Google says it is developing solar thermal power mirrors that could improve on current technology, making utility-scale solar power generation more cost-effective. Google green energy czar Bill Weihl said Wednesday that its efforts to develop renewable energy – which would presumably be used to power its data centers – is making progress.
“We’ve been looking at very unusual materials for the mirrors both for the reflective surface as well as the substrate that the mirror is mounted on,” Weihl told Reuters (link via TreeHugger). “We’re not there yet. I’m very hopeful we will have mirrors that are cheaper than what companies in the space are using.”
5 cents a kWh?
“In two to three years we could be demonstrating a significant scale pilot system that would generate a lot of power and would be clearly mass manufacturable at a cost that would give us a levelized cost of electricity that would be in the 5 cents or sub 5 cents a kilowatt hour range,” Weihl added. That would be competitive with the price of coal-powered electrical generation, one of the key goals of Google’s renewable research.
Solar thermal power systems use reflected sunlight as a heat-source to drive electric generators. Unlike photovoltaic systems, which use semiconductor materials to directly convert sunlight into electrons, solar thermal systems use the sun’s heat to create steam to power electric generators. This video demonstrates how the technology works.
Solar thermal power is not new, and is widely used widely used in residential applications, such as heating swimming pools. One of the largest example of solar thermal power is the SEGS (Solar Electricity Generating Systems) project in California’s Mojave desert, which used 2.5 million square meter array of parabolic reflectors to create a generating capacity of 354 MW.
Google’s data center require enormous amounts of power to operate – tens of megawatts for each facility, by all accounts. The ability to shift to renewable energy could dramatically slash the environmental impact of Google’s data centers. But the company’s solar research, while promising, remains a long way from commercialization.
Photo of solar thermal facility by aflores via Flickr.