Generally, solar panels are self cleaning and can cope well with a bit of dust in-between rainy periods, however, there are some conditions to this rule that every solar panel owner should be aware of.
If you live in a particularly dry area where you don’t get much rain, the build up of dirt on the panels can reduce performance. If you live near the ocean, salt can have the same effect. Living near a major highway can cause an oily residue that’s created from exhaust fumes to settle on your panels creating a ‘shady’ effect, therefore reducing your panels’ ability to absorb sunlight.
The main attribute to poor performance due to dirty solar panels is bird poop! Yep bird poop, and regardless of where you live in Australia, your home will almost always find it’s way under the flight path of our wonderful feathered friends.
Your solar panels do not need to be covered in dust and grime to warrant poor performance, just a few spots here and there are enough to reduce their ability to perform at full capacity. This build up has a shadowing effect on your panels which restricts the amount of sunlight they can absorb, which of course will effect the amount of energy they can produce.