Solar panels lose their output power over time, and it is a common belief that they need to be replaced after 10 years. The Phébus 1 solar array, installed in France back in 1992, refutes this statement experimentally. This is what TechSpot writes about.

A small array of 10 m² solar panels with a capacity of 1 kW, installed in 1992 near Leon and connected to the French grid, was dismantled in 2023 and thoroughly tested in the laboratory. It turned out that after 31 years of service, the solar panel still produced 79.5 percent of its original rated output power. That is, the degradation of the panel was only 0.66% per year and, in general, it performed better than the manufacturer promised, which guaranteed only 80% of the initial performance over 25 years of operation.

The nonprofit association Hespul, which installed the panel, also cites long-term Swiss and recent American and European studies that show that the average degradation rate of solar panels is between 0.36 and 0.75 percent per year. So, while a decline in energy production is inevitable over the years, real-world data demonstrates that solar panels can operate for several decades while remaining at a high level of performance.