3 things. first, 2nd law of thermodynamics, you WILL not get back as much energy as you put in. ie, photovoltaic cells will not be sufficient, I do not care how efficient you make them. secondly, the shortage we have on minerals such as neodymium and lithium (both needed for this sort of thing) makes it look like we have enough fossil fuel to bathe in. thirdly, a nuclear power plant produces about