Thanks for the solar links, folks! Undoubtly you can do a lot of useful stuff with solar, but remember I said "powering a highly-developed, industrialized economy"! I stick with that, because it's physics, and physics cannot be beaten.

Just one argument: Since the sun doesn't always shine, you would need some storage. Some storage? No, you would need tremendous amounts of storage. How much? Tom Murphy has done the math for pump storage in the USA. Read and enjoy: http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/.

(Sorry, if this was off-topic, but I'll shut up now.)