PV's with Concentrators Yield 35% Effeciency Rate
The Boeing Company has signed a contract to provide 600,000 solar concentrator cells to SolFocus, Inc., a California-based renewable energy company that is developing renewable terrestrial energy alternatives.
Under the 12-month contract from SolFocus, Inc. of Palo Alto, Calif., Spectrolab will build and deliver 600,000 solar concentrator cells that will be used to convert the sun's rays into affordable electricity for homes and businesses. The cells produced for SolFocus will be capable of generating more than 10 megawatts of electricity, or enough to power about 4,000 U.S. homes. With the average solar cell efficiency above 35 percent at concentration, Spectrolab's concentrator photovoltaic cells generate electricity at a rate that can be more economical than electricity generated from conventional, flat panel photovoltaic systems.
A significant advantage of concentrator systems is that fewer solar cells are required to achieve a specific power output, thus replacing large areas of semiconductor materials with relatively inexpensive optics that provide optical concentration. The slightly higher cost of multi-junction cells is offset by the use of fewer cells. Due to the higher efficiency of multi-junction cells used in the concentrator modules, only a small fraction of the cell area is required to generate the same power output compared to crystalline silicon or thin-film, flat-plate modules.