Another giant solar plant ditches thermal tech for panels

Yet another massive solar thermal farm in the California desert is ditching the thermal part and opting for solar panels. Solar Trust of America, which has been developing a 1 GW solar farm in California, announced on Thursday that it will use photovoltaic panels (PV) instead of solar thermal technology for the first 500 MW of the project.

The news is both surprising and, in a way, not so unexpected. The company already snagged a federal loan guarantee offer worth $2.1 billion to help build the first 500 MW of the project, and it was supposed to close that deal by Sept. 30 of this year. Solar Trust also already held a ground-breaking ceremony for the project in June of this year that included political bigwigs such as Interior Secretary Ken Salazar and California Gov. Jerry Brown.

Solar Trust’s original plan was to use a solar thermal technology that uses mirrors to concentrate and direct the sunlight to heat up water for producing steam, which is then used to drive turbines to generate electricity. PV technology, on the other hand, uses solar panels. Solar Trust secured permits for the project, called Blythe Solar Power Project, from both the California Energy Commission and BLM last year.

No more loan guarantee

The change of technology means the company is foregoing the loan guarantee and will look for private cash and loans for the project, said Edward Sullivan, the VP of external affairs at Solar Trust. As we have noted before, PV technology offers some advantages that solar thermal doesn’t have in terms of project size and land use choices, which in turn affect a project’s development cost. Solar panel prices also have fallen by more than half in the past two years, making them a more attractive choice for developers. Sullivan noted that private financing for PV projects is readily available.

Developers of several solar farms in California have already announced plans to switch from solar thermal to PV, including the Calico Solar Project and the Imperial Valley Solar Project. NRG, which has invested in a solar thermal power plant by BrightSource Energy, replaced two solar thermal power plant projects in favor of using solar panels.

Solar Trust will ask the federal Bureau of Land Management to amend its permit, Sullivan said. Solar Trust will keep doing some site preparation work for Blythe, but full-scale construction won’t start until the third quarter of next year, he added.

Going through that permitting process must have been costly, especially for a project this size. If it had chosen to use solar panels back then, then it wouldn’t have had to be under review by the energy commission, which oversees solar thermal power plants that are 50 MW or larger. The energy commission doesn’t issue permits for projects using solar panels – that task belongs to the counties or cities in which the projects reside.

Thermal to PV trend

Solar Trust became interested in developing projects using solar panels more recently. Back in May of this year, the company said it was creating a joint venture with Germany-based SolarHybrid to develop large-scale PV projects. Solar Trust, based in Oakland, Calif., is itself a joint venture formed in 2009 between two German firms, Solar Millennium and Ferrostaal. Solar Millennium develops solar thermal technology.

At the time of the joint venture announcement with SolarHybrid, Solar Trust’s CEO, Uwe T. Schmidt, said the company would consider using both solar thermal and PV equipment for the same project if that is more cost-efficient way to do it.

The technology choice for the second 500 MW of the Blythe project is yet to be determined, Sullivan said.

“We are a pragmatic and responsive company. We will assess market reality for the second half of the project when the time comes,” Sullivan said.

Photo courtesy of Oregon Department of Transportation, NREL, via Flickr