A typical solar module consists of 60 or 72 full solar cells connected in series.

Each full cell generates a certain voltage and current.

The current flows through the entire length of each cell to reach the busbars and interconnect ribbons.

If even a small part of a cell is shaded, the output of the entire string of cells can be significantly reduced because the shaded cell acts as a bottleneck, limiting current flow.

In half-cell modules, standard full-size solar cells are cut in half using a laser cutter (often using a nondestructive cutting method like TLS).

A 60-cell module becomes a 120-half-cell module, and a 72-cell module becomes a 144-half-cell module.

Each half-cell produces half the current but the same voltage as a full cell.

The half-cells are then connected in a series-parallel configuration. This typically involves two sets of half-cell strings wired in parallel within the module, each with its own set of bypass diodes.

The Problem: In traditional full-cell modules, the current generated by each cell has to travel through the entire length of the cell to reach the busbars and interconnect ribbons. This leads to resistive power losses, which reduce the overall efficiency of the module.

The Half-Cell Solution: Half-cell technology involves cutting standard solar cells in half, creating two smaller cells connected in series. Each half-cell produces half the current but the same voltage as a full cell. Because power loss is proportional to the square of the current (P = I²R), reducing the current in each half-cell significantly reduces resistive losses within the cell and the cell's interconnect ribbons. While the voltage of each cell remains the same, the strings of cells are wired in parallel, halving the overall voltage, but doubling the current of a string, when compared to a full-cell panel with the same number of cells, all wired in series. However, due to the reduction in resistance, this still results in a net power gain.

Benefit: This reduction in power loss translates to a higher power output for the module compared to a full-cell module with the same cell type and area.

The Problem: In traditional full-cell modules, if even a small portion of a single cell is shaded, the output of the entire string of cells connected in series can be significantly reduced. This is because the shaded cell acts as a bottleneck, limiting the current flow through the entire string.

The Half-Cell Solution: Half-cell modules are typically designed with two independent sections. Each section has its own set of bypass diodes. If one half of the module is shaded, the other half can still operate at full power. This is a significant advantage in real-world scenarios where partial shading can occur due to trees, buildings, or other obstructions.

Benefit: Better performance in partially shaded conditions, resulting in higher energy yield over the course of a day or year. This is because a bypass diode will activate and only cut out half of the panel, as opposed to the whole panel in a full-cell configuration.

The Problem: Hot spots occur when a shaded or damaged cell becomes a resistive load, dissipating heat instead of producing power. In severe cases, hot spots can damage the cell and even pose a fire hazard.

The Half-Cell Solution: Because half-cells generate less current, they also generate less heat. This reduces the risk of hot spots forming and improves the overall safety and reliability of the module. The temperature increase of a hot spot in a half-cell is about half that of a full-cell, which will significantly reduce the risk of damage or fire.

Benefit: Lower risk of hot spots, enhanced module safety, and increased lifespan.

The Problem: The interconnections between full cells can be a point of weakness, susceptible to damage from thermal cycling or mechanical stress.

The Half-Cell Solution: Because the distance between the busbars on the cell is halved, and because each half-cell has its own independent connections in a split-junction box, they're more resistant to bending and other forces that could cause damage. Also, the smaller size of half-cells makes them inherently more resistant to micro-cracks that can develop due to mechanical stress.

Benefit: Improved durability and resistance to damage from thermal stress or physical impact.

Due to the reduced current and resistive losses, half-cell modules tend to operate at a slightly lower temperature than comparable full-cell modules.

Benefit: The lower operating temperature contributes to higher efficiency (as solar panels are less efficient at higher temperatures) and can also improve the module's lifespan.

Reducing power losses

Improving shade tolerance

Enhancing reliability

Increasing durability