What is the difference between LID and first year degradation, and what values should I use?

The difference between LID and first year degradation is that LID (Light Induced Degradation) refers to a temporary reduction in the efficiency of a solar panel, due to the exposure to sunlight during its initial operation. It can last from a few hours to a few days. First year degradation on the other hand are the overall reduction in performance during the first year of operation.

The values to be used will vary per module specification, so we encourage you to check the linear performance warranty graph and obtain these values. But in general the LID averages around 2%, and the first year degradation averages between 0 and 1%.