Not all "electric cars" are as green and economic as you would tant them to be… This goes mainly to differences between different approaches to "electric car" concept…

Three main groups of cars consist of: pure electric cars (not many cars on the market after they killed EV1… mostly quadrouple drives - reva, italcar, and some service/agencies vehicles), gasoline-hybrid electric cars (these are the hybrids that started the electric car era - Toyota Prius, new Honda, and some of upcoming GM and Tesla Motors…) and hydrogen-electric cars (two types: in one hydrogen is used in internal combustion engine; in second, more advanced, hydrogen is used in fuel cells, and electricity is used for electric engine and stored in batteries).