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Solar and photovoltaic panel cleaning. Solar system clean up

Solar and photovoltaic panel cleaning. Solar system clean up

    Solar and photovoltaic panel cleaning

    It was originally said that cleaning and maintenance of photovoltaic systems was not necessary. But now it has become apparent that weather and air pollution do leave their mark. In order to use solar power as efficiently as possible and to keep the electricity yield at the highest possible level, regular professional cleaning with the right equipment is necessary.

    Cleaning and maintenance of photovoltaic systems

    All types of photovoltaic systems should capture sunlight for as many hours as possible and withstand external influences. These include snowstorms, rain, storms and hail as well as, depending on the location, soot, pollen, dust from road traffic, leaves, needles or bird droppings. In agricultural areas, additional films of dirt containing grease and oil form due to particle emissions during the ventilation of poultry houses.

    Why should I clean solar panels?

    Clean the panels regularly, not only because of their appearance. Contamination can reduce the electricity yield by up to 30 percent. Thorough, professional cleaning is necessary, and this does not only apply to the surfaces of the solar collectors. Deposits build up at the junctions between the glass and the frame, which over time can lead to the formation of moss and lichen over a wide area.

    Proper cleaning of the solar panels requires the right cleaning technique due to the heavy soiling. The modules are often mounted on roofs at a steep angle of 45°, so take measures to ensure operator safety.

    When should I clean photovoltaic panels?

    You should clean solar systems using the right technology and, depending on the location, using professional service providers.

    In the agricultural sector, we recommend you clean them two to four times a year, for example after flowering or after harvesting, when the pollution is very heavy.

    Panels that are exposed to less pollution from the environment can be cleaned once a year or every two to three years. In this case green electricity can be generated even more sustainably. a topic that will become increasingly important in the future.

    The right tools for cleaning solar panels

    A professional high-pressure cleaner in combination with a brush attachment or a roller brush and a telescopic lance are among the best ways to clean solar panels efficiently and ergonomically.

    With the right cleaning technique, it is possible to clean a solar panel area of up to 1,500 square metres per day.

    Brush attachment

    We recommend an attachment with two disc brushes that reach a working width of 800 millimetres. The effort required is reduced because the system neutralises the drifting movement with the help of the counter-rotating movements of the two brushes. In addition, the large working width ensures a high area output, which reduces the amount of work required for solar cleaning. The disc brushes have ball bearings and are driven by the water from the high-pressure cleaner. Low-pressure operation with cold water and a delivery rate of 700 to 1000 litres per hour is sufficient.

    A nylon bristle ensures scratch-free cleaning to protect the sensitive surfaces of the solar panels during cleaning. Models with harder bristles on the outside of the plates also ensure very good cleaning results on the module frames.

    It should be possible to control the amount of water comfortably via a lever on the lance while the brushes are guided in paths over the solar modules. Turning the water up a little at the beginning creates a sliding layer that makes it easier to move the brushes on the surface. A self-adjusting articulated joint to which the brush head is attached can help compensate for different working angles.

    Telescopic lance

    Choose the length of the telescopic lance to match the size of the system, or use an infinitely extendable lance. Longer lances made of carbon or carbon composite are lighter and therefore more comfortable to handle.

    If you value more flexibility and have to clean large façades in addition to photovoltaic systems, you are better off with a variable lance system. Pole systems that are suitable for vertical and horizontal surfaces are available and can be combined with different attachments. Use a high-pressure nozzle for spot cleaning, an attachment with disc brushes for working on horizontal PV elements or a rotating high-pressure roller brush, which is also suitable for vertical façades.

    Roller brushes

    The advantage of roller brushes is that they are driven by high pressure and work their way up independently. meaning you need to be holding them with a significantly less force. The roller brushes can work with water flow rates from 350 litres per hour. Brushes with soft or hard bristles are available for different surfaces. We recommend soft brushes for cleaning photovoltaic systems.

    Solar Maintenance: Understanding the Cost of Solar Panels

    At Sunrun TM. we strive to make solar energy accessible to everyone, regardless if you choose to lease or purchase — your solar system still needs proper caring. Maintaining the health of your solar panels will guarantee you the biggest energy savings possible over the next 25 to 30 years.

    How Long Do Solar Panels Last?

    Solar panels have a lifespan of approximately 25-30 years, 1 and often come with warranties to match, stating they’ll produce at least 80% of the rated power after two decades of usage. 2 They’re incredibly reliable! And although solar systems require little regular maintenance, some solar providers offer comprehensive maintenance packages for the life of their products to ensure they efficiently continue generating clean, affordable, and reliable energy for years to come.

    If you lease or buy a solar system from a solar provider who offers a maintenance agreement, your solar technicians will routinely inspect your panels at designated times throughout the year and even clean them for you. Meaning, with a plan of this type, once your system is up, you’ll forget about it — and simply enjoy your electric bill savings; while helping the environment stay clear from harmful greenhouse gas emissions by reducing your carbon footprint.

