BrightSource 400MW solar thermal plant reaches milestone

California and federal reviewers have completed their assessment of the Ivanpah Solar Electric Generating System, a concentrating solar thermal plant proposed by BrightSource Energy on federal land in San Bernardino County, California.

Staff of the California Energy Commission (CEC) and the federal Bureau of Land Management completed a joint Final Staff Assessment/Draft Environmental Impact Statement, which will now be open for public comments until 11 February. A final decision by the full CEC will follow an evidentiary hearing, and is expected in the spring.

BrightSource proposes a 400 megawatt (MW) concentrated solar power tower development on about 16.5 square kilometres of federal land. The project would consist of two 100MW plants, covering about 3.4 square kilometres with each with one 143-metre central tower, on which heliostats would focus the sun’s energy to heat a boiler. High-temperature steam would spin a Siemens turbine generator. A third 200MW plant would cover about 6.5 square kilometres and have five central towers. Up to 214,000 heliostats, each comprised of two 7.04-square-metre mirrors, would be arrayed in circles around the central towers.

Groundwater would be supplied from wells to be built nearby. BrightSource expects the project to consume not more than 40.5 hectare feet of water annually. It will mainly be used for washing mirrors, and replacing boiler feed water.

The 1,248-page review document spells out various mitigation measures BrightSource must take to build the project. These include managing wildlife, such as desert tortoises, some of which will need to be relocated from the site.

BrightSource, based in Oakland, California, has signed power purchase agreements with Pacific Gas & Electric and Southern California Edison for the Ivanpah output. That’s the tip of 2.6 gigawatts it has under contract with the two investor-owned utilities.

According to the document, BrightSource is seeking federal loan guarantees from the Energy Department and a cash grant from the Treasury for renewable energy projects for 30% of its capital cost. The latter requires construction begin by 31 December 2010.

Construction is expected to take 48 months with a targeted completion in the fourth quarter of 2013.

This is the second major solar thermal project to receive a Final Staff Assessment in the last two weeks. The other is NextEra’s 250MW Beacon Solar Energy Project.