How To Clean Rooftop Solar Panels
Everything in life requires maintenance–your car, your house, and your rooftop solar panels.
You made a significant investment in a sustainable power system that would give you freedom and sovereignty over your power. But, the installation of your solar panels was not the end of it.
To perform at their very best, your panels require maintenance and care throughout the year, including an occasional rinse and soft scrub every so often.
Read on to learn how to properly clean and extend the life of your rooftop solar panels by avoiding these common mistakes.
Why You Need To Clean Your Solar Panels
Much like books on a shelf, your rooftop solar panels also collect dust. But, they also collect more than that.
Their position on top of your roof exposes them to several kinds of solar obstructions and weather conditions.
Even though your solar panels work all year round. they benefit from occasional cleans over the year that will help to maximize their solar output.
You may think that the rain is enough to help with your rooftop solar panel cleaning.
To an extent, rain does works.
Gravity works in tandem with the rain, but only for sloped roofs. Flat roofs retain the unfortunate residue and remnants of all kinds of solar panel obstructions that must be physically removed with cleaning.
Dust On Your Panels
The rain can wash away some of the dust, but the rain itself can also leave a deposit on your panels. Rain contains particles of dust that will cling to the surface of your solar panels even after the water has evaporated.
Dust may not reduce panel efficiency by much, but it’s not the only thing sitting on your rooftop solar panels. These next panel obstructions require a good clean every few months to keep your panels working at full efficiency.
Other Rooftop Solar Panel Decorations
Bird droppings, leaves, mud, and hardened debris can accumulate on your solar panels over time, in between cleans. These solar panel obstructions can effectively lower the solar output of your rooftop panels.
Luckily, your solar panel PV system is designed to store excess energy for periods where panels aren’t capturing as much energy as they can.
Even so, to keep your panels operating at the greatest efficiency all the time, clean your rooftop solar panels at least two times a year. Increase cleaning frequency if you live in an area with high pollution or very little rain.
Common Mistakes People Make When Cleaning Rooftop Solar Panels
You do not need a lot of fancy tools to clean your rooftop solar panels. However, there is a technique for cleaning solar panels that helps to maintain and extend their life.
Here are some of the most common mistakes people make when trying to clean rooftop solar panels independently.
Using A Pressure Washer
A pressure washer might work well for your barbeque grill or for cleaning your driveway. But think about how powerful that water is when it hits the surface of what it is cleaning.
You don’t want to use a pressure washer for your glass solar panels. The pressure of the water can crack and damage your panels, and cost you extra to replace.
Not Paying Attention to Temperatures
Rooftop solar panels sit on your roof and absorb all the heat and energy from the sun. They get pretty hot in the process.
If you spray cold water on your hot panels when cleaning them, they can crack.
The best time to clean your solar panels is in the morning or the evening when the sun is not at its peak. This makes it easier for you, too.
Not Reading The Instructions
Your solar panels come with a manufacturer’s guide or instructions on how to take care of your rooftop solar panels.
One of the biggest mistakes people make when they try to DIY clean their solar panels is using the wrong cleaning agent.
Never use harsh chemicals on your solar panels. The most they can handle is dish detergent diluted in water, but even that can damage the film on your solar panels.
Be sure to refer to the manufacturer’s guide before attempting to clean your solar panels on your own. If you’re still unsure, using just water is a safe bet.
Using Regular Water
Or water that is available from the tap.
Most people overlook something as simple as the water source when cleaning rooftop solar panels. This little detail can affect how your panels will look after cleaning.
Professional solar panel cleaners recommend using purified water to clean solar panels. You can use reverse osmosis or deionization to filter your water source.
Using pure water helps your rooftop solar panels to dry streak- and stain-free. That’s the goal–to get them sparkling clean by the end.
Using A Squeegee
Some people think that cleaning rooftop solar panels is like cleaning shower glass after a shower or cleaning a regular glass window.
It’s not. Your solar panels are different than either of those surfaces.
While squeegees work to quickly clean up liquids from glass surfaces, they are not the best tool to use on your solar panels. Think about where you’ll be using the tool.
A squeegee can pick up a tiny rock from your roof and transfer it onto the surface of your panel.
While you’re squeegee-ing your way down your rooftop solar panels, it will drag the rock across the surface and leave a distinguishable mark.
