The degradation rate indicates how much a solar panel's performance declines each year. According to the National Renewable Energy Laboratory (NREL), solar panels typically lose about 0.5% of their efficiency annually. Initially operating at 99% capacity, they drop to 98.05% after the first year, and after 25 years, their efficiency is around 84-85%.
REC panels degrade more slowly, retaining 92% efficiency after 25 years, positioning them as premium options.