Usually financed at a low interest rate. Electricity isn't free, but in my case costs about the equivalent of $1/gallon for gas (locally, gas is currently about $2.40). So overall, still definitely a win.
For gasoline, I consider it as essentially financed as well. Going to the gas station is basically paying off part of the debt I got by buying a gasoline consuming vehicle. Electricity, too, but electricity is much cheaper, and I can get out of debt there by buying a solar power system (unlike gasoline which is not feasible to produce on your own nor store a car-lifetime's worth).