The best tools to use on your solar panels are soft bristle brushes, soft sponges, and plastic scrapers. You can attach these tools onto long poles that can help you to get to those harder-to-reach places.
Be sure to clean only where you can reach safely. You’re on the roof, after all.
Walking Without Caution
This might sound silly, but you need to hear it. Don’t walk around your roof without a game plan.
Professional rooftop solar panel cleaners and professionals who work on roofs know that the roof is a more dangerous terrain to navigate.
The steeper the roof, the more dangerous the clean. Use safety harnesses to secure yourself while cleaning your rooftop solar panels.
For steeper roofs, we do recommend hiring professional rooftop solar panel cleaners to get the job done.
For flatter roofs, you can definitely do it yourself. Just be careful with how you walk on your roof. Clay- and tile-laid roofs are more prone to cracking, so heed caution if your roof is fragile.
After cleaning your solar panels, make a solid game plan to get off your roof safely. Because your roof’s surface and your shoe’s soles are wet and slippery, go slowly until you reach the ground.
How To Clean Solar Panels On Roof
Cleaning your own rooftop solar panels is not hard, and you don’t need super expensive tools.
Here are the tools and steps you need to take to get your panels sparkling clean and operating at maximum efficiency.
Tools You Need
- Purified water
- Angled garden hose with spray nozzle
- Non-abrasive sponge
- Soft bristle push broom
- Plastic scraper
- Long handle tool attachments
- Extension ladder
- Ladder stabilizer
- Safety harness
- Dishwashing detergent
You do not need all the tools listed here. Some are alternatives for others.
For example, you may not need a safety harness and rope if your roof is flat and relatively safe enough to work on.
You may also opt for a soft bristle push broom and forgo the handheld plastic scraper to help get rid of hardened debris.
This is just a list of tools you may need that can set you up for success for your rooftop solar panel cleaning.
Simple Steps For Cleaning
- Extend your ladder to your roof and attach the ladder stabilizer
- Get on the roof and bring up your equipment with caution
- Spray your solar panels down with your hose using purified or filtered water
- Use your soft bristle push broom to sweep the surface and loosen the debris
- Use your plastic scraper to go over the panel surface only where you can safely reach
- Spray your panels down once more to wash away the debris
- Get off the roof with extra caution
When To Hire A Professional
If you cannot safely get onto and off your roof to clean your solar panels, consider hiring a professional team.
Rooftop solar panel cleaners have extensive training for working on roof terrains and are insured in the case of accidents.
We recommend hiring a professional to clean your rooftop solar panels if:
- your roof is too high or steep
- you have a large solar panel system and a lot of surface area to cover
Take Care Of Your Power System
Your rooftop solar panels are not cheap and require the proper care and maintenance.
It’s like having a much more expensive iPhone on your roof, except your panels literally power your entire home. If they’re not working right, your home’s power system suffers.
Keep your rooftop solar panels operating at full efficiency by cleaning them throughout the year.
Have you made any of these mistakes while cleaning your rooftop solar panels?
Share this article to help a friend who’s thinking about attempting their rooftop solar panel cleaning on their own. You might save them these newbie mistakes and a lot of money in the process.
Are you ready to own your power? Reach out to Primitive Power today!
How To Clean Solar Panels (2023 Guide)
Enter your ZIP code below to get a free home solar system quote.
- Cleaning Solar Panels
- Understanding Solar Panel Components
- When and How Often To Clean Solar Panels
- Preparation for Cleaning
- Step-by-Step Guide Cleaning Solar Panels
- The Bottom Line
Leonardo David is an electromechanical engineer, MBA, energy consultant and technical writer. His energy-efficiency and solar consulting experience covers sectors including banking, textile manufacturing, plastics processing, pharmaceutics, education, food processing, real estate and retail. He has also been writing articles about energy and engineering topics since 2015.
Tori Addison is an editor who has worked in the digital marketing industry for over five years. Her experience includes communications and marketing work in the nonprofit, governmental and academic sectors. A journalist by trade, she started her career covering politics and news in New York’s Hudson Valley. Her work included coverage of local and state budgets, federal financial regulations and health care legislation.
