Solar cell degradation refers to the natural decrease in the performance of solar cells over time. It is a gradual process influenced by many factors, including environmental influences, material quality, and solar cell manufacturing technology.
What causes solar panel degradation?
Environmental factors:
- UV radiation: Constant exposure to sunlight can damage solar panel materials, such as plastic and insulation, over time.
- Temperature fluctuations: Daily and seasonal temperature changes can cause stresses in the solar cell structure, which can lead to micro-damage.
- Extreme weather conditions: Hail, wind, snow and rain can increase the wear and tear of materials.
Material quality: Lower quality materials used in manufacturing can result in faster performance degradation. Quality manufacturers use premium materials that slow down the degradation process.
Thermal fatigue: Repeated heating and cooling causes materials to expand and contract, which can lead to mechanical damage in the long term.
PID (Potential Induced Degradation): This is a specific degradation process that can be caused by a voltage difference between the solar cell and the ground, reducing the efficiency of the module.
LID (Light Induced Degradation): Degradation that occurs during first use, when the solar cell material stabilizes under the influence of sunlight.
The extent of degradation
Average degradation rate: The performance of solar panels typically decreases by 0.5–1% per year. This means that over a 25-year lifespan, the performance of a solar panel typically drops to 80–85% of its rated capacity.
Premium solar panels: For higher quality panels, annual degradation can be as low as 0.3%, which ensures higher efficiency in the long term.
Guaranteed performance: Most manufacturers guarantee that the performance of solar panels will reach 80-90% of their nominal capacity even after 25 years.
How can degradation be reduced?
Choosing quality solar panels: Using panels made by premium manufacturers can slow down the degradation process.
Expert installation: Incorrect installation may increase the risk of degradation (e.g. mechanical damage, inadequate ventilation).
Regular maintenance: Cleaning and regularly inspecting solar panels helps maintain optimal performance. Removing shading, dirt, or snow will minimize efficiency loss.
PID protection: Grounding and insulation solutions for inverters can reduce degradation caused by PID.
Choosing a suitable installation location: To minimize extreme weather conditions, it is advisable to install solar panels in a protected but well-lit location.
Degradation and lifespan
- Long-term performance: Solar panels have an expected lifespan of 25-30 years , during which time their performance gradually decreases, but they continue to produce useful energy.
- Further use: Solar panels that are still operational after a 25-year lifespan are generally capable of providing 70–80% of their original output, so they can be used economically.
Summary
Solar panel degradation is a natural process in which the performance of solar panels gradually decreases over time. While it is inevitable, selecting the right solar panels, installing them properly, and maintaining them regularly can help minimize their impact. Understanding and managing degradation will ensure that your solar systems continue to operate efficiently and economically over the long term.