    In case your home solar panels don’t come with a maintenance plan, we’ll walk you through some essential steps you can take to keep them running smoothly.

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    The Best Way to Clean Your Solar Panels

    Remember solar panels need the sun to work. The more sunlight that hits your panels, the more power they’ll produce. But since they are angled toward the sun — this positioning unfortunately allows more dirt, pollen, leaves, birds droppings, and dust to collect on top of them. Even a small amount of grime has the capacity to reduce their energy production. That’s why it’s important to conduct periodic maintenance checks visual inspections of your system.

    Do you live in a rainy climate? In many scenarios, rain will wash off the debris your solar panels collect, especially when installed at a steeper tilt. Yet, if your panels happen to gather an unusually thick coating of filth, or if you’re a desert inhabitant familiar with layers of sand and grit covering your outdoor material possessions — you can easily rinse your panels without leaving the ground with plain ole’ water. Just direct your hose spray up to your panels and shower them off, this will imitating the cleansing action of natural rainfall. 3

    Seeing your roof getting too comfy with a snow blanket? Fortunately, most of the time the snow will melt in around a day or two due to the sun’s rays and the heat your home produces. Besides ice build up, you shouldn’t worry about your solar panels working during the cold weather. 4

    Solar Maintenance Safety Tips

    If for any reason using a hose spray at ground level doesn’t wash off the grime on your solar panels, or the snow doesn’t melt away. At Sunrun, we can’t stress enough how your safety is our #1 concern and advise against further attempts to clean your panels without the proper training and equipment. So please, contact your trusted solar provider to receive professional assistance.

    The United States Department of Energy (DOE) is committed to facilitating widespread adoption of safe, reliable and cost-effective solar energy. 5 One of the reasons it founded the Solar America Board for Codes and Standards (Solar ABCs) organization, with one of their objectives being maintaining quality control and safety standards on PV installations. Click here to learn more about their report: “PV System Operations and Maintenance Fundamentals.” 6

    How Much Does Solar Power Maintenance Cost?

    Solar panel maintenance costs can vary greatly depending on each solar provider because system installations are often tailored to the unique energy needs of each homeowner.

    Sunrun’s BrightSave Monthly TM and BrightSave Prepaid TM plans include worry-free professional maintenance and monitoring for two decades. However, if you’re looking to purchase your own solar system, our BrightBuy TM or BrightAdvantage TM plans also have your back by letting you receive the equipment warranties directly from top manufacturers in the industry.

    And if you have more questions about which maintenance routine your future solar system will need, our team of advisors is ready to discuss your energy needs and help you find the ideal solar solution for your home. Start with a complimentary solar quote today!

    Pro tip: Never use soap to clean dirty solar panels

    One thing learned during the coronavirus pandemic was the effectiveness of soap and water — regularly washing our hands was our best defense. While dirty solar panels do benefit from a regular washing to ward off reduced output and efficiency, soap isn’t the answer here.

    Courtesy: Premier Solar Cleaning

    California-based solar installer and maintenance provider Bland Company never uses a cleaning agent on solar panels, instead relying on deionized water and a rotating-brush system to wash solar panels.

    “Soaps can leave a film or residue that not only shades panels like the dirt that was just washed off, but it can also encourage dirt to stick and build up faster,” said Daniel Green, Bland marketing director. “We use deionized water that is applied through our rotating-brush system. This is the best way to leave the solar panels with a spot-free shine that’s as beautiful as the first day they were installed.”

    Rather than risk Bland employee safety or potential damage to the solar panels they’re cleaning, the company has been using Sola-Tecs brush cleaners since 2018. A rolling brush is attached to wheels that glide across the solar panels, allowing for an almost-hands-free deep clean. Bland also runs the customer’s water through a demineralizing and ionizing system.

    Courtesy: Premier Solar Cleaning

    “[Sola-Tecs] is the only cleaning system we use. We’ve found that in combination with our water treatment procedure, it’s the best way to clean solar panels,” Green said. “It requires less water, fewer passes and no harsh chemicals or detergents.”

    Premier Solar Cleaning (PSC) in Southern California also finds that using deionized water through water-fed poles and brushes works just fine to clean solar projects.

    “If you have ever smelled your hands after washing them with soap, what you smell is the soap left behind, even though you cannot see any soap afterwards,” said Adam Fuller, co-founder of PSC. “If we used soap to clean panels, the very small molecules of soap would leave something behind for dust and dirt to build upon.”

    PSC offers a full maintenance suite, including infrared inspections to find damaged panels that need more than just a good wash. Fuller also stays busy doing year-round “pigeon evictions,” cleaning underneath panels and installing critter guards to ward off birds and other animals. He takes pride in giving customers honest answers and showing how production will increase after panels are cleaned.