Solar panels are very durable — the best solar companies now offer a 25-year product warranty, and most panels have a typical lifespan of 25 to 30 years. However, photovoltaic (PV) cells are only productive when sunlight can reach their surface, so knowing how to clean your solar panels is important. Read on for a step-by-step guide on how to clean your solar panels to prevent dust and debris build-up from reducing your system’s power output.
The Importance of Cleaning Solar Panels
If dust build-up blocks 50% of the sunlight reaching your solar panels, their energy output can drop by half. This decrease in productivity can negatively affect electric bill savings — if you were previously saving 100 each month, you might notice that savings drop to around 50 a month.
Regular cleaning helps keep your solar panels operating at optimal capacity, which means your system generates its expected electricity output. A dirty solar energy system does not operate at maximum efficiency, which can result in higher power bills and, as a result, a longer payback period. Professional solar panel cleaners use the term “soiling losses” to describe the efficiency loss caused by dust and dirt buildup on your PV system.
Understanding Solar Panel Components
Solar panels consist of photovoltaic cells fully encapsulated by other materials, which prevents exposure to dust, dirt, bird droppings and weather conditions. However, grime can accumulate on external surfaces over time, which you should clean regularly. Here are some tips to clean different solar panel components:
Cleaning the Glass Cover
A transparent glass cover protects the PV cells in a solar panel. Ideally, you should clean the glass surface with non-abrasive cleaning tools like a soft bristle brush or squeegee. Avoid using wire brushes, roof rakes or any other tools that may leave scratches.
You can wash solar panels with a garden hose, but you should never do this when they are hot since the drastic temperature change can crack the glass. Keep in mind that solar modules may still be hot after sunset, especially on summer days.
Make sure you have a clean water supply when cleaning your panels. Washing your panels with hard water will leave behind a mineral layer after the water evaporates, defeating the purpose of the cleaning process.
Cleaning the Aluminum Frame
Solar panels have an aluminum frame that holds all other components together. Solar manufacturers use powder coating and other treatments to improve corrosion resistance, making the aluminum frame suitable for outdoor use. However, the frame is constantly exposed to dust, just like the glass cover.
Since the aluminum frame is corrosion-resistant, you can wash it safely with a standard water hose. Never use a pressure washer: it can damage the seals around the aluminum frame, and you may void the product warranty. Cleaning solutions with detergents or other chemical agents can also damage the seals and should be avoided.
If your panels have not been cleaned in a long time, washing may not be enough to remove grime. In this case, you should brush away dried-up dirt before using a hose. You should avoid chemical agents in general but can use a small amount of soapy water to clean spots with excessive dirt buildup.
Cleaning the Polymer Backsheet and Junction Box
The back of a solar panel is covered with a backsheet, typically made of a durable polymer. The back surface also contains a junction box with electrical terminals used to wire multiple panels into a string circuit.
Since the backsheet and junction box are not always outward facing, these components require less cleaning than a panel’s glass cover and aluminum frame.
- In rooftop solar installations, the backsheet and junction box are hidden by a small gap between the back of your panels and the surface of your roof. This positioning creates minimal exposure to dust and dirt.
- But a ground-mount system or solar carport exposes your panels to dust from all directions. In this case, the back surface may also need frequent cleaning.
You can follow the same cleaning recommendations for the glass cover and aluminum frame to clean the backsheets. Soft brushes and non-pressurized water are suitable, but avoid pressure washers and chemical agents.
Never open the junction boxes or manipulate electrical connections in any way. If your solar installation includes a workmanship warranty, you can contact your provider to inspect any electrical malfunctions. Many companies also offer professional solar panel cleaning services.
When and How Often To Clean Solar Panels
Many solar manufacturers and installers recommend cleaning your solar panels at least two times a year, but cleaning needs can vary depending on site conditions. Your panels may need additional cleaning if your home is close to a construction site or industrial zone. You can expect large amounts of dust in the air, which can accumulate on your PV system in a short time. Be mindful of locations with high concentrations of trees or other foliage as leaves and pollen can also build up on your panels.
If you live in a place with frequent rainfall, your panels will require minimal cleaning during their service life since rain washes away most of the dirt for you.
Preparing for Solar Panel Cleaning
We at the MarketWatch Guides Team only recommend cleaning solar panels on your own if you can safely access your system from the ground or have a flat roof. The task should be left to a professional cleaner if you need to climb your roof or other tall structure to access your panels.
