The French association Hespul, established in 1991 to pioneer photovoltaic technology in France, recently conducted tests on panels from their Phébus 1 power plant, operational since 1992. The panels, dismantled last year, were subjected to rigorous testing in accordance with international standards. Results revealed that after 31 years, the panels still produce an average of 79.5% of their initial power, surpassing manufacturers’ longevity claims. The study highlighted a 20.5% performance drop over 31 years, with varying degradation rates among different modules. These findings align with previous scientific studies, including a Swiss PV system from 1982 and recent research by the US Department of Energy’s National Renewable Energy Laboratory.