Battery electric vehicles are only as clean as the energy source used to generate the electricity that powers them. The calculated relative amounts of well-to-wheels emissions of greenhouse gases from eight different energy sources are shown in the table below. (The calculations were based on the data developed by the Union of Concerned Scientists .) These results indicate that coal and oil are the energy sources leading to most emissions, and that hydro, wind, and nuclear are the energy sources leading to least emissions. On the two extremes, coal and oil result in about 176 times the emissions from hydro. This brief study analyzes, for each individual state, the changes from 2008 to 2018 in the use of coal (one of the two most polluting energy sources) to generate electricity. (Oil is used relatively infrequently in the United States as an energy source for electricity. In 2018, only two […]