Los Angeles -- It works like a mirror, but it's actually brownish green and opaque.
The Cool Mirror film from 3M is a multiple layer optical film that essentially rejects solar heat but reflects light. If it is placed at a 90-degree angle in relation to a solar module -- think of a solar module and a panel of the stuff in the picture forming a "V" in a utility-scale solar field -- the film will serve as a 2X concentrator for the panel. Light bounces from the Cool Mirror straight to the panel. Concentration achieved, but no tracker required. The company 10K Solar has performed demonstrations that indicate that the film, in certain circumstances, can nearly double the power output of the panels. Just as important, heat from the concentrator doesn't collect under the panel.
"It is like a concentrator but without concentrating the heat," said John Prince of 3M.
Solar manufacturers have spent millions of R&D dollars and several years boosting the efficiency of solar cells. But now, there's an increased emphasis on overall module design, according to Eric Peeters, business vice president of Dow Corning Solar Solutions. The gains in some instances can be easier. As a result, the large chemical companies are becoming an increasing presence at solar shows, like Solar Power International taking place right now.
Dow Corning's lead product is silicone. The company has sold silicone as a sealant for years for satellite solar systems, but the price has dropped in recent years to make it affordable for ground-based systems. It allows UV light to pass and can effectively protect modules from the elements.
"Anything we do will be based around the silicon atom," he said.
Meanwhile, 3M also showed off its Ultrabarrier film. The film -- based on a fluoropolymer -- can substitute for glass in modules. The company hopes to complete a factory in 2012 that will be capable of producing enough materials for hundreds of megawatts of panels.
3M will initially target thin film manufacturers: CIGS first and later Cad Tel. The material will likely cost more than glass. However, it leads to flexible solar modules, one of the touted promises of thin films. CIGS maker SoloPower has said it will use the material.