Temporal Analysis of the Solar Spectrum in Natal/RN and Its Influence on the Performance of Photovoltaic Systems

de Sousa, Alan Rodrigues, Emiliavaca, Samira de Azevedo Santos, Teixeira, Camila Fernanda Cardoso, Barboza, Amanda Gomes, Oliveira, Dayane Cynthia Pinto, Lopes, Nicholas Medeiros, Silva, Gabriela Rocha Alves, Amorim, Ana Cleide Bezerra, Mendonça, João Vítor Fonseca

ISES Solar World Congress 2025 · Fortaleza, Brazil · 2025-11-03
Published by International Solar Energy Society (ISES)
DOI: 10.18086/swc.2025.04.47

Abstract

This study analyzes the influence of the spectral distribution of solar irradiance in the city of Natal/RN, a lowlatitude region of Brazil, on the performance of photovoltaic technologies. Spectral data measured every minute between 300 and 1100 nm, totaling 33,448 measurements, were synchronized with global horizontal irradiance information from a solarimetric station. The results indicate negligible seasonal variations and a local spectrum enriched in high-frequency components, reflected in Average Photon Energy (APE) values of 1.93 eV, higher than the AM1.5 standard. A comparison between Mono-Si and CdTe modules, using the Spectral Factor (SF), showed greater compatibility of CdTe with the local spectrum, with relative gains of up to 10%, while Mono-Si would have a reduction of up to 4%. These results are similar to those found in the literature for similar latitudes. The high APE values also suggest a greater susceptibility of bifacial modules to Ultraviolet-Induced Degradation (UVID). The results highlight the importance of considering regional spectral conditions and module behavior in real operation, in addition to standard test conditions, for a more accurate assessment of photovoltaic performance.

Keywords

PV performance, Spectral response, APE, Spectral irradiance, Solar irradiance monitoring

← All proceedings papers