Solar Panel Cleaning Checklist
In general, you need the following tools to clean your solar panels:
- A non-abrasive cleaning tool such as a soft brush or a squeegee
- A water hose
- A telescopic extension pole, in case you need to reach solar panels on a roof
If you are not comfortable cleaning your panels on your own, contact your solar installer for professional panel cleaning services.
Step-by-Step Guide to Cleaning Solar Panels
You can clean your solar panels more efficiently by following these steps:
Brush Away Dried-Up Dirt and Residue
Washing your solar panels is quick and effective when they are not very dirty. However, spraying water is counterproductive when there is a lot of dust and grime. Water and dirt create mud when mixed, which will dry up on your panels. Use a soft brush to remove dried-up dirt, bird droppings and other debris when your panels are dry.
Wash Your Panels with Clean Water
Once you have cleaned dried-up dirt and debris, you can wash your panels to remove any remaining dust and particles. Make sure your water supply is clean and avoid high-pressure nozzles. You do not need to wipe your panels dry since the water will evaporate on its own.
Remove the Remaining Dirt
If your solar panels are very dirty, brushing and washing may not be enough to clean them completely. You can scrub trouble spots with water and normal soap, but avoid detergents and other strong cleaning agents.
Maintaining Your Solar Panels Between Cleans
Solar panel maintenance not only involves frequent cleaning. You should also monitor energy production on a regular basis to rule out electrical issues. Many solar inverters include a monitoring app for homeowners, which you can use to track daily power generation with your smartphone.
Low productivity is normal on overcast days since your solar panels are exposed to minimal sunshine. However, you should call your solar provider if the monitoring app shows lower-than-average electricity output on a sunny day.
The Bottom Line
The best residential solar panels have a 25-year warranty to cover product and installation issues but still need regular cleaning to stay productive. Dust buildup negatively affects panel efficiency, which can reduce your power bill savings.
Do-it-yourself (DIY) cleaning is suitable if your solar panel system is installed on the ground or on a flat roof that you can easily access. If you have a single-story home with a pitched roof, you can also use an extension pole with a squeegee. Due to the risks involved, professional cleaning services should be used if you can only access your solar panels by climbing the roof.
Suitable cleaning tools methods for solar panels include:
- A soft cloth, sponge or brush
- A squeegee
- Washing with soft, non-pressurized water
On the other hand, you should avoid these methods and tools:
- Hardwire brushes
- Roof rakes
- Abrasive cleaning tools
- Hard water
- Chemical agents
Solar panels have a high upfront cost, and protecting your investment is important. A solar panel system typically costs 2.85 per watt or 17,100 for a 6 kilowatt (kW) system, and the 30% federal solar tax credit reduces your total to 11,970. With those figures, you can expect a payback period of around 8.5 years. When you combine a 25-year warranty and regular cleaning, you can utilize your solar panels for over a decade after paying off your system.
How To Clean Solar Panels, How Often, Maintenance Trick for Max Power
Installing solar panesl on your home to supplement, or fully power it is an awesome way to help the planet, but did you know that learning how to clean solar panels correctly can have an impact on the performance of your panels?
Dirt, dust and grime can interfere with the productivity of the panel and also shorten its lifespan.
And, you can’t simply count on the rain to do it for you.
Fortunately, it’s not as complicated as it sounds.
Knowing how to clean solar panels – and how not to clean solar panels – is essential to maintaining their energy efficiency. Fortunately, cleaning most solar panels is closer to household cleaning than industrial labor.
Common household items and common safety measures can keep the solar panel operating optimally.
You can easily learn how to clean solar panels and how often you should do it using this complete guide…which will ensure that you retain maximum power output.
Where Can I Learn How Often To Clean Solar Panels?
Due to external factors such as varying climates, the physical placement of the solar panels, and the location’s fauna and pests, there is no standard answer to how often solar panels should be cleaned.
Environments that are more prone to dust accumulation – such as deserts with low precipitation and high winds – will require solar panel operators to perform more frequent cleaning.
Visible accumulation of debris and significant reductions in energy capture are strong indicators that solar panels are due for cleansing.
Visual inspections and energy monitoring will often indicate when a solar panel needs to be cleaned. When a solar panel looks dirty or starts to produce less energy, you should take care of it.
