"To summarize, yes, we only need a small fraction of energy theoretically available in "renewable" forms. But we also can only convert a small fraction of that energy into usable forms. And it is far from immediately obvious that the latter fraction is greater (let alone a lot greater) than the former. Before we even start complaining about costs (not that we should not - the laws of economics are just as unrepealable as the laws of physics), we need to realize that there is just no huge untapped (and almost bottomless) pool of readily available renewable energy for us to play with (which apparently exists in Al Gore's imagination).
Of course, there's still another question: where
to get power at night?"
On the subject of green crazy, the A Green New Deal report, via Tim Worstall, looks truly wacky. I'll try and find some time to go through it in detail.