I all too often hear people try to make the argument that electric cars are no better for the environment than regular cars because most of the electricity comes from coal-fired power plants.
What would be great is to find out how much carbon is released when creating the electricity for moving a car 1 mile. Then compare how much carbon is released when burning gas to move an equivalent car 1 mile.
There are many counter-arguments to this idea of coal vs gas. For example, at least coal is produced locally - your money isn't going to 3rd world dictators. Or at least there is the potential to add improved pollution control to the power plants, whereas changing everyone's tailpipe is impossible.
But it would be great if the argument could be won on the same grounds that it was made - carbon output.
Ok - I did a little more research and it's a bit surprising.
Let's start by figuring out how much carbon is output by burning coal. According to Energy Information Administration (EIA) research, emissions range from 2,791 lbs per short ton for lignite coal to 5,685 lbs per short ton for anthracite coal. However, the coefficients for the coals that are primarily used in electricity production, bituminous and sub-bituminous are 4,931 and 3,716 respectively. Let's take the high-end = 4,931 lbs of CO2 per ton (2000 lbs of coal).
That works out to 2.47 lbs of CO2 per lb of coal.
How much electricity does a pound of coal make? According to numerous sources, 966 lbs of coal produces 876 kwh (kilowatt-hours). So 1.1 lbs of coal per kwh.
Using the Nissan Leaf as our average electric car, the EPA quotes it as using 34 kwh to move 100 miles. Or 34 kwh x (1.1 lbs of coal/kwh) = 37.4 lbs of coal are required to move 100 miles. Or .374 lbs of coal per mile. So .374 lbs of coal x 2.47 lbs of CO2 per lb of coal = .924 lbs of CO2 are emitted to move the Leaf one mile.
Hows does that compare to a dino-juice-burning automobile? The EPA says that a gallon of regular gas (not diesel) produces 19.4 lbs of CO2. Take a typical car that gets 20 MPG and that is equal to .970 lbs of CO2 per mile.
Winner? Electric car. Granted, you could get a super-efficient gas-mobile but the people using this argument are typically driving an SUV.
Also consider that most electric utilities are trying desperately to get away from coal, so the chances that your electrons were produced using pure coal are quite slim.