How To Clean Solar Panels: 7 Steps
Fortunately, the techniques used for cleaning household Windows are exactly how to clean solar panels.
Simply spraying water removes most of a solar panel’s grime, and the combination of a non-abrasive brush and glass-friendly cleaners can take care of more difficult impurities such as biological stains.
The only major complication is applying safety precautions.
Homeowners and cleaning personnel should ensure that solar panels are powered off during cleaning.
It’s also a good idea to ensure that the panel can be accessed safely, so never do the job on a roof by yourself.
How To Clean Solar Panels From the Ground
Cleaning solar panels from the ground is not different from cleaning common glass fixtures such as Windows and glass doors.
However, it’s vital to FOCUS solely on the reflective side of the solar panel and avoid contact with a solar panel’s underside.
How To Clean Solar Water Heater Panels
Unless the manufacturer’s documentation states otherwise, the guidelines on how to clean solar panels are the same for cleaning solar water heater panels.
Consider hiring a professional if the solar water heater panels are installed on high places such as roofs that feature a steep grade.
How To Clean Solar Panels on Garden Lights
The process of cleaning solar panels on garden lights is like cleaning household and industrial-sized solar panels.
Though non-abrasive household cleaners are often sufficient, checking the manufacturer’s documentation is advised.
Typically, it’s safe to use a window cleaner on these easy-to-reach solar panel garden lights.
How To Clean Cloudy Solar Light Panels
The process of cleaning solar light panels uses similar materials and steps as cleaning solar panels.
Solar light panel operators should FOCUS on cleaning the plastic and erring on the side of using non-abrasive cleaning tools and solutions.
If you have cloudy panels, it may be an issue with the manufacturing, or the panels could simply be aging. In either case, check with your manufacturer first. They may have a simple solution.
How To Clean Solar Panels on Roof
Contracting a third-party solar cleaner is ideal for rooftop installations that you cannot safely reach on your own.
If you do not have the equipment and training to reach precariously placed solar panels, contact professionals.
How To Clean Solar Lights
Treat solar lights the same way you would treat solar panels.
Make sure that the photovoltaic panel is clean, without dirt and grime, and check it every month.
Solar Panel for AC Unit: Cleaning Considerations
Solar-powered AC units frequently require multiple solar panels to operate properly.
However, unless the manufacturer’s documentation states otherwise, the guidelines and tools for cleaning a solar panel for AC unit are the same as how to clean solar panels for other uses such as general energy generation and water heating.
Cleaning Solution for Solar Panels
With regards to cleaning, most solar panels can be treated similarly to household Windows. Cleaning solutions commonly found in supermarkets are acceptable if they’re non-abrasive.
Mixtures of soap and water will work as well, but it’s advisable to strongly dilute the soap (to prevent any leftover buildup).
Most of a solar panel’s dust and debris can be removed with water. Rainwater acts as a natural dust remover. Hoses are an acceptable solution if the water is soft, and it is sprayed from a safe distance.
However, there’s more to solar power than installing a panel and enjoying sunny days and lower electricity bills.
Maximizing the benefits and lifespan of solar panels requires consistently monitoring and maintaining the panels.
Carbon Footprint: Solar Panels Lower Than Utility Costs
When properly implemented and installed, solar panels can be a powerful method of reducing the amount of carbon dioxide in our atmosphere.
Addressing the climate change crisis and reducing the global carbon footprint will require multiple actions at once.
Switching from dirty energy sources – such as oil and natural gas – to environmentally-friendly energy will be crucial to the world’s survival.
Cities, groups, and individuals switching to renewable energy such as solar power will be one crucial step toward reducing the average American’s carbon footprint.
One acre of solar panels generating clean energy can generate up to 447 megawatts per hour; replacing an equivalently-producing dirty fuel with carbon footprint solar panels can lower the release of carbon dioxide by 138 metric tons a year. 1
Although solar panels have a heavy eco-cost during production and disposal, the current benefits, especially to homeowners, is significant.
Benefits of Cleaning Solar Panels
Maintaining energy efficiency is one of the most vital benefits of cleaning solar panels. Dust, grime, and biological stains block the sun’s rays, so routine cleaning is crucial to maximizing energy efficiency.
Routine cleaning also extends the lifetime operation of solar panels. Removing stains and particles before they can inflict long-term damage is a key component of solar panel maintenance.
