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Views: 0 Author: Site Editor Publish Time: 2025-11-28 Origin: Site
In the solar energy industry, a widely accepted view is that the nominal lifespan of solar panels typically ranges from 20 to 25 years. This data is not arbitrarily determined but is based on industry standards, extensive research, and long-term practical experience.
Many well-known solar panel manufacturers (such as Ocean solar's solar panels) clearly state in their product specifications that under normal use, their products can maintain a certain level of power generation efficiency for 20 to 25 years.
Under ideal conditions—sufficient sunlight, stable temperature and humidity, and no interference from harsh environments—solar panels experience extremely slow initial degradation, with an annual degradation rate of only about 0.5%.
As time passes, the attenuation will gradually accelerate. However, by the end of their 20-25 year lifespan, most qualified products can still retain approximately 80% of their initial efficiency. For example, a 630-watt solar panel can still reach 504 watts after 25 years, providing considerable power support.
Material aging is a crucial factor in degradation. As usage time increases, internal cells, EVA film, backsheets, and other components will gradually age.
Aging of cells leads to decreased semiconductor performance; yellowing and embrittlement of EVA film affect light transmittance and protection; aging of backsheets reduces waterproof and UV resistance, accelerating component erosion.
UV irradiation is also a key factor. Ultraviolet rays in solar radiation cause photochemical reactions in solar panel materials, damaging their molecular structure.
For instance, chemical bonds in organic encapsulation layers break under UV exposure, reducing material strength and stability, and affecting overall performance.
The impact of temperature changes cannot be ignored. Solar panels absorb heat and rise in temperature during the day and cool down at night. Frequent thermal expansion and contraction cause stress in internal materials.
This stress may lead to cell cracks and solder joint detachment. High temperatures also accelerate material aging and chemical reactions, exacerbating degradation.
Humidity also negatively affects performance. Moisture in the air penetrates the interior, potentially triggering corrosion reactions and damaging the connection between cells and electrodes.
Moisture also reduces the insulation of encapsulation materials, increasing the risk of leakage. This type of degradation is more pronounced in high-humidity areas.
Industry research shows that the average annual degradation rate of solar panels is approximately 0.5%-1%. After 10 years of use, power may decrease by 5%-10%, and by 20 years, it may drop by 10%-20%.
There are significant differences in degradation rates between products of different brands, types, and usage environments. High-quality products with advanced technology experience slower attenuation under proper maintenance; products of poor quality or used in harsh environments degrade faster, resulting in a significantly shortened lifespan.
Silicon wafers are the core of solar panels, and their quality plays a decisive role in efficiency and lifespan. Silicon wafer purity is a key indicator—high-purity silicon wafers can reduce the obstruction of electron transmission by impurities, improving photoelectric conversion efficiency.
Monocrystalline silicon wafers have higher purity and an orderly atomic arrangement, with an initial efficiency of 15%-22% (Ocean solar's solar panels use monocrystalline silicon); polycrystalline silicon wafers have more grain boundary defects, with an efficiency of 12%-18%. Impurities accelerate silicon wafer aging and damage the crystal structure.
The PN junction is a key structure for realizing photoelectric conversion. When sunlight irradiates, photogenerated carriers are produced and separated to form an electric current under the action of the built-in electric field of the PN junction.
The stability of the PN junction directly affects efficiency and lifespan. Over time, the PN junction will gradually age, with changes in electric field strength and carrier recombination rate, leading to a reduction in effective current carriers and decreased efficiency.
PN junctions with defects during manufacturing age faster, further shortening the lifespan.
During the processing process, improper control of silicon wafer cutting and surface treatment can produce microcracks, scratches, and other defects. These microscopic defects become stress concentration points.
In subsequent use, under the influence of temperature changes and mechanical vibrations, cracks may expand, leading to silicon wafer breakage and partial or overall failure of the module.
For example, insufficient cutting precision causes microcracks on the edge of silicon wafers, increasing the risk of breakage after long-term use.
Welding technology is equally crucial. Cells are connected through solder strips to form a circuit. Poor welding quality (such as weak solder joints or cold solder joints) leads to poor electrical connections and increased circuit resistance.
According to Joule's law, higher resistance generates more heat, which not only reduces efficiency but also accelerates aging. Long-term heat accumulation may cause solder joint detachment; excessive flux residue causes corrosion.
