INSTALLATION, FIRE, PROPERTY DAMAGE,
ENVIRONMENTAL DAMAGE AND OTHER LIABILITY RISKS ASSOCIATED WITH SOLAR PANEL SYSTEMS
Green Job Hazards: Solar Energy
Solar is a growing
sector for green energy and green jobs. Various worker health and safety
hazards exist in the manufacture, installation, and maintenance of solar
energy. Employers working in the solar energy business need to protect their
workers from workplace hazards and workers need to understand how to protect
themselves from hazards.
Two commercially
viable solar energy sectors are solar electric and solar thermal or solar water
heating.
Solar Electric
Solar energy can be
converted into electricity using photovoltaics (PV), or concentrating solar
power (CSP). PV systems are the most
common and use semi-conductors and sunlight to make electricity. The more solar modules a PV system or array
has, the more electricity will be generated. Materials presently used for
photovoltaics include monocrystalline silicon, polycrystalline silicon,
microcrystalline silicon, cadmium telluride, and copper indium
selenide/sulfide.
Solar Thermal or
Solar Water Heaters
Types of solar water
heating systems include direct and indirect (Glycol) systems and are chosen
largely by climate; freezing temperatures can damage some types.
Hazards and Controls
Workers in the solar
energy industry are potentially exposed to a variety of serious hazards, such
as arc flashes (which include arc flash burn and blast hazards), electric
shock, falls, and thermal burn hazards that can cause injury and death. Solar
energy employers (connecting to grid) are covered by the Electric power generation, transmission, and distribution standards and therefore may be
required to implement the safe work practices and worker training requirements
of OSHA's Electric Power Generation, Transmission and Distribution Standard, 29
CFR 1910.269. While solar energy is a growing industry, the hazards are not
unique and OSHA has many standards that cover them. This page provides
information about some hazards that workers in the solar industry may face.
Fatalities/Incidents
There have been
fatalities and incidents in the solar energy industry.
Resources
Property Damage Risks Associated with Solar
Panels
Solar installations
are increasing exponentially due to increasing energy prices and decreasing
solar panel hardware and installation prices, which are decreased further by
government subsidies. Furthermore, the power generated by a solar installation
can be sold back to the electrical grid. If you fall into any of the following groups,
however, a solar installation may pose additional risks that you will need to
address:
·
Building
owner
·
Homeowner
or condominium owner association
·
Apartment
building owner or resident
·
Solar
array seller (wholesaler, lessor or retailer)
·
Solar
system installer
·
Fire
department
·
Electrician
·
Roofer
·
Maintenance
staff
·
Others
who require access to the roof
Photovoltaic solar
panels rarely cause house fires directly, but the potential hazards they pose
in the event of a house fire can be mitigated with proper installation and
preparation.
This article
pertains to photovoltaic (PV) solar installations, which turn sunlight into
electricity in a PV cell. It does not
address thermal solar installations, which heat a fluid in pipes or tubes
(e.g., solar hot water heaters). While
there are potential dangers associated with both types of systems, the PV
systems are giving rise to greater confusion and concern among owners, fire
departments and others who come in contact with them.
Solar installations
may have implications for your property, general liability and workers’
compensation insurance. If you are a
seller, installer, maintenance firm or lessor, there are potential implications
for your products liability and completed operations insurance.
Property - Solar
panels can be damaged by fire, hail, wind, snow and ice loading, water and poor
roof drainage. The cost to replace these systems may be significant. One estimate is in excess of $25,000 for a
2,500 square foot home where the homeowner does the repairs (based on a
$25,000, 10.2 kW tied-grid system from a major retailer as of November 7, 2014).
An emerging problem
that may increase the fire hazard associated with these systems is the
reluctance of firefighters to attack fires at homes or business with solar
panels on the roof. One recent case in
Delanco, NJ in which a fire department with-drew was newsworthy due to the size
of the fire and the building’s solar array. A 268,000 square foot warehouse contained 35
million pounds of meat and had PV solar panels that completely covered the
roof. Due to the size of the solar panel
array, the fire department could not effectively attack the fire because they
could not open up the roof to ventilate the structure while posing the threat
of electrocution. They needed 24-hours
to control the blaze and nine days to extinguish it completely.
While it’s unknown
what the loss would have been had there been no panels on the roof, numerous
fire officials have stated that the only reason they could not get on the roof,
or otherwise approach the fire, was the panels. The fire resulted in a total loss to the
building (which has since been demolished) and its contents. There also was possible environmental damage
and neighboring hostile fire losses. While
this one incident cannot predict future fire department responses, it is worth
noting due to the rapid growth of solar installations.
