Over the years, especially pre 2014 when monitoring really became mainstream and stored in the cloud, so we could actually see how systems were working, we thought they would ruin performance with a simple poo.
However, when started seeing systems that had a lot of poo on them, we noticed they didn't seem so affected.
Take one of our team members Inger. One of her 3 systems had afternoon shading and an international-sized bat flight path overhead. (this was back in 2015, and it was a different industry even then, no one had split cell panels, for example, they were way too expensive). We saw huge amounts of poo and cleaned it off when we could. But, regardless of how covered the panels were, we didn't really see any difference in the output day-to-day. Even on the heaviest times, the difference was minimal. This went against everything we'd always been told about how panels worked. It was around this time we started trusting our own experience rather than people representing the manufacturers, lol...
We always recommend you clean your panels when possible with a house, and there's nothing wrong with a sponge and soapy water clean when possible. But please, you don't need to shade part of your panels using a fake owl, or other contraptions to keep the wildlife at bay.
Just make sure nothing is living underneath your panels, which isn't very common as it's a pretty rough life on the roof!
*this is not one of our customers or our photo, but it makes a great point.
