The RT1 has been designed specifically for the commercial rooftop PV. For the best commercial rooftop PV monitoring it is advised to measure both the solar irradiation and the PV panel temperature. The rugged housing of RT1 simply fits to the corner or side of a PV panel and contains the digital electronics. It also houses a sensor that reliably measures the incoming plane of array solar irradiance. The plug-in temperature sensor is easily attached to the back of the panel. RT1 is the perfect solution for monitoring the efficiency of commercial rooftop PV installations. PV panel temperature has a significant influence on the output of the PV panels and shouldn’t be mixed up with influences of e.g. soiling, cable losses and inverter losses.