By Ken Willette and Casey Grant
From the January/February 2014 issue of Today’s Facility Manager
Safety is everybody’s business. Anytime a poor design or installation of a solar power system creates an unsafe condition that results in property loss to an owner or injuries to a firefighter, it is a setback for everyone. While nobody wants to yell “fire” in a crowded solar power marketplace, the ongoing safe use of this technology is a critical foundation for a prospering solar power industry.
Structural fires involving solar power systems can be one of three basic types depending on the point of ignition. These are (1) an external exposure fire to a building equipped with a solar power system; (2) a fire originating within a structure from somewhere other than the solar system; or (3) a fire originating in the solar power system as the point of ignition.
From a fire service perspective, the knowledge that the building has a solar power system is of immediate interest to the incident commander so that fire ground personnel can take appropriate precautions. As with any structural fire attack, size-up is a key step, and the additional hazard characteristic of electric shock from a photovoltaic (PV) system is a concern.
One of the first steps firefighters take at a structure fire is to shut off all electrical power to the building completely. But with PV systems during a sunny day this is a technological challenge, and firefighters are typically not able to readily do so. An additional electrical concern exists for systems that have optional electrical storage batteries that can maintain electrical current when the rest of the system has been isolated (e.g., at nighttime), and can present leakage and hazardous material concerns if damaged in a fire.
How often do firefighter injuries directly occur with solar power systems? The answer is, “We don’t know.” Statistical data from present data collection efforts does not address whether or not PV power systems were involved with any of these occurrences. But firefighters recognize the potential risk, and thus it is important for facility managers and their solar power professionals to work with local emergency responders to understand and mitigate perceived risk adequately.
From the fire service perspective, expansive PV systems on large buildings are a particular concern, based on the appreciable amount of electrical energy and the corresponding hazard. Firefighters normally approach high voltage areas such as transformer switchyards, substations, or power plants with extreme caution, and they do not enter secure high voltage areas without significant pre-planning and direct guidance from the facility owner. With the large-scale PV systems now proliferating on big box stores and similar facilities, facility owners are inadvertently introducing a significant challenge to their local fire departments. To address this, they should work closely with their local fire departments to develop rigorous fire service pre-plans.
In addition to electric shock, firefighters have several other concerns relating to solar power. A rooftop solar array may prevent direct access to the section of roof providing the optimum point of ventilation. The hazard of tripping or slipping is always a concern for fire ground operations on a rooftop, especially in dark or smoky conditions, or at night. During roof operations, firefighters will also need to consider the additional weight of the PV array on a roof structure that may be weakened by the fire. During overhaul, the firefighting activity that involves final fire extinguishment, certain solar power components can pose unexpected cleanup/hazmat issues.
Interestingly, the fire service itself is often a consumer of solar power technology. Multiple examples exist over the last several decades of fire departments effectively installing solar power systems on their fire stations.1, 2 Independence from the electrical power grid is important for disaster planning, and an example is the City of Boston using PV for evacuation routes out of the city for critical traffic controls, gas station pumps, and emergency evacuation repeaters. Meanwhile, the U.S. Forest Service has often used PV systems for its remote fire service facilities.
The use of vehicle mounted solar panels already exists within the fire service. In particular, an approach gaining traction in California is the installation of fire apparatus PV systems to address fire apparatus deployment over long periods of time (e.g., a wildfire event).3 This provides a dependable electrical power supply for radio operation and other critical electrical equipment, and it supplements the energy provided from conventional fuels that need periodic replenishment.4
As with all emerging technologies that find their way into homes, businesses, and elsewhere, the fire service will adapt their tactics to respond to the challenges posed by new technologies like solar panels. Pre-incident planning by noting locations of solar panels, especially on large commercial structures, and making on-site inspections provides critical information that will assist responders and incident commanders during emergency responses. These simple site visits, along with installation and maintenance procedures that follow the recommendations of the National Electrical Code, will go a long way to addressing responders’ needs.
Solar power technology is a good news story, and it is the type of clean, reliable, and renewable energy needed in today’s world. While this technology introduces new and different hazards for firefighters, they are able to handle it with proper training, understanding, and pre-planning. The fire service itself is a beneficiary of this technology, and working together everyone wins when it is recognized that safety is everybody’s business.
Willette is division manager for the National Fire Protection Association’s (NFPA) Public Fire Protection Division. Prior to joining NFPA, he served as a career firefighter, including having served as Chief of Department in both Wilbraham, MA and Concord, MA. Grant is research director of the Fire Protection Research Foundation in Quincy, MA. He is the author of “Fire Fighter Safety and Emergency Response for Solar Power Systems,” a 2010 DHS/FEMA Fire Grant funded study to address fire service safety issues relating to solar power systems.
1 Ross, C, “Here Comes the Sun: Solar Energy for Emergency Medical and Disaster Use,” Emergency, Volume 25, Issue 12, December 1993, pgs. 34-37
2 May, B., “Solar Power: a Hot New Trend in the Fire Service,” Firehouse, April 2005, Pg 134
3 Markley R., “Electricity On The Go,” Fire Chief, May 2008, Pgs 64-67
4 “San Rafael Fire Engine 52 Online,” E-52, San Rafael Fire Department, California, June 2008
The good news – there is a solar safety switch called Remote Solar Isolator that tackles the problem before the panels combine limiting lethal d.c voltages to Extra Low Voltage.
The solar safety switch has the
* ability to switch off both locally and remotely.
* safety of a defined isolating air gap between combining panels (Safest Isolation)
* ability to switch off when a predetermined temperature has been reached (if heat is detected from a fire the entire system will safely shut down).
* never places the operator at risk of electrocution from a damaged solar array
* Retrofitted to any new or existing system.
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