solar panel system may vary depending on the type of panels used, their efficiency, geographic location, available sunlight, and other factors. The number of panels required for a 30 kW system is just an estimate based on the assumed average panel wattage. commercial solar panels typically range in power output from around 250 watts to 400 watts per panel. To achieve a 30 kW solar system, you would need to install multiple panels, depending on their individual wattage.