New Jersey state
legislators responded to the above fire incident by passing a law requiring
building owners to disclose to fire officials if such a system is in place.
One- and two-family residences are exempt under the law.
In the past decade,
firefighters had begun to encounter rooftop solar panels, but didn’t know much
about how to handle them when the home or building was on fire, Willette said.
So after receiving an increasing number of requests from firefighters for
information on how to best protect themselves, the NFPA’s Fire Protection
Research Foundation got funding from the U.S. Department of Homeland Security
to undertake such a research project. Their report [PDF], issued in 2010,
outlined not just the risks, but best practices for emergency response.
One year later,
safety-testing group Underwriters Laboratories followed up with extensive lab
research at their Northbrook, Ill. campus. The organization tested a range of
materials on solar PV emergency fire response and issued a comprehensive report
[PDF] released in 2011.
Risks and solutions
identified by NFPA and UL were:
• Electrical shock: Firefighters
coming into contact with solar panels run a risk as the system is generating
electricity from exposure from sunshine, streetlights or the lights used during
nighttime emergency response vehicles. In
sunlight, panels can generate anywhere from between 60 to 120 V of electricity,
according to Matt Paiss, a fire engineer with the San Jose, Calif. Fire
Department. That number is of course a
lot lower during the nighttime, but the solar dangers for firefighters are very
real around the clock.
“There’s a
potentially lethal situation for firefighters, where anywhere from 40 milliamps
(mA) to 240 mA of DC electric current can lock up the muscles and you can’t let
go,” says Ken Boyce, UL’s manager and principal engineer for product safety.
The current could be strong enough where the firefighter could jump back and
fall off the roof, fall into a solar panel, or be strong enough past 240 mA to
cause ventricular fibrillation and cause death. At 70 mA, electrical burns
causing cell necrosis could come into play, according to UL. Even the amount of
light generated from fighting a nighttime fire adjacent to a building with
rooftop PV could generate electricity in the solar panels, Boyce added.
Fire-induced damage
to the arrays can also create new circuit paths as well, the UL report found,
that can flow along the system’s frame and racks, as well as through a
building’s metal roofs, flashings and gutters.
Solutions:
“The question is how to stop the panels from generating electricity,” said
Willette. While one might think that simply shutting the system off will take
care of the problem, it’s not that simple. Sometimes the firefighters don’t know a
structure has rooftop PV panels beforehand—and even if the inverter can be
located and switched off, the panels cannot be turned off, meaning that in most
cases, electricity will still be generated.
Based on the
complexity of this problem, Willette said that the NFPA is currently looking
into how it can revise its electrical code to reflect requirements for improved
labeling for first responders. But these changes would be limited in impact, as
they’d only apply to new systems installed in the future.
Firefighters also
cover panels as a way to stop the generation of electricity in residential
systems. “But if you’re talking about a commercial building or solar farm with
tens, hundreds and possibly thousands of panels, reducing the electrical
generation is impossible,” Willette said.
UL found that
covering a PV panel with heavy, opaque and densely woven fabric can bring down
the amount of electricity close to zero. In fact, any tarp where light can be seen
coming through should not be used, the report advised. But care should be taken to not place wet
tarps in contact with energized equipment as the tarps can then conduct
electricity.
“It’s also incumbent
upon firefighters to wear robust leather gloves,” Boyce said. UL’s study found
that this material was effective in protecting the first responders from
current, but only when dry.
• Density of rooftop panels can be a hindrance:
As a common tactic among firefighters to contain incidents is by opening a hole
in the roof for ventilation, Willette said, the density of solar panels can
make it impossible for firefighters to create that hole.
And if the
firefighter is opening up the hole from below and doesn’t know that solar
panels are installed on the roof, that creates another shock hazard, he added.
“It’s definitely
enough electricity in the larger arrays or commercial systems to possibly cause
cardiac arrest,” Willette said.
Solutions:
As a result, the NFPA’s safety and national electrical codes have required that
a minimum amount of clearance be present. In California, regulations require a
three feet perimeter around the array for firefighter access.
• Weight of panels: In
already-compromised roofs such as during a fire, the additional weight could
cause it to collapse, Los Angeles County Fire Department inspector Scott Miller
told CBS Los Angeles. The panels can also release harmful chemicals when
exposed to fire as well, he said.