    Courtesy: Premier Solar Cleaning

    “The homes and factories nearest the airport and highways gather smog or oil-based pollution, which resist running off with a normal rainfall,” Fuller said. “These make some of the older blue panels appear black at first glance. Dirt on the surface reflects light away from the panels. A clean panel remains cooler, allowing the flow of electrons to move more easily.”

    National residential and commercial OM provider SunSystem Technology also stays away from soap and uses filtered water and a rotating brush to clean panels, but director of marketing Jeff Struhm said the company uses a mixture of diluted vinegar and hydrogen peroxide to aide in scrubbing away dirt and grime.

    “When rain happens, soil accumulates at the bottom edge of the solar panel, obstructing the lower PV cell row and hindering the production efficiency,” Struhm said. “It’s like a car getting hosed down — you still need to scrub it or use a soil-releasing mixture in order to avoid scrubbing.”

    Sometimes just water isn’t enough, but everyone agrees that soap should never be used. That’s why lubricant manufacturer Polywater released its Solar Panel Wash five years ago. The highly concentrated additive isn’t a filmy soap; instead it enhances water’s ability to clean solar panels, said Charlie Cole, Polywater international VP.

    Non-soap Solar Panel Wash from Polywater

    “We’re giving the water the capacity to lift the soil off the panel as opposed to a solvent, which is basically surrounding the dirt particle and taking it off the panel,” Cole said. “[Solar Panel Wash] is safer for the components of the panel. It’s not going to affect anti-reflective films; it’s not going to corrode the aluminum rails. It’s biodegradable, meaning that it’s non-persistent, making it friendly with the environment. It’s not going to affect the groundwater.”

    Solar Panel Wash modifies the surface tension of the water, so instead of water beading up, it will form a continuous film across the solar panels to lift dirt and debris. Cole said Solar Panel Wash is especially helpful in arid locations where dust is high and water is scarce, because the wash allows for less water to be used in cleaning.

    “A lot of these installations are done in desert regions where the availability of water is really an issue. If we can reduce the use of water, it’s an environmental benefit,” Cole said.

    Polywater works with panel manufacturers to get its wash approved for use to not void any warranties. Canadian Solar and other global brands have confirmed Solar Panel Wash is safe for use on their panels. It can be purchased through Polywater’s global network of distributors and from Amazon in North America.

    Solar OM providers are glad the industry is waking up to the need for periodic panel washing.

    solar, photovoltaic, panel, cleaning, system, clean

    “At the beginning, panel managers were saying, ‘Don’t use anything but rain water.’ People were taking that to heart, and then three years after the panel installation they started to see a significant degradation of productivity,” Cole said. “For a large installation, if your efficiency goes down by 50%, that really cuts into the economic justification that was made in the first place.”

    Even on residential projects, homeowners will benefit from paying some extra attention to the cleanliness of their few solar panels.

    “We oftentimes hear customers say that the rain does just fine cleaning their panels, and while the rain does wash some dirt off, it doesn’t truly clean the panels. If the panels are already filthy, the rain just makes it worse by converting dust to thick layers of mud,” Bland’s Green said. “The perfect analogy is to consider your car. If your car hasn’t been washed in six months, does leaving it out in the rain make the dirt better or worse? The same is true with dirty solar panels.”

    Just don’t use soap — a little elbow grease and water work fine.

    About The Author

    Kelly Pickerel

    Kelly Pickerel has over a decade of experience reporting on the U.S. solar industry and is currently editor in chief of Solar Power World.

    Комментарии и мнения владельцев

    I highly recommend following the advice given in this article and avoiding the use of soap to clean dirty solar panels. Using soap or other harsh chemicals can damage the surface of the panels and reduce their efficiency over time. Instead, it’s best to use a soft brush or cloth and plain water to gently remove any dirt or debris that may have accumulated on the panels. Regular cleaning of solar panel is essential to ensure optimal energy production, and this gentle approach will help to protect your investment and ensure maximum energy output for years to come. I also advise contacting a professional solar panel cleaning company to ensure that the job is done safely and effectively, especially for hard-to-reach panels or larger installations. By taking proper care of your solar panels, you can enjoy the many benefits of clean, renewable energy for years to come.

