Unless you're tapping lightning bolts, electricity isn't a source of energy – it's a way of transporting energy from where it's generated to where it's used. So, when we have to decide whether it makes sense to use electricity for an application like lighting, transportation, home heating, or something else, we have to know where that electricity is coming from, what fuel is used to make the electricity, and what it's going to cost to use electrically-transported energy versus an on-site energy source like oil.
For lighting we've decided not to use kerosene and candles (other than for camping and romance). For transportation we did have lots of electric trolleys but they got replaced by diesel busses and gasoline cars. Oil was cheap and sticking to wired routes was limiting. Now importing oil is an economic and strategic risk; battery technology is better than ever before; electronic controls are cheap; CO2 emissions are a concern; and electricity is close to making a comeback in transportation.
What fuel your electric car is actually running on depends on where the electricity comes from that you use to charge your batteries. Maybe your electric vehicle is running on coal –very likely in the U.S. where coal is the biggest source of electrically-transported energy. Here in Vermont, if you charge up off-peak, your car is some combination of hydro-powered from Hydro Quebec and nuclear from Vermont Yankee. If you charged up on-peak , your car is probably running on electricity generated at least partly from natural gas.
It makes economic and environmental sense to use electricity to charge your electric car even if the electricity is generated by burning oil. It is so much more efficient to burn oil in a power plant than in a car that, despite losses in transmission and storage, less oil gets
