The product warranty is the manufacturer’s warranty that protects the customer against defects that may have occurred due to manufacturing errors, quality issues, or component and material failures. This means the manufacturer must either replace or provide a refund for solar panels which fail within the product warranty period. In general, solar panel manufacturers must provide a minimum 10-year product warranty period, however, a growing number of premium manufacturers now offer 15, 20 and even 25-year product warranties.
The performance warranty also referred to as the power output warranty ensures that the solar panel still produces a minimum amount of power output after the expected 25-year life of a panel. Once installed outside and exposed to sunlight, UV radiation, and high temperatures, all solar panels slowly reduce power output over time due to a well-known phenomenon called Light Induced Degradation or LID. Typically 3% is lost in the first year, while the annual loss over the remaining 24 years is much less, at around 0.3% to 0.7% per year.
