I'm saying that > 50 years is a long time and a lot can happen. I could have also pointed at Google's Sunroof project as an example of a large company betting

I'm saying that > 50 years is a long time and a lot can happen. I could have also pointed at Google's Sunroof project as an example of a large company betting that solar can compete: http://www.extremetech.com/extreme/212363-google-is-launching-sunroof-for-solar-skeptics http://www.extremetech.com/extreme/212363-google-is-launchin... I couldn't guess what energy producing and distribution technologies will be most prevalent in 100 years. Advancements could just as easily be made relating to fission reactors, so I don't think it's fair to say that large power companies shouldn't invest in more reactors. But, I agree there is probably risk in investing in them.