Solutions:
The only solution we discovered in the course of reporting this story is to
install fewer solar panels — which isn’t really a solution.
• Lack of communication/notification from home
and building owners: Clear communication—whether through
signage at the front of the building or diagrams showing where the system can
be shut off—would help fire crews determine their emergency response plan as
swiftly as possible.
Solutions:
New Jersey’s law, signed in January by Gov. Chris Christie, requires buildings
to post an emblem at their front entrance to notify firefighters.
Firefighters, in Part, Respond with Trainings
And as a result,
some fire departments in the U.S. are taking action to train their personnel
before it’s too late.
As soon as firefighters
arrive on scene, they are advised to make the determination between solar
thermal panels and solar photovoltaics as each presents a different hazard
(thermal panels pose the risk of scalding from hot fluid while PV panels carry
the risk of electric shock).
During roof
operations, firefighters will need to consider the additional weight of the PV
array on a roof structure that may be weakened by the fire. Care should be taken throughout fireground
operations never to cut or damage any conduit or any electrical equipment, and
they should be treated as energized at all times. One tactic for minimizing or
eliminating the electrical output from a solar module is to cover it with a 100
percent light-blocking material such as certain types of tarpaulin.
Does the solar industry have solutions?
“We recognize that
we need to do a better job as an industry educating first responders,
especially firefighters, about solar panels,” Solar Energy Industries
Association spokesperson Ken Johnson told The Atlantic Cities blog shortly
after the New Jersey warehouse fire.
“We are working very
closely with firefighters across the United States on the developments of codes
and standards,” Johnson explained to Reuters in September. “After every
incident, we learn from it and improve.”
It’s not clear just
what progress has been made since then, as Johnson did not respond to
SolarEnergy.net after repeated requests for an update.
Yet new products
that seek to fill the fire risk gaps are emerging. A new solar panel sensor and
fuse developed in Germany at the request of the Munich fire department (after
the first responders had to let a building covered with rooftop PV burn to the
ground) could be just what firefighters need. Perched between two solar panels,
the TOPInno company product senses when the temperature reaches a certain
threshold. At that point, the fuse will break, TOPInno General Manager Raymond
Huwaë told Triple Pundit.
“The moment the
fuses are broken due to the heat, the voltage will go down to below 120V, which
is the legal requirement to be able to use water to extinguish the flames,” he
said.
The sensors/fuse
product can also be turned off manually as well.
Boyce says though he
sees momentum within the solar industry to address the fire risk issue, it’s
currently in a transition period so that products being released in the
marketplace will be in compliance with new regulations.
One bright spot is
in California, where CalSEIA has been working with the state fire marshal on an
interim solution to the UL 1703 fire code that regulates how a rooftop PV
system impacts the fire classification rating of the roofing material below it.
CalSEIA has also held a webinar on this topic for the solar industry to
understand the code’s meaning, and how it can come into compliance, according
to Executive Director Bernadette Del Chiaro.
“We just recently
issued our first certification [under the UL 1703 fire code],” Boyce said, “so
that’s exciting news for the code community. They’re excited to see this
implemented with CalSEIA and others, and help them roll it out in the future.”
Hail Damage to PV
Panels. As of the date of this article,
solar panel manufacturers were not required to build solar panels with hail
impact resistance. The market is
changing quickly, however, and most moderate to high-quality panels are now
being built to achieve improving hail impact resistance standards. Inexpensive
or older solar panels, however, may not have been built to those standards,
since they are not yet required in most juris-dictions. It is important to
verify that panels are labeled for hail resistance in accordance with a
recognized standard, such as UL 1703 (Underwriters Laboratories), IEC 61215, or
FM 4476 or FM 4478 (Factory Mutual). Without adequate hail resistance, it is
highly likely that your panels will be significantly damaged in a hail storm.
Wind uplift is
another hazard associated with PV solar installations. Moderate to high-quality
panels will have been tested against wind uplift, but their susceptibility to
damage is also dependent upon the quality of the roof’s construction.
PV modules can be
manufactured to earthquake standards, such as FM Approval Standard 4478, but
poorly mounted PV systems can compromise a building’s response to an
earthquake, which can lead to greater damages than would have occurred without
the presence of the PV system.
