Solar spectrum measurements during 6 month: spectral mismatch induced on crystalline silicon and amorphous silicon photovoltaic cells
Résumé
Currently predicted photovoltaic (PV) yield are made considering solar irradiation, ambient temperature, incidence angle and partially (or not) the solar spectrum. However, the solar spectrum is not always the same. It varies depending on the site location, atmospheric conditions, day of the year, time of the day... This may impact the conversion efficiency differently according to the PV technology. This paper presents measurements of the impact on the short-circuit current of the mismatch between the solar spectrum and the reference ASTM AM1.5G spectrum, for a specific site, throughout the year. A spectroradiometer is used. We investigate these losses every minute during 6 month for a site located at Gif-sur-Yvette and present the results that give an idea of the impact of the spectral mismatch on two different technologies (a-Si and c-Si) under continental sky. We also study the links of the spectral mismatch with the diffuse irradiance. We show in particular that the spectral mismatch has a wider impact for the a-Si and for both has a relevant impact concerning the average on 6 months: Isc(a-Si) is 1.17% higher than the rated one and Isc(c-Si) is 1.4% lower than the rated one (measurements are mainly led during overcast days)