Codes and standards
NFPA Impact: May 2012
By Sean Tracey
The Canada Mortgage and Housing Corp. reports that installation of photovoltaic (PV), or solar, cells has been growing at a rate of 30 per cent, and this trend will likely continue as the price of electricity continues to rise.
By Sean Tracey
The Canada Mortgage and Housing Corp. reports that installation of photovoltaic (PV), or solar, cells has been growing at a rate of 30 per cent, and this trend will likely continue as the price of electricity continues to rise. It is likely that these systems will be installed increasingly in residential buildings. This will increase the risk to firefighters, as the solar cells will introduce new hazards, requiring a re-evaluation of fire-ground tactics as we learn more about these cells and the dangers they present.
An article in the March 2012 edition of Fire Risk Management said that in Germany, “there are cases where fire departments have refused to tackle a fire at a building with PV solar panels because insurance companies have withdrawn their personal-injury insurance for firefighters if they put water on a building installed with panels.” The article also raises concerns about post-fire re-ignition. If the lessons from Germany are accurate, then it behoves us to learn from these and broadcast safe practices. This may also be one more example where the Canadian building codes need to consider firefighter safety.
A recently built home in my neighbourhood looks from the street from like any other new structure. From the back of the home, an array of PV cells is visible (at night the cells might not be apparent on size-up unless you notice the extra electrical panels). In this case, the panels and all associated electrical units will be live until you reach the isolator switches. As a responding firefighter, do your tactics change? In your size-up, would you have noted the presence of PVs? The hazard-marking system found in Annex Q of the NFPA 1 fire code would provide a means to identify unique hazards such as a PV system.
NFPA’s Fire Protection Research Foundation in May 2010 published a report entitled Fire Fighter Safety and Response for Solar Power Systems. This is available for download from the NFPA website at www.nfpa.org. The report states that, “the goal of this project has been to assemble and widely disseminate core principle and best practice information for firefighters, fire ground incident commanders, and other emergency first responders to assist in their decision making process at emergencies involving solar power systems on buildings. Methods used include collecting information and data from a wide range of credible sources, along with a one-day workshop of applicable subject matter experts that have provided their review and evaluation on the topic.”
The report highlights many unique hazards, in addition to the shock hazard of these systems. Due to the nature of the components of PV systems, if they are exposed to flame, they can release known carcinogens such as cadmium and other highly toxic byproducts. Operations should consider the requirements to evacuate downwind populations in the event of fire.
Also of concern is the fact that PV materials may not be readily identifiable following a fire, so added precautions may be necessary. As well, fire-damaged PV panels, when re-energized in daylight, may create electrical shorts and re-ignite. The NFPA report identifies several basic tenets for firefighters as well as for incident commanders that should be incorporated.
In Canada, the Canadian Standards Association (CSA) plans to release its F900 guideline on the installation of rooftop PV units in the spring for public comment. The review will provide an opportunity for all interested parties to review the final-draft guideline and provide feedback for the guideline development process. Publication of the CSA F900 guideline is scheduled for the late summer/early fall. This is intended to also consider fire responder concerns. The technical committee developing this guideline includes representation from the Ontario Office of the Fire Marshal. A copy of the NFPA Research Foundation report has been forwarded to the committee, and the NFPA will reference the public comments that we submit.
One concern is that this will be a guideline document only, and not enforceable. This is a potential concern because, as the NFPA report points out, many systems do not meet safety standards – in France one in three installed PV systems is not meeting safety standards. We cannot count on proper installation, therefore we need to ensure we have proper training programs and standard operating procedures (SOP) and standards, objectives, and goals (SOGs) in place.
PVs are here to stay and are becoming more prevalent in new-home construction, as well as in retrofits. The fire service needs the proper awareness and training to address these risks. The NFPA Fire Protection Research Foundation report is a good starting point with source materials for in-house training. Hopefully the CSA standard will consider the fire service safety concerns in the planned installation guide.
Sean Tracey, P.Eng., MIFireE, is the Canadian regional manager of the
National Fire Protection Association International and formerly the
Canadian Armed Forces fire marshal. Contact him at email@example.com