1. Performance – PV modules produce revenue by creating power and selling this power to the network via PPAs. Less energy production means less revenue. 
2. Reliability – Asset owners need to produce reliable power to make their clients happy.
3. Asset life – Soiling on PV modules reduces asset life significantly.
4. Warranty Compliance – Almost all solar panel manufacturers require that solar panels be cleaned on a regular basis for the warranty to be valid. 

According to a research paper called “Techno-Economic Assessment of Soiling Losses and Mitigation Strategies for Solar Power Generation”, Soiling consists of the deposition of contaminants onto photovoltaic (PV) modules or mirrors and tubes of concentrated solar power systems (CSPs). It often results in a drastic reduction of power generation, which potentially renders an installation economically unviable and therefore must be mitigated. On the other hand, the corresponding costs for cleaning can significantly increase the price of energy generated. In this work, the importance of soiling is assessed for the global PV and CSP key markets. Even in optimized cleaning scenarios, soiling reduces the current global solar power production by at least 3%–4%, with at least 3–5 billion € annual revenue losses, which could rise to 4%–7%, and more than 4–7 billion € losses, in 2023. 

Why Clean Solar Panels

While the monetary value of cleaning PV modules has been calculated, the monetary value created by extending asset life and increasing reliability has not been calculated. However, for those of us who have been in the industry long enough, there is no doubt that solar panel cleaning increases reliability and extends asset lift. 

1. Reliability
2. Performance/ Revenue
3. Asset Life
4. Warranty Compliance

Reduced Performance / Revenue

While there are several very worthy papers that show how PV soiling reduces performance and hence revenue, we conducted our own research in a 100 MW site in California with PPA values of $28 MWh. 

This project was sponsored by DustIQ and NorCal Controls and Soilar Technologies and this information was shared worldwide in a Webinar by PV Magazine called PREDICTABLE PROFITABILITY:

THE IMPORTANCE OF SOILING MONITORING & MITIGATION

In this research project, a solar farm in California clearly showed a loss of 2.9% of its annual revenue due to PV soiling. This amounted to 272,300 dollars.