Opposition Grows To Proposed Solar Tower Project

Near the Palen Solar site | Photo: Ron's Log/Flickr/Creative Commons License

When last ReWire checked in on the proposed Palen solar project, its builders were asking the California Energy Commission to restart hearings on the project that had been suspended in January. That was in March; now, it's becoming clear that there's significant opposition to putting the project back on the table -- including from the CEC's own staff.

The Palen Solar Electric Generating System (SEGS), to be built by BrightSource Energy and Abengoa Solar (doing business as Palen Solar Holdings, or PSH) on four square miles of desert just off Interstate 10 in Riverside County, would generate a maximum of 500 megawatts by using tens of thousands of mirrors to focus sunlight on boilers atop two 750-foot solar towers. That much concentrated "solar flux" is proving to have nasty effects on wildlife at BrightSource's significantly smaller Ivanpah project.

Solar flux damage to wildlife was the main reason that the CEC proposed to reject Palen SEGS' design, just before PSH asked the Commission to suspend hearings on the project in January. Now, the builders say they've collected data that says their design poses no more risk to birds than alternatives suggested by CEC. But opponents aren't convinced -- including Audubon California.

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In 2012, BrightSource bought the Palen project from the bankrupt German firm Solar Millennium, which had planned to use parabolic trough technology on the site. That design was already certified by CEC before BrightSource got the keys, and the discussion at issue is an amendment of that existing certification to reflect PSHs' proposed redesign of the project to use BrightSource's power tower design. In the CEC's preliminary denial of the new design in 2013, Commissioner Karen Douglas suggested a return to the earlier design, or a substantially similar approach using photovoltaic panels rather than 750-foot power towers surrounded by acres of aerial solar flux zones with temperatures running well into four digits.

While all utility scale solar projects pose some risk to birds, a recent USFWS investigation suggests that solar power towers pose a distinctly higher risk to birds and other flying animals than do parabolic trough mirrors or photovoltaic panels.

When it asked for the suspension of hearings in January, PSH said that the company would provide more data on avian mortality and other wildlife harm from different solar technologies. It provided what it said was that data in March, when it asked that hearings be reopened. As ReWire reported at the time, the data provided showed that Ivanpah's bird death toll was significantly higher than either the parabolic trough project Genesis or the photovoltaic Desert Sunlight, with 202 deaths at Ivanpah compared to 146 and 87 at Genesis and Desert Sunlight, respectively.

In March, PSH presented that data without much in the way of explanation or annotation. But at a public meeting in April on the topic of reopening proceedings, the company claimed the data indicated that all three technologies posed about the same risk to birds and other wildlife.

That didn't impress critics, who pointed out that there were way too many variables, including woefully inadequate surveys for carcasses and injured birds, to take Palen Solar Holdings' data as anything more than a rough draft. The U.S. Fish and Wildlife Service has reviewed the information docketed by the California Energy Commission subsequent to a January meeting on the Palen project. Biologist Jody Fraser at the USFWS Palm Springs office was blunt, writing to the CEC that "We submit to you that the supplemental documents provided by Palen Solar Holdings do not constitute substantive new information."

On April 23, the CEC staff -- never a fan of Palen --- weighed in on the motion to reopen the hearings with an unambiguous no. Staff's criticism of PSH's bird data was unsparing, with the document suggesting that PSH "misuses the data and has failed to accurately consider how this information must be corrected for scale and survey methodologies."

In a formal letter of comment on Palen Solar Holdings' request to reopen hearings on the project, Audubon California's renewable energy director Garry George echoes the CEC staff's contention that far more data is needed on solar flux's threat to wildlife before a responsible decision to approve the project could possibly be made.

"We agree with [CEC] staff and Commissioners," wrote George,

that the significance of the impacts on avian and other biological resources of the solar power tower technology proposed for the PSEGS cannot be determined by the current available data on the Ivanpah Solar Electric Generating System (ISEGS) currently in operation until that data are robust enough in time, seasons (especially migratory bird seasons), sample size, and extrapolation for scavenger rate and observer bias to determine a more scientifically defensible estimate of the cumulative impacts of the project on biological resources, especially avian resources, over the thirty years of the project.

George also pointed out that while Ivanpah seems to be doing considerable damage to birds, the Palen project would be built in a much more "birdy" part of the desert:

We also agree with staff in the FSA that "bird use in the vicinity of the PSEGS site has demonstrated to be rather high given proximity to the Colorado River migratory corridor and habitat. Staff considers bird use and risk to be higher in the project area, where large flocks of migratory and resident birds are known to occur, than at ISEGS."

George reiterates the CEC's suggestion that other solar technologies may be more appropriate for the site:

A solar trough project as approved by the Commission previously is still feasible. The applicant Abengoa Solar has considerable expertise with this technology and could use the investment in studies on resources on site for this technology. Additionally, the proponent could take steps to propose a solar PV project on the site.

Abengoa does indeed have considerable experience in other solar technologies, and could adjust fairly well to a reversion back to the previously approved design. But such a strategy would not sit well with Abengoa's partner, BrightSource, which has staked its continued corporate existence on its proprietary power tower technology. It would be interesting to learn whether George's suggestion is being echoed in private Abengoa email discussions. The more it looks like a power tower version of Palen isn't going to fly, the more tempting going it alone will likely seem for Abengoa.

Meanwhile, the CEC will be discussing PSH's request to reopen hearings in closed session on Wednesday. We'll be looking for news on what's discussed.

About the Author

Chris Clarke is a natural history writer and environmental journalist currently at work on a book about the Joshua tree. He lives in Joshua Tree.
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