Dow Chemical Co. plans to start commercial production of its Powerhouse solar roof shingles this year, even before it starts operating its new plant in Midland, Mich. Dow’s thin-film copper indium gallium diselenide solar cells currently are manufactured on a flexible substrate by Global Solar Energy Inc. in Tucson. The cell is then integrated by Dow into a proprietary polymeric-based shingle using injection molding. Dow has completed six pilot projects in various U.S. markets with new-construction builders and residential re-roofing contractors. Dow believes that its focus on making the shingles easy to install will help drive sales as much as the expected energy savings.
The interlocking shingles are designed to be used alongside asphalt shingles on a standard roofing underlayment. They can be installed with standard roofing nails at the same time asphalt shingles are installed. Despite an initial higher cost for solar shingles when compared to asphalt shingles, homeowners will only need to use solar shingles on part of a roof, and their use will potentially save consumers money in the long-run. Dow believes that the typical installation will dedicate 20-40% of the roof to these types of shingles, but their use could offset 50% of the electricity usage. Dow received Underwriters Laboratories certification for its shingles in November 2010.
Dow projects annual capacity at the Midland plant to be 220 megawatts of solar shingles by 2015. Current capacity at Global Solar Energy is 75 megawatts. Dow’s solar business received $20 million in funding in 2007 from the Department of Energy to develop new residential solar products.