Solar Panels: In the Line of Fire

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As more rooftop solar arrays are installed on residential and commercial buildings, firefighters are faced with new challenges when a blaze erupts. But with the proper training and preparation, these new hazards can be safely mitigated. A massive fire erupted in early September at the Dietz & Watson distribution center in South Jersey, a 300,000 sq

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solar_dave

Re: Solar Panels: In the Line of Fire

I had APS out about 2 weeks ago to remove a lock on my AC disconnect so I could fix the conduit issues I was having with the flex conduit. He told me that if a fire breaks out the fire departments are now not fighting them at all because the DC on the roofs will still be live no matter what they do. He said the insurance companies are not happy but have little say in fire fighter safety.

BTW while the lock was off I had the wiring all upgraded from the AC combiner to the back-feed break with #4 in anticipation of a solar add in the future.

The first shot is the new hard conduit that was a replacement for the flex and the second was the fail flex connector.

Cariboocoot

Re: Solar Panels: In the Line of Fire

Right. Building is burning but they're afraid of a little electrical spark?

Pull the other one, it's got bells on.

solar_dave

Re: Solar Panels: In the Line of Fire

Cariboocoot wrote: »

Right. Building is burning but they're afraid of a little electrical spark?

Pull the other one, it's got bells on.

He said there have been 2 cases where they let the building go because of the roof mounted solar. The did do a minimal amount of interior fire fighting, but refused to do the roof at all. I suppose there might be some validity to what he was saying. Most grid tie PV are at pretty hefty DC voltages and a fair amount of amps.

Cariboocoot

Re: Solar Panels: In the Line of Fire

I think they should be more worried about the mower gas and BBQ propane stored in the garage.

solar_dave

Re: Solar Panels: In the Line of Fire

Cariboocoot wrote: »

I think they should be more worried about the mower gas and BBQ propane stored in the garage.

Or the gun powder stored in the reloading room! LOL

sunbunny

Re: Solar Panels: In the Line of Fire

We were told several years ago that the Coast Guard would not assist in the suppression of a fire on a boat with a propane tank.
I'd say that covered the majority of them.

If they covered the PV panels with foam, they should no longer be 'hot', right ?

Cariboocoot

Re: Solar Panels: In the Line of Fire

Yes; it's pretty easy to 'shut down' a GT array without touching a wire.

A system with batteries is a bigger issue, as the inverter output will remain 'live' as long as there's battery power and nothing in the circuit has burned through.

bill von novak

Re: Solar Panels: In the Line of Fire

solar_dave wrote: »

I suppose there might be some validity to what he was saying. Most grid tie PV are at pretty hefty DC voltages and a fair amount of amps.

Agreed. The odds of having a problem are low but they are there.

Could the use of segmenting combiners mitigate the risk to firefighters? If firefighter organizations decided they were OK with the additional safety that a segmenting combiner affords, that might solve the problem for some installs at least.

firerescue712

Re: Solar Panels: In the Line of Fire

I gotta chime in on this one. I understand the firefighters' concern. Education should remedy this situation. A heavy tarp placed over the panels would "turn off" the power generation. I have seen tests that set a roof on fire with solar panels on it. The panels burned furiously due their chemical composition. This added fire load caused the roof to burn so hot and so quick that it collapsed within a few minutes. If the roof and panels are not on fire, cover the panels and forget about them. I agree with Coot. The battery systems are the ones to worry about. I have often wondered how i could set up a disconnect on the outside that would kill the power inside. There is no real answer to this without spending big bucks. Putting foam sounds like a good idea, but the foam will just slide off of the hot panel surface. Education and practice is what is needed.

niel

Re: Solar Panels: In the Line of Fire

as far as i'm concerned their fear and ignorance could and does cost lives and property loss and not the solar. even if there is 600v across the pvs, one cut with wire snips and a welding ding on them kills it. use pry bars to force one pv out off of its mount and access is gained with no fear of shock when you snip the wires at the junction box on the back of the pv. the current and voltage on pv systems i won't say can't be lethal, but far less of a problem than utility stuff.

now as to battery backed systems the inverter is not a problem as by now it is water logged and blown out anyway. the batteries are unlikely to be too much of a problem either unless somebody shorts them out. no different than an auto garage with batteries around. shock from batteries is definitely not a problem unless they decide to put their tongues on the leads.

the article went gaga over the roof load too, but when firefighters go on a roof with even heavier hvac systems they don't get all scared and fearful over them.

as i have said many times that although pvs pose a delay they don't pose an immoveable object. nobody is going crazy because metal roofs cause a delay in access.

i contend that should they be that ignorant and fearful that they endanger lives or property as a result that i would sue, for they then have no place being firefighters being stupid and scared. that isn't what they are paid for. going through pvs is not the high risk they make it out to be due to fear and ignorance.

