The $2.2 billion Ivanpah Solar Electric Generating System project, located on approximately 3,500 acres of federal land in California’s Mojave Desert managed by the U.S. Department of the Interior‘s Bureau of Land Management, is at the halfway point and has reached it peak construction workforce of 1,200 construction workers.

Principals on the project include NRG Energy, Google, BrightSource Energy and construction partner Bechtel.

The 370 (net) megawatt Ivanpah solar power facility is actually three individual power plants that will feature BrightSource Energy’s solar thermal power tower technology to produce clean, renewable energy from the sun. When completed in 2013, the facility will nearly double the amount of solar thermal electricity produced in the U.S.

Power generated from the plants will be sold under separate contracts with Pacific Gas and Electric (PG&E) and Southern California Edison (SCE). The first unit will begin supplying power to PG&E in mid 2013, with units two and three delivering power to Southern California and PG&E, respectively, by late of 2013. In total, the project will power more than 140,000 homes and businesses in California.

Ivanpah will employ BrightSource’s power tower solar thermal technology, which generates power the same way as traditional power plants – by creating high temperature steam to turn a turbine. However, instead of using fossil fuels or nuclear power to create the steam, BrightSource uses the sun’s energy. BrightSource’s system uses a state-of-the-art field of software-controlled mirrors, called heliostats, to reflect the sun’s energy to a boiler atop a tower to produce the high temperature and high-pressure steam. The steam can then be integrated with conventional power plant components to produce predictable, reliable and cost-competitive clean energy.

As to the employment numbers, Bechtel signed a project labor agreement with the State Building and Construction Trades Council of California (SBCTC) and the Building & Construction Trades Council of San Bernardino and Riverside counties to ensure that California‘s local workforce benefits from the project, according to NRG. The project requires the work of skilled craft workers and engineers from a wide variety of trades and disciplines, including pipefitters, millwrights, carpenters, electricians, laborers and civil engineers.