Our own energy and environment columnist Ben Jervey passed along news that America's first "solar thermal" power plant, in Lancaster, California, is now fully operational. Solar thermal uses the sun's light to heat water for steam power rather than using solar panels to convert light directly to energy. VentureBeat reports:Solar thermal has the potential to disrupt the solar industry at large, mostly because it's cheaper to execute. After all, mirrors are much more cost-effective than silicon solar cells. eSolar's chief executive even went as far as saying that the project represents "the lowest cost solar project in history," and that the company could power the entire state of California with just 25 square miles of mirrors and towers.The system devised by eSolar could be good news for consumers too, with the electricity generated costing less than the average homeowner in California usually pays.We're one step closer to the solar tipping point. For more information on the benefits of solar thermal, check out Ben's great primer on the technology.