General Liability –
A PV solar installation is most hazardous to those who encounter it in an
emergency scenario or are not aware of its potential dangers. At the roof level,
where the solar panels are installed, there is an ever-present danger of
electrical shock from the stored electrical energy in the panels (see the
graphic below). As sun-light decreases,
so does the electrical energy but powerful spot lights such as those used by
contractors and fire fighters can generate electricity. It is critical, therefore, that emergency
responders, security guards, maintenance personnel (particularly electricians)
and others who access the roof under-stand the potential hazards. It is important
to note that, like any other electrical system, a properly installed and
well–maintained solar panel system is not inherently dangerous but when damaged
or tampered with, it’s like a powerful battery and can cause severe electrical
injury or electrocution.
Workers’
Compensation – The potential hazards stated above may obviously cause injury to
the employees associated with the activities stated. As such, the hazards should also be considered
in a context of WC. First responders,
electricians, maintenance employees, and others whose duties put them in direct
contact with a solar installation may be at risk from the hazards associated
with the system, particularly if it has been damaged or compromised.
There are other
solar installation hazards that can increase your exposure to loss from a
property, general liability, and workers’ compensation perspective. These hazards include traditional fire
exposures; additional building collapse exposures and roof leaks resulting from
the system installation. All of these
hazards can be mitigated by a well-designed, properly installed and
well–maintained system.
Fire Concerns with
Roof-Mounted Solar Panels
As companies look to
reduce their dependence on fossil fuels, many are turning toward rooftop
photovoltaic (PV) power systems, or solar panels, as a source of renewable,
clean energy. However, this technology comes with specific risks. One of the
many dangers to solar panels is how the panel and its mounting system impact
the combustibility of the overall roof system. Some solar panels, for example,
include a backing of highly combustible plastic.
In laboratory-based
fire tests of roof assemblies,1, 2 the maximum allowable fire spread
is between approximately 20 and 40 ft2 (1.9 and 3.7 m2),
depending on whether an A, B or C rating is desired. In actual roof fires with
roof-mounted solar panels, fire damage has involved areas of between 1,000 and
183,000 ft2 (93 and 17,000 m2). In the most extreme case
the fire spread to the inside and destroyed the entire building (see Fig. 1).
Fig. 1. PV roof fire at a refrigerated warehouse in NJ in 2013 (photo
courtesy of Vince Lattanzio, NBC Philadelphia)
While the results of
a lab test and an actual fire are not always identical, such a wide disparity
is reason for concern. Lab tests conducted by at the FM Global Research Campus
in West Glocester, RI, USA, confirm these concerns. For such testing, an ASTM
E108 test apparatus was utilized, placing PV panels over a commonly used, Class
A-rated roof assembly (when the roof alone was tested), starting near the
flame-exposed end. This roof assembly failed the test (see Fig. 2). While only
one failure mode is required by the test standard, in this test all three of
the following failure modes occurred: Fire spread laterally to both edges of
the sample, material continued to burn after falling to the floor, and fire
spread across the 13 ft (4 m) length of the assembly within 90 seconds.
Fig. 2. Fire test of rigid PV panels over Class A-rated roof consisting
of an EPDM cover over polyisocyanurate insulation (photo courtesy of FM Global)
Why did this happen?
Regardless of the materials used in the construction of a PV panel, its mere
presence changes the dynamics of a fire involving a roof assembly. Research
tests done at Underwriters Laboratories3, 4, 5, 6,7,8, 9, 10, 11
demonstrate that even a cement panel simulating the presence of a PV panel will
increase fire spread across a common roof assembly.
There are three key
considerations that affect fire spread along a roof where a roof-mounted PV
array is installed:
In a typical roof
fire, the flame is primarily vertical, or perhaps somewhat slanted due to wind.
Once such flames spread under a PV panel, the flame is redirected much closer
to the roof surface and nearly parallel to it. This increases the incident heat
flux on the roof surface, often above its critical heat flux.
While the exterior
fire classification of a roof is an effective way to rate the exterior fire
performance of roof assemblies, even a Class A assembly will offer some fuel
contribution to a roof PV fire, with most standing seam metal roof systems
being the exception.
While the top surface
of a rigid PV panel is usually made of tempered glass, the bottom of the panel
may contain combustibles (used to protect the PV circuitry) in the form of
polyester-based encapsulants and back sheets (see Fig. 3). If this ignites and
the heat re-radiates, fire spread is likely to continue back and forth beneath
the roof assembly and the PV back sheet.
Fig. 3. The underside of a rigid PV panel (photo courtesy of FM Global)
PV rooftop fires have
been caused by electrical arcs that occurs near the combiner box, where
numerous wires from PV panels are connected. This is a location where there is
considerable voltage, before the current is converted from DC to AC at the
inverter, and where the roof assembly could ignite and result in fire spread
under the PV panels.