Cariboocoot

Re: Solar Panels: In the Line of Fire

Perhaps manufacturers and retailers of solar equipment could have a little organization to promote and educate on solar? A few videos of chopping through a 600 Volt GT array wire, hacking off aluminium mounts, that sort of thing.

We need facts out there, not lies. (I will not use the spin-term "disinformation".)

Slappy

Re: Solar Panels: In the Line of Fire

A simple way to shut the panels down is just toss a rock at them and it is done and over with even with a series panel set up. Example ....10 panels in series bust every third one?

solarix

Re: Solar Panels: In the Line of Fire

I say this is more fear and ignorance of new technology plus more "special treatment" given to solar. When plastic was invented and homes filled up with new materials which when burned caused all kinds of toxic smoke, did the firefighters refuse to fight those fires? No, they adapted by using breathing apparatus. Yes, society changing to solar as a clean, unlimited power source is going to cost - and one of the costs is going to be firefighters learning a little about how to deal with it (maybe how to protect this high cost part of a building). Another cost is for architects to change roof styles to accommodate solar efficiently instead of all the chopped up little weird roof shapes they've been calling beautiful the past couple decades. I've already had a meeting with my local fire department's training guy (who was clueless about solar) and got him on my side to understand how they can easily handle solar in a fire and not to flip out over it.

solar_dave

Re: Solar Panels: In the Line of Fire

solarix wrote: »

I say this is more fear and ignorance of new technology plus more "special treatment" given to solar. When plastic was invented and homes filled up with new materials which when burned caused all kinds of toxic smoke, did the firefighters refuse to fight those fires? No, they adapted by using breathing apparatus. Yes, society changing to solar as a clean, unlimited power source is going to cost - and one of the costs is going to be firefighters learning a little about how to deal with it (maybe how to protect this high cost part of a building). Another cost is for architects to change roof styles to accommodate solar efficiently instead of all the chopped up little weird roof shapes they've been calling beautiful the past couple decades. I've already had a meeting with my local fire department's training guy (who was clueless about solar) and got him on my side to understand how they can easily handle solar in a fire and not to flip out over it.

I would be interested to hear what you discussed with him. Perhaps you could get a side endeavor going to train FF in AZ about solar.

bill von novak

Re: Solar Panels: In the Line of Fire

Slappy wrote: »

A simple way to shut the panels down is just toss a rock at them and it is done and over with even with a series panel set up. Example ....10 panels in series bust every third one?

At a drop zone we had a student drop a ripcord at 5000 feet. It went straight through the panel. The string kept providing power. (48V system)

Just breaking panels doesn't ensure shutdown.

niel

Re: Solar Panels: In the Line of Fire

bill von novak wrote: »

At a drop zone we had a student drop a ripcord at 5000 feet. It went straight through the panel. The string kept providing power. (48V system)

Just breaking panels doesn't ensure shutdown.

i agree with you bill as it is better to snip a wire to break the string's circuit and then when the pv is pried free then reach to snip the wires at or near the adjacent junction boxes to insure against accidental contact being made. i admit i ran through my previous explanation too fast, but all got my point.

pvs are made with safety type glass so the cells behind the glass may or may not break far enough to break the circuit. i guess this also is an endorsement for pv clearance above the roof as the firefighter would need to be able to reach a wire to snip it. worst case they don't snip it and hack at removing the pv it will spark like crazy if the circuit was active, but what is the worst that would happen? highly unlikely it starts the roof on fire (and with the house already burning and the fireman right there it is not a real problem imo), but it can put welding dings on their pry bar before gaining access to the wires under the pv to snip them?

bill von novak

Re: Solar Panels: In the Line of Fire

niel wrote: »

worst case they don't snip it and hack at removing the pv it will spark like crazy if the circuit was active, but what is the worst that would happen?

