Australian Researchers Break The ‘Solar Barrier’

Australia’s national science agency says it has used sunlight to create “supercritical” steam that can compete with coal and gas to run power stations.

Researchers from the Commonwealth Scientific and Industrial Research Organization (CSIRO) energy center in Newcastle in southeastern Australia say they recently reflected solar heat from a field of mirrors, called heliostats, and focused it onto a central receiver to create the supercritical steam.

Supercritical solar steam is created from water that’s pressurized at enormous force and heated by solar energy. In this case, the CSIRO researchers heated the steam to 570 degrees Celsius (1,058 degrees Fahrenheit), the melting temperature of aluminum alloy. The pressure they achieved was 23.5 megapascals, or about 100 times the pressure of a car’s tire.

The research may sound obscure, but Dr. Alex Wonhas, CSIRO's energy director, calls it a potential revolution for the renewable energy industry.

“It's like breaking the sound barrier,” Wonhas said. “This step change proves solar has the potential to compete with the peak performance capabilities of fossil fuel sources.”

So far, the researchers say, solar power plants have been capable of operating only at “subcritical” levels. The CSIRO researchers have shown that solar energy can now generate electricity with no carbon emissions.

“Well, certainly that’s what we’d like to think,” says Robbie McNaughton, who directed the $9.7 million research program.

In an interview with the Australian Broadcasting Corp. McNaughton said, “It's important to remember that what we've done is really the first step along a fairly long path still, in demonstrating that we can actually do these things with solar technologies.”