The rotor of a modern steam turbine used in a power plant (Wiki)
The environment impact of electric vehicles are highly related to the source of electricity for charging those vehicles and this topic always attracts a lot of interest.
U.S. Energy Information Administration provides data for sources of U.S. electricity generation. As 2015 just closed, these numbers released are for full year 2014 (update: data through October 2015 is also below).
The truth is that on average most electricity comes from steam turbines. Turbine is a power generator driven by steam, that comes from heated water in a boiler. The heat is generated by burning fossil fuels (coal, petroleum, and natural gas) or biomass in a furnace, or in case of nuclear power plants, by nuclear fission.
If we sum all the steam turbines in the U.S., their share we should get nearly 88%.
In 2014, Renewable sources of energy stands at 13% (including biomass). Their advantage is that you don't burn anything (at last not directly). Hydro is 6.24%, while Wind at 4.42%. There's Geothermal at 0.39% and Solar at 0.39%.
Those are average, as there are places with higher and lower values - the ultimate goal is to reverse proportions and have most of our electricity produced from renewable sources.
2015 Update (through October):
- Coal - 34.1% (-4.8% vs 38.9%)
- Nat Gas - 32.4% (+5.0% vs 27.4%)
- Nuclear - 19.2% (-.2% vs 19.4%)
- Renewable - 13.1% (+.2% vs 12.9%
Here’s Where U.S. Electricity Comes From (source: U.S. Energy Information Administration)