WHAT IS PV HALF-CUT OR HALF-CELL TECHNIQUE? (PART 2)

4. FLOW PRODUCTION FROM TRADITIONAL CELL TO HALF-CELL.

The manufacturers only need to add two more stages as cutting cells and add a busbar on it.

The process of cell-cutting using laser technology to cut traditional cells. The battery cells are very flat and easy to crack. Therefore, this process requires extremely accurate technology and machinery.

After that is the process of adding a busbar. The busbar of half-cell is smaller than that of a traditional battery. Therefore, manufacturers need to use extremely accurate devices to put these busbars onto the cell.

Performance at weak radiation conditions of the half-cell battery is lower than that of traditional battery?

The performance of a half-cell PV panel is always superior to that of the traditional one. However, such in low-light conditions, a half-cell battery seems to have more disadvantages.

Does cutting cell make the PV panel size too large?

The length of the PV panel will increase by about 20mm, and the width is unchanged.

How does the By-pass diode connect to the battery compared to the traditional battery?

A by-pass diode connects in parallel with the upper and the lower part of the PV panel. Each diode connects with 20 cells of each half.

So when shaded up to one half of the PV panel, the rest still functions normally.

In the future, will we cut the cell into 4 parts? Is there a limitation in this case?

Based on the theory, we can divide the cell. However, the prerequisite is to maintain the electrical parameters such as off-load voltage and MPP voltage. Half-cell will not affect those. But dividing into smaller parts will be very complicated to maintain these parameters.

Does a half-cell battery help reduce Hotspot?

When a cell in the string of the battery is shaded, the entire amount of energy from the unshaded cells will be poured back to the shaded cell and give off heat. This phenomenon is called “Hotspot” and if occurring in long term, it will potentially damage the PV panel.

The current on half-cell will be only half of the original one, which helps reduce current running on the busbar. We have yet verified how much efficiency will increase. However, reducing the amount of heat released on the shaded cell has already been a point to help protect the battery and increase the lifespan of the system.

Does Half-cell technology contribute to better cooling for the battery?

For a typical PV panel, Junction-box is placed near the top edge of the battery. Meanwhile, with half-cell, Junction-box is divided into 3 small parts, consisting of two-wire boxes and one small box in the middle. Each of these 3 parts contains 1 Bypass diode inside.

Initially, I think there is no difference in connection compared to the traditional PV panel. However, the PV panel has two poles. If it is placed incorrectly (wrong direction), the connection will be very lack aesthetics (although the wires are long enough). Splitting Junction-box helps to make the battery better at cooling than traditional PV panels.