Supermarket News reported the trend Sept. 19 in announcing the opening of at least the fourth U.S. grocer to garner some electricity from the sun. Woodlands Market, a single-store retailer in Kentfield, Calif., became one of the largest solar-powered supermarkets in California when officials recently turned on its 100-kilowatt system, according to the report.
The article also documented similar installations at Wal-Mart Stores in McKinney, Texas, and Whole Foods Markets in Princeton, N.J., and Berkeley, Calif.
“Most electricity is produced by burning coal, but if you create electricity through the power of the sun, you'll end up with the same product without polluting the environment,” said Steve Cohen, manager of architectural glass with RWE Schott Solar in Elmsford, N.Y., a manufacturer of solar panels, in the article. “That is solar energy's main attraction.”
For contract glaziers, installation of solar cells requires close coordination with the supplier of the solar-cell panels and the electrician on the job, says Scott Haber, managing partner of Nanuet, N.Y.-based W&W Glass LLC’s Contract Glazing Division. He recently completed two solar-cell projects in New York City. Such projects definitely require attention to detail, he said, the installer must make sure that the cells face in the right direction top to bottom, right to left and so forth.
A handful of companies have sprung up in the United States to attend to the vast array of details involved in the custom fabrication of solar-cell panels, Haber says. Most of these companies provide exacting installation instructions for glaziers.
Haber’s crews installed a photovoltaic roof on the White Hall Ferry Terminal in Manhattan and a 100-by-20-foot, 2.62-kilowatt solar canopy in front of The Helena, a 38-story apartment building in New York City.
The ferry terminal, designed by Schwartz Architects of New York City, features extensive aluminum skylights by Wausau Windows and Doors of Wausau, Wis. Manufacturer Atlantis Energy System Inc. of Poughkeepsie, N.Y., provided the solar cells. The prefabricated units arrived at the site knocked down and W&W glaziers assembled them on the roof.
At The Helena, Haber worked with AltPower of New York City, whose employees coordinate fabrication and installation of solar cells; and Metals Inc. of Carlstadt, N.J., who provided the frame. The glass solar cells arrived at the job in typical packaging with specific instructions for installation on the labels. AltPower’s technicians provided a specific sealant as well. Most of the panels have power boxes attached to them and must be wired, Haber adds, so the electrician took over after the glaziers completed their work. As solar cells create an active electrical system, proper drainage of skylights and canopies become even more important than on other jobs.
Anthony Pereira, president and chief executive officer of AltPower, notes additional considerations:
1. Solar cells must be exposed to light, so make sure you install low-profile mullions.
2. When installing solar cells in daylight, keep in mind that they comprise an active electric system with a small potential to shock. Probably not a good idea to install on a wet day, Pereira says.
3. Solar cells can be any size, but generally top out at 5 feet by 8 feet.
4. Most solar cells contain laminated glass and polyvinyl butyral or Tedlar laminates with ethylene vinyl acetate copolymer.
“Most solar cells come from Germany,” Pereira says, and many of the companies doing this kind of work have European parents.
On its jobs, AltPower workers arrange for
• Local code approval
• Approval from the utility that will be receiving the power
• Any funding such as state subsidies or tax incentives from local government.
These steps can be time consuming, Pereira warns. “On a big job, you can put up the glass, but that doesn’t mean you can operate it. You have to have all your ducks in order with the utilities and the code officials, or you’ll have a nice façade that doesn’t actually work.”
Most of AltPower’s jobs comply with standards from Underwriters Laboratories, but solar-cell systems for some high-profile projects such as The Helena go through additional testing and gain separate approval from local code officials, Pereira explains.