Solar panels are designed to last for decades; however, the efficiency of generating electricity will decrease over the years, which is referred to as solar panel degradation. Understanding the solar panel degradation process allows you to predict your energy production and savings if you plan to install rooftop solar panels or build any large-scale solar projects.
The good news is that solar panels are usually degraded slowly. As long as you choose reliable solar panels, install them correctly, and maintain them regularly, your solar panel system will produce enough energy for years.
What Is the Solar Panel Degradation Rate?
The solar panel degradation rate is the rate at which a panel’s power output decreases per year. In the case of conventional solar panels, the annual solar panel degradation rate is about 0.5% to 1%. However, depending on your panel type and installation, the actual degradation rate might vary. There is some interesting data provided by NREL on solar module degradation rates.
Let us take a 550-watt solar panel with an annual solar panel degradation rate of 0.5%; during its first year of operation, it will lose approximately 2.75 watts of power output. However, it doesn’t mean that your solar panel stops working or suddenly produces less electricity. Its ability to generate power declines gradually.
How Much Output Can Solar Panels Lose Over 25 Years?
The total loss depends on the annual degradation rate. To understand the difference, consider a 550 watt panel under two different scenarios.
| Years of use | At 0.5% annual degradation | At 0.8% annual degradation |
| At installation | 550 W | 550 W |
| After 5 years | 536 W | 528 W |
| After 10 years | 523 W | 508 W |
| After 25 years | 485 W | 450 W |
These are illustrative estimates assuming a constant annual decline, with degradation compounded each year.
The figures show why degradation matters when choosing solar panels. Even a small difference in annual performance loss can affect the amount of electricity a system generates over its lifetime. However, actual electricity production also depends on sunlight, temperature, shading, and other site conditions.
What Causes Solar Panel Degradation?
Several factors can affect how well solar panels perform as they age.
1. Heat and Weather Conditions
The heat, heavy rain, humidity, and weather conditions that occur in the outdoor installation of solar panels may have an impact on the performance of a solar module.
2. Ultraviolet Light and Aging
Aging of the solar panels can be caused by years of being under the sun, as changes in the materials that protect solar cells may influence their performance.
3. Corrosion Due to Moisture
If poor installation causes a solar panel to be vulnerable to moisture, corrosion and electrical connection issues may cause degradation in the performance of a solar module.
4. Panel Technology and Quality
Not all solar panels perform equally well and degrade the same way. The performance of a solar module is influenced by its materials, cell technology, quality of manufacturing, etc.
How Can Solar Panel Degradation Be Prevented?
Even though the process is impossible to fully eliminate, there are several ways to make sure that your system works efficiently.
Purchase high-quality solar panels: Before buying panels, check out information provided by the manufacturer about the performance warranty and annual degradation. Lower degradation will ensure better performance of your system.
Do the right installation: Your panels must be installed properly, including good mounting, correct wiring, and ventilation.
Maintain cleanliness of the panels: Any dirt, including dust, leaves, and even bird droppings, can prevent light from reaching the panels, reducing electricity production. Make sure you clean your panels from time to time based on the local weather conditions.
Monitor the performance of your system: Make sure you check the performance of your inverter and electricity production from time to time. If the production rate suddenly declines, do not assume the problem lies in degradation. Check for shading, dirt, wiring problems, etc.
Conclusion
Degradation of solar panels is a common phenomenon when dealing with a solar energy plant, but it does not imply that after a few years, your investment will become worthless. Opting for reliable panels, installing them in the right manner, and carrying out maintenance will ensure that you have a reliable source of power for the years to come. Waaree is the foremost manufacturer of PV solar modules in India, boasting a manufacturing capacity of 25.8 GW of solar panels, designed to withstand degradation and be durable. With the help of Waaree’s experienced EPC solar company, you can benefit from your solar energy plant to the fullest.
