The Challenge
A facility's solar installation was located near a highway and industrial area with significant dust and pollution. Panel soiling accumulated regularly. Cleaning was done quarterly on a fixed schedule, regardless of actual soiling.
What Became Visible
Soiling detection (comparing actual output to expected output based on irradiance) revealed that soiling impact varied greatly by season: 3–5% loss in dry season, 8–12% loss during dusty monsoon. Fixed quarterly cleaning was insufficient during high-soiling periods and excessive during clean periods.
What Changed
Automated soiling detection algorithm that calculated soiling impact based on irradiance vs. output deviation. Cleaning was triggered when soiling impact exceeded 5%, instead of calendar intervals.
How it worked: Cleaning was performed when needed, not on a fixed schedule. During high-soiling periods (monsoon), cleaning occurred every 2–3 weeks. During clean periods, cleaning occurred every 6–8 weeks. Output loss to soiling was kept consistently below 5%.
Results
from optimized cleaning
fewer unnecessary cleanings
from soiling prevention
Soiling is an invisible loss that accumulates silently. Panel cleaning is necessary but only when soiling reaches a threshold. When soiling impact becomes visible, cleaning becomes optimized — performed exactly when needed, not on calendar intervals.
Operational Reality
Most facilities either clean too frequently (unnecessary cost) or too infrequently (output loss). The facilities that measure soiling optimize the cleaning schedule.