Cheap solar power?

Bill Gross of Idealab has a new company called Energy Innovations, which is introducing an innovative solar generator called the sunflower. Their generator is a "concentrator" which uses mirrors to focus direct sunlight onto a stationary photovoltaic cell (PVC). Since the PVC is the most expensive component of a solar generator, this makes good economic sense if the mirror array is cheap and robust. Gross and company claim to have solved this problem, using cheap microprocessors and a custom bearing array with only two motors. The sunflowers are built in China and are designed to fit in a shipping container. Gross claims that businesses with flat roofs in states like AZ or CA can pay for the machines in only 3-5 years from electricity savings! (Compare to 20 years for ordinary flat solar panels.)