Solar Powered Thermoplastics Hit The Roof
When it comes to shingles, there are some types you want and some you don't.
When it comes to shingles, there are some types you want and some you don’t.
From a medical perspective, few of us are interested in getting the contagious rash known as shingles. As far as shingles as a rooftop covering, however, our feelings are probably a little warmer — particularly if a new project to manufacture power-generating roof shingles made from plastics proves a success.
For the past year, The Dow Chemical Co. has been at work on a US$50 million project called Dow Solar Solutions, designed to develop thermoplastic roof shingles for the North American market that incorporate solar energy generation materials directly into the shingle design.
Dow is collaborating with Global Solar Energy Inc., an Arizona-based maker of flexible materials, and hopes to start selling the power-generating roof shingles by 2011.
The project, funded from the Solar America Initiative (SAI) Technology Pathway Partnerships program through the U. S. Department of Energy, aims to provide an alternative to traditional solar-powered panels. Consisting of silicon-based solar cells packaged within heavy glass, these panels are expensive and difficult to install, and, while they produce electricity, the cost is many times higher than conventionally generated electricity sold by utility companies.
“Dow’s innovative technology is based on a much more cost-effective photovoltaic material, called CIGS, and these cells are packaged within the roofing product to create a solar shingle,” said Bob Cleereman, Dow’s senior technical director of building integrated photovoltaic technology. “This approach enables lower fabrication and installation costs, because both the conventional and solar roofing shingles are installed at the same time.” The result for the home or building owner, Cleereman continued, is that solar-generated electricity costs no more than power generated by burning green house gas-creating fossil fuels.
“CIGS has proven to be the most efficient, cost-effective thin-film technology for integrated photovoltaic applications, and by teaming up with Global Solar we are working with an industry leader,” Cleereman said. “Global Solar is the only company in full-scale production of CIGS cells on flexible substrates, and has achieved a record-setting average 10 per cent solar cell efficiency, meeting SAI’s requirements.”
At the centre of the Dow Solar Solutions project is a US$2.5 million, 1,350-ton tandem clamp injection molding machine nicknamed “The Beast” that produces the solar cell-imbedded shingles. The project also involves construction of a state-of-the-art market development plant and R&D facility at Dow’s corporate headquarters in Midland, Mich., move that will create 22 new jobs.
“The average cost of electricity purchased from a utility is about eight cents per kWh, and at present, solar energy costs three times more,” Cleereman said. “As part of the SAI, Dow and its team members plan to bring solar-generated electricity costs below 10 cents per kWh by 2015.”
Dow Chemical Company (Midland, Mich.);