The hail resistance maintenance of solar panels in areas with frequent hail requires full-process control from equipment selection, installation and reinforcement, daily monitoring to post-disaster handling. The following are the specific points to note:
First, preventive measures in advance
Selection and Certification
Priority should be given to photovoltaic modules that have passed the hail test in the IEC 61215 standard (with 25-millimeter hailstones hitting at a speed of 23 meters per second). Some high-end modules can withstand hailstones with a diameter of 30 millimeters. For instance, components adopting N-type battery technology have higher material stability and stronger impact resistance. In addition, components with PVEL five-star certification or similar international certifications are more reliable.
Thickening the glass and strengthening the frame are the key. The double-glass module, due to its backsheet design, has stronger impact resistance, and the thickness of its tempered glass should be ≥3.2 millimeters. The frame should be made of high-strength aluminum alloy or stainless steel and reinforced to form a double-layer protective structure similar to a “bulletproof vest”.
Installation and reinforcement
The design of the support must strictly follow the local wind and earthquake resistance parameters. In coastal areas, it should have the ability to withstand winds of force 12 or above. The material of the support should be thickened steel with a thickness of no less than 2.5 millimeters and a galvanized layer thickness of no less than 65 microns to ensure anti-corrosion performance. The installation of the support frame should be fastened with high-strength bolts or anchored on a concrete foundation to eliminate the risk of loosening from the source.
For rooftop photovoltaic power stations, hail nets can be installed. The materials are mostly pressure-resistant stainless steel nets or polycarbonate plates, which can effectively absorb the impact force of hail. Meanwhile, the roof supports need to be supplemented with counterweights, such as cement foundations, to meet the requirements of wind load resistance and snow load resistance. Generally, they are designed based on the local wind pressure that occurs once every 50 years.
Environment and Site Selection
The site selection should avoid areas where objects fall from heights, such as under the eaves of tall buildings, chimneys, electric poles or under big trees. If it is impossible to avoid, additional protective measures should be taken.
Improve the lightning protection and grounding system, install lightning rods and surge protectors (SPDS) in a standardized manner, and ensure that the grounding resistance of the photovoltaic system is controlled at 4Ω or below to reduce the probability of equipment damage caused by lightning strikes.
Second, daily inspection and maintenance
Regular inspection
Regularly conduct a comprehensive inspection of the photovoltaic system to check if the welds of the brackets are cracked, if the bolts are rusted or loose, and promptly clean the dust, fallen leaves and other debris on the surface of the photovoltaic panels to prevent water accumulation on the panels.
Carefully check whether the junction box and cables are aged or damaged to avoid leakage accidents caused by line problems. At the same time, check whether the connection wires and ground wires of the solar panels are in good contact and whether there is any detachment.
Optimize the drainage system to ensure the smooth operation of the drainage system in the photovoltaic panel installation area. Drainage channels can be reasonably set up under the support to quickly lead the accumulated water to the drainage point, preventing the water in low-lying areas from soaking the foundation for a long time and corroding the support.
Meteorological monitoring
With the help of professional meteorological warning platforms, closely monitor weather changes and obtain extreme weather information in advance. Before the arrival of the hail season, temporary reinforcement should be carried out on the easily loose parts by means of adding steel wire ropes for pulling, etc.
For detachable brackets, such as distributed rooftop photovoltaic brackets, they can be disassembled in advance according to the actual situation to avoid damage caused by hail.
Third, pre-disaster emergency preparedness
Temporary reinforcement
Before the hail arrives, carry out temporary reinforcement of the photovoltaic power station. For example, use iron wire, ropes, etc. to bind the component brackets to increase their stability.
For the tracking bracket system, the Angle can be adjusted in advance to tilt the component height and reduce the impact energy of hail. However, it should be noted that this approach may cause the components to deviate from the perspective of achieving the best production capacity, and the pros and cons need to be weighed.
Personnel and Equipment
Arrange personnel to stand guard at the power station to ensure a timely response during hail. At the same time, prepare necessary emergency supplies, such as maintenance tools, spare components, etc.
Cut off unnecessary power supplies to avoid electrical faults caused by hail. For example, turn off the DC switch of the inverter and the circuit breaker of the AC distribution box combiner box.
Fourth, post-disaster handling and restoration
Damage assessment
After the hail, immediately check whether there are cracks, damages or broken corners on the surface of the photovoltaic panels. Even the slightest hidden cracks may affect the power generation efficiency and even trigger the hot spot effect.
Use professional equipment such as electroluminescence meters (EL tests) to inspect the components and identify hidden internal damages. For internal damages that are difficult to observe with the naked eye, detailed inspections are required.
Maintenance and replacement
For minor damage, such as local fragmentation, the frame can be removed, the back plate heated, the battery cells replaced and then repackaged. However, it should be noted that such repairs must be carried out by professionals to ensure the quality of the repairs.
For severely damaged components, photovoltaic panels of the same model as the original one should be replaced in a timely manner. The mixed installation of components with different efficiencies will have a negative impact on the performance of the entire photovoltaic system and should be strictly avoided.
If the support is deformed or the foundation settles, the structure needs to be recalibated. If necessary, the damaged parts should be replaced to ensure that the photovoltaic system still has good wind resistance in the future.
Insurance and Claims settlement
Purchase property insurance covering natural disasters such as hail in advance. After the disaster, contact the insurance company in a timely manner and invite it to conduct an on-site investigation.
Prepare photos, videos of the damaged area and relevant materials such as repair quotations to speed up the claim process and reduce economic losses.
Fifth, long-term maintenance and optimization
Data monitoring and analysis
Install a monitoring system to monitor parameters such as the temperature and current of photovoltaic panels in real time, so as to promptly detect potential problems such as hidden cracks.
Make detailed records of each inspection and maintenance, analyze and summarize the causes of the problems, and provide references for subsequent maintenance.
Technological upgrading and transformation
For frequently affected areas, it is advisable to upgrade the supports and select models with higher wind resistance grades, such as adding diagonal bracing structures or using galvanized anti-corrosion materials.
Tempered glass components with hail protection coating are selected to further enhance the hail resistance capacity. Meanwhile, pay attention to emerging technologies, such as flexible and bendable panels, which have better adaptability in areas with strong winds.
