On a somewhat related note. Despite the setbacks and the bad rep nuclear gets, fusion really could be a better future. The energy density is in a class of its own, compared to that of renewables. Prof David MacKay demonstrates this quite effectively here[1]. This of course is not to take anything away from renewables or imply we shouldn't pursue funding both.
One group of companies I find particularly interesting, are those attempting aneutronic fusion.[2]
Like many good ideas, that became bad ideas (in the 60's), it appears to now be back in fashion.[3] Theoretical advancements have pushed the achievable temperature ceiling northwards, allowing a move towards commercialization.
Whether this particular line of fusion innovation will ultimately pan out, is perhaps anyone's guess. Personally however, I suspect there is a chance it can work. The benefits would be almost too good to pass up. Small, modular, cheap and safe (with almost no radioactive waste)
Some examples in the industry:
Raman-budget: Focus Fusion [4]
Secretive and heavily funded: Tri Alpha Energy [5]
[1] http://www.ted.com/talks/david_mackay_a_reality_check_on_ren...
[2] http://en.wikipedia.org/wiki/Aneutronic_fusion
[3] https://www.sciencenews.org/article/proton-boron-nuclear-fus...
[4] https://www.indiegogo.com/projects/focus-fusion-empowerthewo...