The Half-Cut solar panel is a new generation of solar panels such as bifacial, flexible solar panels produced with special technology and a different cell design compared to traditional photovoltaic solar panels. In this article, we will take a closer look at half-cut solar panels.
What is a Half-Cut Solar Panel?
The reason for using the name “half-cut” is that standard solar cells are cut in half using a special technology. The purpose of the cell cutting here is to create a solar panel with more solar cells than the standard solar panel. The bypass diodes in the solar panel are also located in the middle to separate the upper and lower parts. In this way, the solar panel is also divided into two upper and lower parts. In other words, the upper and lower parts work independently of each other, which means less internal resistance, higher energy output, and less efficiency loss due to shadowing.
Traditional monocrystalline solar panels usually have between 60 and 72 solar cells. When these cells are cut in half, the number of cells doubles. So half-cut solar panels have 120 to 144 solar cells and are usually manufactured with PERC technology, which provides higher module efficiency.
The cells are very carefully cut in half with a laser. By cutting the cells in half, the current inside the cells is also halved, which means resistance losses due to the transmission of energy are reduced. Thus, better performance is achieved.
Since the solar cells are cut in half, the size is also reduced, and more solar cells fit on the half-cut solar panel than on standard solar panels. In addition, the solar panel itself is divided into two parts as two separate panels, top, and bottom. In this way, the loss of efficiency due to shading is also reduced.
How Does a Half-Cut Solar Panel Work?
One of the most important points in the design of half-cut solar panels is the series connection between the cells. Electricity moves through the solar panel with the bypass diode. The bypass diode, shown in red in the pictures below, transmits the electricity generated by the cells to the junction box.
The most prominent feature of the half-cut design is shade tolerance. In standard solar panels, when a single cell in a row is shaded, the entire row cannot generate electricity, which usually means that one-third of the solar panel cannot generate electricity.
For example, in a standard solar panel with 60 cells in the image above. The solar panel is designed in 3 strings with 20 cells in each string. Here, if one of the cells in the 1st section is shaded, all cells in that string will not be able to generate energy, which means that one-third of the solar panel will be disabled.
But the situation is slightly different for a half-cut solar panel. Suppose the solar panel in our first example is converted into a half-cut solar panel. Thus, the newly formed half-cut solar panel has a total of 120 solar cells and a total of 6 strings with 20 cells each.
If one of the cells in the first row is shaded in this panel, the cells in that row cannot generate electricity. But here is a different situation from standard solar panels. Since the number of cells increases and the half-cut solar panel is divided into upper and lower parts, the cells in the 4th part are not affected by the shading in the 1st part. As a result of shading, one-sixth of the panel is disabled, not one-third as in a standard solar panel.
You can see that the solar panel itself is also cut in half. So in total, there are 6 different cell groups instead of 3 as in the standard panel. The bypass diode is also located in the middle of the solar panel, not on one side.
What are the Advantages of Half-Cut Solar Panel Design?
The half-cut solar panel has many advantages. These advantages are as follows:
- High shade tolerance: Half-cut solar panels have less power loss due to shading, which allows these panels to have a higher power output.
- Hotspots effect: Another advantage is there are fewer hotspots on half-cut cells. Since there are more cells in a half-cut solar panel, the hotspot effect can get lower.
- Lower internal resistance: half-cut solar panels also have lower internal resistance. Since the solar cells are cut in half, the current generated by each cell is also divided in half, which means lower internal resistance, which means that power drops due to internal resistance are also lower.
- Efficiency: Electricity generation efficiency reaches up to about 20%.
- More power output: Thanks to factors such as lower resistance loss, hot spot, and less power loss due to shading, half-cut solar panels provide up to 15 W more output power than standard solar panels.
Although half-cut solar panels have significant advantages, they have some disadvantages too. Since they are more challenging to manufacture, they are more expensive. However, despite of advantages of half-cut solar panels, they can be more profitable in the long run.
Are Half-Cut Cells the Future of Solar?
Although half-cut solar cells increase the power output of the panels, the productiond of the half-cut solar panels is difficult for standard panel manufacturers to switch their production to half-cut cells.
In many ways, standard solar panels are still ideal if you have an unshaded roof. But if there is shading such as tree shade at certain times of the day, then a half-cut solar panel can be considered. Of course, in this case, standard solar panels will also work by using more. In short, the solar power system should be designed according to your project and evaluated whether half-cut solar panels are suitable for your project in terms of cost.
Technology is developing very fast. Maybe we can see more half-cut solar panels on the roofs as half-cut cell production becomes cheaper over time.