    Hello all, My name is Randy with Tiki’s SoftWash located in the Inland Empire, Southern California. I own an exterior cleaning service and one service we offer is solar cleaning. This is a great article and the information is absolutely educational. I’ve read a lot of your posts and many of you have questions and/or suggestions. As a professional that has cleaned many solar panels I wanted to speak about what we’ve learned during our time cleaning. First, solar companies don’t speak about the maintenance because this can be an added cost or added personal task to your already busy schedule. Second, we’ve found that most solar companies though are knowledgeable about general info and installation are clueless when it comes to the maintenance of your solar panels. This truth has been realized time and time again in the industry. There are several reasons one would hire a professional to clean. One of the most important reasons to hire a professional is the safety factor. Being on the roof can be very dangerous. Though some may be very comfortable with doing this task themselves doesn’t mean they have the experience to work in that environment. There are many factors to consider while cleaning on either a one story or two story home. Two, many houses in Southern California have tiled roofing materials. If you are not experienced in walking on this type of material you can cause a lot of damage to your roof. I have witnessed much damage from homeowners trying to walk on there own roof for various reasons. Three, we have all the right equipment. Our truck carries 300 feet of hose and utilizes a soft rinse and a soft bristle hand brush with extension handles that reach 30 feet for small jobs and a rotating soft bristle brush for large jobs. We clean with water only and rinse with deionized water for a streak free shine. And last, BEWARE, most solar companies claim that if customer uses any soap or cleaning products or third party companies hired that use soaps or cleaning products, that this can affect the warranty. Definitely check with your solar professional before applying any cleaning products to your solar panels. Using DI water is the safest alternative to keeping your panels clean. If you would like to ask questions or make an appointment please go to our website at: Or call: (909) 375-0408

    I live in the beautiful Central Valley in California. Since it is primarily an agricultural area, dust in the air is common, and will build up on solar panels. This layer of dirt will reduce the amount of energy the solar panels produce. I did a little research as to how the solar panels actually work and what wavelength of light solar panels use to generate electricity. I found that the solar panels use the visible wavelengths. Knowing that UV light destroys everything, especially in California, I wanted a way to block the UV light, and clean my solar panels so the visible wavelength is an obstructed. My conclusion was to use the same soap that I use to wash my car. McGuiar’s wash and wax. This car wash soap is gentle enough to clean the fragile paint on our cars, and contains wax, which will naturally be depleted by the UV rays from the Sun. I also use a car wash pass through Pole and brush that I got from Harbor Freight. Each time I have washed my solar panels, I have gotten between 7% and 12% increase in production the following day. At dusk, after the panels have cooled down, I spray them wet with water, then using a spray bottle with a quarter ounce of the car wash soap and 32 oz of water, I spray a section of panels at a time. I gently brush the panels, then I turn the water on and brush the panels again rinsing them off at the same time. I do not squeegee them dry. My panels are the cleanest on the block!

    Thanks for heads up in research. I live by Fresno. How long does the car wash last? I was using dawn dish soap and it would hold up for about a month or so before needing to be cleaned again.

    I installed 27 panels back in 2020 and clueless on how to clean them after all the months. Being a car fanatic and only taking absolute care for the paint, I figured using the same method on my panels would do no harm. I mean if a wash mitt can’t or won’t swirl the paint, how can it do any harm to the panel right? I was very unsure on using meguiars but your post just gave me some relief, so thank you.

    Panels can last for many years using this method. I have noticed that some bugs like to lay their egg cases on solar PV panels, these leave a waxy blob on the panel that is not always easy to remove. In those cases, warm soapy water, squeegee with a soft rubber blade, repeat until gone.

    Has anyone tried that product called “ Wet n Forget”. Simply because I’m terrified of getting on my roof because of the slope. With this stuff I use it to clean the siding on my house. So I was just asking

    It is pretty amazing how most solar panel cleaning services do not realize this. Down in Albuquerque, we mostly have window washing companies offer solar panel cleaning as a service and they have no access to de-ionized water. They wash the solar panels just like they’d wash any other window. We do it the right way though. Check out our work at

    One thing that is not mentioned here is TEMPERATURE. I live in the desert where the temp. is anywhere between 115 and 130 degrees all days of summer. Yes, it is hot! This (temperature) of the panels is one of the most important things to be aware of. The panels get hot so throwing cool water on them could easily cause the glass to crack! Not good. The ideal time to clean them would be early morning before they even have a chance to heat up. Other than that would be evening after they have had a chance to cool down. Just saying.

    Great article! Solar panels don’t need a lot of aftercare but keeping them clean is a must, avoid using products such as Windex and never use a pressure washer to clean them! As other Комментарии и мнения владельцев have mentioned bird dropping aren’t so easy to remove!

    solar, photovoltaic, panel, cleaning, system, clean

    I have just installed solar panels at my house and I was not sure how to clean that because if it leave water spots it might harm the panels. But I just got what I was looking for, and thank you for sharing such informative article with us.

    We have a very thick layer of soot on our solar panels. It is so thick I can write in it. (We’ve had multiple fires very close to our property in the past two months). Water and a brush do NOT get the soot off. I am thinking of using Dawn dish soap mixed with water and a soft bristle brush. Dawn is really good at cutting greasy substances. However, I also understand it can leave streaks but streaks can not be as bad as leaving the soot, can it? When washing Windows the best recipe is 2 or 3 drops of dawn per gallon; I was thinking of doing the same for the panels. Please let me know your thoughts at your earliest convenience. Thank you, Pam

    Your Homeowners Insurance should cover cleaning them if due to wildfires. I even had ash in the water basin of my coffee pot from the ‘07 WitchCreek Fire in CA. Even though my place didn’t burn, my HO policy covered and entire cleaning inside and out. Since the fires are a natural disaster your rates don’t increase.

