I just watched 'ask Elvis' doing this article, and he pointed out something I had not considered, that Formula E has the SOLE rights to an electric series for the foreseeable future.
This means F1 has to go down a different path and stick with some sort of combustion engine, even if it is mostly used to drive a generator.
It seems that a combination of things are coming together to reshape F1 in short order. It could turn out to be a development race between 'green' technology and electric for not only racing but everyones road car too