A Method to Test Operating Cell Temperature for BIPV Modules

The nominal operation cell temperature (NOCT) is one of the most critical parameters for a photovoltaic (PV) module. We find that for the emerging types of glass/glass and insulating glass modules, the measurement error between the IEC61215 method and the thermocouple direct measurements on the actual cell can be as high as 15°C. To address this problem, a new NOCT measurement method for building-integrated photovoltaic (BIPV) modules is proposed. In the new method, the standard reference environment has the same total irradiance (800 W/m 2 ), ambient temperature (20°C), and wind speed (1 m/s) as IEC61215 but with a closed circuit and a resistive load to ensure the module operates at the maximum power point. This takes into account both the photoelectrical and photothermal conversion effect simultaneously. The cell temperature is measured directly using several thermocouples encapsulated into the BIPV modules at a certain sampling point. The average cell operating temperature for the whole module is further determined by the infrared thermovision measurements after calibration. In addition, the simulated BIPV house was built to simulate the actual installation environment. It is verified that this new method is more accurate to test the NOCT for BIPV modules.