it's 19.4 lbs of carbon produced for every one gallon of gas burned up in a vehicle…[For] a car that meets the 2010 CAFE standard of 27.5 mpg as our comparison…That's 19.4/27.5 = 0.71 lbs of carbon produced for every mile driven…"

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"…Electric Vehicle: 0.19 [Lbs of CO2 per mile]…Gasoline Vehicle: 0.71 [Lbs of CO2 per mile]…Assuming $0.11/kWh price for electricity and $2.50/gallon gas…Electric Vehicle: $0.055 [Cost/Mile to Drive]…Gasoline Vehicle: $0.09 [Cost/Mile to Drive]…In other words, a new car's fuel expense is almost twice that of an electric vehicle's and it emits almost 3X the carbon…

"[And the] calculation is based on the assumption that all the electricity is made by burning coal, which it isn't…[If the electricity comes from] 20% due to nuclear [creates zero CO2], 30% x .25 due to natural gas (gas is roughly 3/4 cleaner than coal) or roughly 8%…So, we need to subtract [28% of carbon emissions]… Electric Vehicle: 0.14 [Lbs of CO2 per mile]…Gasoline Vehicle: 0.71 [Lbs of CO2 per mile]…In other words, a NEW gasoline car emits 5X as much CO2 as an EV plugged into a typical existing US grid…"