Installation of solar panels is a long-term investment. A one-time investment can give customers access to a steady supply of electricity. The typical lifetime of crystalline silicon solar panels now on the market is 25 to 30 years. So what elements affect the solar panels' service life? For instance, solar cells' efficiency will degrade over time; also, the PID effect is a crucial consideration.
What does the PID effect of solar panels entail?
Components that run at high voltage for an extended period of time have the PID effect, also known as Potential Induced Degradation. This may result in a leakage current between the cover glass, solar panel encapsulation material, and frame. Positive ions migrate from the glass, frame, and installation framework to the solar photovoltaic cell due to the difference in electrical charge. The cell's PN junction may become damaged if a significant amount of charge accumulates on the cell's surface. The fill factor, short-circuit current, and open-circuit voltage decline as a result of the passivation effect on the cell's surface getting worse. As a result, the component performs worse than intended, which lowers its overall performance.
What results in the PID effect in solar panels?
Whether a solar panel will experience the PID effect depends significantly on the quality of the raw materials used to make it, including the glass, sealants, and solar panel encapsulation materials. For instance, the PID effect in the solar panel can occur if glass with a high salt content is chosen, or if the material used to encase the solar panel cannot keep water vapor out.
Where to put solar panels: High temperatures and humidity are the key environmental conditions that contribute to the PID effect. The effect of a solar power project on the solar panels depends on where it is situated. Due to humidity, moisture will enter solar panel modules and increase leakage current. This process is increased at high temperatures and reduces the efficiency of solar panels.
System voltage and solar panel size: Generally speaking, the bigger the number of panels connected in series, the higher the system voltage, and the greater the stray current or leakage current produced when there is a potential difference between solar photovoltaic cells and the ground, resulting in The likelihood of the PID phenomenon is increased. In general, 1500 V systems are more vulnerable than 1000 V systems.
How can solar panels' anti-PID performance be tested before they are shipped from 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 specific temperature and humidity, and then cover the surface of the module glass with aluminum foil, copper foil, or a damp cloth.
2. For 96 hours in an atmosphere with 85% humidity at 85°C, 60°C, or 85°C, apply -1000V DC to the output terminal of the module and the aluminum frame.
The components are tested for power, wet leakage, and EL imaging prior to the two testing techniques. Power, moist leakage testing, and EL imaging are repeated after the conclusion. To determine the presence of PID under the specified conditions, compare the results obtained before and after the test. The EL imaging reveals that some cells become blackened when the PID phenomena takes place.
The former method is primarily employed by solar panel producers, whereas the later method is primarily used in experimental institutions. The IEC 62804 certification of PID resistance for the solar panel test module is the final objective of the aforementioned two test procedures.
The Solar Panel Test Module PID Resistance - IEC 62804 certification of Maysun Solar's solar panels guarantees its high caliber.
How can solar panels prevent the PID effect when in use?
Depending on what triggered it, the PID effect may be reversible or irreversible. Unfortunately, PID (potential-induced degradation), when brought on by internal electrochemical reactions, cannot be prevented. Photovoltaic panels may experience thin layer delamination or galvanic corrosion as a result. There are solutions and strategies to avoid the PID effect if outside forces are to blame.
1. Employ a PID-prevention device. The anti-PID box is a device that alters the flow of the inverter's electrical current. This aids in offsetting 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 extended period of time. This enables each module to recover from any potentially negative potential it may have encountered and lowers the likelihood of PID (potential induced degradation).
2. Developing a logical and feasible installation system. Photovoltaic power plants may be negatively impacted by weather with high temperatures. Implementing a well-designed system installation, nevertheless, can solve this problem. Make sure that the parts, inverters, and distribution boxes have the right ventilation and heat dissipation capabilities. Additionally, if the inverter permits, you can solve the problem by grounding the inverter's DC negative terminal.
3. Choosing an efficient encapsulation technique for solar panels. The PID effect may be brought on by humidity. You may stop water vapor from entering and starting a reaction that produces acetic acid in the EVA layer by utilizing the right solar panel encapsulation. On the glass surface, this acid then combines with alkali to produce sodium ions that can move around freely. By doing so, the PID effect is effectively avoided.
To ensure that they constantly create high-quality solar panels, solar panel manufacturers have their own testing processes in place. For fifteen years, Maysun Solar has been making solar panels. They have extensive expertise in this area. They provide top-notch solar panels with PID (Potential Induced Degradation) resistance certification. This indicates that they satisfy the requirements of consumers who want to use clean energy.