Optimizing solar panel cleaning in pv installations
Solar generation is the most cost-efficient way of producing electricity. It is leading the expansion of renewables in many parts of the world. But solar panels get dirty. In fact, accumulations of dust and dirt can have a big effect on performance and put investment at risk. ENGIE Laborelec has developed a complete range of services to help operators tackle solar panel soiling in photovoltaic plants. With two simple aims: driving down cleaning costs and eliminating losses due to soiled panels. Our solution is optimizing solar panel cleaning in PV installations.
In some parts of the world, soiling is the solar farm operators’ biggest challenge, putting investment at serious risk. Routine cleaning is the obvious answer, but costs could easily get out of control, cutting deep into profits. So how can the solar plant operator optimize their cleaning strategy, drive down cleaning costs and eliminate losses?

ENGIE Laborelec’s four stage approach
Is cleaning an investment worth making?
It’s all about knowing the sites’s soiling rate
According to Thore Müller, Product Manager Cleaning Optimization at ENGIE Laborelec, “To find out whether investment in cleaning is worthwhile, you need to know the site’s soiling rate. How much energy you’re losing, and how much it’s worth. And that means getting the right sensors in exactly the right places.”
“From our experience, soiling rates are a bigger problem than many people anticipate, and traditional cleaning methods are very inefficient.” Thore Müller confirms: “Precise information on the extent of the problem is crucial when deciding what to do about it.”
ENGIE Laborelec researches the best soiling sensors on the market so that they can be incorporated into custom made solutions for each individual utility-scale solar plant.
“We look for the most appropriate combination of sensors for the site and deploy them effectively and efficiently, and that’s what makes the difference,” says Thore Müller.
“To find out whether investment in cleaning is worthwhile, you need to know the site’s soiling rate, how much energy you’re losing, and how much it’s worth.”
Thore Müller Product Manager Cleaning Optimization ENGIE Laborelec
Cleaning that works for your site
How do you choose the best?
There are many cleaning systems on the market, all with their advantages and disadvantages. Faced with this, many operators still just clean manually, a labour-intensive and inefficient undertaking which uses a lot of water.
For moderate soiling, traditional tractor-mounted cleaners with large water tanks and powerful brushes can be good for basic cleaning of larger areas. But for heavier soiling, particularly in remote places, robots with dry rotating brushes can be deployed far more intensively, but it depends whether the panel design allows it.
So which cleaning method works best for you? ENGIE Laborelec can find a solution that targets your situation exactly. After identifying the most appropriate methods, we are on hand with professional advice at every stage of the procurement and deployment process. Depending on your staffing and the resources available to you, we can help you with:
- writing specifications,
- tracking down the best suppliers,
- negotiating contracts,
- witnessing during commissioning, and
- quality control.
Adapt cleaning to real site conditions using CleanRight
Drive down operating costs and water consumption
If you clean solar panels more often than you need to, you incur higher costs without getting the desired effect. If you don’t clean them enough, the panels produce less electricity. Operators may not even realize that soiling rates can vary across the plant, depending on their precise location. With no calculation tools, and based on limited data, operators often have little choice but to act on guesswork, whether that means being over-cautious or taking a chance.
You have to find the right balance, and finding that balance may not be straightforward.
CleanRight is ENGIE Laborelec’s answer to this. It’s a computation tool which evaluates the potential impact on costs of every additional round of cleaning. Its sophisticated algorithms allow it to precisely calculate and constantly update a more effective cleaning schedule.
- how the plant performs,
- representative soiling rate throughout the plant,
- predicted weather conditions, and
- electricity prices.
The CleanRight system is Cloud-based, giving operators and maintenance staff total access to the data. Operators get a clear cleaning schedule, available at all times and updated to reflect changing conditions, identifying exactly which parts of the plant to clean and when.
“And the ENGIE Laborelec system makes resource allocation easy. There’s even an alert system,” says Müller. “You don’t clean if you don’t have to, and that’s how you save money.”
