works out to around 80 lb CO2 generated
This is likely an overestimation, since it assumes that you're exclusively burning coal. Electricity production in the US is about 68% fossil, the rest deriving from a mixture of nuclear and renewables; the fossil-fuel category also includes natural gas, which per your link generates about 55-60% the CO2 of coal per unit electricity. This varies quite a bit state to state, though, from almost exclusively fossil (West Virginia; Delaware; Utah) to almost exclusively nuclear (Vermont) or renewable (Washington; Idaho).
Based on the same figures and breaking it down by the national average of coal, natural gas, and nuclear and renewables, I'm getting a figure of 43 lb CO2 / 100 mi, or about 50 mpg equivalent. Since its subsidies came up, California burns almost no coal but gets a bit more than 60% of its energy from natural gas; its equivalent would be about 28 lb CO2.
works out to around 80 lb CO2 generated
This is likely an overestimation, since it assumes that you're exclusively burning coal.
Yes, but that should be the right comparison to make. Consider two alternatives: 1) World generates N kwh + 38 kwh to fuel a Tesla to go 100 miles 2) World generates N kwh and puts 4 gallons of gasoline in a car to go 100 miles.
If we are interested in minimizing CO2 emissions, then in world 2 compared to world 1 we will generate 38 kWh fewer from our dirtiest plant on the grid, which is going to be a coal-fired plant.
So in...
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