Dust aerosol effects on decentralized solar: A cause of systematic undersizing of solar panels in West Africa

Decentralized solar is an emerging strategy for advancing modern energy access among rural populations globally. However, both natural and anthropogenic aerosols can significantly worsen solar panel performance. Although the effect of aerosols is typically assessed using satellite or reanalysis data during system sizing, these datasets often underestimate extreme aerosol conditions in West Africa.

This study evaluates the impact of aerosols on photovoltaic (PV) output by developing irradiance and generation models that accept as input three reanalysis and satellite-derived datasets with varying spatial and temporal resolution. The accuracy of each dataset is evaluated through comparisons to ground-based AERONET measurements. We find none of the aerosol datasets capture the highest aerosol loadings well, underestimating the 99th percentile aerosol optical depth (AOD) values between 18–49 %, which can lead to undersizing PV systems by up to 11 % for high-reliability designs.

To capture total regional dust impacts, we combine dust aerosol with dust soiling loss modeling. Modeled irradiance shows that daily energy losses during the annual Harmattan dry season can reach 50 %, and seasonal energy losses caused by dust can be between 19–40 %. In locations within the Sahel, soiling dominates dust-associated losses (62–66 % of total losses), while for coastal locations near the Gulf of Guinea, dust aerosols drive losses (56 %).

These findings highlight the need for location-specific mitigation strategies to effectively address PV dust losses. The modeling framework developed in this study can be used to improve the siting, sizing and maintenance strategies for PV systems in dry regions worldwide.