A numerical analysis of PV-rating methods

A computer model has been developed to simulate solar cell power production from meteorological data and solar cell measurements. A novel feature of this model is that it calculates the hourly solar irradiance for clear and cloudy skies from readily available meteorological data. The investigation includes a monocrystalline silicon and GaAs cell and the thin-film cells CdS/CdTe, CdS/CuInSe₂, a-Si:H, and a two-terminal a-Si:H/a-Si:H/a-SiGe:H device. This study includes spectra under cloudy skies to study in detail the effect of variations in the solar spectral irradiance on the device´s efficiency. A second intention of this work is to analyze the sensitivity of different power and energy rating methods to spectral irradiance, total irradiance, and cell temperature. As a result, a multivalue energy rating scheme applying the concept of critical operation conditions is proposed and compared with the current single-value power rating procedure under standard reporting conditions