Solar Farm Cleaning Costs

Determining the cost of cleaning a utility scale solar installation is best done by analyzing the entire system vs the cost of just the machinery. Each installation is unique and we have chosen to use a case study to help you understand the costs related to solar panel cleaning solutions.

Our case study covers a solar farm in Southern California with PPA values of USD $28/MWh and average daily soiling levels at 0.08%. By applying soiling monitoring and semi-automated cleaning systems, the solar plant achieves savings of 3.6 Million Dollars over the lifetime of the solar installation. Below you can see what options are available to clean a solar farm and their associated costs.

Solar Farm Characteristics

  • 100 MW
  • Region – Southeast CA, USA
  • USD $28 / MWh
  • Soiling Monitoring – DustIQ by Ott HydroMet
  • Annual Soiling Cost = USD $272,000
  • Labor Rates = $35/hr
Solar Panel Cleaning Costs

The financials above cover 10 years of a utility scale installation the CapEx is prorated over these 10 years.

The cost of cleaning a solar farm is a function of the cost due to soiling and the cost to clean a solar farm. In the case study, you can see that in year one it makes sense not to clean manually but it does make sense to clean with semi-automated solutions.

We analyzed just 3 solar panel cleaning systems and compared the cost of soiling and cleaning to the estimated revenue of the solar farm.

As you can see in the financials above, the cost of soiling and cleaning is a significant part of revenue. In the case study above, if we do not clean, soiling amounts to 2.9% of our revenue, while if we clean in an optimized way, we can reduce this cost to 1.6% of our revenue. Most solar farms have linear revenue and fixed PPA’s so the opportunity to improve earnings over the lifetime of the solar installation is done by reducing O&M costs.

Solar panel cleaning costs should be determined by looking at the cost of the system and not just the machinery or the robotics. Solar panel cleaning systems have a CapEx and OpEx and each installation will require its own unique analysis because

  1. PV Soiling rates and distributions are unique to each site
  2. Optimum solar panel cleaning machinery and or robots is unique to each site
  3. Studying the financials is key
  4. The cost of water should be contemplated
  5. The cost of labor should be contemplated.
  6. When you clean is extremely important and one of the most important variables. Below we established a 5% soiling rate threshold to determine when to clean and compare the cost of being dirty to the cost of each cleaning from an operational point of view.

  • Purple Line – Shows the cost of having dirty solar panels over 365 days with 3 tractor cleanings and rain.
  • Blue Line – Shows the cost of having dirty solar panels over 365 days with 1 manual cleaning and rain.
  • Red line – Shows the cost of having dirty solar panel over 365 days with 0 cleanings and rain.

Solar panel cleaning costs on commercial, industrial and utility scale installations requires

  1. Localized considerations and a financial analysis by people specialized in this topic.
  2. PV Soiling Monitoring to determine how big the problem is and when the problem occurs (soiling distribution values)
  3. Solar panel cleaning engineering – Each solar panel cleaning system has its own pros and cons. It is important to work with a team of people experienced in this field.

If you are interested in cleaning your PV site optimally please feel free to reach out to us at We offer solar panel cleaning system design engineering services and we also sell the robotics to help clean more efficiently.