Fortunately, there
have been some improvements made by manufacturers during the past few years
with regard to the electrical components that can reduce the potential for
ignition. Some PV panels have micro-inverters on each PV panel, which convert
voltage from DC to AC. This can be expensive, but it reduces the probability of
ignition.
Manual firefighting
efforts also can be hampered by the electrical risk associated with PV arrays.
While minimum 4 ft (1.2 m) wide aisle spaces between panels at a maximum of 150
ft (46 m) apart have been recommended12, this does not alleviate all
the risk. Disconnecting electrical power from the PV array is complicated, and
arrays continue to generate electricity, sometimes even at night. The PV array
and the roof assembly should be designed so their construction limits potential
fire spread and the entire burden for fire protection is not placed on manual
firefighting efforts.
There are
several design choices that can limit fire spread if ignition occurs:
Use a complete system
(PV panels, securement, and roof assembly) that has been tested to simulate
actual field conditions. FM Approval is available,13 which includes
testing for fire exposure as well as wind and hail.
If the existing roof
has aged, it is recommended that a new roof be installed before installing a PV
system. Choose roof assemblies that limit potential fuel contribution in the
event of an exterior fire. Appropriate options include metal roof systems, as
well as noncombustible materials (such as gypsum cover boards, mineral wool or
expanded glass roof insulation) installed directly below single-ply or
multi-ply roof covers. In some cases, coatings may need to be applied to the
top of the roof cover.
Where existing roofs
will remain, investigate the need for a coating to be applied to the top of the
roof cover that will improve performance with regard to exterior fire exposure.
Construction materials that melt at low softening temperatures and can flow
when burning (such as expanded or extruded polystyrene insulation or multi-ply
roof covers) may require protection such as a gypsum cover board installed over
the insulation or a coating over the roof cover.
To prevent an
exterior fire from entering the building, protect building expansion joints by
securing mineral wool or other fire-resistant compressible insulation between
wood nailers, covered by steel flashing.
Evaluate the
potential for fuel contribution from the underside of the PV panel. The
underside of the panel may have a glass backing, aluminum or
fluoro-polymer-based back-sheet as an alternative to a polyester-based
back-sheet.
Most importantly, it
is best to use a PV panel that has passed a fire test with the proposed roof
assembly.
For additional
information, see FM Global
Property Loss Prevention Data Sheet 1-15, Roof Mounted Solar Photovoltaic Panels.
References
ASTM E108, Standard
Test Methods for Fire Tests of Roof Coverings, ASTM International, West
Conshohocken, PA, 2011.
UL 790, Standard
for Standard Test Methods for Fire Tests of Roof Coverings, Underwriters' Laboratories,
Northbrook, IL, 2004.
Backstrom, B. &
Tabaddor, M. "Effect of Rack Mounted Photovoltaic Modules on the
Fire Classification Rating of Roofing Assemblies," Underwriters'
Laboratories, Northbrook, IL, 2010.
Backstrom, B. &
Tabaddor, M. "Effect of Rack Mounted Photovoltaic Modules on the
Flammability of Roofing Assemblies – Demonstration of Mitigation
Concepts," Underwriters' Laboratories, Northbrook, IL, 2010.
Backstrom, B. &
Sloan, D. "Effect of Rack Mounted Photovoltaic Modules on the Fire Classification
Rating of Roofing Assemblies - Phase 2," Underwriters' Laboratories,
Northbrook, IL, 2012.
Backstrom, B. &
Sloan, D. "Characterization of Photovoltaic Materials – Critical
Flux for Ignition/Propagation - Phase 3," Underwriters' Laboratories,
Northbrook, IL, 2012.
Backstrom, B. &
Sloan, D. "Report of Experiments of Minimum Gap and Flashing for
Rack Mounted Photovoltaic Modules - Phase 4," Underwriters' Laboratories,
Northbrook, IL, 2012.
Backstrom, B. &
Sloan, D. "Considerations of Module Position on Roof Deck During
Spread of Flame Tests - Phase 5," Underwriters' Laboratories, Northbrook,
IL, 2012.
Backstrom, B. &
Sloan, D. "Validation of 42” PV Module Setback on Low Slope Roof
Experiments - Project 7," Underwriters' Laboratories, Northbrook, IL,
2012.
Backstrom, B. "
Validation of Roof Configuration 2 Experiments - Project 9," Underwriters'
Laboratories, Northbrook, IL, 2012.
