Installing solar panels is a long-term investment. A one-time investment can give customers access to a reliable source of electricity. The typical lifespan of crystalline silicon solar panels now on the market is 25 to 30 years. What elements, then, have an impact on the solar panels' service life? For instance, solar cells' efficiency will decline over time. In addition, the PID effect is another important consideration.
What does a solar panel's PID effect entail?
When components are used at high voltage for an extended period of time, the PID effect, also known as Potential Induced Degradation, takes place. Between the cover glass, solar panel encapsulation material, and frame, this may result in a leakage current. Positive ions migrate from the glass, frame, and installation framework to the solar photovoltaic cell as a result of the difference in electrical charge. The PN junction of the cell may become damaged if a significant amount of charge accumulates on its surface. The fill factor, short-circuit current, and open-circuit voltage drop due to the worsening passivation effect on the cell's surface. Due to this, the component performs worse than anticipated, which lowers the component's total performance.
What results in solar panels' PID effect?
On whether a solar panel would experience the PID effect, a lot depends on the quality of the raw materials used, such as glass, sealants, and solar panel encapsulation materials. For instance, the PID effect in the solar panel may occur if glass with a high salt content is chosen or if the material used for the solar panel encapsulation cannot keep water vapor out.
Where to put solar panels: Humidity and high temperatures are the key environmental conditions that contribute to the PID effect. The effect a solar power project has on the solar panels depends on where it is situated. Moisture from humidity will enter solar panel modules and increase leakage current; this process is sped up at high temperatures and reduces the efficiency of solar panels.
System voltage and solar panel size: Generally, the higher the system voltage and the bigger the stray current or leakage current produced when there is a potential difference between solar photovoltaic cells and the ground, the more solar panels linked in series, the higher the system voltage, and the higher the system voltage, resulting in The likelihood of the PID phenomenon is greater. Generally speaking, 1500 V systems are more vulnerable than 1000 V ones.
How can solar panels' anti-PID performance be checked before they leave the factory?
1. Apply a voltage between the output terminal of the module and the surface covering for a predetermined amount of time at a particular temperature and humidity, and then cover the surface of the module glass with aluminum foil, copper foil, or a damp cloth.
2. Apply -1000V DC for 96 hours in an atmosphere with 85% humidity at 85°C, 60°C, or 85°C to the output terminal of the module and the aluminum frame.
The components are checked for power, wet leakage, and EL imaging before the two testing techniques. Following the conclusion, power, wet leakage testing, and EL imaging are repeated. To determine the incidence of PID under the specified conditions, compare the results obtained before and after the test. EL imaging reveals that some cells become blackened when the PID phenomenon takes place.
The former method is primarily employed by solar panel producers, while the later method is primarily used in experimental institutions. The certification of PID resistance of the solar panel test module, IEC 62804, is the final objective of the aforementioned two test procedures.
Maysun Solar's solar panels are certified by Solar Panel Test Module PID Resistance - IEC 62804, ensuring excellent quality.
How can the PID effect be avoided when using solar panels?
Depending on what created it, the PID effect may be either reversible or irreversible. Unfortunately, PID (potential-induced deterioration), which is brought on by internal electrochemical processes, cannot be prevented. Galvanic corrosion or thin layer delamination in solar panels may result from this. If external circumstances are the origin of the PID effect, there are solutions and strategies to avoid it.
1. Use a PID-prevention device. The anti-PID box is a component that alters the flow of the inverter's electrical current. This aids in reversing the harm that the voltage does to the PV modules. These boxes have the function of preventing each string from remaining on the same polarization for an excessive amount of time. This enables each module to recover from whatever negative potential it may have encountered and lowers the likelihood of PID (potential induced degradation).