Why Do Solar Panels Degrade?

Generally, solar panels degrade after 10 to 15 years of usage. Several factors, such as aging, environmental, and microcracks, can cause this.

Various Environmental Factors

Most homeowners usually search on the internet for how long do solar panels last and what things they should do for maintenance. Various environmental factors can cause solar panels to degrade over time. These factors include soiling, wind speed, and humidity. These conditions can affect the performance of a solar panel, resulting in an average loss of around 0.8% per year. Another factor affecting PV module performance is dust. Dust particles can degrade the open-circuit voltage and short-circuit current of PV modules. If dust particles are less than one hundred millimeters in size, they can significantly decrease the module’s performance.

High temperatures and humidity can accelerate the degradation of solar panels. During humid conditions, dust deposition forms sticky mud on the PV panel.


Besides being one of the most important quality issues in the PV industry, microcracks also harm the performance of solar panels. Micro-cracks are very tiny cracks that form in the silicon cell. They are usually invisible to the human eye and can cause hot spots to form, interrupting current flow. Fortunately, modern solar panels reduce the risk of micro-cracks forming. Many factors, including poor handling and improper installation, cause micro-cracks. Specifically, the presence of micro-cracks increases the cell’s internal resistance, leading to increased temperature. Moreover, thermal cycles in the solar cell can cause stress, which expands the solder and contract metal contacts. Micro-cracks may be formed during transport when the panel is subjected to an unusual load and during impacts. However, the presence of micro-cracks only sometimes causes a major problem. Depending on the crack size, micro-cracks can cause a hot spot or even a full failure of the solar cell.

Aging-Related Degradation

Several factors contribute to the aging of solar panels. These factors include irradiance, weather, materials used in the manufacture of the solar panel, installation process, and maintenance. Weather and irradiance are the most common external factors contributing to solar panel degradation. Weather includes a variety of factors, such as temperature, humidity, wind speed, and rain. Depending on the type of technology, these external factors can have a considerable impact on the durability of a photovoltaic module. The National Renewable Energy Laboratory (NREL) has measured annual efficiency decreases in polycrystalline and monocrystalline PV modules of 0.7%. These degradation rates are based on manufacturers’ performance warranties. The accelerated degradation rate of solar panels ranges from 1% to 3% per year. However, higher degradation rates are common in warmer climates because of the higher temperatures. The higher degradation rate leads to higher energy losses in the PV system. One of the main causes of accelerated degradation is the failure of the back sheet. The back sheet isolates the inner components from external agents, protecting them from UV light. 

Replacement After 10 To 15 Years

Despite the long lifespan of solar panels, they are not invincible. They may eventually break due to extreme physical damage or lose their efficiency. If your panels have been impacted by extreme weather, replace them with more durable panels. A good quality solar panel will start to degrade once it’s over 20 years old. However, if your panels were improperly installed, they may degrade sooner than expected. Consider replacing your inverter. The lifespan of an inverter is typically shorter than that of a solar panel. Generally, the lifespan of an inverter will be between 10 and 15 years. However, some inverters can last up to 25 years.