# Roof-mounted solar panels - hidden danger



## Ashful (Sep 5, 2013)

http://www.nj.com/burlington/index....battling_blaze_much_harder_officials_say.html


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## pen (Sep 5, 2013)

Hmm.  Who would have thought that more stuff on the roof would make things more difficult 

What's your take?  What should be done?


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## woodgeek (Sep 5, 2013)

training issue?


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## Where2 (Sep 5, 2013)

I loved this statement: "any kind of light at all will activate the panels, including streetlights, floodlights, even firefighters’ flashlights. Those panels are extremely efficient."

Best I've seen is about 15% efficient. Partial shading really screws up a panel output too. 

Since I have a stack of 235W monocrystalline panels, I ran a little experiment tonight. I took a 5-cell Ni-Cd Mag Lite similar to those used by your average FD/PD, shined it on a panel. I measured 10.6v @ 0.01A.  So, I turned on a 50W lamp mounted an average of 7 feet from the panel. I measured 16.2v @ 0.02A.

Sounds like a training issue. One swing with your average fire fighting axe will disable a solar panel even at high noon.


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## peakbagger (Sep 6, 2013)

There definitely is a training issue and current NFPA standards require access ways on each edge of the roof as well as along the ridge pole for peaked roofs. Many folks dislike this as it reduces the number of panels they can put on the roof. 

Microinverter based systems are somewhat safer as if the AC power is turned off in the structure the inverters shut down. The panels themselves are still "hot" but the wiring to the microinverter is typically under the panel and very short.


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## TradEddie (Sep 8, 2013)

Or worse yet, the panels cause the fire. This happened here yesterday.

http://pottstown.patch.com/groups/tom-bartmans-blog/p/local-high-school-fire-caused-by-solar-panels



> Firefighters were called to Owen J. Roberts High School Saturday afternoon after a fire broke out on the roof of the building.  The cause of the fire, still under investigation, originated from roof top solar panels.  Officials say the fire caused $50,000 in damages.



TE


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