One large rooftop install (675KW) on a bldg with a severe gull issue has a guy on the roofs weekly. The bldg installed hose bibs at the roofs.
They also have a contractor to low pressure clean the panels every 4-6 weeks, dependent on the feathers, poop & assorted other items on the roofs.
This install cut the utility bill by 40% for the refrig/cliamate controlled whse operation.
