Solar panel washing, cleaning and maintenance

How are solar panels washed?

We wash all solar panels, both roof-mounted and ground-mounted. We use filtered and, crucially, deionised water. Water travels through hoses to telescopic brushes, and we work both on the roof and from the ground to ensure a high standard of cleaning. The brushes are soft and specially designed for solar panels. Water jets flow directly from the brush, providing effective panel maintenance. Read more about the process and technology below.

Click here to find out whether solar panels can be left unwashed.

Solar panel washing

If necessary, an experienced team member will inspect the site before work begins to assess safe access to the panels. Sometimes a vehicle-mounted access platform is needed for safe cleaning, in which case we must assess vehicle access to the site. We also wash ground-mounted panels. Usually, however, photographs are sufficient and no site visit is needed. Our team has completed specialist training and holds authorisation for work at height. We normally use rope-access and work-at-height equipment, using an access platform relatively rarely, on particularly complex sites.

To maintain the solar panels regularly, we may need to install fixed rope-access safety lines. These allow safe working. We generally install these lines on the second cleaning visit, but will discuss this with you on site.

Click here to find out why you should choose us.

Purified and deionised water

Manufacturers advise against harmful chemicals or detergents for washing solar panels. Instead, they recommend regular cleaning with purified water, especially before summer and winter. Manufacturers also state that regular washing maintains the manufacturer’s warranty and helps keep panels operating at optimum output. Read here to learn more about what experts say about solar panel cleaning.

Untreated water leaves mineral deposits on solar panels, especially in hard-water areas. As well as making cleaning ineffective, these deposits attract dirt.

At Kārtība Tīrība, we use only fully purified water for solar panel maintenance. We remove minerals in two stages: filtration followed by deionisation. We will need a water connection at your property. If water is unavailable, we will bring it.

We offer an environmentally considerate cleaning process without harmful or abrasive chemicals and detergents. We will wash your solar panels safely and effectively, guaranteeing an excellent result that helps you get the most from your investment.

Exceptionally, if standard cleaning is not possible, or panels have been neglected and are heavily soiled with lichen and other growth, we use specially adapted pressure-washing equipment with a dedicated nozzle at a substantially reduced pressure to avoid harming the panels. Read here to learn more about what experts say about solar panel cleaning.

Can I clean solar panels myself?

We do not recommend washing solar panels yourself.

Cleaning panels yourself risks damaging them or failing to clean them adequately. The most serious risk, however, is electric shock. Another very serious concern is safety. As the saying goes, safety comes first, particularly for roof-mounted panels: not all can be washed from the ground, whereas we have extensive roof-working experience. To achieve a thorough result, roof access is needed at almost every site. It is better to entrust the work to professional solar-panel cleaners with professional equipment and specialist training. Our staff gained experience maintaining panels in Europe, and we use purified, deionised water. Read more about the importance of purified water here.

Why do solar panels need washing?

Dust, sticky tree sap, pine pollen, birch catkin debris, moss, lichen, soot and bird droppings are just some sources of solar-panel soiling. Dirt also shades the panels, preventing sunlight from reaching the cells. The system consequently loses performance and efficiency, reducing financial returns for the owner and investor. In Latvia, dirty panels cause an annual loss of 7–47% of solar energy generation.

Google’s solar-panel cleaning study: Google’s Mountain View campus in California has a 1.6-megawatt solar array. It had operated for 15 months before its first cleaning, after which energy output doubled overnight. It was cleaned again eight months later, immediately increasing output by 36%. Google’s empirical conclusion was that cleaning solar panels is the primary way to maximise energy generation.

Dirty solar panels: reduced efficiency and service life; reduced overall system performance; possible permanent microscopic and chemical damage to panel surfaces; effects on the manufacturer’s warranty. Regular solar-panel cleaning and washing: ensures maximum output; maintains the manufacturer’s warranty; saves you money; extends the period over which your investment delivers returns; prevents permanent microscopic and chemical surface damage; gives you peace of mind.

Read here about what manufacturers say about washing solar panels.

“Solar panels clean themselves and need no maintenance”

This is a myth! When panels are described as self-cleaning, this means their surface is hydrophobic — in other words, it repels water droplets. Such surfaces do not actually clean themselves; they merely reduce mineral deposits that can block sunlight from reaching the cells. In dusty surroundings, however, one cell that becomes inefficient affects the performance of all the other cells. Since cells are connected in series within the module, shading one reduces the output of the entire panel.

Rainwater alone cannot keep panels free of dirt throughout the year, let alone throughout their service life. How are solar panels cleaned and washed? Read here.

What do the experts say?

Manufacturers state that dirty solar panels lose output and that dirt can also affect the manufacturer’s warranty.

Canadian Solar, a leading solar-module manufacturer, states: “Clean the panels if a significant amount of dirt accumulates on them,” and recommends that “water with a low mineral content and an almost neutral pH is best.”

Trina Solar, one of the world’s leading solar-panel manufacturers, writes in its maintenance manual: “The amount of electricity generated by a solar module is proportional to the amount of sunlight falling on it. A module with shaded cells will produce less energy, so keeping it clean is important.”

Panasonic, a well-known global corporation and photovoltaic-panel manufacturer, recommends in its website FAQs: “What maintenance do solar panels need? Wash dust and dirt off the solar panels twice a year.” Panasonic’s manufacturer warranty exclusions include “insufficient maintenance” and “damage or corrosion caused by environmental pollution, such as soot and mould”.

First Solar emphasises: “In heavily polluted locations, correct and timely solar-panel maintenance can improve energy yield,” and states that “filtered water delivers the best results.”

