A standard 60-cell panel weighs between 35 and 42 lbs (16-19 kg). Solar mounting racks, rails, and hardware add about 2-2. 2 kg/sq m) to rooftop weight loads. This weight makes them manageable, but still requires careful lifting during installation. However, it's not just the weight of the individual panels that matters—it's the. . On average, a complete solar array adds about 2 to 4 pounds per square foot (psf) to the roof. For a standard 6kW system covering 400 square feet, this translates to an additional 800 to 1600 pounds distributed across the roof structure. Live loads are temporary forces that a roof must be able to. . A solar panel roof load calculator can help you determine the size and weight of solar panels your roof can accommodate.