    You can also get a reasonably priced water deionized from Unger on Amazon. Its the blue model for washing cars. I use it for my panels, works great. Little bit of dawn on a rv brush and a long pole then rinse with the filtered water. Good to go.


    Mixed vinegar and water. Splash you car down with it after washing then leave it in the sun to dry. You won’t have any spots.

    Yes that’s a system call RO/DI water systems gives you 100% purify water and thats the only way not to get water marks on your panels and Windows i used all the time. The best results but is very expensive to buy! I have a clean business Check my page i have couple pictures there SUN SOFT WASH Hope that helps you

    We wash our panels with a mixture of water and Dawn soap with a final clean water rinse. We do this once a year after all the pollen has finished falling. Our problem is with stained roof shingles from between the two solar panels (facing south). We have had the roof “soft washed” with no real success. Someone suggested installing a zinc panel below the solar panels. Does anyone out there have an answer? Thank you

    As mentioned in the article, ““When rain happens, soil accumulates at the bottom edge of the solar panel, obstructing the lower PV cell row and hindering the production efficiency…” This is because the Al frame is higher than the glass, thus prevents the soil water flowing out of the module surface. As Ramond Davidalso mentions, “Depends on the tilt of the modules as well. Panels at 30 degrees get cleaner with rain water better that 10 degrees tilt or less…” This is because the low-angle installed rooftop solar module is much easier to accumelate dust nearby the frame edge. Normally for the angle lower than 15 degree, water cannot flow out of the module surface due to the Al frame (like a dam). So there is a solution to add a small component onto the frame, which can help the accumulated soil water acrosss the frame and flow out of the module surface automatically during the rain, thoroughly remove the dust nearby the frame, also help remove the carbon-hydrogen contamination. This is a patent technology, has been sucessfully applied on tile roof top solar installation, of which the installation agle is always lower than 15 degree. If you wang to know more,

    I read the full technical document of a component so called ” Mud killer”,which describes the detail on how to remove the dust from the near-frame glass surface. Find the detail here:

    The need and effectiveness of solar panel cleaning is affected by many factors. The types of soiling, levels of rainfall, size of installation, cleaning methods and mineral content of water used to wash panels can affect the level of efficiency gains from cleaning. For those installations where frequent panel cleaning is required, an assessment must be made of cleaning processes and equipment and whether a chemical cleaning solution is required. If it is determined that a PV cleaning product is required, its panel component compatibility needs to be considered. Glass cleaning products and dish soaps are often used to clean PV panels. They can contain a wide array of solvents and their frequent use can corrode or weaken metal and water-proofing components surrounding the panel’s protective glass to expose underlying solar cells to the risk of damage. Solvents can also damage panels’ anti-reflective films to reduce power generating efficiency. Solvents like ethanol are flammable and Volatile Organic Compounds (VOC). Polywater’s SPW is a non-solvent cleaner that eliminates these risks of component damage. Approved by major solar panel manufacturers, SPW is designed to be a safe and effective PV panel cleaner.

    Actually the worst case that affect the power generation is the dust accumalated around the solar panel frame, which contributes almost 80% of power loss. 20% efforts of dust cleaning for frame-side dust causes 80% power gain, in another word, 80% efforts of dust cleaning for the glass surface only get 20% of power gain. By using the “mud-killer”, all dust around the solar panel frame will disappear thoroughly. So it helps gain the 80% of power loss back. You may need not spend additional product cleaning any more. From the product document and field test, we confirmed the above mentioned. Please read and download the following article(it’s english version):

    Very well put together post! We need more people spreading the word about not using harsh chemicals on solar panels because they really can be harmful and can damage the panels. Many chemicals can be abrasive and can scratch the surface of the panels, which can reduce their effectiveness. Additionally, some chemicals can react with the materials used in solar panels, such as the photovoltaic cells, and can cause permanent damage. We’ve done so many solar panel replacements solar panel replacements due to this problem. It is generally best to use a cleaning solution that is specifically designed for solar panels and to avoid using abrasive materials or harsh chemicals.