8.33 Solar, serving Europe’s solar-energy sector since 2006, emphasises: “Dust and dirt can accumulate on the panel’s glass surface over time, reducing output. Solar 8.33 recommends periodically cleaning solar modules to ensure maximum operating output.”

Solar-panel washing is a service tailored to your needs, delivered professionally with a guaranteed result. Read here about why you should choose us.

Why choose us and what we offer

Solar-panel washing is what we do best. We also have extensive experience in rope access, working at height, window cleaning and roof work. We clean roofs and carry out all other types of roof work, as well as façade cleaning, indoor cleaning and property management. Combining these skills, we offer comprehensive, high-quality service. We have completed more than 200 roof jobs and washed more than 2600 solar panels.

We have worked with solar panels of every size and configuration, from cleaning complex roof-mounted installations to maintaining large solar farms.

Through comprehensive advice and different roof-access solutions, we provide high-quality service to new and existing customers.

Working closely with customers, we have demonstrated our ability to meet deadlines, solve problems and successfully manage employee health and safety, earning an excellent reputation in solar-panel maintenance.

We strictly follow a no-subcontracting policy. We wash the panels ourselves. This lets us maintain consistently high cleaning standards and provide every customer with a safe, effective service.

We do not subcontract. We are one of the few solar-panel maintenance providers who do not subcontract. This enables consistently high-quality work, safe, thorough and conscientious service.

We offer: work throughout Latvia — high demand means you should book well in advance! Authorised work at height and rope-access equipment. Extensive roof-work experience, including cleaning, repairs and regular maintenance. Site inspections. Manual cleaning techniques. Visual assessment of panels and connections. Consultancy and staff training. Various methods of access to solar panels. All work done by us, without subcontractors. Out-of-hours service. Recommendations for cleaning schedules. Without regular professional maintenance, solar panels will not perform as well as they should.

Customer satisfaction. Choosing us gives you complete peace of mind: we provide a safe, reliable and professional cleaning service, completed from start to finish. Read here about how we can help your business.

How often should solar panels be cleaned?

Every solar array is different, and the recommended cleaning frequency varies according to environmental factors.

Particular attention is needed for panels in dusty locations, for example beside roads and streets, near the sea, agricultural land, birch trees and pine trees. These require more frequent cleaning because considerably more dust accumulates on them. Bird droppings and lichen are also major problems.

If panels remain uncleaned for a long time, the modules become shaded and can also develop permanent microscopic and chemical surface damage. The larger the array, the greater the resulting loss of return for its owner!

Your electricity tariff should also be considered when deciding maintenance frequency.

Our experience shows that residential solar arrays need cleaning once or even twice a year. Systems in towns, on agricultural land, near roads, the sea and trees become the dirtiest, so more frequent washing is needed in these settings.

Many customers contact us before their next scheduled visit because they notice a fall in generation caused by environmental conditions. This most often happens after prolonged dry periods.

Removing snow from panels substantially increases generation — by up to 95% —. Read more here about preventing birds from perching on panels and leaving droppings.

How we can help your business

Alongside our extensive experience and knowledge, we stand out for our complete dedication to the work entrusted to us.

To extend the period of returns on your solar-energy investment, we provide specialist consultancy and support on every aspect of cleaning, from purified-water technology to safe-access solutions.

Before installation and during regular maintenance, we advise many new and existing customers on suitable, safe access to their panels. Solutions range from external ladders and fixed safety lines to vehicle-mounted access platforms. Choosing safe access saves money over time, especially when the decision is financially informed and accounts for the investment’s duration and timescales.

We recognise that every project and customer is unique. Our expert, focused practical support can help your company manage panel cleaning. We will help choose the water-purification process best suited to your site, and train and equip the staff responsible for maintaining your solar panels.

We advise customers worldwide on both rooftop panels and ground-mounted arrays.

Protective barriers and bird-deterrent spikes

Pest prevention for residential and commercial solar panels!

There are 5 threats to roof-mounted panels and the roof covering beneath them. Kārtība Tīrība successfully deals with them all:

Panels shade the roof, allowing moss and lichen to grow beneath them. They retain water and damage the covering in freezing weather. We address this by treating the roof with products that control growth, selecting the most convenient and suitable product for each project.

Squirrels and other rodents chew cables and can damage your solar-panel system.

Damaged electrical wiring can cause a fire.

Pigeons and other birds nesting beneath panels pose serious health risks and damage property. Nesting debris, droppings and pecked cables are an increasing problem for owners. If panels are installed on your home or business and there is a swimming pool or other body of water nearby, within 3–4 km, we can almost guarantee birds are nesting beneath them. You then certainly need protection against bird damage.

Leaves and debris accumulating beneath arrays can damage panel fixings and roof coverings and cause rot. Material such as leaves and small twigs from nearby trees can cause problems if left beneath panels for prolonged periods.

To address these problems, simply surround the panels with our protective barriers. Solar-panel systems are designed to last 20–25 years; attractive barriers can help achieve this by keeping out birds, rodents and debris, giving you peace of mind throughout the system’s life. We can also fit barriers beneath roof eaves and terrace canopies.

We can also install bird-deterrent spikes. These spikes and wires are another essential measure if birds perch on panel edges. Droppings do more than block sunlight: left on panel surfaces for a long time, they cause chemical damage and reduce efficiency.

Even if protection against natural threats does not yet seem relevant, a protective system adds value by concealing unsightly cables. Professionally installed barriers look attractive, keep the array looking neat and tidy, and withstand whatever nature brings.

Make a booking or ask a question

To receive an approximate quote or make a booking, complete the enquiry form. Please describe the service you need in as much detail as possible. We may ask you to send photographs or visit the site to assess the work.