Solar Panel DANGERS!!!

[1900]

Hey All,

This was an email sent to me...

Subject: Solar Panel System Dangers

Everyone -

As I had mentioned at this past Monday's Twp. Chief's meeting, I went to the presentation put on by the State of NJ last night at Amwell Valley Fire concerning solar panels and the danger they present to the Fire Service.

The presentation lasted for about 2 1/2 hours and was what I believe time well spent. It really opened my eyes to the potential danger and problems they will be for us for any dwelling fire we will encounter where they are present. I'm going to attempt to give everyone a quick snapshot of what was covered.

The thing to know with solar panels are that they cannot be shut down - they are ALWAYS ENERGIZED. And they are energized with up to 600 volts of DC current. For example, you cannot put an ax through them to open up a roof to vent - your putting the ax through 600 volts. If fire is infringing upon solar panels on the roof it will compromise the integrity of the panels. You then have 600 volts of live electrical energy - and what don't you do when you have live electrical energy? - you don't put water on it. Even if the roof burned through and the panels fell into the structure, unless the panels were destroyed (de-energized) by the fire and/or falling into the structure, they are still have the potential to be live, have to be treated as such and have the potential of 600 volts of DC current.

A basic solar system consists of: The solar panels themselves; a combination box; a disconnect box; and a inverter. The panels all feed into a combination box. The combination box (which is almost always located on the roof) takes in all the energy and sends it to a disconnect box. The disconnect box takes the energy and then sends it into the inverter which converts the DC current into AC current. From there the AC energy "pushes" into the structure's normal electrical system.

The combination box has fuses in it that come from the solar panels themselves. If you access that box, you can pull the all the fuses inside and "kill" anything after the combination box. But remember the panels are still live and have up to 600 volts in them. If you "kill" the energy at the disconnect box - anything up to that box is still energized - the solar panels, the combination box, the line going from the combination box into the structure and into the disconnect box are all still energized. The power company pulling the meter for normal service has no effect whatsoever on the solar panel system - it is all still live and has up to 600 volts of DC current. The only "good" thing when it comes to the disconnect box and the inverter is that they need to be co-located with the normal service panel for the structure and each should be marked as appropriate.

Even if it's nighttime and the solar panels have not been exposed to direct sunlight for several days, they still are energized and can kill you. It is estimated that the panels would need to be covered with an opaque tarp for 7-10 days before the panels will "de-energized" down to minuscule levels. (although the handouts specify that this as an option for safety steps - it is not accurate per the presenter)

In closing there are people who have greater minds and resources than we do in developing a process to safely handle fires which may involve these systems - such as the NFPA, OSHA, etc. Per the presenter, the situation - and these organizations, are now starting to become aware of the potential problems. So far in the State of NJ, there is no recorded injury to a Firefighter being caused by coming into contact with a solar panel system. Ironically, New Jersey comes in 2nd when it comes to solar panel system installations in the nation, behind Califorina.

The final question which was asked really put things in prospective - someone asked that since Califorina is number one when it comes to Solar Panel Syatem installations, "...what do their Firefighters do when a structure fire involves these systems?" Answer was "... they let it burn!"

Please, I'm not suggesting that we adopt this strategy. But the reality is - I really don't have an answer and it seems as if the Fire Service industry, nor the Solar Panel Companies, don't either.

Just - please be aware and please be careful if you roll up to a structure where a solar panel system is installed - bottom line, if can kill you.

Take care,

Jack Leechan


PS - I have the handouts if anyone would be interested.

PPS - I'm sending this to everyone I know who are in my e-mail contact list who I think have a need to know.

[papacheese]

Good stuff, Chief...thanks for passing that along.

[voyager9]

Dec 18, 2008 3:05:13 GMT -5 1900 said:

Even if it's nighttime and the solar panels have not been exposed to direct sunlight for several days, they still are energized and can kill you. It is estimated that the panels would need to be covered with an opaque tarp for 7-10 days before the panels will "de-energized" down to minuscule levels. (although the handouts specify that this as an option for safety steps - it is not accurate per the presenter)

7-10 days?? Jebus! I wonder why the panels are designed for that kind of long-term storage.. unless it has something to do with the material used. I can't think why they'd purposely add a capacitor/battery of that size to the panels.. I would think any filtering/storage would be done at the breakout box... odd.

