What is the live load of photovoltaic panel construction

Dead load: This is the weight of permanent materials on the roof—structural components, insulation, and roofing materials. When calculating the necessary load capacity of a roof, you need to figure in what's known as the dead load along with live loads or environmental loads. Live loads demand flexibility and adaptability. It's measured in pounds per square foot (psf) and typically falls between 15-30 psf for most residential roofs. This capacity includes both dead loads (permanent weight) and live loads. . Adding a new solar Photovoltaic (PV) panel system to an existing building's roof structure where the existing building is not undergoing a change of occupancy. If any portion of system rises over 24. . [pdf]