Florence’s brutal winds will test the Carolinas’ solar boom

Source: By Brian Eckhouse, Bloomberg • Posted: Friday, September 14, 2018

The nation’s second-biggest solar region is facing the first real-time test of its systems, with Hurricane Florence threatening the Carolinas with winds well in excess of 100 miles per hour and torrential rains.

The Category 4 storm was packing 130 mph winds as of yesterday, with landfall expected by the weekend. While most newer systems are designed to withstand 140 to 160 mph winds, the Carolinas haven’t sustained a direct hit by such a large hurricane since its solar boom expanded in 2014.

Developers have built scores of solar farms in the region since that year, making North Carolina second to California among states, according to the Solar Energy Industries Association. The mix of large farms and rooftop systems in the region has solar proponents concerned.

“Absolutely,” said Tom Werner, chief executive officer of SunPower Corp., said by phone Tuesday. “If the panels were vertical to the ground, it would be like a sail to the wind. That would be the worst case.”

SunPower has already begun preparations, including shifting the angles of its solar-power trackers, according to Werner. It’s a type of preparation new to the Carolinas, but one that solar companies are getting used to, thanks to the spate of dangerous hurricanes in recent years. SunPower had a “dry run” last month when a hurricane hit Hawaii, Werner said.

In 2017, many solar farms withstood devastating hurricanes elsewhere by taking such actions. Some, though, fell short with “airborne solar modules, broken equipment and twisted metal racking,” according to a June report by the Rocky Mountain Institute.

Solar panels mounted atop homes will also be tested. Rooftop systems installed by Sunrun Inc., the largest U.S. residential-solar installer, “are built to withstand hurricane-force winds,” said spokeswoman Georgia Dempsey in an email Tuesday.

“As long as the roof stays on, so do the solar panels,” she said.