Solar Shingles Replace Regular Shingles

When scientists at Dow Chemical looked at the possibility of manufacturing solar panels a few years ago, the company rejected it out of hand, says Chief Executive Andrew Liveris. Dow had no experience building solar panels. Yet their concept was alluring: integrate thin-film solar cells into roofing shingles. In place of traditional asphalt shingles, several hundred of these nailed onto the roof could generate enough electricity to power a home. Liveris sent them back to the lab, then decided to take the plunge.

Today those scientists are testing prototypes of the product, which Dow calls Powerhouse. Dow's aim is to start selling Powerhouse next year. Because they look like traditional roofing material, the solar shingles are more likely to get the nod from uptight homeowners' associations. Now, says Liveris, "I believe this will be solar for the masses."

That change of heart reflects the sunny outlook of Dow's solar champion, William Banholzer, whose title is chief technology officer. "I don't see any reason why people wouldn't want to generate clean electricity from their roof," he says. He adds that the market for this product could be $5 billion by 2015 and envisions that "someday Dow would be a solar company that happens to make chemicals."

Dow didn't invent the idea of a solar roof shingle. Uni-Solar, a division of Energy Conversion Devices, has been selling a version for a decade. But the difference is the technology behind the solar cell. United Solar uses something called amorphous silicon technology, while Dow has set its sights on a newer technology known as Cigs--photovoltaic cells made of copper, indium, gallium and selenium, which, when they work, are more efficient--able to turn 13% of the sun's energy into electricity. Cigs' big drawbacks are that it's tricky to manufacture, and if any water gets inside a cell it will oxidize the metals, rendering it kaput. That's why most Cigs installed today (only 1% of all solar panels out there) are covered with a layer of glass. But glass is too stiff and unwieldy for residential roofs.

So Dow, exploiting its 70 years of plastics research, has devised a transparent and flexible coating that encapsulates the cell to protect it from the elements. At least that's the plan. Dow still has a year of testing its top-secret formula before Banholzer will be ready to put Dow on the hook for an industry-standard 25-year warranty.

Dow's solar efforts benefited from a $10 million handout from the Department of Energy in 2007. The company has invested $100 million of its own in research and in the construction of a small manufacturing plant near its Midland, Mich. headquarters that can annually make 4 megawatts (peak power) of Cigs, enough for 2,000 homes. Banholzer says Dow will need to sell 50 megawatts a year to turn a profit, so he'll be buying cells from the likes of Global Solar and has invested in upstart Cigsmaker NuvoSun. Even so, Paula Mints atNavigant Consulting ( NCI - news - people ) says manufacturing snafus make it unlikely that Dow will be able to procure anywhere near 50 megawatts of Cigs for years. Banholzer says if that's the case Dow will use something else. Dow has funded Caltech researchers looking for an all-new solar technique.

Source:   Forbes