Plug and play: Dow’s Powerhouse Solar Shingles nail in like conventional shingles and interconnect electrically through rigid plugs at the end of each shingle.
To address cost and performance challenges, Dow partnered with solar cell producer Global Solar Energy, one of the early developers of copper, indium, gallium, and selenium (CIGS) thin films. CIGS thin-film semiconductors are less expensive than conventional crystalline silicon solar panels and offer some of the highest conversion efficiencies of emerging thin films.
For each of Dow’s shingles, Global Solar will manufacture strings of five interconnected solar cells. Dow will then encapsulate each string with glass and polymers and embed it into a shingle with electrical plugs at each end that link the individual shingle into a larger array.
Dow is leveraging its ties within the building materials and construction industries to develop, test, and distribute its shingles. Installations can be completed in half the time of conventional solar installations, and an electrician is only needed to make the final connection to the building’s electrical system, according to David Parrillo, senior research and development director of Dow Solar Solutions.
The DOE also awarded United Solar Ovonic of Rochester Hills, MI, $13.3 million in tax credits to ramp up production and increase the efficiency of its building integrated photovoltaic materials. Unlike Dow, the company produces amorphous silicon thin films that are encapsulated entirely in polymers. Amorphous silicon offers lower efficiencies–currently 6.5 to 7 percent at the array level–than the CIGS shingles that Dow is developing. Silicon, however, is a less expensive material than CIGS and is less susceptible to moisture. As a result, the integrated solar cells built by United Solar Ovonic don’t require glass covers like Dow’s shingles, allowing them greater flexibility.