The impact of coal-burning power plants and gasoline can be quantified. The EPA estimates that the average passenger vehicle emits 5.1 metric tons of carbon dioxide equivalents per year. Coal-burning power plants, on the other hand, produce more than 4 million metric tons per power plant, per year. The overall carbon dioxide output of coal-fired electric power plants exceeded gasoline by more than 30 percent in 2010.
My math may be way off, but:
coal: 1,933,130,000,000 kwh/yr plants: 518 kwh/plant: 373,191,120 tons/plant: 4,000,000 ton/kwh : 0.01 37.4% of electricity in US
nat. gas: .0005675 ton/kwh 30.3% of electricity in US
tesla S: .3kwh/mi
Coal only: .003 ton/mi Gas only: .00017 ton/mi Coal + Gas + Renewables: 0.0012 ton/mi
avg ICE: 12,000 mi/yr 5.1 ton/yr 0.000425 ton / mi
As we move away from coal and towards renewables, it's obvious that electric cars become the winners. In areas with mostly coal power production, though, ICEs are more environmentally friendly.
It's really telling how freaking dirty coal is.
I can't seem to find any more recent data showing how that coal energy use has declined in the last two years, the most current seems to be 2013.
They appear to have projected to be getting 20gwh of energy from coal in 2015. [3]
[1] https://en.wikipedia.org/wiki/Energy_in_California
[2] http://www.washingtonpost.com/news/wonkblog/wp/2013/06/07/ca...
[3] http://www.energy.ca.gov/renewables/tracking_progress/docume...