BrightSource Energy said today it has secured financing for a utility-scale solar plant in the California desert, the first project of this type to be built in the U.S. in decades.

The Oakland, Calif.-based company said that it has finalized $1.6 billion in loans guaranteed from the U.S. Department of Energy for the Ivanpah Solar Electric Generating System, a facility which will have three concentrating solar thermal plants.

The company also said today Google will invest $168 million in equity into the project, joining BrightSource and NRG Solar, a division of utility NRG. The Ivanpah facility will have a capacity of 370 megawatts (it will have a total 392 megawatt capacity and require 22 megawatts to operate) and is expected to be operating in 2013. It will generate enough electricity to supply about 85,000 homes, according to the DOE, while BrightSource Energy estimates 140,000 homes based on its utility power purchase agreement.

In a company blog, Google said it is investing in the Ivanpah project to ensure that it has sufficient funding and to earn money. Google and its Google.org philanthropy has invested in a few renewable energy start-ups, including BrightSource Energy, and last year invested $38.8 million in a wind farm, but its stake in the Ivanpah project is its largest energy investment to date.

"We hope that investing in Ivanpah spurs continued development and deployment of this promising technology while encouraging other companies to make similar investments in renewable energy," said Rick Needham, director of green business operations.

A sketch of the three solar towers and 170,00 heliostats of the Ivanpah solar project will look when finished in 2013.

The Ivanpah project has been under development for years and will be the first large-scale project for BrightSource and its concentrating solar power technology. The company is one of dozens of solar start-up hopefuls, many of which have struggled to commercialize their technologies at scale.

The Ivanpah project will have 170,000 software-controlled heliostats, or mirrors, which will track the sun and direct light onto a tower. The heat from the concentrated sunlight turns water into steam which is piped to a turbine to generate electricity.

BrightSource Energy needed to make adjustments to its original design to reduce the amount of water used and had to do extensive environmental reviews to minimize impact on the desert ecosystem. To cool steam, BrightSource will use air cooling, rather than water cooling, a change which makes it far more water-efficient than other solar thermal technologies.

The company says the project will double the amount of solar thermal-generated electricity in the world. The project started construction last fall and will be done in phases between this year and 2013.

The power supplied by the plant will be sold to California utilities Pacific Gas & Electric and Southern California Edison. California utilities are purchasing electricity from renewable sources to meet a state mandate to increase electricity from renewables to 33 percent by 2020.

The project will avoid 640,000 tons of carbon dioxide emissions annually, the equivalent to taking more than 120,000 cars off the road, according to the Energy Department.

Updated at 4:00 p.m. PT with additional details and clarification on the size of the plant. A more recent image was also added.