August 29, 2011

Ivanpah plant closer to completion


Construction workers build the 493 foot solar receiver tower for the Ivanpah Solar Electric Generating System, five miles out of Primm, Nevada on Monday. (Al Cuizon/Staff Photographer)

Andrew Edwards, Staff Writer
Contra Costa Times


IVANPAH - A white crane towers over the Mojave Desert floor where hundreds of workers gather below and inside a hulking gray structure that is part of a multi-million dollar bet that solar energy will prove a reliable technology for powering California homes and businesses.

Sitting on 3,600 acres of public land near the Nevada state line, the solar project - its formal name is the Ivanpah Solar Electric Generating Station - has been under construction for nearly a year. Its backers say that upon completion in 2013, the solar plant will be capable of providing electricity to some 140,000 homes.

"This is one of the crown jewels that we have in our growing solar energy program," John O'Brien, a senior vice president for NRG Energy, said during a media tour of the Ivanpah site Monday.

BrightSource Energy, based in Oakland, is the Ivanpah project's designer and developer. The company has hired San Francisco-based Bechtel to build the power plant.

NRG, based in Princeton, N.J., has signed up to invest up to $300 million in the solar plant. BrightSource has also received a $168 million commitment from Google.

The U.S. Department of Energy is also providing support to the project in the form of a $1.6 billion loan guarantee.

That money is paying for the construction of the massive gray edifice where construction workers - about 480 people work directly for the project - assemble in the dusty, scorching Mojave environment.

As of Monday, construction crews have raised the edifice to 120 feet of a planned 469 feet. The project's design calls for two additional towers and the 175,000 mirrors that have yet to be installed around the towers to capture the sun's energy.

The mirrors, the precise term is heliostats, do not convert sunlight into electrical energy as photovoltaic solar panels do. Instead, the mirrors are designed to track and reflect the sun's rays to boilers installed at the summits of each tower. Water inside the boilers vaporizes and the resulting steam flows through pipes to power turbines where electricity is generated.

"We basically take a boiler that's similar to what you have in a high-efficiency (fossil) fuel plant," BrightSource president John M. Wollard said.

Upon completion, the Ivanpah complex's gross output is expected to reach 392 megawatts. A recent fuel burning plant, Southern California Edison's Mountainview Power Plant in Redlands, began commercial operation in 2005 and can produce 1,045 megawatts.

Southern California Edison and Pacific Gas and Electric have already signed on to buy power from the Ivanpah plant. California law requires utilities to obtain one-third of their electrical power from alternative sources such as solar by 2020.

BrightSource is not the only solar project planned in the Mojave Desert. The California Energy Commission's list of planned projects includes the Calico Solar Project near Barstow, the Abengoa Solar Project between Barstow and Kramer Junction, and the city of Victorville's hybrid gas-solar project as being in the pre-construction stage.

Although solar energy is typically considered to be environmentally friendly when compared to power plants that burn coal or natural gas, large-scale solar projects in the Mojave Desert often receive scrutiny from environmentalists who are concerned about impacts to desert lands, particularly as construction may reduce habitats for the endangered California desert tortoise.

Accordingly, the environmental review process for another proposed solar plant, the Stateline Solar Farm, is at its earliest stages. The U.S. Bureau of Land Management is collecting public comments on Tempe, Ariz.-based First Solar's plan to build a photovoltaic solar plant near BrightSource's project.

Those comments will be used to prepare an environmental report required to include an assessment of how construction would affect tortoise habitats and other environmental considerations.