Professional Solar Panel Cleaning at Industrial Scale

When it comes to maintaining the efficiency and long-term operation of industrial-scale solar systems, regular maintenance—and in some cases, cleaning—can play an important role. While cleaning isn’t always necessary in every environment, it can be highly recommended in regions with heavy dust or pollen exposure.

According to research by the National Renewable Energy Laboratory (NREL), natural rainfall alone is not sufficient to remove pollen from solar panels, which can lead to significant energy loss. Another study highlights that dust buildup can also noticeably reduce performance, and removing such contaminants may increase output by 2–7% on average in Central Europe, including Hungary.

The necessity and frequency of cleaning depend entirely on the location and environmental factors. Modern technologies—such as specialized cleaning equipment, automated machines, and even drone-based solutions—offer safe and efficient methods to maintain panel performance.

In this article, we’ll explore the conditions that may justify solar panel cleaning, the tools and methods available, and how proper maintenance can impact your system’s efficiency and return on investment..

Why Is Solar Panel Cleaning Important at Industrial Scale?

Cleaning industrial-scale solar systems isn’t just a matter of appearance—it’s crucial from both economic and technical perspectives. For larger systems, the effect of contaminants is cumulative, which can lead to considerable energy production losses.

Dirt, pollen, bird droppings, and leaves accumulating on solar panel surfaces reduce their ability to transmit light, directly impacting power generation. Some sources suggest that dirty panels can generate up to 20–25% less electricity.

Regular cleaning helps prevent long-term issues such as wear on the panels and potential mechanical or electronic malfunctions. It allows the system to operate reliably for longer, reduces unexpected maintenance costs, and minimizes potential downtime.

Contamination and excess moisture buildup can also damage panel surfaces over time, often requiring expensive repairs. Proper maintenance extends the lifespan of solar panels and shortens the payback period of your investment.

Increased efficiency through clean panels also benefits the environment, as more clean energy is produced, reducing reliance on fossil fuels and lowering carbon emissions.

When Is Solar Panel Cleaning Absolutely Necessary?

The necessity of cleaning solar systems heavily depends on environmental conditions at the installation site. In some cases, contamination levels become significant enough to noticeably affect performance. For instance, in agricultural zones or dusty industrial areas, airborne particles can quickly form a thin layer on the panels.

Panel tilt angle is another factor. Panels installed at a low angle are less likely to self-clean through rainfall, making it harder for contaminants to wash off naturally. In addition, bird droppings, insect remains, leaves, or pollen can stubbornly stick to the surface—especially in dry climates or regions where the microclimate does not support self-cleaning.

In such cases, contamination not only impacts current performance but may degrade panel condition over time. The combination of dirt and moisture can harm the glass surface, so regular professional cleaning is advisable.

What Cleaning Equipment and Fluids Are Recommended?

Choosing the right tools and cleaning fluids is key to safely maintaining solar panels. Industrial-scale systems require appropriate techniques—improper tools can scratch the surface, and unsuitable fluids may reduce efficiency.

Below, we’ll review the types of machines, brushes, robots, and other technologies that can be used effectively, as well as the potential role of drones in solar park maintenance.

Solar Panel Cleaning Machines, Robots, Brushes…

Professional equipment is essential for maintaining large solar parks. The SolarCleano robot, for example, is an automated device that moves across panel surfaces independently, cleaning them without causing damage.

The Kärcher iSolar 800 is another effective tool, using low-pressure water jets and specially designed bristles to gently but thoroughly clean panels.

Manual tools, such as telescopic brushes, are still valuable for smaller systems or hard-to-reach areas. These allow for precise and controlled cleaning when automated solutions aren't feasible due to layout or location.

Cleaning with Drones: Innovation or Gimmick?

Using drones to clean solar parks is a relatively new approach, especially for large, hard-to-reach systems. Drones can spray water or cleaning solution along predefined paths, covering thousands of square meters in a short time.

The key advantages are speed and flexibility—drones can access areas that ground tools can't, and they reduce labor requirements, minimizing costs and physical risk. Some models even include sensors to assess dirt levels and enable targeted cleaning.

However, there are downsides. Drone spraying generally only removes surface dirt and may not handle stubborn contaminants like bird droppings or greasy residue. Special permits, trained operators, and in some cases airspace coordination are required—adding cost and logistical complexity. Weather also poses limitations; wind or storms can prevent safe operation.

