Photovoltaic Rooftop Patent

Active Fire Blocking Wind Deflector


A common indusry problem with rooftop photovoltaic systems is the incerased fire-risk posed to the structure the system is installed on. For example, a photovoltaic system installed above the roof's Class A fire-rated surface can end up reducing the overall fire rating of the roof down to even Class C. This is not only because a hot zone is produced between the panels and the roof, but also that the panels theselves contain highly flammable materials and adhesives. When ignited by an electrical fault or natural cause the fire can traverse the rooftop nearly unstoppably in the enclosed environment.

The active fire blocking wind deflector reduces the likelihood of a natural event igniting the root of the photovoltaic array at the base of installation. This device prevents a fire on the outside of the house from spreading into the highly flammable and unprotected region under the panels.

The device also has the additional benefit of providing a Class A fire-rating for a combined PV and roof installation system. This rating is determined by applying a flame to the root of the array and monitoring how quickly it traverses up the rooftop. With the active fire-blocking system the flames applied are redirected above the array and thus significantly reducing rate of fire transmission.

The final design was patented by SunPower Corporation after the need for Class A PV rooftop systems was demonstrated. The granted patent can be found here.