Where does the energy which generates the charging electricity come from? Some places will use nuclear energy or some other non-oil energy source, but many plac

Where does the energy which generates the charging electricity come from? Some places will use nuclear energy or some other non-oil energy source, but many places will use oil to generate the electricity used in an attempt to save importing oil. Then the problem is that generation and charging losses will mean that more oil rather than less oil will be imported.