@spivonious: Geothermal isn't too bad for domestic heating, but I don't think it works out for generation of electricity,  And it should be used more, but I think it's just not advertised enough.


As for hydrogen fuel cells, the energy required to produce pure hydrogen is quite high in the first place -- so how do you generate that?  There has been some success using solar mirrors to crack it, but it's not really scalable.

Now portable Thorium reactors on the other hand ...