Backstrom, B. &
Fischer, C." Report on Spread of Flame and Burning Brand Performance of
Generic Installations," Underwriters' Laboratories, Northbrook, IL, 2012.
"Solar
Photovoltaic System," Los Angeles City Fire Department Requirement No.
96,Los Angeles, CA, February, 2009.
Class Number 4478,
" Approval Standard for Rigid Photovoltaic Modules," FM Approvals,
Norwood, MA, 2012.
EMERGENCY OPERATIONS Photovoltaic Panels Cumru Township Fire Department
03/31/2014 Standard Operating Guidelines Page: 1 of 2 Section 15.30
15.30 Scope
Photovoltaic panels, commonly known as solar panels, are an alternative
electrical generation system which converts solar energy to electricity. These
systems are known as photovoltaic systems, or simply PV. This system consists
of photovoltaic solar panels and other electrical components used to capture
solar energy and convert it to electrical power. Many systems are roof mounted,
and present hazards to firefighting operations. Strings of photovoltaic modules
are wired together to form an array, which can produce up to 600 volts commonly
in a residential system. Photovoltaic modules are commonly mounted above
existing roof surfaces. These modules and arrays can be powered by sunlight and
by artificial light that could be produced from street lights and fire
department scene lighting. These modules/arrays are then wired to an inverter
that is used to convert the power generated by the PV modules from direct
current to alternating current.
15.301 Guideline
Operating at incidents that involved PV systems may require adjustments
to standard firefighting tactics to mitigate the situation in the safest and
most effective manner.
The primary hazard to firefighters working around a PV system is an
electrical shock. It is important that a thorough scene size-up is complete
that identifies the presence of a PV system. After detecting the presence of a
PV system it shall be important to note of the system itself is involved in the
fire and if it is able to be de-energized. A risk-benefit analysis should be
conducted. Incidents involving a PV system are unique in that components may
remain energized within the structure or on the roof even after all utility supplied
power has been de-energized.
It is important to note, that when controlling utilities, controlling
the power at the electrical box and also at the inverter only controls the flow
of electric from that point forward. All wiring leading from the PV modules and
arrays to the inverter will still be energized if the module is receiving
sufficient light to produce power. A qualified PV technician or electrician
should be called to the incident to de-energize any system that has been
compromised or creates a hazard.
After a size-up is complete the incident commander shall select a
strategy and assess the fires impact on the structure and change strategy if a
delay in attack caused by the PV system results in excessive time loss. The IC
should also consider the presence of sunlight and artificial lighting. The IC
should also consider the additional of the weight added to the roof by the PV
system, especially in light weight truss or wooden I-beam construction could
result in collapse if the fire has sufficiently degraded the roof’s structural
components.
Utility companies should be notified in the event of a working fire to
control the utilities, but the utility company may not be able to control
electric generated from a PV module and/or array. A contractor specializing in
PV may be needed to control the PV system.
When personnel are performing roof operations and overhaul in a
structure that has a PV system extreme care should be taken.
At fires that involved the PV module or an array, water streams can be
directed onto the PV module or array as long as the hose stream originates at
least 25 feet away from the module and/or array and is applied with a fog
pattern set at 30 degrees or greater. Straight streams and foam will not be
used as both are conductors and increase the risk to firefighters.
If roof operations are employed, roof crews should determine
if the PV system components themselves are on fire, or are the PV components
being impinged upon by fire. When working around a PV system that is on fire, firefighters
should use respiratory protection. Roof objectives should be accomplished
quickly and firefighters should then exit the roof, limiting their exposure to
the PV system. Any vertical ventilation required will not be conducted in areas
where PV modules or arrays are present. At no time shall personnel walk on a PV
module.
PV system conduit containing energized conductors on the
roof deck and in attic spaces poses a serious shock hazard to firefighters
performing ventilation and overhaul. These PV systems may also be located in
any portion inside the building and present a shock hazard. If PV system
conduit is identified it should be communicated, including the location of the
PV system conduit, with the Incident Commander and all personnel operating at
the fire ground.
It is important to remember that the PV modules and arrays
will still produce electricity to the inverter during the daylight hours and at
night when artificial light is absorbed by the module. Traditional “Hot Sticks”
are not recommended for use to detect the presence of electricity in PV
systems.
Transferring the scene post incident, the Incident Commander
should ensure that the property is safe. If hazards exist, they should be
appropriately marked or barricaded. |