Firefighters battling the massive 11-alarm blaze at the Dietz & Watson distribution center in South Jersey faced an unlikely foe during the fight — solar panels.
A solar array with more than 7,000 photovoltaic panels lined the roof of the nearly 300,000 square-foot refrigeration facility which served as a temporary storage center for the company’s deli meats and cheeses. But the panels, while environmentally sustainable and cost-saving, may have led to the complete destruction of the warehouse.
Fighting the fire under bright blue skies Sunday, Delanco Fire Chief Ron Holt was forced to keep firefighters from attacking the blaze from the roof because of electrocution concerns.
“With all that power and energy up there, I can’t jeopardize a guy’s life for that,” said Holt. Those electrocution fears combined with concerns of a collapse forced firefighters to simply spray the building with water and foam from afar.
Ken Willette from the National Fire Protection Association, a nonprofit that develops standards for firefighting, says electrocution is one of the hazards firefighters are increasingly facing fighting blazes at structures where solar panels are deployed.
“Those panels, as long as there’s any kind of light present, whether it’s daylight or it’s electronic lamp light, will generate electricity,” he said.
A 2011 study from the Underwriters Laboratory found solar panels, being individual energy producers, could not be easily de-energized from a single point like other electric sources. Researchers recommended throwing a tarp over the panels to block light, but only if crews could safely get to the area.
SLevy: The issue is the series connection of many panels result in high voltages being developed which could be lethal if improperly handled. There are several answers but the one that makes the most sense to me is to modify the junction box in the back of each panel with an intelligent converter (either a DC-DC converter or a DC-AC inverter) that can disconnect itself from the string either from an internal sensor detecting a fault condition, like heat, or by the main disconnect for the solar system being activated so that all panels are isolated from each other. Then the danger is controlled and fire-persons can do their job and not worry about high voltage danger. A wireless remote monitor will verify the safe condition allowing firefighters to do their job in safety. The other benefit to the solar array owner is the same detection system will warn of panels being stolen. The cost of the intelligent converter should be 10% or less than the cost of the basic panel. Present fire safety regulations do not address this problem.