This part of IEC 61853 describes the standard reference climatic profiles used for calculating energy ratings. IEC 61853-1 describes requirements for evaluating PV module performance in terms of power (watts) rating. IEC 61853-2 describes test procedures for determining module temperature from irradiance@ ambient temperature and wind speed@ a method for measuring angle of incidence effects@ and spectral responsivity. IEC 61853-3 describes the calculation of PV module energy rating values@ using the data from IEC 61853-1@ IEC 61853-2 and IEC 61853-4.