Why are electric vehicles considered green ?
The internal combustion engine (ICE) has a thermodynamic energy conversion efficiency of 17%. This means that 83% of the energy present in the fuel is wasted as heat, with only 17% being converted to useful mechanical energy. An electric vehicle’s motor has an energy conversion efficiency of 88%. A power plant with regenerative turbines has an energy conversion efficiency of 55%. Therefore, the net electric vehicle’s energy conversion efficiency is 48%. Presuming both are powered by fossil fuel (directly, or via an electric utility burning fossil fuel), the electric vehicle is 2.8 times more efficient turning fossil fuel energy into useful mechanical energy. This is why it is considered green. Perhaps the relative phrase, “Greener by a factor of three”, would be a better description, as few things, if any, are completely green. Regarding batteries, lithium magnesium oxide (including graphite electrode) contains no toxic elements. Lithium is the lightest metal of the elements (vs. heavy
