Dive Brief:

• California Energy Commission (CEC) data shows the natural gas burned to supplement solar production by the Ivanpah Solar Electric Generating System in 2014 emitted over 46,000 metric tons of CO2, enough that the project will be required to participate in California’s greenhouse gas  cap-and-trade program.
• If burned by a conventional power plant, the natural gas used by the Ivanpah concentrating solar power (CSP) project would have provided electricity for about 25% of the number of California homes Ivanpah served in 2014. Natural gas is used in small amounts when clouds block the sun to start or sustain the process of solar generation.
• Ivanpah used more than 95% solar energy in its generation in 2014, so its output may be counted as renewable energy by Southern California Edison and Pacific Gas and Electric, which hold the contracts for its output, toward their obligations to meet the state’s 33% renewables by 2020 and 50% by 2030 mandates.

Dive Insight:

Ivanpah escaped being classified by the CEC as a non-renewable resource because natural gas burned at night to maintain the system is not counted toward its 5% fossil fuel allowance. Its 46,000 metric tons of CO2 exceed the 25,000 metric ton allowance for power plants and factories excluded from the state’s cap-and-trade program.

Detractors say they were misled abou the project because the limited use of natural gas makes Ivanpah a “hybrid” facility and that was not satisfactorily disclosed. A spokesperson for project developer BrightSource Energy says the natural gas use was fully disclosed in explanations of the technology.

Ivanpah’s designers did not expect it to require energy storage to be economically viable when construction was begun in 2010, based on 1980s and 1990s concepts. But BrightSource’s newer design iterations include a storage capability which would both increase value and eliminate the natural gas consumption.