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Photovoltaic solar panels, also known as solar panels or photovoltaic panels, are devices that directly convert sunlight into electrical energy.
The working principle of photovoltaic components is based on the photoelectric effect. The following is the process of how do photovoltaic cells work.
- Firstly, there must be illumination from light, which can be sunlight or a simulated solar source.
- Secondly, after injecting photons into the semiconductor, electron hole pairs are excited, which must have sufficient lifetime to ensure that they are not recombined before separation. Next, an electrostatic field (such as a PN junction) is needed to separate electrons and holes.
- Finally, the separated electrons and holes are collected by the electrode and output to the outside of the battery, forming a current. Half cut solar panels can provide significant advantages and improve performance in shaded conditions, which is of great significance for increasing the overall photovoltaic power generation of buildings that are easily affected by other building obstacles.
Half cut solar panel technology has become an important means for improving module performance in the photovoltaic industry and has been widely adopted in practical applications. Therefore, this article will explore the technology in half cut solar panel, in order to help you grab the latest news about the photovoltaic industry.
What is half cut technology in solar panels
Half cut of photovoltaic cells is a process improvement that involves cutting a single crystalline silicon into two halves and then connecting the two halves to form solar cells, aiming to improve the performance and efficiency of photovoltaic modules.
For half cut solar panels, they are actually cutting ordinary solar cells in half. Unlike common photovoltaic modules that have 60 or 72 cells, half cut solar panels contain 120 or 144 half cells while maintaining the same design and size as conventional modules. Simply put, half cut solar panel technology involves cutting standard battery cells in half, shortening the current path, and thus reducing resistance losses.
A more detailed explanation is that the half cell technology uses laser cutting method to cut standard specification battery cells into two identical half cells along the direction perpendicular to the main grid line of the battery, and then weld them in series. Like conventional components, the half cut solar panel is also packaged with tempered glass, EVA, and backplate.
Conventional solar panels typically consist of 60 series connected 0.5-0.6V solar cells. The voltage increases in series, so the operating voltage of 60 components is 30-35V. If half cells are connected together like in standard components, they will generate half the current and twice the voltage.
Manufacturing process of half cut solar panel
Cutting process
The manufacturing process of half cut solar panel mainly includes the following steps.
Slicing
Use laser cutting technology to cut standard sized photovoltaic cells in half. Laser cutting has the advantages of high precision and low damage, which can ensure the integrity of the cutting edge and the mechanical strength of the battery cell.
Passivation treatment
Passivation treatment is applied to the cut edges to reduce edge defects and minimize surface recombination losses.
Assembly process
Series and parallel connections
Due to the halving of the current of each battery cell, the half cut solar panel needs to redesign the series parallel connection of the battery cells to ensure that the output voltage and current of the components meet the design requirements.
Packaging
Package the half cut solar panel and ensure its environmental resistance during the packaging process, ensuring that it has good mechanical strength and environmental resistance during use.
Advantages and disadvantages of half cut solar panel
Advantages
Are half cut solar panel better? The answer to this question is yes. Here are the reasons.
One significant advantage of reducing resistance losses with a half cut solar panel is that the current path is shortened, the current is halved, thereby reducing resistance losses. Power loss is proportional to current, and half of the current and a quarter of the resistance allow a half chip component to reduce power loss by four times, resulting in an increase in output power and power generation.
By reducing resistance losses, the power output of half cut battery modules is higher, resulting in increased component power. In practical applications, the power of half cut solar panels can be 5% -10% higher than traditional full panel components.
Half cut solar panel technology can also effectively reduce the hot spot effect. The hot spot effect is a local overheating phenomenon caused by the reduction of current or lack of power in certain battery cells inside the component due to shadows, dust, and other reasons. The current of the half cell battery is relatively small, and the risk of hot spot effect is correspondingly reduced, which improves the reliability and service life of the component.
And due to the reduction of internal losses, the operating temperature of the components and junction boxes also decreases. In the outdoor working state of the components, the temperature of the half piece component itself is about 1.6 ℃ lower than that of the conventional whole piece component. The lower temperature allows the component to have higher photoelectric conversion efficiency.
Improve performance under shadow occlusion. Half sliced components perform better under partial occlusion. When some battery cells are obstructed, the output current of the entire component will not immediately decrease significantly because the current of each battery cell is small, and the impact of obstruction on the overall output current is reduced. Half cut solar panel does not have 3 panel battery strings like standard components, but instead has 6 battery strings, making it a 6-series battery panel. Although a small portion of shadows on the components (such as leaves, bird droppings, etc.) can cause the entire battery string to fail, the design of the bypass diode (marked in red in the figure below) does not affect other battery strings, reducing the impact of shadows.
Disadvantages
The half cut solar panel process requires additional cutting, passivation, and bonding steps, which can increase manufacturing costs. In addition, the new series parallel connection design and packaging process also require more process and material investment.
Although laser cutting technology can minimize damage to the battery cells during cutting, half cells are still more fragile than full cells in terms of mechanical strength. Be more careful during transportation and installation to avoid mechanical damage.
FAQs about half cut solar panel
What is the difference between monocrystalline and half cut solar panels?
The classification of the two types of solar panels is different. Monocrystalline silicon photovoltaic modules refer to photovoltaic modules processed from monocrystalline silicon wafers. Monocrystalline silicon is made using polycrystalline silicon block materials and pull rod technology (circular silicon rods).
Half cut solar panel refers to the process of cutting a solar cell into two pieces and assembling them into a photovoltaic module. Half cut technology is a type of structural process for photovoltaic modules.
What is the difference between half cut solar panel and bifacial solar panel?
The bifacial solar panel can capture sunlight from both sides. In addition to directly receiving sunlight for power generation on the front side, the back side can also use light reflected back from the ground or surrounding environment for additional power generation, improving energy output and suitable for various environments.
Half cut solar panel technology can be used for both single-sided and double-sided solar panels. Half cut solar panels are commonly used in practical applications for bifacial solar panels. These two technologies are often used in combination to achieve higher efficiency and better power generation performance.
How many solar panels are needed to power a house?
In an ideal situation, a single crystal silicon solar panel with an area of about 1.6m can generate approximately 1.8 degrees of electricity per day.
Air conditioning requires about 4 solar panels to work in hot summer days. Electric water heaters, rice cookers, and electric kettles require approximately 2 solar panels. Refrigerator, washing machine, TV, computer - a total of 1 battery board is required. 0.5 solar panels are enough for various lighting fixtures at home. In addition, if solar power is used to supply energy to electric vehicles, based on an average daily travel of 50 kilometers, 4 solar panels are required.
However, considering the actual lighting conditions and weather factors that cause about 20% energy loss, to meet the daily electricity needs of a family of four, approximately 14 photovoltaic panels with an area of 1.6 square meters each need to be installed. If you are looking some high efficiency solar panels, here is some tips for your reference.
Conclusion
Half cut solar panel technology significantly improves the efficiency and reliability of photovoltaic modules by reducing resistance losses, increasing module power, reducing hot spot effects, and enhancing performance under shadow shading. Half cut cells can increase photovoltaic power generation system, but their system design is similar to that of full cell components, without increasing installation costs, ensuring lower LCOE.
With the popularization of large components and large silicon wafers, the trend of half or even three slice is becoming increasingly evident. According to industry related institutions, the market share of chip components is expected to exceed 60% in the next three and a half years.
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