Tuesday, April 17, 2012

How Green Are Electric Cars?

Great article in the NYT today, following up on a Union of Concerned Scientists report on the full-cycle efficiency of electric cars.

Electric cars - I mean all-electric, like the Nissan Leaf - tout their green credentials: zero carbon-dioxide emissions!  Well, it's true, there is no CO2 coming out of the tailpipe, because there is no tailpipe.  But the electricity to charge the car's battery has to come from somewhere.  Depending on the mix of fuels used for electricity generation (coal, natural gas, nuclear, hydro, solar, wind) and the costs of distribution, the net CO2 effect can be quite substantial.  How substantial? Well, the result is a map showing some regions of the country with relatively "green" electric generation mixes, where your electric car would definitely do better.  But there are other regions where from an emissions perspective you could be better off driving the most economical cars currently available with a regular gasoline engine.

Read the full article here.

PS: I wonder whether the emissions associated with the production and distribution of gasoline were included in this "full cycle" analysis?  But gasoline is so energy dense that these may be a rather small proportion.

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