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Do Rooftop Solar Panels Really Hinder Firefighters?

Jan Lee
Jan Lee | Thursday September 26th, 2013 | 12 Comments

Solar_install_ODOT_2Imagine 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.

Ancient_and_modern_in_Llanwrin_OLU_John_Lucas

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 …

Image of solar panel installation courtesy of Oregon Department of Transportation
Image of historic house with rooftop solar panels in England courtesy of John Lucas (OLU)

▼▼▼      12 Comments     ▼▼▼

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  • Mickey Askins

    Right wingers love to scare people about solar, it is their nature. Fight the ignorance and go solar.

    • Disney on Ice

      Wait wait, no, it must be GWB’s fault, right? Now that Mickey Mouse has cast the first stone, does anyone have something intelligent and relevant to the topic at hand to add to the discussion?

      This article brings up a valid concern and I don’t remember anything about this addressed in my state Code Enforcement classes. Much of the teaching was geared towards directing us to hire a specialist (plumber/electrician/HVAC etc.) when inspecting unique or complex situations.

      I have a few volunteer firefighters that I sit near and will bounce the question off of them.

      • J_N_Lee

        Hi Disney on Ice –
        Thanks for the comment – valuable info. We’d love to hear what you find out.
        I can also be contacted through Twitter @janleethiem.

    • J_N_Lee

      Thanks Mickey for your comment.

  • Damien Johnson

    The lack of education within this article is astounding. There should be no disagreement that solar panels CAN NOT BE TURNED OFF whe the sun is shining. Aside from covering the array with a very large, very dense tarp, which is impractical, if the sun is shining, DC power will be flowing. The ONLY exception is if the panels are connected to micro-inverters, which is a more expensive alternative to the more common “string inverters”. A micro-inverter system can be shut off from the ground so that all wires below the panels are dead, although the panels themselves will still be “hot”. That’s it. That’s the answer the author claims no one knows and she apparently wasn’t able to find by calling any reputable solar installer.

    • J_N_Lee

      Damien, Nancy and Bzzzt!

      Ah guys, I don’t think I advocated any answer – instead, I related the questions that came up in the incident. I didn’t say *how* to handle the problem, other than to repeat the assertion made by the fire chief that there would need to be a “shut off” box on the ground below. (Ergo, my last line and our invitation for comments on this.)

      The point being made in this post dovetails with what you are saying Damien: the procedures you underline should be common knowledge, certainly by fire departments. And if they were commonly known, they shouldn’t have generated all of the debates over comment boards as to what should have been done (see the links in my post).

      So thank you guys for pointing out exactly what we’re trying to say here.
      As a side note, I found it interesting that I reached out to several different sources that we have either reported on (that includes facilities that have arrays on their rooftops as well as installers) or connected with for information on solar arrays. ONLY ONE was willing to go on record to discuss what is done during a fire. Another told me that they “are not prepared to talk about this at this time.”

      Thanks again for jumping in and answering this question. It now begs the question why the “more expensive alternative” is not universal (as I asked) if the alternative concern is what occurred.

  • Nancy

    Thank you, Damien, for pointing that out. Microinverters are now more than 30% of the residential market and growing strong. In the next five years residential and much of commercial rooftop will likely be all MIs or AC modules, which mean NO high-voltage DC going over a roof at all. ACPV is the future of rooftop solar, and firefighters need to be aware of it. http://www.solarbridgetech.com

    • J_N_Lee

      Thanks Nancy. Please see above

  • Bzzzt!

    Seems to me that Ms. Lee’s sources were all “old generation” technology companies. While it’s true that much of the existing arrays use the dangerous DC cable technologies, newer, safer technologies exist. Microinverters (like SolarBridge’s), which attach to individual panels, deenergize as soon as AC power is cut to the structure. While individual panels continue to generate electricity, the power does not extend past the panel’s microinverter.

    Looks like the industry is seeing this as the upcoming solution: a good chunk of new arrays are installed with this safer, more scalable, solution.

    (And yes, full disclosure: I work for SolarBridge Technologies: http://www.solarbridgetech.com)

    • J_N_Lee

      Great! Please see above. Thanks!

  • Bzzzt!

    Seems to me that Ms. Lee’s sources were all “old generation” technology companies. While it’s true that much of the existing arrays use the dangerous DC cable technologies, newer, safer technologies exist. Microinverters (like SolarBridge’s), which attach to individual panels, deenergize as soon as AC power is cut to the structure. While individual panels continue to generate electricity, the power does not extend past the panel’s microinverter.

    Looks like the industry is seeing this as the upcoming solution: a good chunk of new arrays are installed with this safer, more scalable, solution.

    (And yes, full disclosure: I work for SolarBridge Technologies: http://www.solarbridgetech.com)

  • michael

    An alternative to a shut-off switch is to use a low-voltage solar panel technology. See tenKsolar.com.