Finding the optimum is what CleanRight is all about. The graph shows how cleaning costs and production losses depend on the frequency of cleaning. Cleaning too frequently cuts losses but leads to high costs. Cleaning too little cuts costs but leads to heavy losses. Guessing is not a reliable option and could be costly. CleanRight eliminates guesswork and calculates the optimal cleaning sweet spot.

4 – Evaluating the results
Counting the savings
Continuous monitoring over the longer term evaluates the savings achieved by this data-driven strategy compared to cleaning schedules based on guesswork. This is an important ENGIE Laborelec service to investors and asset managers, with clear charts, graphs, and figures, and a detailed analysis allowing stakeholders to see for themselves the real tangible benefits.
ENGIE Laborelec’s CleanRight system makes solar panel cleaning cost-effective so that asset owners can take back full control of investment and profitability.
German manufacturer of PV cleaning systems SunBrush® mobil breaks into the U.S. market
Henderson, Nevada, 14 January 2021 (Solar Business Hub) — The world market leader for PV cleaning systems from Germany, SunBrush ® mobil, is breaking new ground with the opening of its branch office SunBrush USA in the city of Henderson, Nevada. There, the joint venture of SunBrush ® mobil and its importer for the UK and Irish market Halse Solar Ltd will sell and maintain the PV cleaning systems of the German company and deliver spare parts to PV power plant operators, OM companies and site owners across the US.
Edward and Philip Halse present a SunBrush ® mobile Compact device at the World AG Expo in Tulare, California. © SunBrush USA Inc.
“We will fill a major gap with our products. Up to now, there has been no similar solar panel cleaning device in the US,” says Franz Ehleuter, Managing Director of SunBrush ® mobil.
The perfect products for various applications
The US branch office offers the whole range of SunBrush ® mobil’s solar panel cleaners, which can be mounted quickly and easily on carrier vehicles, such as tractors or wheel loaders and guarantee efficient and gentle cleaning either dry or wet. The multi-purpose device SunBrush ® mobil Compact removes dust, sand and bird droppings from ground-mounted PV systems. To remove snow, the company offers a Winter Kit upgrade for the Compact with a brush motor having twice the power, a reinforced frame of the PV cleaning system and Aluminum snow deflector blades, which deflect up to 10 centimeters of snow in one run on either side of the brush. Customers can see how the units work at a demonstration in Henderson.
For Roof-Top or Car-Port cleaning, SunBrush offers SunBrush ® mobil Crane, whereas SunBrush ® mobil Rapid, mounted on mini-excavators, is the ideal solution for sites with narrow passageways or tracking beams across the row. SunBrush ® mobil Trackflex has, on the other hand, been developed for PV tracking systems. With the larger 20” brush fitted, even NexTracker Horizon arrays can be cleaned, as the brushes are designed to sweep straight over the protruding brackets.
Receiving the first cleaning devices from Germany: SunBrush USA’s Operations Manager Jordon Tillman in the warehouse. © SunBrush USA Inc.
From sales to spare parts
Besides sales, the team of SunBrush USA provides services and consulting to ensure that the machines run effectively and safely. A 400 sqm warehouse guarantees a spare part delivery within one day.
“It is very exciting to oversee and manage this new venture. Having seen SunBrush® mobil become the answer to utility scale panel washing in Europe, I am looking forward to working with customers all over the USA to find their solar cleaning solution”, says Edward Halse, Sales Manager of SunBrush USA
Edward Halse and his team are currently building a distribution network of effective dealerships and are always looking for more partners across North America.
“With the first machines sold in2020, and with stock in the warehouse for almost immediate delivery, we are well placed to sell more units in 2021”, says Jordon Tillman, Operations Manager of SunBrush USA.
