No-fly zone: California solar thermal farm proves fatal to birds


California’s massive 393 MW Ivanpah Solar Electric Generating System, which began operation in December, is facing increasing criticism for the potential danger it poses to birds through the intense heat it generates.

One of the world’s largest solar thermal power projects, the $2.2. billion solar farm covers nearly 13 square kilometers of federal land southwest of Las Vegas, Nevada. It consists of three 137-meter high towers and some 350,000 mirrors that reflect sunlight onto boilers atop the towers, creating steam that drives power generators.

According to the Wall Street Journal, state regulators are having second thoughts about approving similar solar projects due to growing evidence that the tower-and-mirror solar technology is killing birds.

The newspaper reported that the California Energy Commission was hesitant to approve plans by Brightsource Energy for a second tower-based solar farm in Riverside County, proposing instead that the company use safer technologies, such as photovoltaic panels or mirrored troughs.

According to federal biologists and documents filed with the state Energy Commission, some of the dozens of dead birds found at the plant site during testing in the months prior to the start of initial operation in December had singed or burned feathers, leading to the conclusion that the BrightSource system appeared to be scorching birds that fly through the intense heat surrounding the towers, which can reach up to 538 degrees Celsius (1,000 degrees Fahrenheit).

While regulators had anticipated the deaths of some birds with the start of the plant’s operation, the Wall Street Journal reported that watchdogs did not expect so many to be killed during the plant’s construction and testing. Dead birds included a peregrine falcon, a grebe, two hawks, four nighthawks and a number of warblers and sparrows, according to the report.

State and federal regulators are now conducting a two-year study of the facility’s effects on birds.

"We’re trying to figure out how big the problem is and what we can do to minimize bird mortalities," Eric Davis, assistant regional director for migratory birds at the U.S. Fish and Wildlife Service, told the paper. "When you have new technologies, you don’t know what the impacts are going to be."

Biologists for the federal agency expressed concern about BrightSource’s plans for a second large-scale solar farm in Riverside County, telling state regulators that heat produced by the project could kill golden eagles and other protected species.

NRG spokesman Jeff Holland said it was far too early in the process to draw any conclusions about the plant’s long-term impacts on birds or other species of wildlife.

A joint effort between Brightsource, NRG (the plant’s operator) and Google, Ivanpah received a $1.6 billion loan guarantee from the U.S. Department of Energy’s Loan Programs Office. Bechtel served as the engineering, procurement and construction contractor on the project, which is expected to generate enough electricity to power 140,000 homes a year.

The solar energy harnessed from Ivanpah’s Units 1 and 3 are being sold to Pacific Gas & Electric under two long-term power purchase agreements, while the electricity from Unit 2 is being sold to Southern California Edison under a similar contract.