NEGATIVE TOLERANCE
Level Of Importance #3
Why Is It Important ?
Negative tolerance used to be one of the industry's best kept secrets. And is still a subject that many manufacturers try to avoid. The negative tolerance rating of a solar panel is the amount of power that a solar panel can be "off specification" and new, right out of the box.
For example if you purchased a 200 watt solar panel with a 9% negative tolerance rating then that solar panel might provide only 182 watts and the manufacturer would consider this within normal specifications.
If the same 200 watt solar panel had a 5% negative tolerance rating then that panel might only produce 190 watts and would still be considered normal
3% might be only produce 194 watts. So as you can see, the lower the negative tolerance rating the better the guaranty you have of getting the power that you paid for.