For more information about SunBrush USA, please visit: https://www.sunbrush-usa.com
About SunBrush ® mobil GmbH
SunBrush ® mobil GmbH develops, produces, and sells cleaning devices for photovoltaic installations and building facades. The company was founded in 2014 by Managing Director Franz Ehleuter in Lachen, Germany. It utilizes its engineering expertise in the in-house development of its cleaning systems and operates its own test center. The innovative engineering company supplies customers around the globe. SunBrush ® mobil maintains research cooperation with the Institute for Energy and Drive Technology at the Ulm University of Applied Sciences. All SunBrush ® mobile products are covered by German and European patents. Renowned solar module manufacturers have authorized the use of SunBrush ® mobil brushes on their products.
Publisher: SunBrush USA Inc. V.P. Edward Halse 7565 Commercial Way, Suite F Henderson, Nevada 89011 Phone. 1 (702) 749-7865 Mail. [email protected] Web. www.sunbrush-usa.com
Press Contact: Krampitz Communications Dillenburger Straße 85 51105 Köln Germany Phone. 49 (0) 221 912 49949 Mail. [email protected] Web. https://www.pr-krampitz.de/
Press release by SunBrush ® mobil. Photo credit: From left to right: SunBrush USA’s President Philip Halse, SunBrush ® mobil’s CEO Franz Ehleuter, SunBrush USA’s Sales Manager Edward Halse and SunBrush ® mobil’s International Sales Manager Oliver Köster at the headquarters in Germany. © SunBrush ® mobil.

Post Title
There are several challenges, mainly due to the area where the cleaning is needed. For example, in Saudi Arabia, there are a lot of sandstorms. Therefore, the panels need to be dry cleaned almost every day.
QA with Romain Gourmet | SolarCleano
Tell us about yourself and SolarCleano.
My name is Romain and I am from Belgium. I have worked at SolarCleano for more than 3 years with the current position of sales manager. We have the chance at Solarcleano to have a team talking at least 10 languages and working in more than 55 countries.
SolarCleano is a dynamic young company created in 2017, by a cleaner and an engineer. The idea of SolarCleano was that cleaners needed a more efficient way than the manual cleaning used for solar arrays. At first, the company was developed thanks to our customers feedbacks from Germany and France. 5 years later, more than 500 robots can be found all around the world.
In order to answer every cleaner’s needs, we developed a large range of products, from the smallest, the M1, to the biggest robot, the B1. All our robots can be equipped with different kinds of brushes and can work with or without water, which proves that our main objective is to always satisfy our customers interests.
Share with us why keeping solar panels clean is so important?
The main reason is the loss of efficiency. The loss of efficiency cannot be always felt, but on large scale facilities, a gap is easily made between the cost of electricity and the declining performance due to soiling.
F1 robot for wet and dry solar panel cleaning with a camera for safe remote operation
When a solar panel is not correctly maintained, its durability can heavily decrease. As well, the shadow made by the soiling can create hotspots, which is a small point of shadow that makes the cells of the panel explode.
Why do you think cleaning solar panels has been a widely overlooked task to this point?
At the beginning of the solar industry, the belief was that “rain does the job”. Meaning that it was not necessary to clean the solar panels. We can compare the solar panel with a car; if the car is left outside every day, it remains dirty, even with the rain.
The issue is that most solar panel facilities are relatively new, most of them were built within the last 10 years. After 5 years, we realized that soiling began to appear on the panels, followed by the loss of efficiency.
We came to the conclusion that a lot of negligence can cause major performance problems.
What are the challenges with solar panel cleaning?
There are several challenges, mainly due to the area where the cleaning is needed. For example, in Saudi Arabia, there are a lot of sandstorms. Therefore, the panels need to be dry cleaned almost every day. On the other hand, in the islands of England, or in northern Europe, there are many bird droppings, which means that the panels require to be cleaned with water and powerful brushes. In the countries with a high level of humidity, the soiling may be very sticky. In this case, the cleaners must adapt their brushes according to the situation.
One of the biggest challenges is the mindset of people thinking that solar panels don’t need to be cleaned. While more and more countries understand the matter of cleaning, there are still areas where it is not practiced.
How is SolarCleano responding to these challenges?
