It's been in the works since 2008, but Solar Reserve's 150 megawatt Rice Solar Energy Project just leapt a critical hurdle: a contract to sell the plant's power to Pacific Gas and Electric (PG&E) just won approval from the California Public Utilities Commission. The Riverside County plant, expected to break ground in 2014 and come online in 2016, would be California's first solar power plant to incorporate thermal storage.
Thermal storage is intended to extend the daily power production cycle of concentrating solar plants by storing some of the sun's heat in the form of a molten liquid, usually a salt. The heat in that storage fluid can then drive turbines to generate power long after the sun has set.
Solar Reserve is now building a 110-megawatt concentrating solar plant with thermal storage northeast of Tonopah, Nevada; that plant is scheduled to be completed later this year.
The Rice project will occupy about 1,500 acres of private land in the Rice Valley, at the south end of the Turtle Mountains, along Route 62 75 miles east of Twentynine Palms. It will cover land that was once part of General Patton's Rice Camp and the camp's associated airfield, which has some historic preservationists upset. The Rice Solar Energy Project will include a 500-foot-tall tower surrounded by hundreds of mirrors, visible for many miles.
Desert protection activist Bob Ellis of the environmental group Desert Survivors described Rice in 2010 as a "best of the bad" project, saying that it had escaped scrutiny from activists partly due to its location and partly due to the fact that other proposed projects at the time were of far greater concern:
No environmental group had commented on this project. It is out-of-the-path for most non-hikers and non-backpackers. The other larger projects were taking all the activists' energy. This seemed to be a "best-of-the-bad" project and had gotten no attention from desert protection groups including Desert Survivors. We were notified that not only had no one commented on the project, but that the draft decision proposed for adoption concluded that construction of the project had no significant environmental impact and that routine approval should be granted.
Responding in part to Ellis' comments, the California Energy Commission (CEC) changed the wording of its decision on the Rice project, saying that the project's visual impact on surrounding wilderness areas and undeveloped public lands would be "unmitigable." The CEC then approved the project anyway, stating that meeting the state's Renewable Portfolio Standard goals overrode the CEC's duty to protect the landscape.
It's no surprise that the CPUC would approve Solar Reserve's power purchase agreement with PG&E, two years after the CEC gave the project the thumbs-up. The CPUC is determined to develop energy storage technology for renewables, even if the cost to the ratepayer is higher than Commissioners would prefer. Storage was the main reason behind the CPUC's partial approval of BrightSource Energy's now-moribund Rio Mesa project in October. The Rio Mesa project didn't include a storage component, but BrightSource had persuaded Commissioners that the incremental technological progress Rio Mesa represented was needed for future BrightSource projects with storage. That argument was enough for CPUC to approve a power purchase agreement for half of Rio Mesa despite concerns about the high price of the energy being sold.
It's small wonder that the CPUC would line up behind Rice, where Solar Reserve is offering thermal storage without an expensive intermediate step.