CPUC Makes Split Decision on BrightSource Desert Projects

Artist's conception, Rio Mesa Solar facility | Image via BrightSource Energy

There's some good news and some not so good news for concentrating solar power developer BrightSource Energy as it works to get state approval for its proposed Rio Mesa Solar plant in the California desert near Blythe. The good news is that the California Public Utilities Commission today unanimously approved two agreements under which Southern California Edison would buy power from BrightSource projects starting as early as 2015.

The bad news is that BrightSource and Edison had five contracts up for review by the Commission, and two is all they got.

Story continues below

The CPUC approved contracts between SCE and BrightSource to provide power from one half of its proposed Rio Mesa Solar project, planned for lands owned by the Metropolitan Water District southwest of Blythe, as well as from the Sonoran West Solar Energy Generating System a few miles northwest of the Rio Mesa complex and just south of Interstate 10. Sonoran West, also known as Palo Verde II, won't get going until BrightSource gets some experience under its belt with Rio Mesa.

According to Desert Sun reporter K Kaufman, who was monitoring the meeting, Commissioners cited BrightSource's proposed thermal storage technology as the reason for approving two of the five proposed power purchase agreements. As Kaufmann tweeted:

BrightSource plans to incorporate a component at its proposed 540-megawatt Sonoran West project that would use the solar energy to heat a reservoir of molten salt to a high temperature. The heat from this salt would then allow BrightSource to generate power well after the sun has set, says the company.

Thermal storage is a commonly cited approach to the problem of renewable energy intermittency -- in other words, the problem that the sun goes down every evening. In order for the state to meet the Renewable Portfolio Standard obligations cited by Kaufmann to generate a third of its power from renewable sources by 2020, some sort of storage will need to be developed to even out that intermittency.

Rio Mesa does not include a thermal storage component, but BrightSource apparently persuaded the CPUC that it needed revenue and real-world experience from building and operating Rio Mesa to develop the thermal storage technology to be used at Sonoran West.

Things could have gone worse for BrightSource at the CPUC meeting today: CPUC had set out to withhold approval of either Rio Mesa contract, citing the cost to ratepayers of the power the facility would generate. The CPUC's draft resolution on the Rio Mesa contracts stated, in part,

The [Rio Mesa 1 and 2] projects compare poorly on price and value relative to other solar thermal projects offered to SCE at the time the amended and restated PPAs were being negotiated and executed. SCE had the option to choose from 18 of 19 solar thermal projects totaling over 2,300 MW in combined capacity resulting from its 2011 RPS Solicitation that were all materially higher in value than the Rio Mesa 1 and Rio Mesa 2 projects.

The CPUC also departed from the draft resolution by withholding approval of contracts between SCE and BrightSource over the company's proposed Siberia solar project, which would be sited in the central Mojave Desert, in the Bristol Valley between Ludlow and the Twentynine Palms Marine Corps base. The draft resolution included an approval of contracts between SCE and BrightSource for power from the two proposed units at Siberia, which would each have delivered 200 megawatts with a thermal storage component.

Joseph Desmond, BrightSource's Senior Vice President for Government Affairs and Communications, told ReWire that the CPUC's complex decision on the five proposed contracts reflected negotiations over ratepayer concerns, technical issues such as transmission availability, and BrightSource's position that it needed to approach its thermal storage technology by increment. "We can't just jump into building thermal storage without experience with the second phase of our technology, which we've planned for Rio Mesa," Desmond said.

Desmond added that BrightSource planned to push ahead with both Rio Mesa units, dipping into its rolodex to find potential buyers for the power the other unit would produce, and that construction on both plants would proceed on schedule.

As for Siberia, that project has taken significant criticism on environmental grounds due to its habitat value -- even the usually BrightSource-friendly Natural Resources Defense Council (NRDC) has come out in opposition to the project, as has the U.S. Marine Corps, whose Twentynine Palms base would be immediately adjacent to the site.

Desmond stopped short of calling Siberia doomed. "We're keeping the Siberia project in our portfolio," he told ReWire, "but we'll be focusing on our other projects for the moment."

Though today's decision included approval of the Sonoran West contract, it's unlikely that plant will be in operation anytime soon. BrightSource itself readily says it needs the experience it will gain by building and operating Rio Mesa before it can properly design facilities with thermal storage components like those proposed for Sonoran West. CPUC is gambling that its approval of relatively expensive power from Rio Mesa will pay off in more reliable renewables; the Commission may not know for some time whether its gamble will pay off. The second half of the California Energy Commission's preliminary staff assessment on Rio Mesa came out last week, and that report identifies a number of problems -- ranging from damage to up to 100 cultural sites to possible bird injury -- that the CEC's staff says may not be mitigable. The Energy Commission has approved a number of renewable energy projects in recent years over the objections of its own staff, citing "overriding considerations," but even the half of Rio Mesa given the green light today by the CPUC still isn't a slam dunk.

ReWire is dedicated to covering renewable energy in California. Keep in touch by liking us on Facebook, and help shape our editorial direction by taking this quick survey here.

For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.

We are dedicated to providing you with articles like this one. Show your support with a tax-deductible contribution to KCET. After all, public media is meant for the public. It belongs to all of us.

Keep Reading