    When I was about 30 years old, I had made friends with a retired UPS supervisor, his brother, in a fast growing town in central Kentucky, (this was back around 1980, just before the Chicago Bears got on a roll for the 1985 Superbowl, … they owned a carwash/full service gas station, with a oil change bay, … they were quite energetic, in coming up with ways to provide a number of services for the community, … The one thing I remember JS, saying about that business, is that soap, does not clean cars, … and he showed me a barrel that provided the customers “seller”, … You see, the customers love to see suds, believe that it is the soap which is cleaning their vehicle, … And JS, acknowledged that the soap only helps in providing a medium to carry the dirt away from the vehicle, … The real “magic behind the curtain” was sitting just to the side of it, in a dry corner of the contents room sat several bags of water softener salt, … packed up 6 high on pallets, covered with plastic so it did not get wet too early, … just in case a water leak sprang from somewhere amongst the equipment, … Soft water was the key to cleaning, hot “soft” water would degunk just about anything you could find on any automotive vehicles, … from heavy trucks that worked the coal mines, to old grannies, that only use the car on Sunday, to go to church, to the ingle guys who would “cruise” the malls, … there was a lot of traffic that got washed at the self-service/full service car wash, you could buy a carwash, fill up your car, get the oil changed, I’d be there if you wanted to get your car waxed, … or to have the luster restored to the paint, then waxed, … I was too cheap, for the I was charging, but made enough to feed my family, barely, … but that is another story, … lol, … lets just say that I learned how to have, keep a nice ride without a lot of expense, very little upkeep, …

    Airborne Hydrocarbons like to stick to glass, paint metal and, much to the surprise of researchers, who were investigating the Lotus Effect of extreme hydrophobicity; Hydrocarbons also like surfaces that have been treated to shed water or are in some manner modified to be self cleaning. TiO2 coating may be an exception but they may interfere with photon transmission. The hydrocarbon build up attracts airborne particles. Where I work in the SF Bay area, I’m sandwiched between 10 lanes of I-880 and one of the main off ramps to Tesla. Suffice to say, my car gets dirty. On occasion, I have noticed that a gentle but persistent rain, unaccompanied by wind and thus Rapid evaporation, practically leaves my car and the windshield, streak free. My car is 20 years old, the paint has signs of bossing from the car wash and yet a gentle, persistent rain leaves it pristine.

    I measured before and after cleaning my panels at the end of a dry summer in Portland and found 1% or less output increase only. Very dusty locations probably more.

    Seven years after installing PV on my Chandler, AZ home, I have concluded that cleaning PV modules is unnecessary. After a full year of operation I cleaned my modules and compared before and after kWh production. The day before cleaning and the day after were identical cloudless days at the exact same temperature. I discovered there was absolutely no change in kWh performance. While cleaning modules may be worthwhile in heavy bird dropping area or Fresno with heavy soiling from agricultural activity, in my firm opinion, it does not pay to do this in the vast majority of residential PV applications.

    Car windscreen cleaner solution would seem to fit the task. It removes road film, bird effluvia and squashed bugs….

    Use SWP Solar Wash Protect a concentrate Bio degradable solution mixed with water for better wash for long period. It is dust repellent cleaning solution for Solar Panels only.

    Depends on the tilt of the modules as well. Panels at 30 degrees get cleaner with rain water better that 10 degrees tilt or less

    Getting it soaked with ordinary water (without soap) for a few minutes before washing is sufficient to remove it.

    I tried Rainx it works fine with rain, but in the winter snow tends to hang up more than on plain panels.

    Must taste pretty good I’d say…you’re drinking everything else that LEACHES off your roofing materials.

    I would have to imagine that he runs it through some kind of filter, most people don’t drink rainwater directly

    This article seems to be using the word “soap” rather broadly. Of course you aren’t going to rub your panels with a bar of Dial soap! Detergents and surfactants are another story. They really help to remove surface contaminants, rinse easily, and don’t leave a sticky film. You need to avoid consumer products that have other junk in them like skin softeners, and the final rinse should be D.I. water. D.I. water by itself is fine, but sometimes an oily contaminant needs more.

    The best way to clean solar panels is with rotating brushes or robots that have rotating brushes mounted on them. In our extensive cleaning experience (our machines have cleaned 100s of GW) soap is not necessary, just de-ionized water!

    I’ve had my 5KWh system for about 6yrs now and I’ve been keeping a detailed log on its energy production, I’ve never had a service done and never had anyone wash the panels, I let the rain clean the panels and to this day it’s producing the same it was when installed, when I say same I mean no great reduction in power, very happy with mine.

    Long ago, when Sanyo made the HIT solar PV panels, their product sheet called out “cheap” dish washing liquid, not the stuff with skin softening aloe Vera or something like that. Warm water dish soap and a (towel) to wash down the panels. First step was spray down all the panels and let the water drain, second step wash down panels with dish soap, then spray off and squeegee with a soft rubber blade. I’d say most solar PV manufacturers will absolutely say not to use harsh chemicals like Windex or cleaners with any kind of cleaning “grit”. Panels can last for many years using this method. I have noticed that some bugs like to lay their egg cases on solar PV panels, these leave a waxy blob on the panel that is not always easy to remove. In those cases, warm soapy water, squeegee with a soft rubber blade, repeat until gone.