[1900]

Here is a link that Scotty (thecutman) found...

www.city.newport-beach.ca.us/Fmd/Guidelines%20for%20Publication/D.04-Solar%20Photovoltaic%20Systems%207-10-08.pdf

[voyager9]

Here's another one from the CA State Fire Marshall's office.
osfm.fire.ca.gov/training/pdf/photovoltaics/lp06emergencyresponse.pdf

It's harder to read, though.. appears to be set up as a course synopsis. It does mention that the PV cells won't produce power at night but could in all conditions during the day time. Specifically:

E. Where there are accessible system disconnects at the inverter, battery controller, and battery bank these
too should be locked out and tagged out as an extra measure of electrical safety

F. Realize that in day time firefighting operations the solar panels are still generating electricity

G. Care should be taken not to cut into or walk across the PV modules or array

H. Breaking through the protective glass could potentially release all of the energy inherent in the entire PV system. You cannot effectively block all the sunlight with foam or salvage covers during a day time operation

K. During night time operations you do not have to worry about the PV system generating electricity

L. Use of spotlights during an evening operation is not bright enough to generate electricity from the PV system

M. However, the brightness of a lightening storm could send a surge
of power though the system

O. If conduits and wires are cut into during an evening firefighting operation, they could become energized by the PV panels in the daytime exposing personnel to potential shock or reigniting a fire via an electrical short

[thecutman]

Voyager,

I have recently spoken with Randy Slaughter who wrote this program for the power company. You are correct about not producing power at night. However during a thunderstorm these units can produce power during a lightning strike. The one thing that we need to do is operate on the other side of the roof and stay away from the solar panel side.

[thelurker]

COPIED FROM THE SECRET LIST

Hey....
Regularly, "stuff" floats around the Internet that is less than technically accurate. Surprise. But it happens.
Look, we aren't talking about the mayor who said this week, that since they haven't lost anyone in his town in a fire, he could drastically reduce services and staffing...which is what we call "soon to be inaccurate"
Nope, this time it is about solar panels and firefighting operations.

While we didn't originally send anything about this on The Secret List, we did have some information that was sent to us as a submission that we posted on the website-and the info was inaccurate. Many of your probably saw the e-mail "floating around" on the "solar panel" issue as well. Due to the amount of submissions that come into www.FireFighterCloseCalls.com, it is impossible to not have something slip through once in a while, albeit rarely. We have always taken technical accuracy extremely seriously since we started The Secret List and the FFCC website 11+ years ago and we do our best.

We are fortunate and appreciative to have alotta readers. One of them is a San Jose (CA) FF. A FF who teaches classes on FF Safety related to PV (photovoltaic) systems, who has a degree in Solar Technology, and is also a member of the California State Fire Marshals PV Task Force. While we heard from many in the manufacturing community about this issue, we were very glad to hear from Fire Engineer Matt Paiss of the San Jose FD who wanted to offer some "firefighter" clarity to this discussion. It is an area we all need to be aware of, but as is often the case; a few misconceptions can create miscommunication.

We will turn this over to Matt so he can provide his training and knowledge to address the issues one by one so you can develop your own FD SOP:
1. Panels are only energized in daylight. Overcast days too, but NEVER at night. Scene lights will NOT energize the panels.
2. If the panels, or the roof are on fire, you will not get shocked by spraying water on them. Put the fire out.
3. The voltages of panels are anywhere from 24-48 volts each and generate from 125 to 200 watts in optimal conditions.

These panels are "strung" together in series to increase the voltages to 120 vdc to 400 vdc. While 600 vdc is possible, it is pushing the UL ratings of the enclosures, etc.. The current of these strings is usually from 5-9 amps. And that is only when there is a load (or put more simply, the inverter is sending the power back into the grid). If the inverter is off, there is no current only voltage, i.e. open circuit.

4. The inverters that change the power from DC to AC, are powered by AC. If you shut off the main service breakers, the inverter is OFF and there is NO AC power being sent into the structure. There are capacitors in the inverters that can hold a charge for about 5 min, but in the daytime the panels are producing power anyway. When the sun goes down....everything is de-energized.

FIREFIGHTER WARNING:
There is ALWAYS energized DC power in the conduit from the panels to the inverter IN THE DAYTIME. So, secure all utilities (per SOP's) and stay away from the panels and the conduit in the daytime. That is the danger.

5. Do not break a panel with your axe or related forcible entry tools. Each panel in the string could be carrying the FULL VOLTAGE of that string (120-400 VDC), not just one panel, so if you put a tool through it, you will very likely be getting the rest of the shift off....so don't do it....there is no need to do it, vent somewhere else, and kill the utilities at the main panel based upon your SOP's.

6. There are often junction boxes on the roofs (residential systems). If they do have fuses (not all do), and you pull a fuse while under load, you will very likely cause a fire. Not to mention the time it will take to open the box and do this. Bad idea-leave it alone.

7. In California, we will not let a house burn because it has PV Panels on the roof. I may not be able to put my hole in the best place, but I will put one in where I can when required.

Thanks Matt.

If you have any questions or comments for Matt, he can be reached thru our submissions page:
firefighterclosecalls.com/submit.php
Firefighters and Officers should do their best within their own FD SOP's, to know where in their 1st due area they have these panels...thru pre-planning. Once they are identified, determine the plan before the fire and do followup thru the installer/mfg of the panels. We will also have links to a video and related info posted soon so you can further learn and followup.
Take Care-BE CAREFUL.
BillyG
The Secret List 1-7-09 / 2246 hours
www.FireFighterCloseCalls.com