Photo by Gustavo Muleey

In late September, Congress passed the Energy Improvement and Extension Act of 2008. The new and extended tax credits associated with this bill have meant the go-ahead for solar plants such as the one being built by companies New Solar Ventures and Solar Torx in Deming, New Mexico and the Solana plant funded by Abengoa Solar and Arizona Public Service Company in Arizona which will be the largest solar plant in the world. Together, these two plants will be capable of producing over 580 megawatts of electricity.

Traditionally, most solar power plants have used PV technology to generate electricity, but these new projects will utilize new and more efficient ways of harnessing energy. Rather than simply capturing the sun’s rays through PV cells on a larger scale, companies such as Ausra are using solar thermal technology to create industrial amounts of electricity. Solar thermal plants use large mirrors to reflect and focus sunlight onto a central tower, where water is heated to boiling point. The resulting steam drives a massive turbine, creating electricity.

Photo by Valerie Everett

The three largest solar power plants in the world are currently being built in the Mojave Desert, and when operational in 2011, will be able to collectively produce over 1500 megawatts of electricity. While this amount is modest in comparison with fossil fuel power stations, plants like these are a vital step towards energy independence,

The AUSRA project not only looks set to be one of the largest solar plants in the world, but also one of the most cost-efficient. That gave two ‘green’ reasons for venture capitalists such as Vinod Khosla to invest in the project.

Khosla’s company has a history of investing in cutting edge research into renewable energy, but this is the largest investment made to a single project. Khosla’s $25 million investment in the plant shows a confidence that solar power is here to stay. The company claims it will be able to match the price of electricity generated from fossil fuels within 1 – 3 years. (Current solar plants produce energy which is roughly 3 times the price of electricity from oil or coal burning plants.)

A low energy price is not the only ambitious claim that the company has made. In an interview with VentureBeat in 2007, Khosla and Executive Vice-President of Ausra, John O’Donnell, boasted an ambitious plan that would enable their technology to produce enough electricity to provide power for the entire US.

Photo by afloresm

With the US Congress extending its tax credit program for solar power for another 8 years (and only 1 year for wind power), and more efficient solar thermal plants being built across the world, it looks like solar power may well be the light at the end of the energy-crisis tunnel.