Rooftop Array of PV Shingles
The Southface Energy Institute is a nonprofit organization whose mission is to promote the development of sustainable, environmentally sound energy technologies through education, research, and technical outreach. The institute built this energy-efficient residence as a technology demonstration and to provide office and meeting space. The Southface Energy & Environmental Resource Center in Atlanta, Georgia, is a showcase for cutting-edge energy efficiency and renewable energy technologies for the building sector. The Center is used to educate students, teachers, architects, design engineers, and builders about the installation, cost savings, environmental benefits, and overall desirability of using advanced energy technologies in buildings.
The PV shingle shown here won Popular Science Magazine's grand award for What's new in Environmental Technology. The rooftop array of PV roof shingles was developed by United Solar Systems and Energy Conversion Devices under the DOE PV:BONUS program. The PV shingles installed on this residential-type building replace common roofing shingles. The PV shingles look much like ordinary roofing shingles, but they generate electricity. The PV shingles cover the inner portion of the lower roof section. They were laid out and nailed to the roof using the same methods as are used to lay conventional shingles. Like their non-PV counterparts, these shingles overlap providing for water shedding capability. The modules are multi-junction amorphous silicon (a-Si) PV. The a-Si is deposited on a thin, flexible, and lightweight stainless steel substrate and laminated in a polymer. The modules are approximately 0.3 m x 3 m (1 foot x 10 feet). Depending on the local climate, roof orientation, building features, and system operation, these modules produce 54 - 65 Wac/square meter (5 - 6 Wac/square foot) peak power in full-sun conditions and average greater than 70 Wh/square meter (25 Wh/square foot) daily energy output. Electrical connections are made with wire pigtails fed into the attic through the roof deck. The system is UI, with excess power sold to the local utility, Georgia Power.
Credit: John Haigwood
