Comparing Whole Cells to Half-Cell Photovoltaic Modules

Introduction

Photovoltaic (PV) technology has seen significant advancements, with one notable innovation being the half-cell module. This article compares traditional whole-cell PV modules to the newer half-cell configuration, highlighting the benefits and operational differences.

Whole Cells vs. Half-Cells

Traditional PV modules use square cells. In the half-cell design, these square cells are cut exactly in half, creating rectangular cells. This doubles the number of cells in the panel while reducing the surface area of each cell by half.

Wiring Configuration

In a half-cell module, cells are divided into two sections: top and bottom. Each section is wired in series (end-to-end connection). These two sections are then wired together in parallel.

1. Top Section: Cells connected in a continuous series loop.
2. Bottom Section: Cells are also connected in series.
3. Parallel Connection: Top and bottom sections combined in parallel.

Bypass Diodes

Three bypass diodes are placed in the middle of the half-cell module, unlike traditional modules where diodes are typically located at the bottom side.

Impact of Shading or Malfunction

If shading occurs on the top left cells, the first bypass diode activates, isolating the shaded cells. This isolates only a small part of the module, reducing power loss to one-sixth instead of one-third, as would happen in a traditional module.

Diagram

• Local Shading: Affects only a small portion of the module.
• Bypass Diode Activation: Redirects current, minimizing power loss.
• Damage: Faulty section isolated, preserving the majority of the module's functionality.

Advantages of Half-Cell Configuration

1. Reduced Amperage: Each section carries half the current, reducing inefficiencies due to lower amperage.
2. Improved Efficiency: Lower current through the wires reduces energy loss, enhancing overall module efficiency.

[Image Placeholder: Diagram illustrating reduced amperage and improved efficiency]

Real-Life Example: Canadian Solar Half-Cell Module

Let's examine a real-life example from Canadian Solar. This module features high power output, bifacial technology, polycrystalline cells, and PERC technology.

• High Power Output: Relative to its size.
• Bifacial: Can capture light from both sides.
• Polycrystalline: Efficient and cost-effective.
• PERC Technology: Passivated Emitter Rear Contact for higher efficiency.

Mechanical Data

• Junction Boxes: Ingress Protection 68.
• Cell Arrangement: 144 cells (2 x 72) compared to the regular 72-cell module.2 x 12 x 6: Two sections of 12 rows by 6 columns

Mechanical data sheet of Canadian Solar half-cell module]

Conclusion

Half-cell photovoltaic modules offer significant advantages over traditional whole-cell modules. With improved efficiency, reduced power loss due to shading, and enhanced overall performance, they represent a noteworthy advancement in solar technology. Users can make informed decisions about their solar energy systems by understanding these benefits and configurations.

Photo source 
https://www.infiniteenergy.com.au/new-release-canadian-365w-hiku-canadian-solar-split-cell-panels/
https://youtu.be/QwOGjo_5dxw?si=IXWdcS7tribW3MuC
https://www.pinterest.com/pin/380976449710709589/
https://youtu.be/0qJQGWnrzts?si=vRwgbRsmUiiHE0j6
https://youtube.com/shorts/u2jA2OuisTo?si=ibjq5yl_32PSk7mB