Case studies

Friesian Dairy Farm

Friesian Dairy Farm

Up to 35.1%

Increase in production

$25,595 per year

In additional value

"The RST system was more effective than we originally thought. We have had it operating for 4 months now – we were surprised how clean it has kept the panels with zero effort or hassle for us. It has required no maintenance and we can control the entire system from our phone. It has been great to see our panels looking clean and productive everyday."

Friesian Dairy Farm used RST CleanTech to make their solar project more profitable – with little hassle. On March 11, 2020, RST NightWash was installed on one of Friesian Farm's inverters – 1.107 MWdc Canadian Solar 315W Panels, and compared against the other inverters at the site.

  • Friesian Farm is a dairy farm owned by the Leyendekker Family. It is located in Tulare, CA and has a fixed tilt ground mount 1.107 MWdc solar array.
  • Every dairy farmer knows that their operation kicks up a lot of dust in the air. If you have solar panels nearby, that means panels get dirty quick and production drops. But it's a hassle to wash the panels every month in the dry season. There has to be a better way.
  • It was decided to install the RST CleanTech Solution on one of the solar array's 37 inverters. By comparing the inverter that had RST on it's panels to the non-RST inverters, it was possible to measure real time the difference in production.
  • The Leyendekkers set up a 1" female valve and a 120V outlet next to the PILOT location and the RST system was installed in one day.


The case study shows an increase in production of 35.1% on the panels that had the RST CleanTech system installed.

  • 35.1% Increased Production $25,595 in additional production first year. $872,579 over 25 years.
  • *15% production increase, $0.10/kWh, 1107 kW system
  • <1% soiling losses.At this site, the panels would lose up to 0.66% production every day. Over 10 days, that is a 6.6% loss. RST stayed ahead of the soiling and kept panels clean.
  • 3-5% production increase from rain. Rain only helps a little bit when it comes to taking off caked-on dirt.
  • Total Water Usage: $3.37 - cost of water for 37 washings (878 gallons)
  • Hassle Free: Not once did the owner need to do anything with the RST system or the panels with RST technology. The system can be controlled by phone so increasing the number of cleanings during the dry season only took a few seconds.
  • Warranty Compliant: Due to RST CleanTech's gentle rinsing with filtered water. No detergents, high pressure or abrasive material were used.
  • Friesian Farms had the RST CleanTech solution installed on panels on one of their 32 inverters. Average increase in production was 12.53% even after 3 brush cleanings and uncounted water truck.

For more information, download

the case study here.

Why RST CleanTech?

Over 10 years ago, we set out to solve one of the biggest problems facing solar – panel soiling. We wanted to find a way to keep panels clean, maximize energy production, protect panel warranties, and increase revenue for system owners.

We knew there had to be a way to achieve our goals that didn’t entail deploying thousands of bristle-wielding workers or robots onto high voltage solar arrays across the world. When we realized there wasn’t, we created one. Enter, RST NightWash™.

RST NightWash™ is a safe, cost-effective, and eco-friendly automated solar panel cleaning solution.


Request a quote.