In what could be a big boost for the fledgling building-integrated photovoltaic sector, Dow Chemical last week unveiled a solar shingle that promises to address two of the biggest issues hampering expanded solar deployment on homes—installation cost and residential aesthetics.
After two years and $100 million in development costs—aided by some $20 million in Energy Department cost-share funding—Dow Wednesday unveiled a thin film solar array that looks much like a strip of standard black asphalt shingles, albeit a bit shinier.
The Dow shingle utilizes copper indium gallium diselenide, or CIGS, cells that can convert about 10 percent of the solar energy hitting them into electricity. As with other thin film solar cells, CIGS panels have roughly half the conversion efficiency of conventional silicon-based solar modules, meaning rooftop arrays have to be bigger to generate the same amount of electricity.
Dow’s real breakthrough—if it is confirmed in field tests planned for next year—is that its “Powerhouse” shingle can be installed by roofers with the standard nail-it-in method used for regular asphalt shingles.
The arrays also plug into each other through a proprietary connector, eliminating the need for extensive wiring typically required for rack-mounted roof-top solar arrays; electricians still will be needed to attach the arrays to an inverter and house electricity systems.
A Dow system capable of providing 60 percent of an average-sized home’s electricity needs could cost around $27,000, with subsidies bringing the after-tax cost down to $7,400.
While optimistic about the new shingle, Dow officials made clear that a commercial roll-out of the new shingle is still more than a year away. They note that their pilot production facility has an annual output of only 3 to 5 MW, and they also plan extensive market testing next year to see if their research on installation and homeowner acceptance pans out in the field.
I hope this is just the tip of the iceberg for greener options for homeowners.