Sun Cable: Cannon-Brookes wins battle for world’s biggest solar and battery project, page-66

one metric is cleaning the panels eg dust, bird stuff, then the issue of dirt etc accumulating on the edges of the panels


"A one-time cleaning for a 10-megawatt solar farm— which provides enough electricity to power 2,000 homes for a day—can cost an estimated $5,000.

Simpson said in some areas, such as California’s Central Valley where “soiling rates get sufficiently high and the rain sufficiently low,” it makes economic sense to clean the panels more than once a year. "

https://www.nrel.gov/news/features/2021/scientists-studying-solar-try-solving-a-dusty-problem.html

not cheap