Solar panel

How To Clean Solar Panels


CAUTION: Be sure to check with your solar installers and providers read the manufacturer's installation safety, maintenance, and instructions prior to taking care of or cleaning your solar panel. Engaging in these activities carries the constant risk of injuries, property damage and even loss. Utilizing harsh cleaning products, industrial strength or sharp tools to maintain or clean the solar panels can cause the cancellation of warranties or guarantees on products.


Solar panels don’t have any moving components, so there’s not much maintenance to be taken care of. However, cleaning is one aspect of solar panel maintenance that should not be taken lightly. We want to see your solar system functioning at its highest potential continuously all year round.

In this article, you will learn how to clean solar panels the right way.


Do Solar Panels Require Regular Cleaning To Ensure Their Optimal Efficiency Is At Its Highest Or Will A Few Rainy Days Suffice?


It all is dependent on the conditions. In certain situations rain or snow can eliminate the bulk of the dust, However, under certain conditions, it can do greater harm than benefit. In both dry and humid ones the environmental conditions, the different kinds of dust, and the location and type of installation are all factors that affect:

  • What amount of dust will build up on buildings over time.
  • What impact will dust buildup has on the production of energy from solar panels?
  • If the rain will clean the dust away enough to bring panels back to a minimum 95% high level of performance.


solar panels


Does rain help or hurt? How much?

In a study that was conducted in Spain, researchers found an average performance decrease of just 4.4 percent after a full year’s worth of dust build-up. Many solar panel owners could easily accept this. However, the study also showed that during “long periods without rain, daily energy losses can be higher than 20%.”1  Therefore, in dry climates, where dust build-up is the primary problem, the solution is quite simple: the absence of rain causes dust accumulation that can get more severe the longer the dry spell continues.
In addition, most solar panels are tilted to a high enough degree that most buildup will run right off the panel instead of sticking to the top of it. 

While normal rainfall may wash away dust and allow solar panels to operate at approximately 90% of full capacity. This could cause you to believe the solar panel in regions that have frequent rainfall will require less maintenance. But not that quick! There’s usually more to it than dust. The pollen of birds, the bird’s droppings leaves as well as ash and a hazy layer that forms when smoke or smog hangs in the air may all be an overlying layer of soil that could or might not be able to wash away when it rains. 

Here’s a study by the Renewable and Sustainable Energy Reviews2  which delves into the myriad of factors that are involved. The study concluded that the use of rain to perform the cleaning work on the solar panel is a good decision only if, you reside in a good area, like:

  • A space where dust is the main component of the buildup that develops on solar panels.
  • A region where the composition of dust so that rain can clean it.
  • A location that rains at the appropriate frequency to prevent dust from depleting the solar energy produced by panels.

Imagine this: if rain was a successful method to clean then why would the car wash the first to stop at the end of a rainstorm? If you’re using the wrong mix of pollutants, even a small amount of rain won’t necessarily remove everything. It could be the basic ingredient in the process of combining an assortment of pollutants into a sort of Slurry. For instance, the story of a family living in a humid rainforest, where the climate completely rules out dust as a problem. Three years after the installation of the solar panel, they saw an improvement of 10 percent. 

When they contacted local installers to inquire about the cleaning service, they were given an answer that was essentially about the frequency of rainfall in their area would prevent the formation of any significant buildup. However, when a window cleaner who was later hired by the homeowner came to clean their panels, they discovered an unctuous brown haze that was not likely to wash off during rain. Once the panels had been cleaned, the homeowners reported that their productivity increased by 20 percent, which was more than the original level of production of 10 percent!

Solar Panel

It If rain doesn’t be enough How do you know whether it is worth the effort?

If you’ve owned solar panels for some time ago a year or so, perhaps more, you’ve likely observed how their energy output varies each month due to changes in weather and the sun’s shifting direction over the sky in the course of the seasons. With just a little knowledge of your solar array, you’ll be able to figure out the degree of fluctuations you can anticipate during the year. 

If you begin to notice decreased output during a time that conditions are consistent with what you’ve grown to anticipate, dirty panels may be the cause. If that’s the case take a look at these concerns:

  • Do your panels seem to be flat, ranging from zero to five degrees? If yes, then they might be more prone to soiling on the surface than other panels.
  • Do you live near an airport, highway, or farmland? If yes the air you breathe in your region could be contaminated with significant levels of dust.
  • Does your rainfall be sufficient to prevent dust accumulation to build up? If not the panels could need to be spray-off with water.
  • Are you in an area that is susceptible to pollution caused by the smoke of wildfires or industrial smog? If so, you might see a film of haze on the solar panels, which could not be rinsed off.
  • Do you live in an area is surrounded by tall trees? If yes, you could see a buildup of fallen leaves or Bird droppings on your walls.
  • Are you currently in an era of high levels of pollen? If so, you could encounter a sticky residue that prevents rain from washing dust and dirt away.
  • Are your local climates humid enough to allow moss to be able to grow around your house? If not, can you suppose that rain keeps your panels in good shape? Rain might be the issue.