    The complete guide to the cleaning and maintenance of solar panels

    Rooftop solar panels may become dirty as a result of exposure to dust and pollution.

    With that being said, is it necessary to clean solar panels? Does dirt interfere with solar energy production? Don’t the wind and rain provide sufficient cleaning? Should this task be carried out by a specialized cleaning company?

    Look no further than this guide to find out everything you need to know about the cleaning and maintenance of solar panels!

    What are the components of a solar installation?

    First and foremost, let us introduce the two different terms discussed in this article:

    • Solar panel cleaning: this entails washing the panels like Windows. The cleaning may be combined with preventive maintenance of the solar collectors.
    • Solar panel maintenance: this refers to technical maintenance carried out by a professional and should ideally take place once a year.

    The reason why photovoltaic panels must be cleaned is to ensure solar panel efficiency. An unclean panel runs the risk of producing less electricity and thereby reducing the profitability of the installation.

    For that matter, the cleaning and maintenance of solar panels encompasses all types of solar installations, including:

    What are the components of a solar installation?

    The main components of a grid-connected photovoltaic installation are:

    • The photovoltaic solar panels
    • The support structure
    • The inverter or the microinverters
    • The direct current (DC) circuit breaker and protection unit
    • The alternating current (AC) circuit breaker and protection unit

    The main components of a solar thermal installation are:

    • The thermal solar panels
    • The primary and secondary circuits
    • The heat exchanger
    • The heat storage tank and hydraulic pumps
    • The expansion tank
    • The tubes
    • The main control panel
    solar, photovoltaic, panel, cleaning, system, clean

    The main components of a hybrid solar installation are:

    • The hybrid solar panels which contain the heat exchanger
    • The support structure
    • The inverter or the microinverters
    • The direct current (DC) circuit breaker and protection unit
    • The alternating current (AC) circuit breaker and protection unit
    • The primary and secondary circuits
    • The heat storage tank and hydraulic pumps
    • The expansion tank
    • The pipes
    • The main control panel

    There are a myriad of companies which offer cleaning services for each of these solar panels.

    When to call upon the services of a solar cleaning company

    Enlisting the aid of a solar panel cleaning company is a reasonable choice for very large installations known as solar farms or solar parks.

    Why is that? Because if we build off the premise that unclean solar panels deliver a.5% solar output, this translates into a significant energetic shortfall in the context of a very large installation5% is an average calculation presented by the International Solar Energy Society. Declined efficiency will be discussed in more detail in a later paragraph regarding verification through monitoring

    Apart from this scenario, a residential user need not necessarily secure the services of a cleaning company as long as the panels are slightly tilted. If the panels are laid flat, there is a higher chance of dirt build-up.

    When all is said and done, cleaning solar panels is an uncomplicated procedure that you can take care of just as well as a professional. If you have a small installation, it pays off to clean it on your own because the cost of professional cleaning would exceed the estimated energy gain associated with clean solar panels.

    As a matter of fact, you may also ask your solar installer to clean your panels while he is performing routine technical maintenance. He can execute this task in complete security.

    Preventive maintenance

    Preventive maintenance involves booking an appointment with your solar installer to verify that everything is in order. This procedure should generally occur once a year and differs from curative maintenance, which involves the resolution of an identified fault or failure.

    How frequently should solar panels be cleaned and maintained and during what time period?

    Ideally once a year

    In truth, there is no regulatory maintenance frequency to adhere to with respect to your solar installation (whether photovoltaic or thermal). It all depends on where it is installed and how rapidly it accumulates dirt.

    All the same, you should aim for an annual inspection as part of a maintenance contract with your solar installer. At any rate, this is what we advise our DualSun clients to do. Therefore, cleaning can also occur at this time.

    In reality, the cleaning frequency of a solar installation depends on its location. A solar panel will certainly accumulate dirt more quickly if it is particularly exposed to agricultural dust, bird droppings, sand or pollution.

    Alternatively, a long period of drought can also contribute to dirt build-up on the panels seeing as they do not benefit from a natural rain rinse.

    The optimal period to clean solar panels

    There is no optimal period to clean one’s solar panels. However, the end of winter seems to be a more favorable time to clean them because the sun returns and output levels are on the rise.

    Bear in mind that your solar installer may be very busy during this time since it is also the ideal period to perform installations. So expect a Rapid intervention on his part.

    Lastly, there is no specific time of day to clean your solar panels either. Nevertheless, to avoid interfering with the solar output, you may want to opt for dawn or dusk when the panels are less warm.

    Types of solar panel maintenance operations

    Verification through monitoring

    Apart from a visual appraisal of your collectors, the best way to know if your solar panels need to be cleaned is by verifying your solar output. Has it decreased due to unclean solar panels? If that is the case, a lower-than-normal output level will notify you that it is time for a cleaning.

    The DGS eV, which is the German section of the International Solar Energy Society, states the following in the Photovoltaic Guide: on average, an unclean photovoltaic solar panel generates 2 to 7% less energy than a clean panel.