Electrocution and death I would imagine. 400 volts DC is a lot worse than 240 volts AC - especially on a wet roof.

niel

Re: Solar Panels: In the Line of Fire

bill von novak wrote: »

Electrocution and death I would imagine. 400 volts DC is a lot worse than 240 volts AC - especially on a wet roof.

not with gloves on and the cutters are what is in contact with the wire and cutters have insulation on the handles too. yes, they have to be careful, but it isn't gloom and doom to do that. far worse i think to enter a building that is on fire. ftr, i have been both shocked with 30kv and burned by fire in my lifetime and i have no qualms about snipping a wire even with 600v on it. i won't go into a burning building.

Cariboocoot

Re: Solar Panels: In the Line of Fire

"Cover and Cut" ought to do it.
A little information will go a long ways to alleviating a lot of anxiety.

bill von novak

Re: Solar Panels: In the Line of Fire

niel wrote: »

not with gloves on and the cutters are what is in contact with the wire and cutters have insulation on the handles too.

Agreed with all that. But a typical firefighter might not have the tools/expertise to do that, and thus might be told "stay off the roof until we get the specialist up there." (And if there's no specialist just avoid the roof altogether.)

yes, they have to be careful, but it isn't gloom and doom to do that. far worse i think to enter a building that is on fire.

I suspect fire fighters see it the other way. Generally the less familiar someone is with something (fire fighting, electricity) the more worried it will make them.

niel

Re: Solar Panels: In the Line of Fire

bill von novak wrote: »

Agreed with all that. But a typical firefighter might not have the tools/expertise to do that, and thus might be told "stay off the roof until we get the specialist up there." (And if there's no specialist just avoid the roof altogether.)


I suspect fire fighters see it the other way. Generally the less familiar someone is with something (fire fighting, electricity) the more worried it will make them.

gloves are available to firefighters and anybody can put heavy duty wire cutters onto the truck's supplies so a specialist to cut a wire is nonsense to me.

your 2nd point is exactly what i was talking about as they let something they are uneducated about bring up fear in them unnecessarily. ignorance and fear. these are not qualities for a firefighter. now the ignorance part may not be their fault as they need educated on this just as they are educated in other areas.

bill von novak

Re: Solar Panels: In the Line of Fire

niel wrote: »

gloves are available to firefighters and anybody can put heavy duty wire cutters onto the truck's supplies so a specialist to cut a wire is nonsense to me.

Really? If the metal part of the cutter is resting against the frame as you are cutting it, can you guarantee that nothing will happen? How about a partial cut, or a cut end that is released to lie against the frame? Where do you cut it to guarantee no dangerous potentials for a one string system? A three string system?

your 2nd point is exactly what i was talking about as they let something they are uneducated about bring up fear in them unnecessarily.

Fear of dangerous things that you do not understand is a quite valid fear. If there are people out there not comfortable around high voltage DC circuits I would recommend that they don't screw around with them.

I'm comfortable climbing around the outside of an aircraft in flight. Most people would be afraid of that, quite rightly - because a fall would kill them. Since I am a pilot and a skydiver it's not as dangerous for me.

ignorance and fear. these are not qualities for a firefighter. now the ignorance part may not be their fault as they need educated on this just as they are educated in other areas.

I'm all for education - but I am even more for people not screwing around with what they do not understand. Of all the mistakes I have seen in solar installations, the people who think "this isn't that hard; if I wired a car stereo I can do this" make the biggest (and most dangerous) mistakes. They would be better off with more education - or, failing that, would be much better off not screwing around with it to begin with.

niel

Re: Solar Panels: In the Line of Fire

that is what i was saying that they need trained and there is no excuse for them not to be properly trained in my view. if they grounded the cutters it's because they didn't know what they were doing or were careless. this is not as complicated as being outside an aircraft in flight. it is their job to know what to do with things they can encounter. do they stop going on a roof because there is electric going to hvac units? these are 240vac and usually much heftier amperage. oh and don't tell me they kill the ac electric first because i've watched many first hand fail to do that. put it into perspective as these guys aren't supposed to be joe blow off the street going into situations blindly and the fear is unfounded based on my comparisons to hvac. none of them give the hvac a second thought as being hazardous in any way and that laxness is what will get them killed when they do have the education or should know better.

