The plant is the first built by Ausra which is already planning a similar plant in Las Vegas. They're somewhat famous for their claim that they could power all of America with a mere 92 square miles of land. While technically true, 92 square miles of solar is a pretty daunting project.
The plant basically uses flat mirrors to concentrate sunlight on a pipe containing oil. The oil is heated to magnificent temperatures and then the pipe runs through a vat of water. The water instantly boils, creating steam that then drives a turbine, creating electricity.
The plant is small, only 5 megawatts, but their second project, planned for next year, will be 117 megawatts. An average coal plant is roughly 800 megawatts.