In the ideal scenario, you’ll want to cleanse those panels in such a manner that balances costs, effort, and efficiency gains to your advantage. If it is clear that your panels should be cleaned in one way or the other then your next task is to figure out the most efficient method. Consider this list of questions based on your observations.

  • The buildup appears to consist of mostly dust or do you see more sticky substances such as pollen, bird droppings, and smoke?
  • Do you have the ability to spray your panels with a garden hose from the ground? Or do you require ladders?
  • Do you have a secure method, either by ladder or other means, to climb up your roof, in the event of a need?
  • Have your screens set away enough away from the edge of the roof to allow you to move them around and reposition yourself to reach them all safely?
  • Are your roofing materials and roof pitch provide an adequate platform for workers to work from? Is it too steep, too high, or slippery?
solar panel

Tips for cleaning solar panels

Cleaning your solar panels should not cost an arm and leg, and it shouldn’t be an arduous process. If it’s feasible spraying them down from the ground is the simplest and most effective. However, the more sticky the buildup the more likely it is that you’ll require cleaning tools and equipment to wash the panels clean from a distance.


To Avoid Soiling On The Surface Made Most Of Dust Consider Cleaning Your Solar Panels From The Surface.

If your roof panels appear to be failing, or your roof’s not too high and your examination of environmental influences suggests that the simple accumulation of dust could be the issue, consider hosting your panels away from the floor first. 

This is the most secure, simple, and least expensive option, and it’s the most effective option, with the best return. Be aware that if your roof is not low enough to allow spraying from below, but high enough to need an electric pressure washer or nozzle that concentrates the pressure of the hose, make certain not to hit those solar panels using harsh, high-pressure waves of water. 

Abrasive pressure on the surface extreme pressure could cause scratches. The scratches can create tiny shadows onto the cells of photovoltaics under the glass layer that is tempered, forever reducing the power output of the solar panels.


To Get A More Substantial Buildup Use Soft Scrubbers, Mild Soapy Water And A Squeegee Clean Off Your Solar Panel.

The type of soiling, the level of rainfall, the size of the installation, cleaning methods, and the mineral content of water that is used in the process of clean panels can impact the number of effectiveness benefits from washing.

Cleaning supplies you’ll need:

  • A gentle brush and squeegee are enough to reach wherever the area you’re working. *
  • A water hose that is long enough to reach the panels.
  • A bucket of water and some mild soap. **

*Pro-tip If you do not have the proper tools at hand There are a variety of cheap, all-in-one window cleaning tools that include an easy scrubber that gently cleans the glass on one side and a squeegee in the other, which is mounted on a pole that can be extended, such as this.

**Pro tip: You may get special biodegradable solar panel cleaners such as this, in a disposable hose mix sprayer.


Box Clean Solar Panel

Cleaning process:

  • Fill the bucket up with fresh water, and add a tiny amount of soap.
  • Clean solar panels by rinsing them with pure water to wash away the dirt that has accumulated.
  • Make use of a soft scrubber and detergent water from the bucket — or mixing sprayer — to gently wash the panels’ surfaces.
  • Rinse solar panels with clean water from the hose a second time.
  • Squeegee panels dry.
  • Repeat the process and change your position as required until all panels are clear. ***
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Solar Panel Cleaning Equipment
***Pro tip: Take care to stay clear of touching the sides or the underside. Be sure to stay clear of any wiring harnesses and cables.
night clean

It is important to keep in mind that solar panels can get very hot during midday. Therefore, it is best to plan your cleaning time for dusk or dawn, or on days with overcast skies in which their surface is quite cool. When you clean the panels using soapy water, while they’re hot, the soapy water would quickly evaporate, leaving a film that would require further cleaning steps to get rid of.

panel cleaning

Sometimes, it’s less expensive as well as safer to contact professionals for cleaning services.

You may have considered the factors involved, taken a look at the tools that you have available, and decided the task of cleaning solar panels by yourself isn’t an option for you. For instance, perhaps you’ve discovered:

  • Your roof is high, steep, or slippery for you to walk on.
  • There’s no ladder or a set of adequate cleaning tools, and the thought of purchasing and storing all the equipment you only use a few times a year is not logical.
  • There are physical limitations that can make climbing ladders or hop about on roofs a risky possibility.
  • It’s better not to be the one to do everything.

For many solar owners cleaning services from a professional can be the most beneficial alternative. In this case, the most sensible option is to contact the solar companies that installed your panels initially to inquire about cleaning services. 

They should be able to provide information about the roofing materials, roofing pitch, area of the solar array as well as digital renderings of the way the solar panels are placed over your roof.

Based on the size of your solar power system as well as the region where you reside and the various levels in the cleaning services your business offers, solar panel cleaning services could cost anything from $100-$600 per visit.


The final thoughts

Based on your climate dust, as well as other pollutants that can accumulate on the solar panels are crucial to regularly wash off your panels. Then, should you need to follow the steps below to thoroughly clean them or employ professionals to clean them? If you do it correctly and regularly, cleaning your solar panels will ensure that your system is operating to its maximum efficiency, so that you will reap the maximum advantages of going solar each year.



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