Shading Analysis in Photovoltaic Systems: Impacts and Solutions

Watch to visually understand how shading affects your photovoltaic system.

When planning the installation of a photovoltaic energy system, several factors are crucial for its success. Among them, shading analysis stands out as one of the most important. A photovoltaic system produces electricity from sunlight; therefore, any obstruction that blocks this light can significantly impact its performance.

Shading can come from trees, neighboring buildings, chimneys, poles, dirt on panels, and even other modules within the same arrangement. Consequently, understanding the impact of shading and how to mitigate it is vital to ensure maximum efficiency and return on investment (ROI).

The Impact of Shading on Energy Generation

The impact of shading on photovoltaic systems goes far beyond the proportional loss of solar irradiation. When a part of a solar panel is shaded, the electrical current generated by those cells decreases. In modules connected in series (common in photovoltaic systems), this decrease can reduce the energy production of the entire string of panels. This occurs because the on-grid inverter tends to level power based on the cell with the lowest performance.

A single shaded panel in a string can compromise the energy production of the entire array.

Additionally, shaded cells can become resistors, dissipating the energy generated by illuminated cells as heat. This phenomenon is known as "hotspot," which can lead to extreme temperatures (up to 160°C) and cause permanent and irreversible damage to solar cells, reducing the module's lifespan. In extreme cases, shading losses can exceed 75% of expected production.

Common Types of Shading

There are different types of shading that must be considered:

• Fixed Shading: Caused by permanent structures such as buildings, chimneys, large trees.
• Seasonal Shading: Varies according to the season, such as the shadow of a tree that loses leaves in winter or changes in the solar trajectory.
• Dynamic Shading: Generated by moving objects, such as clouds, birds, or even accumulated dirt.
• Self-Shading: When a row of panels casts a shadow over another row of the same system, especially in multi-row arrangements.

Methods and Tools for Shading Analysis

Shading analysis is a fundamental step in the design of photovoltaic systems. It allows for accurate prediction of energy losses throughout the year and optimization of module layout. Various methods and tools are available to perform this evaluation.

Manual Analysis and Direct Measurement

Historically, analysis involved on-site measurements with instruments such as the Solar Pathfinder or Solmetric SunEye, which create shading maps for different periods of the year. Although effective, these methods can be time-consuming and depend on the accuracy of manual data collection.

Computational Simulation and Advanced Technologies

Currently, most shading analysis is performed through computational simulation software, such as PVsyst, Pylon Solar Design & CRM, and Aurora Solar. These tools allow modeling of the installation site in 3D, considering all surrounding objects, and simulating shadow patterns at different times and dates.

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3D simulation software provides accurate shading analysis and optimizes panel layout.

Advanced technologies, such as LiDAR and AI-assisted 3D modeling (used by platforms like EagleView), elevate the accuracy of shading analysis. They capture thousands of data points per roof, allowing layout optimization based on advanced algorithms, resulting in performance gains of up to 17.3%. Sunergia utilizes best practices and tools for this analysis, ensuring the efficiency of your project.

Solutions to Mitigate Shading

The good news is that there are various technologies and strategies to mitigate the negative effects of shading, ensuring that your photovoltaic system continues to produce energy efficiently.

Bypass Diodes and Hot-Spot Free (HSF) Technology

Bypass diodes are crucial components integrated into photovoltaic modules. They act by creating an alternative path for electrical current, diverting it from shaded cells. Thus, cells exposed to light can continue to generate energy efficiently, preventing the formation of hotspots and protecting the module from damage. For more information, see our article on cell-level bypass diode in solar panels.

Hot-Spot Free (HSF) technology, such as the AE-Solar 370W HSF modules (awarded TOP INNOVATION 2018), utilizes these diodes in an optimized manner. This drastically reduces temperature in shaded areas (below 85°C), eliminates risks, and can generate up to 30% more power under partial shading conditions compared to conventional modules. Consequently, fewer modules may be required for the same power output.

Bypass diodes protect shaded cells, ensuring production continuity.

The Importance of Professional Consulting

Shading analysis and the selection of ideal solutions are complex tasks requiring technical knowledge. A professional evaluation ensures that all factors, from annual solar trajectory to roof characteristics, are considered for precise sizing and an optimized design.

Sunergia has engineers with expertise and the necessary tools to perform detailed shading analysis, proposing the best solutions to maximize the performance and durability of your photovoltaic system. Investing in a well-designed project is the key to the success of your solar energy generation.

Optimize Your Solar Project

Avoid losses and ensure the efficiency of your system. Contact Sunergia for professional shading analysis and a personalized quote.