Thanks to our client feedbacks and experience we have the opportunity to adapt ourselves, our robots and our brushes. For instance, our products are not the same in South Africa than in Canada. over, the advices given to our customers also change according to their area.
As our objective is to inform about the necessity of solar cleaning, we try to organize as many trade missions, roadshows and demonstrations as possible. We also participate in a lot of conferences around the world.
Why have you chosen to develop robotic solutions over other options?
There are many ways to clean a solar panel. A person can do it manually, with a brush, but these solar arrays are not very secured in every situation and can cause injury. As well there is also a rail system for cleaning, which can easily be attached to the panels. It is safe, fast and cheap, but it can only work on ground installations. Finally, it is possible to set brushes on a tractor, which is only useful on big facilities on the ground.
The key value of our robot is that it can be used in any given situation. It is safe, fast and useful on any kind of facility.
Why robotic cleaning is important in the preventive maintenance of solar fields?
Preventive maintenance with robots helps to avoid disasters and negative consequences on the solar panels. The main goal of preventive maintenance is to also avoid performance loss and damages on the panels.
The robots allow all of it to be done quickly and safely. We are currently developing digital tools with an AI to collect data.
Solar Panel Cleaning Kit How to Clean Solar Panels
Cleaning the solar panels is a very simple process and can be done by yourself. All you need is a great solar panel cleaning kit.
A solar panel cleaning kit is essential for maintaining clean solar panels. It will maximize the efficiency of your solar energy system and capture as much solar energy as possible.
Without regular cleaning, dust and dirt can accumulate on solar panels over time and cause a decrease in power production.
Fortunately, it’s fairly easy to create your own solar panel cleaning kit with basic tools.
- Why To Clean Solar Panels
- Why Do Solar Panels Get Dirty
- How Often You Should Clean The Solar Panels
- How To Properly Clean Solar Panels
- The Complete Solar Panel Cleaning Kit
- Ladder
- Garden hose
- Solar panel cleaning brush
- A simple bucket
- Distilled water
- Microfiber cloths
- Cleaning solution for solar panels
- Gloves
Why To Clean Solar Panels
Cleaning solar panels is an important process that should not be overlooked.
Over time, dust and dirt accumulate on the solar panels and will prevent them from working at maximum capacity.
In affected areas, no sunlight or only a little sunlight can be absorbed and converted into electricity, which reduces the overall efficiency of the system.
That is why it is advisable to clean the solar panels. Thus, they will produce more electricity.
Why Do Solar Panels Get Dirty
Solar panels get dirty easily because they are installed outdoors, making them exposed to all kinds of factors that can produce dirt and dust. Tree leaves, pollution, pollen, bird droppings, or other various debris can reduce the productivity of solar panels.
How Often You Should Clean The Solar Panels
Each photovoltaic system comes equipped with a user manual that you can consult to find out how often the solar panels need to be cleaned. However, sometimes the frequency with which the solar panels must be cleaned depends on the area where you live.
If the area is one with more pollution, then the solar panels must be cleaned once every 4-5 months. If you live in a greener area, then you can clean them once a year.
However, you can always check the solar panels regularly and see how dirty they are. Depending on the level of dirt deposited, you can decide for yourself whether they need to be cleaned or not.

Finally, it is important that the solar panels be cleaned once a year!
How To Properly Clean Solar Panels
The process of cleaning solar panels is quite simple and easy. You just have to be careful not to step on the panels and have the necessary tools.
Careful! The equipment and solar panels are very delicate, so try to be careful.
The Complete Solar Panel Cleaning Kit
With some skills and the right tools, you can clean solar panels by yourself in a very short time. So what equipment do you need to clean solar panels?
