The ongoing quest for solar power technology that continues to work even when the sun goes down has focused a lot of attention on thermal storage, which saves solar heat for use at night. A recent announcement that an Arizona solar power plant had continued to generate power for six hours after sunset got a lot of attention, for example.
And for people who don't obsessively track every solar thermal power plant that comes down the pike, it can be hard to sort out which projects incorporate ways to store heat and which don't. Take, for instance, the Ivanpah Solar Electric Generating System, being built by Bechtel for BrightSource Energy in the Mojave Desert. Over the years we've seen discussion of the project in online comment threads where commenters assume BrightSource has built storage capacity into the project.
That isn't the case: BrightSource has long said it needs to get a couple projects built and running before it can implement storage at subsequent projects. But a recent profile of the Ivanpah plant says just the opposite. And we thought we'd try to clear up the confusion.
In the above short video report on the Ivanpah project by AFP, reporter L. Paterson speaks with BrightSource's Joe Desmond about the plant, which is set to go online sometime around the end of the year.
About 40 seconds in, this exchange occurs:
Paterson, narrating: "this technology is different from the solar cells found on rooftops, because it can even work at night.
Desmond: "We can store the sun's thermal energy in the form of molten salt so we can produce electricity even when the sun goes down."
Desmond has spoken with ReWire at length on enough occasions that we're quite confident he wouldn't knowingly mislead viewers. We suspect that the video's creators inadvertently omitted the important context that Desmond was speaking of concentrating solar's capabilities, rather than the actual specs of the Ivanpah plant.
But a casual viewer of the piece would have no way to know this. So setting the record straight:
BrightSource's Ivanpah Solar Electric Generating System will not store heat in molten salt for power generation after the sun goes down.
Nor will the company's proposed Palen Solar Electric Generating System, unless that project is radically redesigned.
The process by which BrightSource has planned to incorporate thermal storage into its next-generation designs is well-documented, the topic of lengthy discussions by at least two state agencies. There are solar power tower projects, under construction and proposed, that do incorporate thermal storage. One, Solar Reserve's Rice Solar Energy Project, is planned for northern Riverside County.
But not Ivanpah. And it's important to keep that clear.