Consequences of Leaving Solar Panels Dirty
Failure to routinely clean solar panels can dramatically reduce their energy efficiency. One month of gathering dust and other ray-blocking impurities can lead to a 30% drop in a solar panel’s energy-capturing ability. 2
In addition, excessive buildup of dirt and grime can damage solar panels. Biological waste and large quantities of dust can cause problems such as scratches and hot spots.
Size of Standard Solar Panel: Myths Versus Reality
The size of standard solar panel depends on the size of its solar cells, the number of its solar cells, and its intended use. Most solar panels used for residential and industrial buildings have square cells with side lengths of 156 millimeters (approximately 6.14 inches). 3
Solar panels for residential use commonly have 60 cells. When those cells are arranged in a 6-by-10 grid, the resulting solar panel would be 1.56 meters long (roughly 5.12 feet) and 0.94 meters wide (about 3.07 feet).
Solar panels for commercial use often have 72 cells. When those cells are arranged in a 6-by-12 grid, the resulting solar panel would be 1.872 meters long (roughly 6.14 feet) and 0.94 meters wide (about 3.07 feet).
Solar Panel Cleaning Tips
Prior to any cleaning attempts, review the documentation that corresponds to the solar panels. Solar panels can vary significantly by manufacturer, so complying with the manufacturer’s instructions and warnings is essential when formulating how to clean solar panels.
Clean their solar panels during the coolest parts of the day. Excessive heat can cause water and cleaning solutions to evaporate, which can lead to efficiency-reducing smears and streaks.
So, early morning or late evening is the best time.
Since solar panels are electrical devices, an error can seriously injure a person who is attempting to clean it without the proper access, or damage the solar panel. This is especially the case for solar panels installed in high areas such as residential roofs.
Avoiding Common Mistakes During Solar Panels Washing
Non-professionals should not leave the ground in attempts to clean solar panels. High and hard-to-reach solar panels should be treated by professionals who have the experience, training, and equipment to safely reach and cleanse them.
Cleaning materials that scratch household glass will also scratch solar panels. Applying hard water and coarse cleaning agents will permanently damage solar panels.
Do not attempt to clean any part of the solar panel other than the surface.
Attempting to clean the underside of the solar panel or other concealed parts could lead to injury or damage.
Solar Panel Maintenance
Regular monitoring is the best method for solar panel maintenance.
Routinely monitor solar panels’ energy efficiency as well as any indicators or alerts from inverters and other monitoring tools.
Consistent exposure to shade, in addition to lowering solar panels’ energy collection, can damage solar panels. When shade routinely or completely covers a solar panel, the solar panel can develop hot spots, parts of the solar panel whose temperature is significantly higher. 4
Failure to resolve consistent shade issues could drastically reduce the solar panel’s lifespan or completely break it.
Do Solar Panels Need Cleaning?
Do solar panels need cleaning regularly? Yes. Knowing how to clean solar panels is essential to preserving their energy efficiency.
Accumulation of dust, grime, and other impurities can dramatically lower the amount of energy they capture.
And some types of grime can permanently damage solar panels.
How Much Does It Cost To Clean Solar Panels?
Cleaning residential solar panels at ground level can frequently be completed with household items and over-the-counter cleaning tools. The cost for these do-it-yourself cleanings is comparable to the cost of a bag of groceries.
Professionals typically charge between 15 and 25 per panel. In addition, they may charge between 150 and 300 for panel inspections.
Do I Need To Turn off Solar Panels To Clean Them?
Solar panels must be deactivated prior to any cleaning attempts, even if no liquids are being used.
Solar panels that are actively collecting energy pose electrical hazards for those who would attempt to clean them.
How Long Do Solar Panels Last?
Solar panels’ operational lifetime varies due to a variety of factors, including the type, the manufacturer, and the environment.
However, some types of solar panels, properly maintained, can operate for up to 30 years before they need to be replaced.
Do Solar Panels Work on Cloudy Days?
Solar panels can capture indirect sunlight.So, when asking, do solar panels work on cloudy days, the answer is yes, but limited.
Although the energy generated from indirect sunlight is lower, solar panels can still function and generate electricity on cloudy and overcast days.