In order to achieve a high yield and finish in a short time, your solar panel cleaning kit must contain the following tools:
Ladder
– ladder to climb up to the height of solar panels
Related video:
Garden hose
– a long, garden hose to wash the surface
Solar panel cleaning brush
– solar panel cleaning brush with a telescopic shaft that will help you clean a larger area of panels Shop Now
Or you can choose a cheaper solar panel cleaning brush: Shop Now
A simple bucket
– a simple bucket in case the dirt is more extreme and you have to use a solution
Distilled water
– distilled water because it will reduce the chance of mineral deposits left on your solar panels after cleaning Shop Now
Cleaning solution for solar panels
– a special cleaning solution for solar panels. Do not try other solutions because they may be corrosive or not suitable for using the surface exposed for a long time in direct sunlight. Shop Now
Gloves
– gloves to protect your hands from the effect of the window cleaning solution Shop Now
With all that being said, you just have to acquire these tools, create your solar panel cleaning kit and get down to business.
Tip: When cleaning solar panels, avoid using sharp objects as they may scratch the solar panels and reduce solar panel efficiency.
Protection Measures For Cleaning Solar Panels
Although cleaning is a simple and easy procedure, it is necessary to take certain precautions for your safety and not to damage the equipment:
- Turn off the solar panels before you start cleaning them. In this way, you will minimize the risk of possible accidents.
- Do not clean the solar panels when the sun is intense. It is best to schedule the cleaning of solar panels until 9 o’clock in the morning or after 6 o’clock in the evening.
- Do not step on the solar panels. Do not exert pressure on the solar panels when trying to remove the mess.
- Pay attention to weak or misplaced wires.
- Rinse the microfiber cloth frequently. This helps prevent dust from spreading to other places.
Attention! The panels get very hot, so to clean them, you will need to check first if they have cooled down enough. Therefore, the best time to clean them is on cool days or in the morning or evening.
Turn Off The Switch On The Electrical Panel
Panels should have their own switch. So, before starting to clean the solar panels, it is necessary to turn off the power.
Check All Equipment Carefully
Before starting the cleaning, inspect the surface of the solar panels. Solar panels have glass on the entire surface, which can sometimes be damaged. If you find breaks, cracks, or exposed cables, it is better not to continue the cleaning process. First, ask for the help of a professional to solve the identified problem.
Use Lots Of Water
After checking that the solar panels are disconnected from electricity and that the entire surface is intact, you can proceed with the cleaning process.
If the layer of dirt is very thin, the best way to clean them is to use a garden hose and lots of water.
Do not use a pressure hose, but the one you use to water the flowers. over, do not use tap water! To clean the solar panels, use only distilled water. In this way, you will prevent the formation of limescale.
If a lot of dirt has accumulated, then the operation will be a bit more difficult, but not impossible. You need a bucket in which you add the cleaning solution and water. With the help of microfiber cloth or a soft sponge, clean the surface of the panels, but without pressing to avoid scratches.
Be sure to move in a circular motion when wiping to ensure that all dirt is removed. You can also use the cleaning brush with a telescopic handle.
Once done, rinse the solar panel completely with water.
Attention! Never use cold water to rinse the solar panels, especially when they are already heated by the sun because their surface may crack!
Clean All Panels
After you cleaned them with water, you can use the microfiber cloth and clean the panels carefully, gently, and without applying pressure during the movements. It is recommended to make the movements in a linear way, always in the same direction.
Lightly Polish The Surface
At this point, the solar panels should be mostly clean. For a brilliant shine, use another clean, damp microfiber cloth.
Have you ever cleaned your solar panels yourself? Is the operation easy or not for you? What other tools do you have in your solar panel cleaning kit? Please share your knowledge tips with our community.
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Solar panel cleaning tractor
Solar Panel Cleaning – Why, How By Who?
Steve Williams, Managing Director, Clean Solar Solutions, U.K talks to Clean Middle East about Solar Panel Cleaning.
