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. And it has high hopes that the shingles will not just succeed, but that they will become a mass-market product. 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. Right now, Dow is making the shingles in limited quantities at its solar market development plant, in Midland, which is being retooled to support commercialization. "Dow has completed six pilot projects in various U.S. markets with new-construction builders and residential re-roofing contractors, said Pezolt. "A number of additional projects will be completed in the coming weeks," he said.