Since Bitcoin uses ASICs, which do basically only one operation, most probably the generic computation won't be affected significantly by this. As a comparation, altcoins may have been driving GPUs into getting more powerful, but Bitcoin.. I don't know...

And about the cheaper energy, Bitcoin indeed can (and should!) get people and companies invest into renewable electricity sources, since sooner or later only the mining with free electricity may remain profitable. Will this make people and companies expand their use of free electricity to everything else? I don't know, I wouldn't be so sure, since the mining facilities will probably be away from the place they're living and transporting that electricity around may or may not worth it. Plus, let's be honest, people are generally lazy. They need quite a push to do the right move and Bitcoin alone may not be the one in this case. Maybe the energy war though.