It seems to me that all this discussion about efficiency and output levels, etc, is like a group of engineers debating what shape the electrical outlet should be; it all kinda misses the point.
The real weakness is storage and transmission. We have plenty of methods for making power. What we don't have is a good way to store it for when we need it, and to transmit it from one place to another (ex: from a solar plant in Nevada to NYC in the winter).
We need a good way to store vast amounts of power, and transmit it with much less loss, over much larger distances.
Generating power if/when you want it, seem backwards to me. Shouldn't we take power when we can get it (solar, wind) and then store it for when we need it?
I've been thinking a lot about that plan somewhere to store the energy by pushing a bunch of water up a hill into a reservoir... and then thinking of a series of dams, like a fish ladder... and we push water uphill when power is being generated... and let it flow downhill and generate hydro power when we need it...
I dunno. That still means we have the power transportation problem, but if cities had hydropower generators instead of water towers, then power could be transmitted in stages, from city to city to city... and...
Ok, it's a huge infrastructure project, but hey... it worked for the WPA! (Which, incidentally, would also get a whole bunch of people trained into the Trades - concrete, electrical, plumbing, etc - and provide a boost to the Trades industry with newly trained, skilled workers, and, and, and provide people with options other than going into enormous debt for a college degree... and help people in depressed areas get good-paying jobs, and...)