Most crystalline silicon modules have a temperature coefficient of -0.3%~-0.5%/℃. For every 1℃ increase in temperature, efficiency decreases by 0.3%~0.5%.
In hot regions, the surface temperature of panels can exceed 60℃ in summer, which not only causes efficiency decline but also accelerates EVA film yellowing, cracking and backsheet hydrolysis.
High-humidity environments also pose a severe test for solar panels. A large amount of water vapor in coastal or tropical rainforest areas can erode modules, causing electrochemical corrosion of cells and electrodes and increasing contact resistance.
It also reduces the insulation of encapsulation materials, increasing the risk of leakage or short circuits. High humidity is also conducive to mold growth, affecting light transmission and corroding surfaces.
In environments of -30℃, the efficiency of polycrystalline and monocrystalline silicon solar panels decreases by approximately 25% and 23% respectively compared to normal temperatures, and this decreasing trend will continue.
Low temperatures cause microcracks in materials, make encapsulation materials hard and brittle, and surface ice and frost block sunlight, further reducing power generation capacity.
Research shows that the output power of clean modules is at least 5% higher than that of dusty ones, and the higher the dust accumulation, the more obvious the performance decline.
In areas with high pollution or sand and dust, if not cleaned in time, efficiency may drop by more than 10% within a few months, because dust blocks and reflects light.
In this case, the temperature of the shaded area rises sharply to form a hot spot, which not only reduces output power but also causes irreversible damage to the cells.
Severe hot spots will burn the cells, leading to a lifespan reduction of more than 30%. Shaded cells not only do not generate electricity but also consume the power produced by other cells.
In recent years, perovskite solar cells have made remarkable achievements in material innovation, bringing new hope for extending the lifespan of solar panels. They have the advantages of low-cost printing preparation and high conversion efficiency, and are regarded as representatives of next-generation solar cells.
After 16 years of development, their efficiency has increased from the initial 3.8% to more than 26%, approaching the level of monocrystalline silicon.
The team achieved the coordinated improvement of efficiency and stability by introducing alkali metal oxalate to restrain the disordered migration of chlorine elements and preparing perovskite films with high carrier lifetime and low defect state density.
The prototype device developed by You Jingbi's team from the Institute of Semiconductors, Chinese Academy of Sciences, has an efficiency of 27.2%. After operating under standard sunlight for 1529 hours, it still maintains 86.3% of its initial efficiency; after 1000 hours of 85℃ photothermal coupled aging, it still maintains 82.8%.
Daily cleaning is a basic and important part of maintenance. Solar panels are exposed outdoors for a long time and are prone to accumulating dust, bird droppings, leaves and other debris, which not only affects light transmittance and reduces efficiency but also may cause surface corrosion and scratches.
Clean quarterly with high-pressure water guns, special cleaners and soft mops; use neutral cleaners to avoid damaging components.
Regularly inspect brackets, connectors and panel surfaces; avoid impact or heavy pressure during installation and use.
Installation Optimization: Angle and Orientation Adjustment
Reasonable installation angle and orientation have a positive impact on lifespan. The installation angle should be adjusted according to the local latitude and season to ensure maximum sunlight reception for most of the year. In the Northern Hemisphere, it usually faces due south. Adjusting the orientation, tilt angle and installation distance in combination with climate and geographical location can improve efficiency, reduce losses, lower costs, and indirectly extend the actual lifespan.
Clean up surrounding debris in windy weather; take good protection in hail and heavy snow weather. These measures can slow down the degradation rate and extend the service life.
Research on solar panel lifespan is advancing rapidly. Currently, there is a clear understanding of degradation mechanisms, and material innovations such as perovskite have broad prospects.
Future technologies will extend lifespan: new stable semiconductor materials, nano/quantum technologies to improve efficiency, and smarter and more precise manufacturing processes can reduce defects and lower costs.
At the application level, it will be deeply integrated with energy storage (solving intermittency), architectural design (as building materials) and smart grids (efficient transmission).
The growing demand for sustainable development will drive innovation, making solar panels a key energy source for global carbon neutrality.
NOTE:The author has tried his best to ensure the accuracy of the above content. If you have any questions, please contact us directly for more accurate and updated industry information.
