Autonomous Soiling Monitoring Station

Soiling on photovoltaic (PV) modules is considered a major operations and maintenance cost factor for PV power plant owners. Soiling loss can be heavily influenced by various factors, such as tilt angle, site conditions or environment (urban, rural, agricultural), installation type (fixed vs. 1-axis) and season (dry, windy, humid or rainy).

ASU’s Autonomous Soiling Monitoring System wirelessly collects and records location and tilt-angle specific soiling loss information for PV plants without the need to have a connection to water supply or access to the electricity grid. 

The Autonomous Soiling Monitoring System is capable of providing thirteen different ratios for data analysis and monitoring. Four of the ratios alone, contribute to the soiling loss factor (SLF) determination. This information serves as a tool to determine module cleaning frequency and best site-specific methodology of cleaning as well.



  • Fully automated and autonomous system does not require physical interaction for cleaning, oper-ations or data transmission 
  • Solar module and battery provide power for daily operations, no need to connect to an electricity grid 
  • Automatically collects, transmits and uploads data wirelessly to a cloud-based server 
  • Measures and records thirteen different sensor ratios to determine location and tiltspecific soil-ing loss factors 
  • Determines cleaning frequency and quantifies sitespecific soiling rate (g/m2/day) and daily/annual soiling loss (%) over long term field exposure 
  • Station based on two clean sensors and two soiled sensors to improve data redundancy and accuracy  

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