No. The weight of the panels and the strength of the roof are accounted for when the system is designed.

Modern lightweight truss construction fails so quickly under a fire load, we're unlikely to make an aggressive attack if the fire has been burning in the attic space for any length of time, panels or no.

It smells of the anti-hybrid astroturfing from a decade or so ago where numerous Ford and GM employees would be glad to tell you on social media that if you get into a car accident in a hybrid, emergency services will leave you to bleed out and die because its a hybrid so you should have bought a SUV or truck like a RealAmerican(tm).

My father in law did the volunteer fire dept thing in his rural area and its very depressing how quickly a typical house becomes unsaveable in a fire. So it is true that most houses with solar panels, in a fire, will end up a total loss, but that's true of most houses ... period, nothing to do with solar panels.

My advice from the frozen north is solar panels are extremely light weight compared to slush/snow covered shingle roofs, which don't seem to slow down firemen very much. The total mass of a couple inches of rain soaked slush snow is unbelievable, many thousands of distributed pounds on a typical roof.

Everything above is correct. (I'm a volunteer firefighter.) Firefighters nowadays are trained to deal with the high-voltage DC that's present in hybrid and electric cars. It may take a little longer to extricate a victim, but it won't stop us. As for houses, we won't bother entering a burning residence at all unless we're likely to find a person still alive, or the nature of the fire is such that the danger to us -- with our PPE and training -- is minimal.

I assume part of the training is how to locate the right stuff to cut to shut off the high-voltage connection? Have you ever had to do that in practice, and if so how hard is it on a car that's been mangled?

The car manufacturers use bright colors (typically fluorescent orange) on cables that carry high voltage. We don't cut them! Too dangerous. Instead we avoid them, and assume that the car is energized.

http://www.nfpa.org/~/media/files/research/research%20founda...

I know you wouldn't cut high-voltage wiring, but I know at least on a Tesla there's a low-voltage loop exposed for firefighters to cut, which then isolates the high-voltage system as well as disabling the air bags and such. That's shown on page 10-13 here:

http://www.teslamotors.com/sites/default/files/downloads/en_...

I have no idea if this is a common thing or not. Anyway, thanks for the PDF, very interesting stuff. Assuming the car is energized seems sensible. Even with a loop like Tesla has, I imagine you can't count on that having the intended effect after the car has crashed.

Tesla actually does a really nice job of providing training materials to first responders:

http://www.teslamotors.com/firstresponders

You can watch a Tesla get cut up in this video:

https://www.youtube.com/watch?v=ntK3rvVl2Qw

Very nice. I was somewhat aware of the materials they provide, but I didn't know that video existed. I'm kind of impressed they sacrificed a car for it (although I suppose many of the valuable spare parts remained untouched).

Thanks for the reply, and the job you do.

Seems like it's likely mostly anti-solar propaganda, but I guess there is some concern regarding the electrified nature of solar panels rather than their weight.

http://solarenergy.net/News/tackling-risks-solar-panels-pose...

I care little about the house in a fire. I do care about its occupants, and also the safety of the firefighters attempting to extract anyone still inside.

I've not encountered discussions of solar panels in firefighter training, but my intuition suggests it's probably not a big deal. For nighttime fires, the panels won't be generating any electricity anyway. For daytime fires, smoke and water will likely occlude the panels and decrease their voltage. Firefighters ventilating the roof would need to be trained to avoid HVDC wires connecting a series-connected panel array to the inverter. We might also just lob foam onto the panels and turn them off that way.

Three layers of asphalt shingles (which many houses have) is a lot heavier than solar panels. Firefighters assume residential roofs to be generally pretty crappy in a fire. Their decision to enter will be based more on the extent of the fire and whether they believe anybody's in the house who can be saved.