Solar Project Stalled over Avian Impact Concerns
Environmentalists and members of the California Energy Commission turned against a major solar power project in Riverside County when preliminary evidence suggested the type of solar power generation planned for the site is a hazard to birds.
The Palen solar project was a proposal to build a large solar plant in the desert west of Blythe, California. The design involved acres of mirrors which would focus light on two boiler towers, each one 200 feet taller than the Washington Monument.
The project, which is a joint effort by BrightSource Energy and Abengoa Solar, was suspended by the California Energy Commission back in January at the request of the companies. In April they asked that the project be put back up for consideration, but opposition to the project seems to have grown in the interim.
The main concern is that the boiler towers will have a serious impact on wildlife, particularly birds, in the area. A report issued by the US Fish and Wildlife Forensics Laboratory found bird deaths at three major California solar stations. Each of the stations uses a different method of power generation. However, the one which uses tower-based boilers, just like the ones under consideration for the new plant, had the worst record. More than half of the dead birds examined came from that one project.
The USFW report speculates that the bright light of the boiler tower attracts insects, which were found dead in significant numbers near the tower. The insects in turn attract birds which feed on the insects. However, flying near the concentrated light of the tower can result in "solar flux" injuries to the birds. In fact, the forensic team that gathered the birds found evidence of burns or solar damage in 47 of the 141 carcases collected. They also reported witnessing "a falcon or falcon-like bird with a plume of smoke arising from the tail as it passed through the flux field."
The companies behind the project have claimed, contrary to the USFWS report, that avian impact is similar at various types of solar projects. However, in its decision not to re-open the project last month, the California Energy Commission disputed this and suggested more data will need to be gathered before it will reconsider the project.
California's Audubon society has also weighed in on the project. In a letter to the CEC dated May 5th, Audubon wrote, "We agree with staff and Commissioners 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." The letter suggests switching the proposed tower generating plan for a trough-based system which focuses light on a pipe running near the mirrors rather than a central tower.
Solar towers are not the only green power source which has been connected to avian deaths. Estimates vary, but one meta-study found "somewhere between 140,000 and 328,000 birds die each year from collisions with wind turbines." Another study by the US Fish and Wildlife Service found wind turbines had killed "85 golden and bald eagles between 1997 and 2012." The study excluded the Altamont wind farm "where various studies suggest that between 40 and 116 golden eagles are killed annually."