top of page
  • Sunshine Windows

Cleaning Solar Panels

Updated: Jan 25, 2023

There doesn't seem to be a lot of consensus on why, when or how often homeowners should get their solar panels cleaned. Some solar company installers recommend cleaning, some offer it as part of their installation package (usually bi-annual cleaning for a certain number of years), and others contend that it is simply not necessary. All of this can be very confusing for a consumer who just spent $10,000 on putting in a new system.

Each year, Sunshine Windows cleans over 30,000 solar panels. We have experience with large systems used by commercial property owners as well as the smaller systems used in typical residential settings. We get calls every day with questions from homeowners and business owners. Our goal in this article is to help answer some of your most common questions.

Should I clean my solar panels?

It should not surprise anyone that just like a car that is well maintained, a solar panel that is regularly cared for will produce more electricity and give you a better return on your investment. The question that we most frequently get is "How often do I need to clean my solar panels". The answer: "It depends".

Common reasons for reduced solar efficiency.

Dust/Dirt buildup is the most common reason your solar panels begin to loose efficiency. Some of this buildup may be washed away by the occasional rain storm, but that is not necessarily always the case. Where your panels are located and the amount of angle they are installed at is going to play a big factor in how dirty your panels get. Panels that are installed on a roof with a normal slope / pitch are going to stay cleaner than panels that are installed on a flat roof or flat surface.

However, there are more factors to consider when examining how often your panels need to be cleaned. The location of your house may cause your panels to get much dirtier. If your house is located next to a freeway, or if your house is close to the beach, your panels will get dirty much quicker. If you have trees close to your solar panels, leaves or needles from the trees may be building up on your solar panel array. In addition to possible leaves, if your panels are located close to trees, it is likely that they will get a buildup of bird droppings over time.

Can I hose down my solar panels?

It is almost always a bad idea to hose down your solar panel system. The hard water from your tap will likely leave residue on your panels making them less efficient and harder to clean. Some of our customers have had to replace panels because they regularly hose them down or have adjusted a sprinkler to water their panels each night.

How much efficiency will my panels loose if i do not get them cleaned.

The amount of efficiency loss will be different in every case, but Sunshine Windows conducted an informal survey of our customers who reported an average of a 30% increase in Solar Output after cleaning. "Every time [Sunshine Windows] cleans my panels, I can immediately see a 30-40% difference in energy output", said Sunshine Windows Customer Mike Hale.

A study by CleanTechnica showed that panels that had not been cleaned in 1 year calculated a 30% energy yield loss. Panels that went multiple years without cleaning resulted in as much as a 100% loss of yield. (

Regardless of if you clean the panels yourself, or if you hire professionals that specialize in Solar Panel Cleaning it is important to make sure to clean your panels at least once a year if not more.

Looking for the Solar Panel Cleaning Services in Upland or surrounding areas?

Contact us now at: 909-981-7406

Recent Posts

See All


bottom of page