firerescue712

Re: Solar Panels: In the Line of Fire

OK. If this is such a concern, those concerned solar specialists need to step up and help teach. There are no courses or classes in the fire service concerning solar PV fires and disconnects. The panels on the roof add weight, and a lot of it. A roof is weakened as a structure burns. As it weakens, the weight it can bear drops dramatically. If the fire breaks through the roof and catches the panels on fire - BIG FIRE. Search the internet for pv and roof fires. The panels burn ferociously. I am not scared or in fear of working on a roof of a burning structure. With the newer electric cars, new training had to be formulated to teach the firefighters where they could safely cut into the car bodies and not get electrocuted. It is the same with solar installations. Niel, I know you are well versed in solar. Come up with a training class in this and present it to your local fire department, insurance companies, and fire academies. The National Fire Academy would probably the thrilled for someone to set this up.

About the electrical systems energized during a structure fire. I have been in many houses where the electrical system was still energized. Solar is no different than commercial power. If you inverter is not in the area of the fire, there will be no water applied anywhere near this area. This allows the inverter to continue to produce AC power through the circuits until a breaker finally trips, or someone with knowledge of the whereabouts and operation of the disconnect is on hand. Shutting off the main breakers or pulling the electric meter is common for a structure fire. If none of these are in visible on the exterior of the structure, the firefighters have no way of knowing how to disable the AC circuits without venturing into a structure they are unfamiliar with and look for the shutoffs inside. This takes precious minutes to do. The fire is building as this operation is completed. Think of solar like this...it is a generator somewhere inside a structure providing power to the electrical circuits. Only the people that are familiar with that particular setup know where it is, how it is configured, and where it can be shut down. Would you be willing to put your life on the line to go crawling through a smoke filled building to find it and try to figure out how to shut it down? I have been a firefighter since 1978. Life is worth more than a structure. You can rebuild the structure, You cannot bring back the life. Firefighters go against the odds at every call. Most of the time, they are lucky. Some of the times, the odds are not in their favor and they pay the ultimate price. A majority of fire departments are volunteer. Many of these firefighters get no pay for their service. They have a job and a family. They do this because they have a compassion to help those in need. They also need help. No one can know everything. It takes sharing of information both directions.

Sorry for the long post. Firefighters do not LIKE to allow structures to burn down. They do like to live to see their families and friends again. Safety is number one. With training, everything is made safer. I ask anyone out there to help the fire service by teaching them about solar PV, hydro, and wind systems.

Be safe.

niel

Re: Solar Panels: In the Line of Fire

firerescue712 wrote: »

OK. If this is such a concern, those concerned solar specialists need to step up and help teach. There are no courses or classes in the fire service concerning solar PV fires and disconnects. The panels on the roof add weight, and a lot of it. A roof is weakened as a structure burns. As it weakens, the weight it can bear drops dramatically. If the fire breaks through the roof and catches the panels on fire - BIG FIRE. Search the internet for pv and roof fires. The panels burn ferociously. I am not scared or in fear of working on a roof of a burning structure. With the newer electric cars, new training had to be formulated to teach the firefighters where they could safely cut into the car bodies and not get electrocuted. It is the same with solar installations. Niel, I know you are well versed in solar. Come up with a training class in this and present it to your local fire department, insurance companies, and fire academies. The National Fire Academy would probably the thrilled for someone to set this up.