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Steve Williams, Managing Director, Clean Solar Solutions
Solar panels are generally self cleaning, but in dry areas or where panel tilt is minimal, dust and other substances accumulate over time and impact the amount of electricity generated by a module. This is where the need to clean solar panels arises. We caught up with Clean Solar Solutions, Managing Director, Steve Williams. during his stay in Dubai, U.A.E. Steve is a global solar panel cleaning consultant, having written for many renewable energy magazines across the world and conducted world-first research into lichen growth on solar panels. He has also spoken at solar conferences across the world about solar panel cleaning, from Milan to Mexico. He is the chairman of the Rooftop OM Working group for the U.K. Solar Trade Association. He created Clean Solar Solutions and turned them into an international, award-winning OM company and was given an award in late-2019 and named U.K. Solar Industry Innovator of the Year.
What brings you to Dubai?
I have come to Dubai for a month to research the scale of the solar panel cleaning market here in the U.A.E. and to understand how we can address the challenges that desert solar panel cleaning can bring. We are actively seeking partners across the Middle East whom we can train for solar panel cleaning and expand our global reach.
Please explain why solar panel cleaning is important.
In more mature markets such as the U.K., solar panel cleaning is now firmly established as a core element of Operations Maintenance (OM) on a solar array. Soiling of all kinds accumulates on solar panels, from sand to traffic film, all of it reduces the output of the solar array and depending on soiling type, can create hotspots on the modules too. Hotspots are to be avoided as they not only reduce output, but can also cause permanent cell failure within modules.
What are the benefits of solar panel cleaning?
The benefits of solar panel cleaning are manifold. You increase output, which results in increased output and revenue. You also reduce hotspotting, which will maintain the life of the solar panels. In many cases, regular solar panel cleaning is required in order to maintain the terms of the Original Equipment Manufacturer’s (OEM) warranty.
What is the best way to clean solar panels?
There are multiple ways to clean solar panels, and each has advantages and drawbacks. Above all, your chosen cleaning method must maintain the terms of the OEM warranty. Water quality is also very important. Solar panels should be cleaned with ‘ultra-pure water’, meaning water that has been purified to a level of 10 parts per million (PPM) or less. This will leave a streak and spot-free finish on the solar panels. Cleaning with mains or tap water can result in streaky or spotty finishes, which result from mineral deposits being left on the glass after the water has dried. This is not providing a high-quality clean.
One method on small, residential systems is manual cleaning. This usually involves cleaning via telescopic water-fed poles. This can be the only effective way to clean small systems.
On utility-scale ground mounted solar farms, tractor cleaning has been the preferred method of cleaning. However, while the machines clean to a high standard and can clean a lot of modules per day, they can also damage the framework and solar modules if the tractor is not driven very carefully. Due to the weight of the tractors, they can also create soil compaction, which is not desired.
Robotic cleaning is fast becoming the accepted method of cleaning. Robots provide a lot of flexibility, being able to clean both ground, roof mounted and floating solar arrays of all sizes. It provides an even finish, whereas manual cleaning leaves room for human error. The robots do not create compaction, and it is very difficult to cause damage on a solar array with a solar panel cleaning robot. Technology is developing every year on solar panel cleaning robots and I believe that this will be the preferred method of solar panel cleaning in the long term.
How costly is solar panel cleaning?
Solar panel cleaning costs vary hugely from country to country and from site to site. However, there are some general rules of thumb. Firstly, ground mounted solar panel cleaning is cheaper than roof mounted cleaning and cleaning floating solar arrays is the most expensive. Secondly, the bigger the solar array, the cheaper the cost/KW or MW will become. Currently, the cheapest method of cleaning is tractor mounted cleaning, followed closely by robotic cleaning, with manual cleaning being the most expensive.
If we were looking to appoint a solar panel cleaning contractor, what should we look for?
Their approach to health safety should always be the most important consideration. The contractor should be able to provide you with a detailed Risk Assessment Method Statement (RAMS) which will highlight the risks of solar panel cleaning, including electrocution and explain how each risk will be mitigated and managed.
Next should be the equipment that they will be using. Any contractor looking to pressure wash the solar panels should not be used. Pressure washing invalidates very many OEM warranties, so should not be viewed as an acceptable cleaning method. Beyond this should be their reporting.