a) I love a bit of solar panel porn, bring it! b) it's non-trivial how much generation capacity you can lose from bird droppings, worth the bother to do this. At that angle the panels should self-clean on your property, but odd things can happen. Early in the life of our first row of panels, I noticed the power generation drop off considerably - we lost 15% of generation. It turned out one panel was approx. 1/3 covered in bird poo from a defunct TV aerial which overhung it. That is enough to shade the panel enough that its internal resistance builds up - this kills the output from that panel, and can even harm it. We had the TV aerial removed, the panels scrubbed, and the lot has stayed clean for 9 years now!