    However, a very sharp drop in production levels is more so indicative of a technical problem. Therefore, if efficiency levels drop by more than 10%, you should have your system serviced by a professional.

    Your solar monitor provides all these details. Simply log in to your online interface and verify your energy output data.

    The tools needed to properly clean photovoltaic panels

    To clean the surface of the panels, all you need is soft, lukewarm water and a non-abrasive sponge. Nothing more.

    Please be aware that applying cold water to a warm panel could result in thermal shock, thereby damaging your panel. Furthermore, cleaning with hard water may leave white residue on your glass panels and thus affect their performance.

    If possible, use a telescopic pole to avoid taking the unnecessary risk of climbing onto your roof.

    Last but not least, it almost goes without saying that you should avoid leaning too heavily on your panels.

    What to avoid when cleaning solar panels

    Certain cleaning products can damage the solar panels and should therefore be avoided:

    • Hard water. It can leave white residue that diminishes photovoltaic output.
    • Abrasive sponges. They may scratch the panels.
    • Very cold water: Using very cold water on a warm panel can result in thermal shock and permanently damage the solar panel.
    • Very high-pressure water. This can damage the joints in the panel frame. Kärcher-type high-pressure cleaners must therefore be avoided.
    • Solvents and detergents. Such products may damage the surface of the solar collectors.

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    Photovoltaic cleaning and maintenance

    As we previously stated, solar panels can only perform at an optimal level if they are clean and free of any object or element that could block the sun’s rays. This includes shade!

    In France, there is sufficient wind and rain to adequately clean and rinse off photovoltaic solar installations, but you may also wipe down the panels with a sponge if you wish.

    As far as maintenance is concerned, it serves to remind that photovoltaic solar panels do not require any special technical maintenance.

    That’s right. They are extremely reliable and sturdy— and can operate for up to 30 years! All you need to do is ensure an occasional verification of the cables, the output meter, and the inverter. A mere glance at the monitor will alert you to an unexpected drop in production levels.

    Thermal solar panel cleaning and maintenance

    The cleaning procedure is similar to that of any other panel type.

    However, this type of solar installation requires rigorous thermal maintenance based on recommendations outlined by each manufacturer in part. These are specified in the care and maintenance manuals.

    The thermal maintenance of an installation is carried out by a solar installer once a year, at which time he:

    • Verifies the water pressure by using the pressure gauge to ensure that it is not less than 1 bar. If the pressure sits below 1 bar, this could jeopardize the circulation of the glycol water and negatively affect the entire solar installation.
    • Controls the quantity of glycol, which is the antifreeze found in the panels. There must be enough glycol to prevent the panels from freezing in the winter.
    • Monitors the operation of the installation’s safety devices, such as the mixing valve at the outlet to the domestic hot water tank or the solar safety valve.
    • Ensures that the installation is perfectly sealed and waterproof. Confirms the absence of fluid leaks on the accessible portions of the system.
    • Verifies the pump, the expansion tank, and the electrical connections.

    All actions performed on the thermal installation must be recorded by the installer in a maintenance notebook and safeguarded so as to ensure precise tracking throughout the service life of the installation.

    Hybrid solar panel cleaning and maintenance

    The distinguishing feature of hybrid solar panels is that they combine two systems in one: photovoltaic panels on the front and thermal panels on the back, towards the roof.

    Hybrid solar panels are cleaned in the exact same way as a photovoltaic or thermal panel, meaning with soft, lukewarm water and a non-abrasive sponge.

    As far as of the photovoltaic side is concerned, this procedure is identical to that of a classic panel, which consists of verifying the cables, the production housing, and the solar inverter.

    Maintenance of the thermal side is similar to that of a thermal solar installation. The difference is that solar hybrid panels such as DualSun do not overheat. This advantageous feature preserves the heat transfer fluid as well as the panel components for a longer period of time, rendering it unnecessary to replace components and therefore drastically reducing maintenance costs.

    Please note that a solar panel maintenance guide is made available to anyone who wishes to install a DualSun hybrid installation.

    Inverter and housing maintenance

    To begin with, we remind that the solar inverter is an indispensable part of a solar installation which converts direct current output into alternating current. It also comes in a smaller format, called a micro-inverter.

    Maintaining an inverter is a hassle-free task. Once a year, the air inlets must be cleaned so that the device can cool down properly. The indicator lights and various displays must also be checked at this time.

    This procedure limits the decreased productivity of the device at the end of its service life. It should be noted that a solar inverter has an estimated service life of about 10 years. In addition to being cleaned and maintained, it will need to be replaced at least once during the service life of the photovoltaic system.

    Last but not least, we turn our attention to the other connector housings. Their maintenance consists of dusting off and verifying the indicator lights.

    For further reading, we invite you to browse the following articles:

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