As an unintended benefit, cloudy days can make solar panel cleaning easier. Overcast days with lower temperatures give you additional flexibility when scheduling cleanings, as the cloudy weather often leads to lower temperatures.
Also, rainfall acts as a natural dust remover, washing away loose particles that accumulate on the solar panel.
When Is the Best Time of Day To Perform a Solar Panel Wash?
A general rule of thumb is to clean solar panels at the coolest parts of the day. Like watering plants, cleaning solar panels in the morning prior to peak heat is optimal, though an early-evening cleaning will suffice.
Cleaning solar panels can sound like a daunting task at first.
The process is very similar to cleaning Windows and glass doors. Applying soft, soapy water and a soft-bristled brush once a month is often as complicated as cleaning solar panels can be.
And the benefits of these easy and cheap actions can be dramatic. Consistent and careful solar panel cleaning can maximize the solar panel’s lifespan and energy capture.
And a few minutes of washing solar panels can prevent costly and time-consuming technical issues that would otherwise require costly repairs or replacements.
However, it’s imperative to ensure that solar energy is applied in an environmentally friendly way and treated as part of a multi-faceted solution instead of a cure-all. Failure to properly clean and maintain solar panels can negate their benefits or even be detrimental in terms of energy consumption and environmental impact.
Proper installation and usage of solar panels can be an effective way to reduce carbon emissions, but solar panels’ benefits – both to the person who is cleaning them and to the environment – can be enhanced when you know how to clean solar panels correctly.
Carbon Footprint: Solar Panel Manufacturing In 1 Simple Explanation
How Many Solar Panels Do I Need? Calculator Shows Correct Sizing (Free)
How To Test Solar Panels’ Power Output (Both With and Without a Multimeter)
Solar Farm Income Per Acre Calculator: See Profit Margin, Costs, Money Made
1 Eisenson, M. (2022, October 26). Solar Panels Reduce CO2 Emissions Per Acre Than Trees — and Much Than Corn Ethanol. Columbia Climate School. Retrieved March 9, 2023, from
2 Chandler, D. L. (2022, March 11). How to clean solar panels without water. MIT News. Retrieved March 9, 2023, from
3 Wikipedia. (2023, March 9). Solar cell. Wikipedia. Retrieved March 9, 2023, from
4 Tinker, L. (2016, September 16). Getting the Most out of Solar Panels. Energy Gov. Retrieved March 9, 2023, from
Solar System Maintenance: Do Solar Panels Need Cleaning?
Home / Blog / Solar System Maintenance: Do Solar Panels Need Cleaning?
Cleaning your solar panel system
Do solar panels need to be cleaned? While you probably don’t need to clean solar panels for daily dust and pollen, if you live in an area where it doesn’t rain a lot or where airborne particulate matter such as smog is dense, then your solar panels should be cleaned more often.
Types of solar panels
When you shop for solar panels, you will encounter three types of panels. Those are:
- Monocrystalline (single crystal): Monocrystalline solar panels begin with a single silicon crystal with super clear qualities, from that single-crystal an ingot is made. The ingot is sliced to create ultra-clear cells that become one PV Cell.
- Polycrystalline (multi-crystal): Polycrystalline solar panels are like monocrystalline solar panels. The exception is that inside each PV Cell are multiple crystals. That tightly packed formation slows down the movement of electrons.
- Thin-film (amorphous): Thin-film (amorphous) solar panels – are not crystalline; they are amorphous. They are one of the highest efficiency solar panels available but only if you can apply them to a larger area. The advantage is that these are much easier to build, so they are often less expensive. They are also flexible and work on surfaces where it would be difficult to use a mono- or polycrystalline solar panel.
The differences are how they are made, their cost, maximum efficiency in creating energy, and their best use scenarios. But, of course, those factors also change based on the solar panel manufacturer.
The key to understanding when to clean your solar panels has everything to do with solar panel efficiency.
All three types of solar panels need cleaning at least annually. The actual frequency of cleaning depends on the environmental condition that your solar array faces.
To clean or not to clean
The efficiency of a solar panel is all about how many photons the cells can collect. For example, sunshine has photons in it, and as it strikes the surface of the solar panel, some of those photons are captured by the solar cells. However, if you have dirty panels, the dirt and grime block more of the solar photons, and few are captured by the solar cells. Generally, that is not a big deal, but cleaning the panels will help keep electricity production at its peak efficiency. Here’s a closer look at what that means.
