Solar panel power attenuation, also known as solar panel degradation, refers to the gradual decrease in the efficiency and power output of solar panels over time.

1. Exposure to Sunlight: Ironically, one of the primary causes of solar panel degradation is exposure to sunlight itself. Over time, exposure to sunlight can lead to the breakdown of the solar cells and the materials used in the panel. This is known as “light-induced degradation” or “LID.” Manufacturers have developed methods to mitigate LID, such as using special coatings or treating the panels after production.
2. Temperature: High temperatures can accelerate solar panel degradation. Solar panels are designed to operate in a wide range of temperatures, but excessive heat can cause stress on the materials, leading to degradation. Cooler operating temperatures are generally better for panel longevity.
3. Humidity and Moisture: Moisture and humidity can infiltrate the panel over time, leading to a phenomenon known as “humidity-induced degradation” (HID). This can affect the performance of the solar cells and other components within the panel.
4. Dust and Dirt: Dust, dirt, and other environmental contaminants can accumulate on the surface of the solar panels, reducing their efficiency by blocking sunlight. Regular cleaning can help mitigate this issue.
5. Shading: Even partial shading of a solar panel can lead to a significant reduction in its power output. Shading causes “hot spots” on the cells, which can damage them over time.
6. Quality of Materials and Manufacturing: The quality of the materials used in solar panels and the manufacturing process can also impact degradation. Higher-quality materials and precise manufacturing techniques can lead to slower degradation rates.
7. Cell Type: Different types of solar cells have varying rates of degradation. For example, monocrystalline cells typically degrade more slowly than polycrystalline cells.
8. Environmental Conditions: Local environmental conditions, such as air pollution, can affect solar panel degradation rates.

It’s important to note that not all solar panels degrade at the same rate, and the rate of degradation can vary depending on the specific brand and model of the panel. Manufacturers often provide warranties that guarantee a certain level of performance over a specified period, which can range from 10 to 25 years or more.

Overall, while solar panel degradation is a natural and expected phenomenon, modern solar panel technology and improved manufacturing processes have led to slower rates of degradation, longer lifespans, and more reliable performance over the years.