Fire safety of photovoltaic elements
Solar photovoltaic panels are devices that convert sunlight to electricity by way of semiconducting materials. The panels are only part of the system, since auxiliary equipment to connect the panels to the building wiring or to the electrical grid is also essential. Although fire safety issues with solar photovoltaic panels have been rare, they may increase as the technology becomes widely used. As an example, last year, a photovoltaic rooftop installation caught fire in Bürstadt, Germany, damaging 80 square meters of the modules. The fire causes are often electric connections within the modules generating hot spots which in turn triggered the fire.
To date, firefighters still only had limited experience with fires involving photovoltaic systems. The main problem is that photovoltaic systems and all their components are virtually always electrically energized through the solar cells with direct current up to 1,000 V. This may lead to a deadly shock hazard. To address these issues, guidelines and technical leaflets for firefighters have been developed, for example in Germany.
Safety testing of solar photovoltaic panels has become an important field of activities for testing and certification organizations. Underwriters Laboratories (UL) has developed the SU 8703 UL draft standard, a new comprehensive code defined specifically to test safety parameters of concentrated photovoltaic (CPV) products. The Tests fall under three general categories: electrical safety, mechanical safety and fire safety. A US manufacturer of CPV products worked closely with UL to define a fire test method for CPV products to be used on commercial rooftops. The company then underwent the whole testing process and received the first UL Listing under the new UL standard..
PHOTON August 2009, p. 60