New insights on the empirical predictability of spectral indicators for pv performance

Abstract

Accurate produced photovoltaic (PV) energy estimation is critical to business decisions under long-term investments in PV projects. The variability of the spectral distribution after temperature and irradiation is a site condition that impacts energy harvesting estimates. Evaluating the spectral impact on the PV performance generally requires accurate information about the PV device's spectral response and the site's measured spectra. This study analyzes the interrelations between device-dependent and device-independent spectral indicators with spectral data from nine sites with different climates and latitudes, aiming to relax the requirement for detailed device and spectral information. Notably, the monthly Spectral Mismatch Factor exhibits a global linear relationship with the monthly Average Photon Energy. This linear relationship provides a method allowing estimating the spectral impact from the Average Photon Energy, potentially for any site (annual - monthly). The proposed method was also validated using synthetic spectral data from the National Solar Radiation Database.