GM offers big price cut on Chevy Volt

[wercal]

28. Some calculations

In a worse case scenario, coal would be used to generate electricity, at around 2 lb co2 per kwh...and it takes around 14 kwh to charge a Volt to go 40 miles...it all comes out to 0.7 lb co2 per mile (in electric mode).

A gallon of gasoline makes around 19.6 lb of c02...so the breakover point, where a car would produce less co2 than a Volt (in electric mode) would be 28 mpg. Of course, many cars get better mileage than that - some pickup trucks actually create less co2 than a Volt. And, a Volt in gas mode creates less CO2 than a Volt in electric mode.

If you happen to get electricity from natural gas, at around 1.22 lb co2 per kwh...leads to 0.43 lb per mile, or a gas breakover point of 46 mpg. So, a Volt powered by electricity from natural gas is competitive with current compact cars on the co2 front.

There are lots of ways to confuse this issue - by looking at the entire extraction and refining process of gasoline (but oddly most who do that seem to ignore the mining and transportation processes of coal). Or, some will claim the electricity could come from wind power of hydro-electric.....well maybe it could, but statistically, you are very likely getting power from coal of natural gas. And, some would argue that burning gas produces other pollutants that coal doesn't, or is at least controlled better at the power plant through hydrostatic scrubbers. That is a valid argument, but not a game changing argument.

So what does this mean? Well, frankly, electric cars are not an environmental magic pill. And, you could buy a nice compact for 2/3 the cost.