Nominal Operating Cell Temperature (NOCT) is the temperature a solar panel's cells reach under standardized outdoor conditions: 800 W/m² irradiance, 20°C ambient air, and 1 m/s wind speed. Spec sheets list power at Standard Test Conditions (STC). Rooftops and fields run closer to Nominal Operating Cell Temperature (NOCT). The rest of the system—racking, wiring. thod reject ambient temperatures outside the range (between min T and max T is 5°C). In this paper we calculating the NOCT of two different technology of PV modules (glass to glass (PV1) and backsheet to glass(PV2)) b this three methods according to the standard IEC 12 5 and conclude 2 has been.