When Oakland-based solar developer BrightSource bought the 5,200-acre Palen Solar Power Project from ailing firm Solar Millennium this summer, it was generally assumed that the company would completely redesign the project. In an interview late last week, BrightSource's CEP John Woolard confirmed that his company would be changing the Palen plant from parabolic solar trough technology to his company's signature power tower design. But the plant's approval by the California Energy Commission (CEC) was based on Solar Millennium's trough plans. How will the agency address the significantly different environmental impacts of a new power tower design?
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The Palen Solar Power Project as approved by the CEC in December 2010, when Solar MIllennium was still the project owner, consisted of two 250-megawatt parabolic solar trough arrays in the Chuckwalla Valley north of Interstate 10. BrightSource's redesigned version may have more or less the same capacity, but aside from that the whole project will be very different from Solar Millennium's version. In an August 24 interview with the San Jose Mercury News' Dana Hull, BrightSource CEO confirmed that the Palen project would be reengineered to use his company's power tower technology:
Q: When Solar Trust of America went bankrupt, BrightSource offered $10 million to build the Palen Solar Power Project as part of Solar Trust's bankruptcy auction. Has that deal closed?
A: The deal closed Aug. 15. Palen is currently permitted by the California Energy Commission as a solar thermal plant using parabolic trough (a long, curved mirror); we will convert it to a solar thermal plant using our power tower technology. The Palen site is in a good spot, with good transmission.
What the California Energy Commission's assessment of changes to the plan are as yet unknown, even within the CEC. CEC representative Sandy Louey informed ReWire this afternoon that BrightSource has not as yet taken the first step of filing an amendment to the project plan with the Commission. Once BrightSource does so, Louey told ReWire, the Commission staff will need to assess just how different the impacts of the new design will be from those of the previous design, and make appropriate changes to the set of conditions under which the CEC first approved the project.
The agency's certification of the project's first draft noted that the project would contribute to cumulative impacts to visual and cultural resources, and land use and that those impacts could not be mitigated, but approved the project anyway using the "overriding considerations" argument. (Under CEQA, a project that will cause irreversible damage to the environment can be approved if the state determines its other positive impacts would outweigh the negative. Those positive impacts are termed "overriding considerations.")
BrightSource maintains that its power tower design allows for less-destructive placement on the land than is true for parabolic trough deigns, or for that matter utility-scale photovoltaic facilities. On the other hand, glowing power towers between 500-750 feet in height almost certainly pose a more significant impact to visual resources than parabolic troughs. The complex differences between the technologies, positive and negative, would seem to demand a thorough reassessment by CEC staff -- an assessment that BrightSource is likely to resist.
The Palen plant would be BrightSource's fourth large California project along with its Hidden Hills and Rio Mesa plants, still in the planning stages, and the Ivanpah Solar Electric Generating System, under construction and slated for completion in 2013.