The approval and environmental certification process for the Calico Solar project has complexified, as legislation to allow the undertaking to proceed has advanced in Sacramento even as environmentalists intensified their opposition to the project.
The project, to be built on 4,604 acres of public land in the Pisgah Valley north of Interstate 40 roughly 37 miles east of Barstow, was originally intended to utilize a cutting-edge process for converting the heat of the sun to drive a turbine and generate electricity. In that form the project’s then-sponsor, Arizona-based Tessera Solar, in 2010 obtained from  U.S. Secretary of the Interior  Ken Salazar approval for the project and qualified for federal stimulus money to defray a portion of the cost of the project. But last year, Tessera sold the project to New York-based K Road Power.  K Road has elected to abandon the original design, which involved parabolic mirrors to catch the sun’s rays and produce heat, and instead substitute photovoltaic cells.
Late last week, a bill to allow the Calico Solar project to receive state approval to change the technology upon which the project will rely, AB 1073, moved closer to passage in the state Legislature. AB 1073 was authored and sponsored by Assemblyman Felipe Fuentes, D-Sylmar. The bill passed the state Senate 28-2 on March 28 and is now being considered by the Assembly.
AB 1073 is an emergency measure, and as such it will take effect immediately upon passage by both houses and its signing into law by the governor. AB 1073 closes a loophole in a bill passed and signed by Governor Jerry Brown last year, SB 226, which permits the California Energy Commission to okay changes to approved projects rather than requiring rehearings and a repermitting process before local land use authorities. Under SB 226, opponents can still force rehearings or repermitting on altered projects if they are challenged in court, even if the case was dismissed.
Environmental groups have long been opposed to the Calico Solar project on the grounds that it will destroy or disrupt the habitat of the desert tortoises and golden eagles in the environs of Pisgah. The National Resources Defense Council last week filed a suit related to those issues in federal court, a move that under SB 226 would have forced K Road Power to reapply for approval.
As first proposed, the Calico Solar plant was to employ SunCatcher units, computer controlled parabolic mirrors.  The SunCatchers were to track the sun during daylight hours and focus an intense beam of light, i.e. heat, onto a glass tube filled with a synthetic petroleum product known as therminol. Therminol, based on its grade and rating, is capable of absorbing heat up to 1,400 degrees Fahrenheit. The therminol was then to be pumped across the outside of the differing chambers of a Sterling engine to heat gases within those chambers to drive the engine’s pistons. The engine would then turn a turbine that generates electricity.
Tessera’s  design was an improvement upon a similar computer-guided parabolic mirror solar ray-focusing set up that heated therminol, which was then routed into a heat converter that was brought into contact with water to create steam, which was used to run a turbine. It was believed the use of the Sterling engines would boost the efficiency  by as much as 17 percent over the steam driven turbine approach.
In October 2011, K Road abruptly switched to a plan to employ photovoltaic panels on the project.
Part of the rationale for changing the technology stemmed from the September bankruptcy filing of Sterling Energy Systems, which rendered ready availability of the Sterling engines problematic. Another factor was the decrease in the cost of photovoltaic cells over the last three years.
“The switch to PV was primarily based on our decision to use a more proven technology and to be online faster than we could with the SunCatchers,” K Road put out in a public statement.
While the photovoltaic cells will not generate as much electricity as the mirror/therminol/Stirling engine configuration, they can be erected and be brought on line much more quickly. Originally planned to generate 850 megawatts, the plant has been pared back to 663.5 megawatts. When fully operational, the project will provide electricity sufficient to power about 250,000 homes.