It’s all over the news lately, and – even though not all that new – represents the next phase of solar development.
We’re talking about Dow Chemical Co., America’s premier chemical company, and its development of solar shingles, which will be mass-produced by next year and commercially available in quantities by 2011.
Dow suggests the market potential for these shingles is $5 billion, and the materials involved – copper indium gallium diselenide, or CIGS – are, while expensive, used so sparingly that cost is a small factor in their production, at least compared to traditional solar panels. In addition, the manufacturing process uses molded plastic, which makes them adaptable to a wide range of shapes and surfaces, where most panels are rigid.
These BIPVs, or building-integrated photovoltaics, generally combine solar photovoltaic (PV) elements like crystalline silicon with asphalt, fiber-cement, metal or even slate to create a roofing material that protects while it also provides electricity.
For example, Florida-based OkSolar offers what it calls SHR shingles, which – textured to blend with conventional asphalt shingles – offer rolled surfaces 12 inches wide by 86.5 inches long which can be nailed in place and which bond in place under the heat of the sun. Lead wires are passed through the roof and connected on the underside with an inverter to deliver electricity.
Michigan-based Uni-Solar also offers a solar shingle which won Popular Science’s “Best of What’s New” award and Discover Magazines “Technical Innovation Award”. And San Jose, California-based SunPower makes SunTiles, an all-black solar shingle design that integrates into both flat and clay-tile type roofs.
So why does Dow come in for so much press? Because it’s big, well financed, experienced, and can back its claims with a wealth of materials and technical expertise that will likely make the dream a reality very quickly. It also helps that Dow says its solar shingles are easily installed – 10 hours versus 20 to 30 hours for solar panels. This is important because installation costs represent about the half the expense of a roof-mounted solar array.
Dow also plans to keep the cost of its solar roof shingles lower (about 30 to 40 percent lower, in fact, than solar panels), and – though nothing has been said about connectivity features – one would suppose a company of Dow’s standing could find an inexpensive way to tie all the shingles together to produce electricity. Their efficiency rating (about 10 percent) is well below that of most polysilicon cells, but would also cost 10 to 15 percent less per watt.
The biggest plus, in an America increasingly divested of production facilities, is that the solar shingles will be made here in the United States, most of them at Dow’s Husky Quadloc Tandem injection press facility in Midland, Michigan, near where Dow has its corporate headquarters.
The 2010 rollout will take place at new housing developments planned by Pulte Homes, Inc. and Lennar Corp., both of whom will reportedly partner with the chemical giant to field-test the solar shingles. The U.S. Department of Energy is funding part of the process with a $20-million loan.