About the electrical systems energized during a structure fire. I have been in many houses where the electrical system was still energized. Solar is no different than commercial power. If you inverter is not in the area of the fire, there will be no water applied anywhere near this area. This allows the inverter to continue to produce AC power through the circuits until a breaker finally trips, or someone with knowledge of the whereabouts and operation of the disconnect is on hand. Shutting off the main breakers or pulling the electric meter is common for a structure fire. If none of these are in visible on the exterior of the structure, the firefighters have no way of knowing how to disable the AC circuits without venturing into a structure they are unfamiliar with and look for the shutoffs inside. This takes precious minutes to do. The fire is building as this operation is completed. Think of solar like this...it is a generator somewhere inside a structure providing power to the electrical circuits. Only the people that are familiar with that particular setup know where it is, how it is configured, and where it can be shut down. Would you be willing to put your life on the line to go crawling through a smoke filled building to find it and try to figure out how to shut it down? I have been a firefighter since 1978. Life is worth more than a structure. You can rebuild the structure, You cannot bring back the life. Firefighters go against the odds at every call. Most of the time, they are lucky. Some of the times, the odds are not in their favor and they pay the ultimate price. A majority of fire departments are volunteer. Many of these firefighters get no pay for their service. They have a job and a family. They do this because they have a compassion to help those in need. They also need help. No one can know everything. It takes sharing of information both directions.

Sorry for the long post. Firefighters do not LIKE to allow structures to burn down. They do like to live to see their families and friends again. Safety is number one. With training, everything is made safer. I ask anyone out there to help the fire service by teaching them about solar PV, hydro, and wind systems.

Be safe.

firerescue,
that's a nice complement to me, thank you for that. now i'm saying i'm confident enough that i could evaluate and do it if i deemed it doable, but i'm not the expert in this area as i believe a top level electrician with strong backgrounds in fire and solar (leaves wiles out) may do this better for the guidelines. even pv manufacturers can and should be involved in this to give their input as i don't know the various flash points of pvs with differing materials in them. even manufacturers of solar equipment should be in on this too as it was one of the guys at midnite that told me if water hits an inverter inside it would destroy the thing as it would fault and stop the output.

now should pvs be fully involved then i'm supposing you've already got your hole in the roof letting fire through it to catch the pvs on fire. in my opinion the roof is too hot and may be too far gone to trust walking on it so why worry about going through the pv now, but that's only my opinion. btw at that point i seriously doubt these pvs are producing power. in fact to add there's no way in he double toothpicks they're producing when on fire.

you state that pv is on par with utility power and i disagree. now i concede that in big systems this could be true in some cases, but usually not for most. for example a 10kw pv system with produce 240vac at about 41a. seems sizable, but disabling the utility ac stops that full power from being realized. most of you know this already. now what you don't seem to know is that the pvs are in strings. the most power anyone can be exposed to is what is in the string you are cutting the wire on as the power from any other string cannot backfeed through the string you are cutting. this can be still sizable, but is in no way comparable to the utility and of course we are talking of a central inverter here as the type on ac panels (never did like that term) is moot because the inverters there also have anti islanding. so if the 10kw system has say 3 strings each at 3.33kw then that is the limit one can be exposed to and this may be a good rough real life figure for such an example. 3.3kw with 450v gives a potential current of about 7.33a. (600v is max most inverters can work at without blowing so most design lower) reminding again that water will destroy a working inverter and disable it unlike the power coming in from the poles. i will grant you that one may not know if and when that inverter would trip so i won't press this that far as only inverter manufacturers can elaborate on this as my info to you can be considered second hand.

see i told you more than you knew and i can't say i'm expert enough to give guidelines to all firefighters on this only that i could confidently do it myself. i also don't expect them to go in blindly and is why some education is needed. my own father was a volunteer for some time too and even volunteers get training as towns need to carry insurance on them as they are still doing a job for the town although unpaid. it is a good thing that nobody get hurt as this benefits nobody, but to tell me i've got 2 pvs on my roof and they're too scared to put out a fire at my house with a let it burn attitude would bring about a lawsuit from me.

SolarPowered

Re: Solar Panels: In the Line of Fire

Most firefighters in California are trained to shut off DC and AC disconnects.
Local fire jurisdictions actually dictate how we build solar on a commercial scale. Fire departments approve the open roof vent shaft opportunities where we cannot build solar at designated areas of the roof and in most cases have to leave a 3' wide open egress path to that venting opportunity. Fire departments also approve parking lot structure height of all public and private PPA projects, so that the fire trucks can pass through, along with submittal of parking structure elevation, a layout of where each disconnect is provided for shut down has to meet approval.
In California the local fire department has to approve before the city engineers will even accept the drawing sets. Why other state jurisdictions haven't adapted to this yet just blows my mind.