Introduction

In the realm of solar energy, technological advancements continually strive to enhance the efficiency and reliability of photovoltaic (PV) modules. One such innovation is the half-cell photovoltaic module, which offers distinct benefits over traditional full-cell modules. This article delves into the physical and operational differences between these two types of solar modules, exploring the advantages of the half-cell design and its impact on performance.

What are Half-Cell Photovoltaic Modules?

Half-cell photovoltaic modules, also known as Helfgott modules, involve a unique configuration where a standard photovoltaic cell is divided into two smaller rectangular cells. This results in a reduction of the surface area of each cell by half while doubling the number of cells per module. Instead of arranging all the cells in a single long series connection, the cells in half-cell modules are coupled both in series and in parallel.

Why Choose Half-Cell Modules?

The design modifications in half-cell modules are not arbitrary; they offer significant performance benefits:

 

1. Reduced Resistive Losses: By halving the size of the cells, the current passing through each cell is reduced. This lowers resistive losses, which occur due to the internal resistance of the cells, enhancing the overall efficiency of the module.
2. Improved Shading Tolerance: In a traditional full-cell module, shading a small portion of the module can significantly impact its performance. This is because the cells are connected in a single series string. If even one cell is shaded, it can hinder the current flow through the entire string. In contrast, half-cell modules have more strings of cells, meaning shading on one part of the module affects a smaller portion of the total output.
3. Increased Power Output: The combination of reduced resistive losses and improved shading tolerance contributes to a higher power output compared to traditional modules. This makes half-cell modules particularly beneficial in environments where partial shading is a concern.

Comparing Traditional and Half-Cell Photovoltaic Modules

To understand the advantages of half-cell modules better, let's compare them side-by-side with traditional full-cell modules.

Traditional Full-Cell Modules

In a conventional full-cell PV module, square photovoltaic cells are arranged in a grid pattern and connected in series. This creates a long, snake-like string of cells where the current flows through each cell sequentially. Under ideal conditions, with full sunlight and no shading, this configuration works efficiently. However, if a portion of the module is shaded—for instance, by a large leaf falling on it—the entire string's performance is compromised. This is because the shaded cells block the current flow through the series string, effectively reducing the module's power output.

To mitigate the impact of shading, manufacturers install bypass diodes in full-cell modules. Typically, one bypass diode is used for every two columns of cells. If shading occurs, the bypass diode deactivates the affected section, allowing the remaining sections to continue operating. While this reduces the impact of shading, it still results in a loss of one-third of the module's power output for each bypassed section.

Half-Cell Modules

Half-cell modules, on the other hand, split each cell into two smaller cells and connect them in a combination of series and parallel strings. This configuration inherently reduces the impact of shading. If shading occurs on a half-cell module, only a smaller portion of the total module is affected, thanks to the parallel connections that maintain the current flow through the unaffected cells. Additionally, the reduced current in each cell decreases resistive losses, further enhancing the module's efficiency and power output.

Conclusion

Half-cell photovoltaic modules represent a significant advancement in solar technology, offering improved efficiency, better shading tolerance, and increased power output compared to traditional full-cell modules. By understanding the differences in design and operation between these two types of modules, consumers and solar energy professionals can make more informed decisions about which technology best suits their needs. As solar technology continues to evolve, innovations like the half-cell module will play a crucial role in optimizing solar energy systems for a wide range of applications.

Photo Source:
https://youtu.be/0qJQGWnrzts?si=5MEczegNfVe-su3v
https://blog.ibc-solar.com/2018/09/new-module-technologies-lhs-half-cut-mbb/
https://www.linkedin.com/pulse/half-cut-solar-module-overview-solarisourpassion-1f?utm_source=share&utm_medium=member_android&utm_campaign=share_via
https://www.maysunsolar.com/blog-half-cut-solar-panels-unleashing-the-power-of-efficiency/