Lifespan of PV Systems Operating for Over 30 Years in High-latitude Regions
Abstract
Photovoltaic (PV) module warranties typically assume a degradation rate of 0.8% per year over a 25-year lifespan, with some premium manufacturers offering up to 30-year warranties and industry efforts pushing toward 50-year guarantees. As PV adoption expands, particularly in high-latitude regions, module longevity is increasingly critical for project bankability and environmental sustainability. However, long-term performance data remain scarce, especially in these regions, where over 85% of installed modules are less than 10 years old. This study reports a 0.5% annual power degradation over 30 years for a PV system installed in Sweden in 1994. Visual inspection and electroluminescence testing revealed no major defects, while near-infrared spectra indicated no significant degradation of the encapsulants or backsheet. Additionally, we report on a second legacy system currently being installed on-site, incorporating modules over 40 years old. These results offer valuable insights into the long-term PV reliability in Nordic climates.
Keywords
Photovoltaics, Reliability, High-latitude, Long-Term Performance, Nordic Climates.