Project Sunroof is a solar calculator from Google that helps you map your roof's solar savings potential. Learn more, get an estimate and connect with providers. . Caution: Photovoltaic system performance predictions calculated by PVWatts ® include many inherent assumptions and uncertainties and do not reflect variations between PV technologies nor site-specific characteristics except as represented by PVWatts ® inputs. For example, PV modules with better. . In a perfect world, the average roof in the U. can generate around 21,840 kilowatt-hours (kWh) of solar electricity annually—that's more than most homes need. But also, the world isn't perfect. These calculators help homeowners, businesses, and. . Estimate how many solar panels fit your roof and the total system capacity (kW) based on roof area and panel specifications. Formula: Panels = (Roof Area × Usable % × (1 − Spacing Loss %)) ÷ Panel Area → Total Capacity (kW) = Panels × Panel Wattage ÷ 1000. Adjust your electric bill to fine-tune your savings estimate and the recommended number of solar panels for your home. This setup is also known as solar rooftop photo-voltaic system. It produces a clean, Eco friendly form. .
