Supersize solar farms coming to CaliforniaWhat's cooler than a solar energy plant 10 times larger than any ever built? Two of 'em! Two plants to be built in San Luis Obispo County will deliver a planned total of 800 megawatts to PG&E. That's four times the output of San Francisco's Hunters Point plant, or enough to run 800 big Wal-Marts. The bad news: They won't be fully online until 2013. (Photo of Israeli solar farm by Getty Images/Uriel Sinai)