Lower Carbon Footprint
Even if 100% of the electricity for plug-in vehicles came from coal-fired power plants, there would be 25% less CO2 generated per mile using plug-in vehicles driven on electricity than driving the same distance with internal combustion engines (2007 study by the Natural Resources Defense Council and the Electric Power Research Institute).
Over time the impact should be even less, because electricity is now produced in the U.S. from a diverse source of fuels including natural gas, nuclear, wind, solar and hydro power. Also, the majority of new electricity generators being built today use natural gas or renewable fuels. Many states, including Ohio, mandate that a certain portion of the electricity generated and sold must come from renewables.
More Energy Efficient
The electric utility system is more energy efficient than an internal combustion engine. Burning a carbon-based fuel, such as coal, at a power plant turns slightly less than half of the energy into electricity. Compare that to an internal combustion engine where only about 25% of the energy in each gallon of fuel is actually converted to miles and the rest is wasted as heat and to overcome friction.
Less Oil Usage
Plug-in electric vehicles for the most part have little to no dependence on oil for day-to-day operation. This is especially true for all battery vehicles. Plug-in hybrids could use oil products for fuel when the battery power is used or low.