Does cleaning your panels increase production? And what is Panel Soiling?

The energy lost annually from soiling amounts to as much as 7% in parts of the United States to as high as 50% in the Middle East.

Rain and wind can be enough to scour some dust from PV panels, said Lin Simpson, who served with Muller as the co-principal investigator at NREL for a $6 million Department of Energy-funded research effort into soiling from 2016 to 2019. However, because PV panels cool down at night and attract morning dew, the dust can go through a process called cementation (Soiling).

“Depending on what area you’re in, you can have different minerals that are deposited as dust on the surfaces,” said Simpson, a senior scientist. “Once it goes through the cementation process, it can become much more difficult to remove to where even a strong rain won’t remove it.”

A one-time cleaning for a 10-megawatt solar farm—which provides enough electricity to power 2,000 homes for a day—can cost an estimated $5,000. Simpson said in some areas, such as California’s Central Valley where “soiling rates get sufficiently high and the rain sufficiently low,” it makes economic sense to clean the panels more than once a year.

Solar Unsoiled, working in conjunction with the system owner, measured performance increases from 5% to 11%, following mechanical wet brush cleaning.

https://www.nrel.gov/news/features/2021/scientists-studying-solar-try-solving-a-dusty-problem.html

https://www.nrel.gov/news/program/2023/nrel-research-finds-rain-not-enough-to-wash-pollen-from-solar-panels.html