A reader points out that in talking about utility scale solar, only mature technologies are used — usually 20 to 30 years mature or more. He observes how long it’s taken PV to be seriously considered for plants over 10mW. But he goes on to talk about the Stirling Dish System, noticing that the system holds the efficiency world record for sun to grid electricity at 31.5%, and has minimal water use and half the land area and prep requirements of PV.
The only caveat I would offer about CSP and Stirling is energy storage. Once heat energy is converted to electricity, it has to be used, since storing electrical energy is expensive, and converting it back into some other form of energy is inefficient. The beauty of CSP is that storing heat energy (e.g., in molten salt) is much easier and less expensive than storing electricity.
I try to pay attention to the activity of the big boys, figuring that multi-billion dollar companies are extremely unlikely to bet on the wrong horse. Note, in particular, that earlier this year, French energy giant Areva bought Ausra, a venture-capitalized CSP innovator interest in molten salt technology is quite obvious.