USA reports that several years ago, SunPower, a unit of Cypress Semiconductor came to realize that the top metal plate was reflecting the sun's rays, cutting efficiency by reducing the percentage of sunlight converted to electricity. So Cypress Semiconductor decided to put both plates beneath the silicon. It now has an industry-high efficiency of 22% vs. an average of 16%, says analyst Dan Ries of Monness, Crespi Hardt & Co. That means fewer solar panels are needed to produce solar power, shaving solar installation costs and making solar energy systems more affordable for homes, which have smaller roofs than most commercial buildings.