Over time, the performance of solar panels gradually decreases, a phenomenon known as degradation. Understanding solar panel degradation is crucial for assessing the long-term benefits and reliability of solar power systems.
Types of Solar Panel Degradation: Initial and Long-Term Degradation
Solar panel degradation can be classified into two types: initial degradation and long-term degradation.
Initial Degradation: This typically occurs within the first few months after the solar panels are installed, and the degradation rate is relatively high. Initial degradation mainly results from unstable factors during manufacturing and the initial operating phase after installation. Generally, the initial degradation rate ranges from 1% to 3%.
For example, if a solar panel has an initial power output of 300 watts, and the degradation rate is 2%, its output could drop to 294 watts.
Long-Term Degradation: After a few years of use, the degradation rate slows down. Long-term degradation is influenced by various factors, including the material quality, manufacturing process, environmental conditions (such as temperature, humidity, and sunlight intensity), and daily maintenance.
Under normal operating conditions, the average annual long-term degradation rate for crystalline silicon solar panels typically ranges from 0.5% to 0.8%. For instance, if a solar panel has an initial power output of 300 watts and a long-term degradation rate of 0.7%, after 10 years, its power output would be approximately 207 watts.
Factors Affecting Solar Panel Degradation
Environmental factors play a significant role in solar panel degradation. Some common factors include:
- High Temperature: High temperatures accelerate solar panel degradation. If solar panels operate in environments that exceed the standard working temperature (usually 25°C), the degradation rate may increase by 0.03% to 0.05% per degree Celsius. For example, if the solar panel operates in an environment of 50°C (a 25°C increase), the degradation rate could rise to approximately 1.45% per year.
- Humidity: In high-humidity environments, moisture may penetrate the solar panel, leading to the aging of encapsulation materials and the corrosion of cells, which can accelerate degradation. In environments with humidity above 80%, the degradation rate may increase by 0.2% to 0.3% annually.
Dust and Dirt: Accumulation of dust and dirt can reduce the amount of sunlight the solar panels receive, leading to a decrease in power output. If the solar panel surface is 20% covered with dust, the output could drop by 30% to 40%.
How to Delay Solar Panel Degradation
To reduce solar panel degradation, the following measures can be taken:
- Regular Cleaning: Ensure that the solar panel surface is free from dust and dirt to maintain its light absorption efficiency.
- Optimize Installation Location: Avoid installing solar panels in high-temperature or high-humidity environments. Choose an appropriate location to minimize environmental factors that contribute to degradation.
Regular Maintenance and Inspection: Periodically check the condition of the solar panels and address any potential degradation issues promptly to maintain the system’s high efficiency.
Conclusion
Solar panel degradation is a complex process influenced by a variety of factors. When designing and installing a solar power system, it is essential to consider these factors thoroughly. Selecting high-quality, reliable solar panels and ensuring regular maintenance and cleaning can slow down the degradation rate, extend the lifespan of the solar panels, and maintain high power output efficiency.
Since 2008, Maysun Solar has been dedicated to producing high-quality photovoltaic modules that contribute to combating climate change. Our advanced technology in IBC, HJT, TOPCon panels, and balcony solar stations ensures exceptional performance and reliability, capable of withstanding harsh weather conditions for long-term operation. We have established offices and warehouses in multiple countries and built lasting partnerships with top installers to provide comprehensive support. For the latest quotes or any inquiries related to photovoltaics, feel free to reach out to us—we’re here to help!
Does Summer Heat Reduce Solar Panel Efficiency? What Really Happens to PV Output
Table of Contents Many PV users notice an unusual phenomenon in summer: although sunlight is strongest at noon, the power curve shown in the monitoring app does not reach the expected peak. In contrast, on a sunny spring day, or just after a
Low-Carbon PV Procurement in France: Why ECS, PEP Ecopassport and Solar Carports Matter
Table of Contents France is becoming one of Europe’s most documentation-driven solar markets. For EPC companies, developers and commercial project owners, module selection is no longer based only on price-per-watt, efficiency or linear power warranties. Carbon documentation, supply-chain traceability and project-specific compliance files
PV Module Installation Beyond Rooftops: Multi-Scenario Applications for Bifacial N-Type Modules in Europe
PV module installation is not limited to rooftops. For residential users, small commercial users and distributed PV projects in Europe, spaces such as balconies, gardens, fences, carports, terraces, façades and pergolas can also provide additional installation areas when conditions allow. As solar use
Europe’s Grid Cap Era: Why High-Efficiency Solar Panels Matter More in 2026
Introduction In 2026, the economics of distributed solar in Europe are changing. Grid congestion, export limits, negative electricity prices and zero-export requirements mean that a solar project can no longer be judged only by how much electricity it generates. The more important question
How Do Solar Panel Delivery Delays Affect Installer Costs?
Solar panel delivery delays can affect installation schedules, project acceptance and payment collection.
The Forgotten “Invisible Assets”: Why Repowering Is the Strategic Key for European Solar in 2026
As grid congestion delays new solar projects across Europe, existing PV assets are becoming a strategic source of growth. This article explains why PV repowering can help EPCs and C&I asset owners unlock hidden value from already-connected solar plants, improve LCOE, and extend long-term asset performance with high-efficiency TOPCon, IBC and HJT modules.