Should you clean solar panels?
For the most part, you do not need to clean solar panels, but there are situations where cleaning is essential. That may sound like a contradiction, but here is why that is not so.
First, solar panels are tilted. That means when it rains, the rain will wash all the loose material off the panels. If you live where it does not often rain, consider having your solar panels cleaned at least twice per year. Some materials require a garden hose and a soft brush to remove them. Those include bird droppings, pitch from trees, leaves, and debris too large for the rain to remove.
So, the basic rule of thumb is that you do not need to clean solar panels often, but they do need cleaning. How often you clean them depends on the environmental abuse they suffer.
How often do solar panels need to be cleaned?
How often does a system need to be clean? The answer to this question is “it depends.” If you live in an area with a lot of wind, dust, smog, or near trees, the answer is each season. On the other hand, if you live in an area where the solar panels are sheltered and not prone to dust storms, flocks of birds, or sappy dripping trees, you may only need to have the solar panels cleaned yearly.
How do you know the solar panels need cleaning? The best way to tell is when you notice a drop in energy production from the solar array. Dirt on the panels can build up and cause a drop in energy output. You can also be proactive and clean before you notice a drop in energy.
When Should You NOT clean solar panels?
Never clean solar panels when they are turned on or when the array is active. Always clean them when the system is turned off for both the AC and DC isolators. Remember that electricity will always follow the path of least resistance. With a solar system, the energy can flow in both directions.
Never clean the units in bright sunlight. Not only will the sunlight charge the solar panels, but it will also heat the surface of the panels and cause soapy water to stain the surface. So instead, clean the panels in the morning, later afternoon, or when weather conditions are favorable, such as on cloudy, overcast days when the temperature is cooler and never allow the water to dry on the panels.
Cleaning methods for solar panels
Water, a soft brush and a long garden hose with a suitable nozzle are all you need to clean most solar panel systems. Make sure the brush is rated for use on glass surfaces so that it does not scratch the panels.
A rubber squeeze or a plastic blade is also helpful to remove the water from the solar panel’s surface. Finally, never use harsh chemicals on solar panels. Some may have a chemical reaction that mars the solar panel’s glass.
If there is a substance on the solar panel that will not come off with a light brushing and water, use a mild detergent, but make sure that the surface temperatures of the solar panels are cool. You do not want the detergent to dry on the glass as it will cause a haze and block more solar photons.
Another option is to hire service like Coldwell Solar that specializes in cleaning and maintaining commercial solar installations. The benefits of using a professional solar company means:
- A professional will handle turning on and off the electricity
- You don’t need to be on a wet, slippery roof.
- They will have the tools and solutions to clean the solar panels safely.
- They will also have the experience to handle hard-to-clean residue off the panels, such as pitch.
- Some solar maintenance programs also include solar panel cleaning as part of their regular maintenance programs.
What are the overall benefits of solar maintenance?
With most things “solar,” the most significant benefit is that the array continues to run at peak efficiency. That means your array produces the most energy possible given its location and the amount of sunlight it receives.
Solar panel cleaning is akin to removing “shading” from the solar panel. That is especially important if your solar system is set up with string inverters.
Shading occurs when something blocks the sunlight from striking a solar panel. Usually, it is a tree branch or a shadow. Remember that solar panels do not function without sunlight. If the panel becomes shaded, it stops producing electricity. If the solar panel is wired in a string and becomes shaded, then the entire production of the string of panels decreases. That drop can be significant and large enough to cause a reduction in power.
If a panel has debris, dirty, or grime on it and it is wired in a string, the substance on the panel can cause shading. You may not notice the power drop until you get a larger bill from your utility company.
Other reasons why you should consider a professional solar maintenance company to clean and maintain your commercial solar array:
- It is safer to let professionals clean your solar panels because they keep you off the roof and from electrical components.
- They understand how to properly turn the system off and back on.
- They check for and repair other solar issues, such as faulty panels.
- They have the tools and expertise to safely and efficiently clean hard-to-remove debris from solar panel glass, including pitch, tar, and pollen, without damaging them.
Learn more about solar panel cleaning and maintenance by giving our team a call. We are happy answer your questions or schedule a service and maintenance call.