[RE-wrenches] PV and Roof Flammability

[Michael Welch]

Hi gang. It seems to me that an upward sloping gap between the flammable roofing materials and the PV modules would result in a chimney effect for any fire in the roofing materials whether the fire is a result of the PV system or not.

Combine that with the modules blocking access to a roofing fire, and maybe you have their concern.

Just guessing here.

Ryan LeBlanc wrote at 12:43 PM 9/23/2010:
 
>Good points all, 
>
>Has anyone had an experience where you've seen new shingles and PV installed
>at the same time, where the shingles became prematurely brittle beneath the
>array, where you could say for sure it was PV's fault?  I too have tried to
>keep an eye on that, but I never can pin it on PV, most are still retrofits,
>not lending any credible data.  
> 
>As long as the PV doesn't cause the fire, due to:
>- Ground-faulted or otherwise compromised wiring
>- Melted cheap-o junction boxes (lowest cost import products)
>- Improperly wired roof mounted combiners (reverse polarity)
>- Conduit/expansion fitting errors (like the TARGET fire)
>- The fact that they simply will be in the way if firefighters have to
>vent...
>
>Are we saying there is evidence that the "PV shade structure" can increase
>the flammability of the roof product from combustion, due to proximity?
>Trapping a combustible level of heat beneath the array that can dry out and
>set fire to comp shingle? Hypothesis = 1 in a billion, necessary to look at,
>sure.  Maybe 1 in a 1/2 billion for wood shake.  
>
>Solutions I see then:
>-They can be stuck to the roof, no air gap no problem.  Well, except no
>possibility of removal for firefighters.
>-Integrated into the roof, then maintenance and wiring is buried.
>-0-5" (or whatever), no go due to too close.
>-5" (or whatever) and higher, Ok, due to adequate airflow and lack of
>proximity. 
>
>So now we're going to need PV compatible roof product ratings?  PV has a
>great track record ratio of installs to related fires, and this is with a
>majority of installers NOT really knowing what their doing, me included.  I
>hope we don't have to get more expensive as a result, let's make the roofers
>tell us which ones are not compatible, and then we can just tell them to
>stop installing it.  PV is too important. :o)
>
>I have to believe that having a roof covered by PV, especially in CA, could
>also Help Prevent fires from falling embers from forest and field fires, the
>occasional PG&E GAS LINE EXPLOSION BLOWING UP WHOLE NEIGHBORHOODS, etc. 
>
>Most material science would indicate that shading of the roof, the
>overwhelming majority of the time, will extend roofing product lifespan,
>often significantly, and help keep the attic a bit cooler.
>
>Let's not let officials overdo it, as I get more frustrated and educated
>about this overly passive and tolerant society of ours, I'm beginning to
>believe a little collateral damage is completely acceptable.  It obviously
>is for the big boys of energy, money, automobiles, policy, etc.
>
>*See BURNING THE FUTURE (Coal), GASLAND (Natural Gas), FLOW (For Love of
>Water), all the oil movies (oil), The Cove (Dolphins)... etc.  
>
>We could probably have a roof fire per day, and still be doing better than
>these "A" for alternative holes, except we'd get blitzed by the bad guys.
>Thanks again for keeping watch guys.
>
>$.0001 
>
>P.S. WHERE IS OUR FEED-IN TARIFF?... oh what, the PPA's have it covered, oh
>yeah, they don't want one, great for us.  Is anyone watch-dogging these PV
>finance guys?  They're the ones that scare me the most, you know, the ones
>that get lost at the "T" for "truth-in-lending".
>
>Thanks for your relentless service to the industry that could save America,
>if only they would let us.  
>
>Ryan J. LeBlanc
>NABCEPT Certified Solar PV Installer
>Cell: 707.591.1950
>Direct: 707.536.9839
>ryan at NaturalEnergyWorks.com
>http://www.NaturalEnergyWorks.com
>
>
>
>
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