Assessing the impact of climate change on solar energy production in Italy

This study assesses climate change’s impact on solar energy production in Italy until 2100, focusing on solar radiation, temperature, and photovoltaic (PV) energy production through capacity factor. Regional climate models (RCMs) coming from the European branch of the Coordinated Regional Climate Downscaling Experiment (Euro-CORDEX), which incorporate time-evolving aerosols, are utilized for accurate future solar radiation trend estimations under various scenarios of greenhouse gas concentration evolution—the so-called Representative Concentration Pathway (RCP). Bias correction, employing the third edition of the Surface Solar Radiation Data Set—Heliosat (SARAH-3) and the MEteorological Reanalysis Italian DAtaset (MERIDA) for temperature data, enhances the capacity factor accuracy. Solar radiation exhibits a slight decline under the most optimistic emission scenario RCP 2.6, but a significant increase under other RCPs, particularly in central Italy’s mountains, with the Alps showing an opposite trend, especially under RCP 8.5. The temperature is projected to rise, particularly under RCP 4.5 and RCP 8.5, potentially affecting production efficiency and snow cover in the Alps. The decrease in snow cover may affect the diffuse component of solar radiation with a subsequent decrease predicted by Euro-CORDEX RCMs. Trend analysis reveals significant PV production decreases under RCP 8.5, especially in the Alps, due to reduced solar radiation. Despite the increase in solar radiation, most of Italy experiences decreased PV production due to rising temperatures, potentially reducing solar panel efficiency. RCP 4.5 and RCP 2.6 scenarios exhibit less pronounced capacity factor decreases, with RCP 2.6 showing the lowest climate signal magnitude. Seasonal cycle analysis reveals variations primarily linked to changes in solar radiation throughout the year. RCP 8.5 shows significant winter production decreases, followed by slight summer increases dampened by rising temperatures. RCP 4.5 exhibits similar characteristics, with a milder winter decrease and stable production in other months, while RCP 2.6 shows a slight spring increase and generally stable production throughout the year.