Solar panel shading solutions have become critical to maximizing energy production in photovoltaic systems. As demand for clean energy grows, so does the need to understand shading in solar panels and its effect on performance. Shading can greatly reduce solar panel efficiency. So, we must find ways to fix this.
Novel technology and design strategies have been developed to solve the issues raised by darkened areas. These changes aim to reduce the shade on solar panels. They should maximize performance in less-than-ideal conditions. This post explores several options for shading solar panels and looks at both their usefulness and efficacy. It also reviews the best solutions for managing solar panels in shaded areas. It offers useful insights to homeowners and businesses looking to improve their solar energy systems.
Assessing Shading Impact on Solar Panels
A comprehensive site survey is crucial to evaluate the shading impact on solar panels accurately. This means finding things, like trees or buildings, that could cast shadows on the panels.
Site Survey Techniques
To commence, an on-site shadow analysis must be carried out. Make a note of any surrounding buildings or vegetation that rises above the roof. Use portable gadgets like the Solmetric Sun Eye or Solar Pathfinder to gather data points across the rooftop. Every roof facet should have a reading, with one in the center and one at least in each corner. Make sure the equipment is level when using it, as any tilt may have an impact on the outcome.
As an alternative, use EagleView’s Inform Advanced. It estimates solar access value (SAV) and can perform remote surveys. EagleView’s technology collects hundreds of data points. In contrast, handheld sensors collect only a few. This allows for precise system designs that maximize energy production.
3D Modeling and Simulation
After collecting site data, a 3D model of the location is created, measuring the height, direction, and placement of potential obstructions using specialized instruments. Solar experts then analyze the shade patterns using simulation software. This predicts how much sunlight the solar panels will get at different times throughout the day and year.
Shade Analysis Tools
Effective solar shade analysis requires specialized methods and tools. sun Pathfinder, Sun Eye, and software for analyzing sunshades are some of these instruments. The study can assess the solar system’s energy production. It can also measure how shading will affect its performance by examining the shading patterns.
Accurate shade estimation methods enable precise computations. These include Solar Access Values (SAV) and Total Solar Resource Fraction (TSRF). They are obtained from high-resolution aerial photography. These data points can help designers. They can find the best spots for solar panels in solar PV systems. This will boost energy output.
Designing Shade-Resistant Solar Arrays
When designing solar arrays, consider shading issues. Use strategies to reduce their impact on energy production. Solar systems can perform well in partial shade by selecting the right modules and optimizing the array’s config, tilt, and orientation.
Module Selection for Shade Tolerance
The choice of solar modules plays a significant role in determining the system’s shade tolerance. Certain module technologies and features can enhance performance in shaded environments:
- Modules with bypass diodes: These diodes allow the electrical current to bypass shaded cells, preventing them from impeding the performance of unshaded cells within the same module.
- Modules with microinverters or power optimizers: These devices perform maximum power point tracking (MPPT) at the module level, enabling each panel to operate independently and mitigate the effects of shading on the overall system.
- Shade-tolerant modules: Innovative technologies like Optivolt’s Pulse shade tolerance system can deliver up to 25 times more power in shaded conditions compared to conventional solar panels.
Array Configuration Strategies
Proper array configuration can help minimize the impact of shading on solar panel performance:
- Grouping shaded modules into separate strings: By connecting shaded modules in parallel strings, the unshaded strings can operate at their maximum potential without being affected by the shaded modules.
- Utilizing module-level power electronics (MLPEs): MLPEs, like microinverters and DC optimizers, improve individual module performance. They let each panel reach its maximum power point, even if other modules are shaded.
Tilt and Orientation Optimization
The tilt and angle of solar panels can affect their shading. This is true both throughout the day and year. Optimizing these factors can help maximize energy production:
- Tilt angle: While the general rule of thumb is to match the tilt angle to the local latitude, the optimal angle may vary based on local weather patterns and shading conditions. In some cases, a flatter angle can be more productive, especially in areas with frequent cloud cover.
- Azimuth angle: The azimuth angle, or the direction the panels face, should be adjusted to account for shading patterns and weather conditions. For example, the most productive azimuth in San Diego is 190 degrees, slightly west of due south, to capture more afternoon sunlight.
- Backtracking algorithms: Backtracking algorithms can control the positioning of tracking system panels. This limits shading between rows as the sun moves.
By using these strategies, solar installers can predict and reduce shading. This will ensure optimal energy production and a high ROI for solar PV systems.
Advanced Technologies for Shading Mitigation
Module-Level Power Electronics
Devices called Module-Level Power Electronics (MLPE) boost solar panel performance in the shade. Among them are DC power optimizers and microinverters. Each solar panel has a microinverter, a tiny inverter that converts DC to AC at the module level. AC optimizers retain maximum power without reducing the output of the entire string by adjusting the output voltage and current.
MLPEs use Maximum PowerPoint Tracking (MPPT) at the module level. This ensures that every panel performs at full capacity, regardless of shadowing on other modules. This removes orientation mismatch losses and reduces partial shading losses by 20–35%.
In a conventional system with a string inverter, shading on one module reduces the output of the entire string. But, with microinverters or DC optimizers, each module works at its best. It is unaffected by shading on others.
MLPEs offer design flexibility, allowing for system expansion and mixing module types. They provide module-level monitoring and improve overall energy production through distributed MPPT.
Bifacial Solar Panels
Bifacial solar panels capture sunlight on both sides. They boost energy yield by up to 30% over traditional monofacial panels. The rear side’s effectiveness, known as the bifaciality factor, typically ranges from 65% to 90% of the front side’s capacity.
These panels excel at capturing diffused and reflected light. They extend daily operating hours and improve performance in low-light conditions. They are versatile for many installs, like ground mounts, rooftops, and building facades.
Bifacial panels are less susceptible to shading, soiling, and temperature fluctuations, making them well-suited for challenging environments. Their durability and longevity make them cost-effective. They require less maintenance and improve ROI.
Tracking Systems
By changing the panel orientation during the day, tracking systems can reduce shade. Backtracking algorithms control the location. They limit shadowing between rows as the sun moves.
Tracking systems can optimize energy production by maximizing tilt and azimuth angles. They should also account for weather and shade patterns. Panels will perform better if they capture the most direct sunlight.
