Could solar power replace fossil fuels? An Australian plant says it is one step closer to proving so. Up until now, generating supercritical steam, an ultra-hot, ultra-pressurized steam that’s used to drive the world’s most advanced power plant turbines, has previously only been possible using fossil fuels, such as coal or gas. This moth, however, the Australian plant reports that it was able the generate supercritical steam with a solar system. "Instead of relying on burning fossil fuels to produce supercritical steam, this breakthrough demonstrates that the power plants of the future could instead be using the free, zero emission energy of the sun to achieve the same result," says Dr. Alex Wonhas, the plant's energy director.