In summary, drone cleaning is promising but not always cost-effective or sufficient on its own. It works best as a supplementary method in locations where other techniques are impractical or when rapid intervention is needed.

When and How Often Should You Clean Solar Panels?

For industrial-scale systems, cleaning frequency should not follow a fixed schedule but rather be based on cost-effectiveness. Cleaning a multi-megawatt system can be expensive—especially with robotic equipment—so it’s only justified if the extra production clearly outweighs the cost.

In areas with well-angled panels, frequent rain, and minimal pollution (no factories, farms, or bird colonies nearby), cleaning may be needed only every 3–4 years. On the other hand, in places with constant dust, soot, bird droppings, or where panels are flat and don't self-clean, multiple cleanings per year may be necessary—especially if buildup threatens the panels or leaves lasting marks.

Cleaning schedules should be based on site conditions, contaminant type and level, and production loss. The best practice is to monitor performance regularly and schedule cleanings only when cost-effective or when dirt poses a risk to the panels.

Why Is DIY Solar Panel Cleaning Not Recommended?

Though cleaning might seem simple, maintaining industrial systems is far more complex than spraying water or using a household brush. The panel surface is delicate—a brush with bristles that are too stiff or a high-pressure washer can cause micro-damage. These scratches not only reduce efficiency but may void the warranty.

Another common mistake is using tap water, which contains minerals like calcium. These can leave deposits on panels, impairing light transmission over time. Professionals use distilled or deionized water to avoid leaving residue.

Safety is also a concern—industrial systems are often ground-mounted on support structures or located on rooftops. These can be hard to access and pose slip hazards. Without proper gear and safety procedures, DIY cleaning can result in serious injury.

Ultimately, an experienced professional knows what method, frequency, and tools to use under different conditions. This not only extends panel lifespan but avoids unnecessary costs—a particularly critical factor in large-scale systems where mistakes can cause not just cosmetic but functional and financial damage.

How Does Cleaning Affect System Efficiency?

Return on Investment: When Is Professional Cleaning Worth It?

At industrial scale, professional cleaning involves logistical and financial planning. It’s essential to base the decision on objective data—typically drawn from the monitoring system's performance history. While such data isn’t always a perfect indicator of cleanliness, long-term patterns (under similar weather conditions) can highlight declining performance.

If no technical faults are found, contamination is often the cause. In such cases, it makes sense to request a cleaning quote—factoring in panel layout, accessibility, and contamination type. If calculations show that the regained output will quickly offset the cleaning cost, the intervention is both justified and profitable.

This decision should always rely on solid technical and economic data, not guesswork. A well-timed cleaning not only improves current efficiency but supports long-term, cost-effective operation.

In Summary: When and Why Should You Clean Industrial-Scale Solar Systems?

Many factors affect solar system efficiency, and cleanliness is one of the most important. Dust, pollen, bird droppings, and other buildup can obstruct sunlight from reaching photovoltaic cells, reducing output. NREL research shows that rainfall alone often can’t remove pollen, which tends to stick stubbornly to surfaces.

Cleaning doesn’t just improve current performance—it also helps prevent lasting surface damage. For example, bird droppings are acidic and can cause micro-scratches or other damage over time. These issues not only affect output but also shorten the panels’ lifespan.

Frequently Asked Questions About Cleaning Industrial Systems (FAQ)

1. How often should industrial solar panels be cleaned?
It depends on environmental conditions. In clean, rainy areas, cleaning every few years may be enough. In dusty, polluted, or bird-heavy areas, multiple cleanings per year may be necessary.

2. How does dirt affect panel efficiency?
Dirt reduces light transmission to the cells, directly decreasing production. Over time, some contaminants can even damage the panel surface.

3. Why is DIY cleaning not recommended for industrial systems?
Incorrect tools or fluids can harm the panels, and working at height is dangerous. Always use professional service providers for large-scale systems.

4. How can you tell if cleaning is necessary?
Compare current output to previous periods using your monitoring system. If performance drops significantly without technical faults, dirt is likely the cause—get a quote for cleaning.

5. Is professional cleaning worth the investment?
Yes, if production loss due to dirt is greater than the cleaning cost, it pays off. It boosts yield and helps preserve panel condition over time.