AUSTIN, Texas--When most people think of solar energy they think of panels on people's homes. But if you follow the money, investors are betting that large-scale solar from companies like Ausra are the most cost-competitive.
Ausra, which presented at the Clean Energy Venture Summit here on Tuesday, is testing a system to generate power at centralized stations. These solar parks use concentrating solar power to create steam that turns a turbine to make electricity.
If constructed on a large enough scale,these solar thermal plants are already cost-effective when compared with fossil-fuel power generation, according to advocates of the approach. (See photo of another concentrating solar plant here.)
Ausra's twist is "thermal storage." In addition to generating steam from its array of special metal tubes, Ausra stores hot water that a power plant can draw on during times when the sun is not shining.
That thermal storage is key to competing on price even at peak demand times, said Robert Morgan, the chief development officer of Ausra, who spoke on Tuesday.
The company's system, which is now testing in Australia, can operate at 10 cents per kilowatt hour for plants between 100 and 200 megawatts. For plants between 100 and 500 megawatts, the cost goes down to 8 cents per kilowatt hour, said Morgan
That means they can compete with existing natural gas plants, which operate at 12 cents per kilowatt hour, he said.
"With thermal storage, we can compete with coal on price," he said. Coal-fueled plants are typically the cheapest sources of power.
Ausra, which has been relatively quiet about its plans until now, is backed by venture capital firms Kleiner Perkins and Khosla Ventures.