Rooftop Solar Stood Up to Sandy
Big solar installers report almost no damage, even in hardest hit areas
15 November 2012—Glass panels on rooftops and hurricane force winds don’t sound like the greatest of combinations, but solar power companies say their customers’ rooftop installations stood up very well to Hurricane Sandy’s onslaught.
New Jersey’s solar-power capacity is second only to that of California, in spite of average amounts of sunshine that are no greater than those of Minnesota and northern Montana. One of the states hardest hit by Sandy, New Jersey installed 103 megawatts of photovoltaic capacity in the second quarter of 2012 alone, and it appears that the hurricane didn’t make a dent in that progress.
“There have been really minimal reports of damage,” says John Ordona, a spokesperson for Sungevity, a company that installs rooftop solar systems and leases them to homeowners. Sungevity has more than 200 customers within the hardest hit regions of New York and New Jersey. Ordona says a couple of conduits—the metal casing that covers wires heading from the panels down to an inverter—were damaged by flooding. One very large system had two panels come loose, but otherwise the systems held up fine, he says.
Other companies, including Sungevity’s main competitor SolarCity and high-efficiency PV cell and panel manufacturer SunPower Corp., report similar success. “Following Hurricane Sandy, the overall damage to SunPower solar systems that were properly installed per the company’s manufacturing and required design guidelines is quite limited, and more systems are coming back on line daily as the grid returns to normal,” according to Jorg Heinemann, the company’s executive vice president of customer operations and engineering, procurement, and construction.
Heinemann adds that industry certification standards for solar panels call for an ability to withstand 2400 pascals when it comes to wind, a pressure equivalent to constant winds of 130 kilometers per hour for a solid hour. The standard installation of SunPower panels calls for even more robust wind resistance, up to 176 km/h, which is 56 km/h higher than that for hurricane-prone areas like Puerto Rico.
Solar power didn’t perform completely without incident, though. Disaster forensics expert Alexis Kwasinski drove around and flew over some of the affected areas and did spy one fairly big bit of solar panel fallout in New Jersey. The Gloucester Marine Terminal, just across the Delaware River from Philadelphia and home to the largest rooftop solar installation in the country, saw some of its 27 528 panels blow off in the storm. An employee at Holt Logistics Corp., which owns the terminal, acknowledged the damage but would not speculate on dollar costs or the number of panels.
Kwasinski, an assistant professor of electrical and computer engineering at the University of Texas at Austin, guesses that a design or construction issue might have led to the damage, as standard solar installations should have been able to withstand the winds. “This is the first time I found such damage in any PV farm after any hurricane I studied,” he says. “I couldn't find such damage level, or any damage at all, in any of the [other] sites I saw in the affected area.” He notes that some coastal areas couldn’t be observed but clearly suffered more extensive damage than inland regions, though overall that represented a small percentage of the affected area.
While the region’s solar installations seem to have generally survived the storm unscathed, that doesn’t mean solar can necessarily help keep the lights on when a storm like this hits. Heinemann says that “when the grid is down, so are grid-connected solar panels, even if they are in perfect working order.”
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