One of my panels is under-performing. What is the reason? Here's 4 common possibilities:
Dirt - Check if you might have excessive bird droppings, leaves or other dirt that is reducing your solar panel’s output. Here’s what you should know regarding cleaning solar panels.
Shade - Is your system near a tree, or does your chimney provide a shadow at a certain time of day? While there’s little to be done apart from clearing the tree, as long as you have microinverters or power optimizers, you can at least limit the production loss to the affected panel(s) instead of all the panels connected to the same string. Learn more about the different types of inverters here.
Inverter - If you have microinverters or power optimizers, it might be a good idea to check if the issue is with the microinverters or optimizer itself. Trade it out with another panel and see if the issue switches to the new panel. If it does, you’ll know that you just need to replace that optimizer/inverter.
Product Defect - If you’re not finding the reason, and your panel was clearly not shattered by the neighbor’s kid, it might be a manufacturing defect. Your solar panel might fall under a performance or product warranty, in which case you should contact the manufacturer regarding a replacement.