Why cleaning matters...
Estimated global loss in PV energy production due to soiling: €4–7 billion per year
Source: International Energy Agency, 2022
Cleaner panels support more stable long-term returns
After irradiance, soiling is one of the most influential factors affecting solar PV system performance over time.
Without regular management, soiling accumulates on panel surfaces, reducing efficiency and causing performance to reduce. Industry data indicates annual losses ranging from around 5% to over 50% in extreme environments.
The scale and rate of soiling vary widely depending on environmental, geographical and system-specific factors - see Soiling section below.
The financial impact of unmanaged soiling can therefore be significant.
For example, in Northern Europe, a 1 MW system in a low‑soiling location may lose approximately €23,000–€44,000 in its first year. Over five years, cumulative soiling effects can result in total losses of €313,000-€535,000.
Why choose Lavee Solar?
Lavee Solar enables fast, simple, water‑free solar panel cleaning-no pumps, hoses or setup required.
It’s built‑in SmartShield™ protection helps panels stay cleaner for longer, supporting more stable energy performance and reducing performance drift over time.
Apply at installation or during planned maintenance to help protect panels from day one.
Common questions - the dirty truths about panel maintenance
Do panels need to be cleaned if it rains often?
Yes.
While it is sometimes assumed that solar panels are maintenance‑free, they still require care to maintain consistent performance over time.
Rain can remove loose debris, but it does not prevent the gradual build‑up of soiling. Depending on the site, panels typically accumulate different types - or combinations - of soiling, including:
- Dust
- Sand
- Pollution
- Pollen
- Lichen
- Moss
- Bird droppings
- Tree sap
- Cement dust
Although soiling is often more severe in dry, sandy or dusty environments, it also occurs in regions with high rainfall. Case studies from wet climates show that removing accumulated soiling can restore lost performance even where rainfall is frequent.
To manage soiling‑related risk and protect long‑term panel performance, regular cleaning using a product approved by PV manufacturers is recommended.
Can I just clean my panels with water?
It depends.
If water is readily available on site and can be sourced without complexity, it can be used. However, water alone is not an ideal long‑term solution. While it can temporarily improve panel cleanliness, the effect is short‑lived and offers no ongoing surface protection.
Costs and risks of using water (see section below for more detail):
• Water quality - Minerals such as calcium, chlorine and other impurities can leave residues, contributing to long-term glass and frame degradation.
• Thermal stress - Applying water to warm panels can create temperature differentials, increasing the risk of micro‑cracking over time.
• Environmental impact – Water‑based cleaning increases resource use, adding cost and reliance on site infrastructure.
Missed performance and operational efficiency
Water cleaning removes surface dirt but does not prevent re‑soiling. Fine particles quickly adhere to cleaned panels, forming a base layer that attracts further contamination. This can lead to repeated interventions and inconsistent results if not actively managed.
Comparative cost analysis shows that waterless, protective approaches are often more efficient over time, supporting higher cumulative retained generation and more predictable outcomes.
Challenges with traditional water-based cleaning methods
Accessibility of water
The installation, operation and maintenance of water-related infrastructure can add significant time, cost and complexity to solar maintenance programmes.
Many solar sites face ongoing challenges with water availability - either because no water source exists on site or because accessing and moving water around the site presents logistical difficulties.
Solar installations are often located in remote or previously undeveloped areas, where cleaning requirements are not always considered at the design stage. As a result, water dependency can introduce operational issues later in the asset lifecycle.
Common challenges include:
• Limited access locations – Remote sites or farmland with little or no access to a reliable water supply
• Hard-to-reach installations (e.g. rooftops) - Large volumes of water must be transported to the location, often requiring tanks, hoses, pumps or additional handling on site
Costs & risks
- High water consumption Traditional cleaning typically uses multiple litres of water per panel, compared to approximately 50 ml when using Lavee Solar. This contributes to an estimated 38 billion litres of water used globally for solar cleaning each year (Source: MIT, 2022).
- Infrastructure requirements Pipes, pumps, hoses, tanks and drainage systems introduce additional installation complexity, capital costs and ongoing maintenance requirements.
- Time-intensive operations Preparation, cleaning and site tidy-up take significantly longer when water is involved - particularly where infrastructure must be installed, transported or adapted for each site. Waterless application typically takes around 30-45 seconds per panel.
- Water quality risks Mains water may contain calcium and other minerals that contribute to residue buildup, while chlorine can affect seals and surrounding materials. Boreholes and wells may introduce unknown impurities. Demineralised water reduces some risks but is costly and often difficult to source.
- Panel damage risks Applying cool water to warm panels can create sudden temperature differentials, increasing the risk of thermal stress and micro‑cracking over time.
Soiling
Soiling losses in different environments
Every installation is different and must contend with localised soiling conditions. However, industry benchmarks for annual soiling losses across typical environments are shown above.
Taking the local environment into account when developing an ongoing maintenance strategy is essential for solar asset owners to manage soiling-related risk, protect panel condition and support stable long-term performance.
Factors affecting soiling
Beyond general dirt and debris that accumulate on solar panels, a range of additional environmental and site‑specific factors influence the level and rate of soiling.
Managing soiling effectively is important for protecting panel condition and maintaining consistent system performance. A planned cleaning approach helps limit the impact of soiling and supports reliable operation throughout the year.
Cost Benefit Analysis
Our analysis shows that Lavee Solar delivers the highest Return On Investment (ROI) across all cleaning methods
Our analysis assesses the full cost-benefit of different solar panel cleaning methods over a five-year period, taking into account operational costs, cleaning logistics and the financial impact of soiling-related performance drift.
The comparison covers five common approaches:
- No cleaning
- Manual cleaning with water
- Manual cleaning with Lavee Solar
- Robotic cleaning with water
- Robotic cleaning with Lavee Solar
For a 1 MW commercial installation in Northern Europe, cleaned once per year, waterless cleaning using Lavee Solar - whether applied manually or via selected automated systems - delivers the lower overall cost of ownership while retaining more usable energy output over time, across the evaluated methods.
This is driven by reduced operational complexity, lower ongoing costs and the elimination of water-related infrastructure, logistics and risk, alongside more stable retained performance over time.
If you’d like more detail on the assumptions and methodology behind our cost–benefit analysis, our team can walk you through the tool on request.
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Contact us to learn more or discuss your requirements.