California may reject Palen plan

BrightSource’s plans for its 500MW Palen project have been preliminarily rejected by the California Energy Commission due to the potential impact on wildlife, in a serious blow for the company and its power-tower CSP technology.

Switching the project to PV or the more common parabolic-trough CSP technology would be an “environmentally superior” choice, the regulator suggests.

Having cancelled and iced its Rio Mesa and Hidden Hills projects earlier this year, respectively, Palen represents the last large US project in BrightSource’s pipeline after the nearly completed 377MW Ivanpah is commissioned.

Palen was originally approved by California regulators in 2010 as a parabolic-trough CSP plant developed by a subsidiary of Germany’s Solar Millennium.

Two years later, however, Palen was acquired by BrightSource after Solar Millennium toppled into bankruptcy, with BrightSource applying to switch technologies to its own power-tower platform.

Spain’s Abengoa was brought on as a partner, and was slated to handle the EPC work.

Many observers assumed that regulators would quickly sign off on BrightSource’s amended plans for Palen, located in Riverside County.

The state has acknowledged a number of environmental benefits of using power-tower instead of parabolic-trough at the site, including the elimination of “millions of gallons” of flammable Heat Transfer Fluid; a significant reduction in water use, both during construction and operation; a smaller project footprint; and a major shrinkage in the amount of necessary site-grading and earthworks.

However, regulators have flagged up one major environmental downfall to power-tower technology: its impact on local bird populations.

BrightSource’s plans for Palen call for two 750-foot (230m) towers topped with 130-foot solar receivers, upon which “solar flux” from the project’s heliostats would be reflected.

In issuing its denial of the Palen application, the California Energy Commission acknowledges there is still a limited amount of data on the impact of power-tower plants, a result of technology’s newness.

“However, other evidence in the record about avian species mortality from solar flux, including preliminary compliance monitoring information from the Ivanpah project, convinces us that the benefits of the [Palen] modified project do not outweigh its significant adverse environmental effects,” the CEC says.

“When we compare [Palen’s] entire suite of benefits against its suite of impacts, we find that the impacts outweigh its benefits.”

Fifty three birds were found dead at Ivanpah during the month of October, 22 of them with singed feathers, ostensibly from the solar flux, according to press reports.

The regulator, which operates under the guidance of the office of California Governor Jerry Brown, a Democrat, suggests that switching the project back to parabolic-trough technology or to PV may be a better choice for Palen.

BrightSource, whose backers include Alstom, has vehemently denied that its power-tower technology represents an unusually hazardous form of solar power.

Palen, which is intended to comprise two 250MW blocks, would provide enough power for 200,000 California homes during the peak hours of the day, BrightSource claims.

California's full commission will vote on the regulator's proposals early next year.

BrightSource has not yet issued a statement on the decision, which was issued on 13 December.

Note: Amends earlier version to clarify that proposal is subject to vote of full commission