With the development of photovoltaic technology, Jinko Solar modules have become a popular choice in the global photovoltaic market due to their high efficiency and reliability. However, during long-term use, solar panels may be affected by various environmental factors, among which the hot spot effect is a common but serious problem. The hot spot effect not only reduces the power generation efficiency of photovoltaic modules but may also cause module damage or even fire. Therefore, understanding the causes of the hot spot effect and taking effective preventive measures are crucial to ensure the stable operation of photovoltaic power stations.
1. What is the hot spot effect?
The hot spot effect refers to the phenomenon that some cells in a photovoltaic module rise in local temperature due to shading, internal defects, or current mismatch, forming a hot spot. This phenomenon will cause the shaded cells to change from power generation units to resistive loads, consume the power of other cells, and convert it into heat, eventually causing abnormal local temperature increases, thereby affecting the performance and life of the entire solar module.
2. Causes of hot spot effect of Jinko Solar modules
Although Jinko Solar modules have excellent weather resistance and high-efficiency conversion capabilities, the hot spot effect may still occur due to the following factors:
2.1 Partial shading
If the solar panel is blocked by leaves, bird droppings, dust, snow, billboards, etc., the blocked part of the cell cannot generate electricity normally, while the other unblocked parts are still working. In this case, the blocked part will become a "consumption point", absorbing the current of the surrounding cells, causing the local temperature to rise and form hot spots.
2.2 Internal defects of components
During the production process, photovoltaic modules may increase internal losses due to factors such as poor welding, hidden cracks, material aging, and packaging defects. These defects may affect the conductivity of the cell, hinder the passage of current in certain areas, and then cause hot spots.
2.3 Connection problems
If the wire connection points, solder joints, junction boxes and other parts of the photovoltaic module are loose, oxidized, or damaged, it will cause uneven current, resulting in local current accumulation and the formation of hot spots. For example, a solder joint may fall off or break, which may cause some cells to fail to output current normally, thus forming a high-temperature area.
2.4 Inconsistent cell performance
In the same solar module, if some cells have low conversion efficiency (such as due to manufacturing tolerances, material differences, etc.), it may cause uneven current transmission, and some cells are forced to bear a larger current load, thus forming hot spots. This phenomenon is particularly obvious in large-scale photovoltaic arrays.
2.5 Bypass diode failure
The function of the bypass diode is to prevent current from flowing back to damaged or blocked cells, thereby reducing the hot spot effect. However, if the bypass diode is damaged or short-circuited, the cell may not be able to bypass effectively, resulting in local overheating.
3. Hazards of hot spot effect
The hot spot effect will bring a series of adverse consequences, affecting the normal operation of photovoltaic modules, including:
Reduced power generation efficiency of photovoltaic systems: Local hot spots will cause the current output of the cells to decrease, thereby affecting the power generation capacity of the entire module.
Accelerated aging of photovoltaic modules: Long-term high temperature will accelerate the aging of cells and packaging materials, shortening the service life of photovoltaic modules.
Damage to cells or glass: Continuous temperature rise may cause cell cracks, or even glass breakage, increasing repair costs.
Fire hazards: If the temperature is too high and not handled in time, it may cause electrical fires in extreme cases, affecting the safety of photovoltaic power stations.
4. How to prevent the hot spot effect?
To prevent the hot spot effect from affecting Jinko Solar photovoltaic modules, the following preventive measures can be taken from multiple aspects such as design, installation, and operation and maintenance:
4.1 Choose high-quality photovoltaic modules
When purchasing, you should choose a reliable solar module brand, such as Jinko Solar, to ensure that its products undergo strict quality control during the production process. At the same time, high-quality modules usually have better weather resistance and lower current mismatch rate, which can effectively reduce the probability of hot spot effect.
4.2 Use appropriate installation methods
Avoid shading: When installing solar panels, ensure that there are no tall buildings, trees, or obstacles around to avoid shadows affecting the modules.
Tilt angle optimization: A reasonable tilt angle not only helps to improve power generation efficiency, but also reduces dust and rain accumulation, and reduces the risk of local shading.
Good ventilation design: Ensure that the photovoltaic modules have enough heat dissipation space to avoid the aggravation of the hot spot effect due to high temperature accumulation.
4.3 Regular cleaning and maintenance
Clean up foreign matter on the surface: Regularly remove bird droppings, dust, leaves, etc., on the surface of the photovoltaic modules to prevent local obstruction.
Detection of hidden cracks in the cells: Use thermal imagers or EL (electroluminescence) detection technology to regularly check whether the modules have hidden cracks or failed cells.
Check the wiring and solder joints: Ensure that the electrical connection of the module is stable to avoid broken solder joints or loose wiring.
4.4 Optimization of bypass diodes
Regularly check whether the bypass diodes are damaged to ensure that they can work normally, to reduce the risk of hot spots.
Select low-loss diodes to reduce additional power loss and improve system efficiency.
4.5 Monitor the operation status of the photovoltaic system
Use an intelligent monitoring system to monitor the current, voltage, temperature, and other parameters of the photovoltaic modules in real time to detect abnormal conditions in a timely manner.
If a hot spot effect is found, the obstruction, cell damage, or circuit failure should be checked immediately, and corresponding repair measures should be taken.
For photovoltaic power station investors, operation and maintenance teams, and photovoltaic module purchasers, understanding and preventing the hot spot effect can not only improve the power generation efficiency of the photovoltaic system but also extend the system's life and ensure the maximization of investment returns. Choosing high-quality components from Jinko Solar Modules Company and combining them with scientific operation and maintenance management will be the key to the success of photovoltaic projects.
As a Jinko Solar module manufacturer, we are always committed to providing efficient and reliable photovoltaic products, and effectively reduce the risk of hot spot effects through advanced production processes, strict quality control, and intelligent monitoring technology. At the same time, we provide customers with professional operation and maintenance support to ensure that the components operate stably in various environments, extend their service life, and improve power generation efficiency. In the future, Jinko will continue to promote technological innovation and provide global users with safer and more efficient clean energy solutions.
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