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Soiling Band Solutions: Cleared for Sunshine, Maximizing Solar Panel Efficiency

Soiling band on Solar PV Modules: Causes, Effects, and Mitigation

Soiling band
Soiling band on solar panel

Soiling on solar photovoltaic (PV) modules is the accumulation of dirt, dust, and other pollutants on the surface of the PV modules. It reduces the efficiency of the PV modules and can result in significant energy losses. In this article, we will explore the causes, effects, and mitigation measures of dust on solar PV modules.

Causes of Soiling on Solar PV Modules

Soiling can occur due to a variety of reasons, including environmental factors such as dust, pollen, bird droppings, and air pollution. Factors such as the angle of the solar panels, their height above the ground, and the slope of the land can also contribute to the accumulation of dirt and dust on the panels. Moreover, the proximity of the PV array to roads, highways, and construction sites can also affect the soiling level. Let’s explore each topic:

  • Dust and Airborne Particles: Fine dust, sand, and airborne particles carried by wind can settle on the surface of solar panels over time, forming a layer of soiling.
  • Pollen and Plant Debris: During certain seasons, pollen, leaves, and other plant debris can accumulate on solar panels, particularly if trees or plants are in close proximity to the installation.
  • Bird Droppings: Bird droppings can create localized soiling on solar panels. Areas with frequent bird activity may experience more significant soiling issues.
  • Industrial and Urban Pollution: Solar installations in urban or industrial areas may be exposed to higher levels of air pollution, which can contribute to soiling.
  • Traffic Emissions: Solar panels located near roads or highways may accumulate soiling from vehicle emissions, including exhaust fumes and particulate matter.
  • Rain and Humidity: Paradoxically, rain and high humidity can also contribute to soiling. Rain can wash dust and pollutants onto the panels, which then dry and adhere to the surface when the water evaporates.
  • Geographic Location: The geographic location of the solar installation can impact soiling rates. Arid and desert regions, for example, often experience higher dust accumulation.
  • Local Environment: The immediate surroundings of the solar installation, such as nearby construction sites or agricultural activities, can generate dust and debris that settle on panels.
  • Proximity to Bodies of Water: Solar panels near bodies of water, such as lakes or ponds, may be more prone to bird activity, algae growth, and other forms of soiling.
  • Lack of Regular Cleaning: Solar panels that are not cleaned regularly are more susceptible to soiling. Over time, soiling can become more stubborn and challenging to remove.
  • Climate Conditions: Weather conditions, such as strong winds and storms, can dislodge and distribute dirt and debris onto solar panels.
  • Terrain and Topography: The terrain and topography of the area can influence soiling. For example, installations in hilly or windy areas may be exposed to more dust and debris.
  • Tilt angle of solar PV modules: The tilt angle can impact the accumulation of soiling. Steeper angles are generally less prone to soiling, while shallower angles are more susceptible to soiling because rainwater may not wash away dirt as effectively. Dust and particles can accumulate over time.
soiling band all over the modules
Image: Marai Kikai

Effects of Soiling band on Solar Modules

Soiling on solar PV modules results in a reduction in their efficiency and energy production. As dirt and dust accumulate on the surface of the panels, it blocks the sunlight from reaching the solar cells, reducing the power output of the panels. Moreover, the reduction in energy production can also lead to increased operational costs and maintenance requirements as more power is needed to achieve the same output. Here are the key effects of the soiling band on solar PV modules:

  1. Reduction in Energy Production:
    • The primary effect of the soiling band is a decrease in the amount of sunlight reaching the solar cells. This reduces the energy production capacity of the solar panels, resulting in lower electricity generation.
  2. Loss of Efficiency:
    • The layer of soiling near the frame can act as a barrier, preventing sunlight from fully penetrating the panel’s surface. This reduces the efficiency of the solar cells in converting sunlight into electricity.
  3. Decreased Output Power:
    • As the soiling accumulates, it can cause a significant drop in the output power of the affected solar panels. This decrease in power output is directly proportional to the extent of soiling.
  4. Financial Losses:
    • Reduced energy production and efficiency lead to financial losses for solar panel owners and operators. They receive less electricity or revenue from their solar installations.
  5. Long-Term Damage:
    • Prolonged exposure to the soiling band can potentially cause long-term damage to solar panels. The accumulated dirt and pollutants may etch or scratch the surface, impacting the panel’s lifespan and performance over time.
  6. Impact on Tracking Systems:
    • For solar installations that use tracking systems to follow the sun’s path, the soiling band can interfere with the tracking mechanism’s smooth operation. This can further reduce energy capture.
  7. Temperature Increases:
    • The presence of soiling on the solar panels can lead to localized temperature increases. This can result in hotspots on the panel’s surface, potentially damaging solar cells and further reducing efficiency.
  8. Maintenance Costs:
    • To mitigate the effects of the soiling band, solar panel owners may incur additional maintenance costs for regular cleaning and upkeep of the panels.
  9. Environmental Impact:
    • Reduced energy production due to soiling means a higher reliance on non-renewable energy sources, contributing to increased greenhouse gas emissions and environmental impact.
  10. Aesthetic Concerns:
    • Besides affecting performance, the soiling band can also diminish the aesthetic appearance of solar installations, which may be a concern for residential or commercial installations with visible solar panels.

In summary, the soiling band near the frame of solar PV modules can lead to reduced energy production, financial losses, decreased efficiency, potential long-term damage, and additional maintenance costs. Effective cleaning and mitigation measures are essential to address these effects and ensure the optimal performance and longevity of solar panels.

Soiling band Mitigation Measures – Solarud

Soiling can be mitigated by regular cleaning of the PV modules. However, the frequency and methods of cleaning depend on the site-specific conditions such as the level of soiling, the type of soil, and the location of the PV array. Typically, it is recommended to clean the PV modules when the reduction in energy production due to soiling exceeds 2-3%. You can estimate the soiling loss with an IV Curve tracer.

Various methods are used to clean the solar panels, including manual cleaning with water and a soft brush, mechanical cleaning using automated systems, and chemical cleaning using specific detergents. Moreover, several emerging technologies aim to reduce the frequency of cleaning required by incorporating self-cleaning mechanisms such as hydrophobic coatings, antistatic layers, and water drain clips on the PV panel surface. These technologies aim to reduce the accumulation of dirt and dust on the surface of the panels and minimize the need for regular cleaning.

Conclusion on soiling band

Soiling on solar PV modules is a significant problem that can result in a reduction in energy production and increased maintenance costs. Regular cleaning of the PV modules is essential to mitigate the impact of soiling on solar PV modules. However, emerging technologies and optimization of the PV array can also help reduce the impact of soiling on solar PV modules. By implementing these measures, we can improve the efficiency and sustainability of solar energy production, contributing to a cleaner and greener environment.


All the best,
Solarud team

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