Google goes green by investing $168 million in Ivanpah Solar Electric Generating System (ISEGS), California. ISEGS is the first large scale solar project built in California in two decades and the world's largest solar project under construction. It is a 392 megawatt solar thermal power facility developed by Bright Source Energy in Mojave Desert, California.

We're excited to be making our largest clean energy investment to date. With this investment, we're helping to deploy the first commercial plant of a potentially transformative solar technology able to deliver clean energy at scale, said Rick Needham, Director of Green Business Operations at Google.

US Department of Energy has guaranteed $1.6 billion in loan for the project. Another $300 million was invested by NRG Solar LLC, a wholly owned subsidiary of NRG energy.

By driving energy innovation in the field, not just in the labs, the DOE's loan guarantee program is playing a vital role in realizing our nation's clean energy and economic goals,said Jack Jenkins-Stark, Chief Financial Officer for BrightSource Energy.In partnership with the DOE, NRG, Bechtel and now Google, we're building at Ivanpah cost-effective, environmentally friendly and reliable solar power plants. We're thrilled to work with two of America's leading utilities - PG&E and Southern California Edison - to provide their customers with clean, reliable and cost-effective solar power at a meaningful scale.

Google said it has invested $250 million in the clean energy sector so far.

About Ivanpah Solar power project:

Located in a 3,500-acre land managed by US department of Interior Bureau of Land Management, the Ivanpah Solar project is a 392G MW solar power facility with three thermal power plants to be built in phases between 2010 and 2013. Bright source energy may help it to power 140,000 homes, the company said.

Bright source energy has estimated that the project will reduce carbon dioxide emissions by more than 400,000 tons annually which is equivalent to taking off more than 70,000 cars on the road. The plant life would be 30 years. The project will produce electricity by creating high temperature steam to turn a conventional turbine, the way any solar project works. Added with other innovative technologies, the project hopes to achieve maximum benefit.

It will be using 95 percent less water than the competing solar tech units because of the use of dry-cooling technology. Bright source will be using mirrors on individual poles that would be placed directly on to the ground. The mirrors will reflect on a boiler filled with water heating it up. These innovations make the whole project cost-effective, the company said. There is also an air cooling system that will convert the steam back into water saving water usage further, it said.