Imagine you own a commercial building with enough office space for about 10 tenants. There’s a cozy diner at one end of the one-story building and the rest is retail. One day, one of your tenants that sells solar panels suggests you use that nice flat roof on top of the building for a solar array – you know, just like the big guys: Costco, Staples and Walmart, who generate their power from rooftop panels.
You decide to go for it. He installs the panels to spec, leaving enough room for plenty of walk space, of course. The sunny fall days you’re now getting from global warming seem like a blessing to your energy bill, and everything hums along nicely.
But one early morning, the unthinkable happens. The corner diner has a small grease fire that engulfs the restaurant in smoke. Soon, it’s no longer a small fire, and when the fire department arrives to put it out, you find out your real problem: in order to properly ventilate the noxious gases and fight the fire, the fire department needs to cut a hole in the roof.
Your suburban fire department however, is unprepared to deal with solar panels, and certainly an array as big as yours, you’re told. They aren’t sure they can turn them off, and the fire chief doesn’t feel his crew should risk getting electrocuted while negotiating the array. Meanwhile, your building and that expensive solar park upstairs is at risk of burning.
Solar panels and fire
This scenario is not far-fetched at all. When one fire team encountered this problem earlier this month, the answer made headline news. A refrigeration warehouse used to store meats and cheeses for the deli company Dietz and Watson burned to the ground because fire crews were unable to determine how to disconnect the 7,000 solar panels that covered the manufacturer’s 300,000 square-foot roof.
According to Delanco, NJ Fire Chief Ron Holt, there was no clear shut off switch or mechanism that would have ensured that firefighters would have been able to access the roof safely. There was also a question of where a hole could be cut, although a representative from Solar Energy Industries Association who had inspected the array saw it differently.
“There were wide walkways, there were areas where you could’ve vented the roof. Obviously [the fire department] would’ve liked more areas,” said Ken Johnson in an interview with Mike Riggs, a reporter for Atlantic Cities (posted on Grist). Johnson is vice president of communications for the association.
Firefighters battled the fire from a distance using water and foam in an attempt to retard the flames, since they were unable to climb to the roof while the panels were activated by the hot sun. By the time the sun had set, however, the building was beyond recovery.
A universal shut-off switch?
Several experts including Johnson have pointed out that there have been hundreds of thousands of solar systems installed on roofs over the years, and very few fires.
“By contrast, there have been tens of thousands of fires related to toasters, microwaves, TVs, washers and dryers, computers and entertainment equipment,” Johnson said.
Since this story broke a week ago, the forums and comment boards have been abuzz with speculation about how this scenario should really have played out. Several solar installers have argued that the panels can be shut off (although there appears to be no consistent answer as to how).
Firefighters and supporters have argued their cases just as passionately. But, of the hundreds of comments left on major media websites, none has presented a reassuring textbook answer as to how thousands of active solar panels that aren’t connected to a breaker switch (which is required only in certain states) can be switched off quickly and the roof accessed with water hoses.
Rooftop arrays: Worldwide use
So to put this in perspective, consider the following:
- In addition to those “hundreds of thousands of solar systems” that Johnson notes exist around the U.S., even more exist in Spain, Germany, Israel, France and other countries.
- As we have covered previously, rooftops are considered a premium in Spain, where the space is often leased to community solar companies.
- The White House first installed rooftop solar panels during the Jimmy Carter administration before the Reagan administration pulled the plug. A smaller version was then reinstalled by G.W. Bush to heat the swimming pool. A full array now sits on the Whitehouse rooftop, courtesy of the Obama administration. So far, there doesn’t appear to have been any discussions about whether they pose a danger to the First Family.
- Seven of the largest retailers in the U.S. maintain solar arrays on their rooftops. That includes Macy’s in Goodyear, AZ, which had the largest rooftop array in the U.S. in 2010, and Costco and Walmart, which together are said to generate more solar power than the State of Florida.
- State regulations governing the presence of a breaker switch are still in their nascent stage, but it’s no surprise that New Jersey, with one of the highest concentrations of rooftop solar arrays, already has pending legislation requiring better signage on solar-energized buildings.
But that nagging question still remains: Where’s the universal cut-off switch and should solar panels really be considered that much of an impediment to first responders?
These are valid questions that lead one to assume that with the millions of panels that have already been erected on rooftops, there is someone out there, either on the well-guarded roof of the White House, or on the sunny plains of Spain, who has already successfully addressed this issue and would know how to shut the solar panels off in the case of a fire.
May the most knowledgeable engineer please step forward …