What is PID (Potential Induced Degradation)?

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Potential Induced Degradation (PID) is a threat to solar panel efficiency, caused by electricity, high temperature, and humidity. PID occurs because of high voltage differences between a solar module and the ground, leading to unwanted electrical currents within the cells. This is especially problematic in large rooftop systems with long panel strings, which can face significant power loss over time.

The key to mitigating PID is choosing high-quality panels with built-in resistance. Panel manufacturers are addressing PID through improved sealing and diffusion barriers. Investing in these advanced panels ensures long-term efficiency and maximises your solar energy generation.

What is Potential Induced Degradation in Solar Panels?

Solar panels are a good option for using clean energy. They can help homeowners and businesses lower their environmental impact and save money on electricity bills. However, even the best solar panels can face problems. One such problem is Potential Induced Degradation (PID), which can slowly reduce a solar panel’s efficiency over time.

PID happens when there is a high voltage difference between the solar cells and the ground. This can create unwanted electrical currents that damage the solar cells, leading to less energy production. Several things can cause Potential Induced Degradation, such as the type of glass used, the materials that cover the cells, and special barriers in the panel.

The type of glass is important because sodium ions in the glass can move into the solar cells and cause damage. Using high-quality materials to cover the cells can stop these ions from moving. These materials act as barriers, protecting the solar cells. Adding special diffusion barriers to the panel design can also help prevent damage.

The best way to prevent PID is to choose solar panels that are made to resist it. Look for panels with high-quality, low-sodium glass. Make sure the panels use good encapsulation materials that protect against ion movement. Also, check if the panels have diffusion barriers for extra protection.

PID-resistant solar panels have many benefits. They stay efficient for longer, producing more energy over time. They are also more durable, lasting many years and saving you money on electricity bills and maintenance costs.

Understanding why

PID occurs when three key elements converge: electricity, high temperature, and humidity. Unfortunately, most solar modules encounter this combination sometime during their lifespan. It’s important to note that PID doesn’t affect all panels uniformly.

The culprit behind PID is the high voltage potential difference between a solar module and the ground. This voltage difference is particularly pronounced in long solar panel strings, especially when the frames are grounded. This creates an unwanted electrical current flow within the solar cells, ultimately degrading them.

Why Does Potential Induced Degradation Matter? 

The impact of PID becomes particularly significant in large rooftop solar systems. These systems often utilize long strings of panels, resulting in higher voltage differences. String voltage can range from a few hundred volts on a small roof to a thousand volts or more in a large project. This increased voltage creates a more significant potential for PID to occur and can lead to a more substantial power loss over time.

What is the cause of Potential Induced Degradation?

Potential-induced degradation (PID) is a problem that happens when solar power systems interact with their environment. This issue can lower the performance and lifespan of solar panels. Since changing the environment to fix PID isn’t practical, the best solution is to use solar panels designed to resist Potential Induced Degradation.

When picking solar panels, it’s important to look at factors that affect PID. Research shows that the type of glass used in solar panels is crucial. Sodium ions in the front glass can cause PID because they move under high voltage, damaging the solar cells.

The materials used to encapsulate the solar cells also play a key role in preventing PID. High-quality encapsulation materials act as barriers, stopping sodium ions and other contaminants from moving and causing damage. This protection keeps the solar cells working well over time.

Additionally, diffusion barriers within the solar panel design can enhance PID resistance. These barriers prevent harmful ions from moving, protecting the solar cells.

In summary, choosing solar panels with built-in PID resistance is the best way to combat this issue. By focusing on the type of glass, encapsulation materials, and diffusion barriers, you can reduce the risk of PID and ensure your solar panels perform well and last longer. Investing in high-quality, PID-resistant solar panels is essential for maximising power output and extending the life of your solar power system.

Solar panels with yellow backing sheet
Large rooftop systems with super long strings might be more prone to PID due to the increased voltage difference

Investing in Quality: Long-Term Protection

The good news is that solar panel manufacturers are actively addressing Potential Induced Degradation. Solar panels with robust sealing and improved diffusion barriers demonstrate greater resistance to PID-related degradation. By investing in high-quality panels from reputable brands, you can ensure your solar system operates at peak efficiency for a more extended period.

The Takeaway

Understanding Potential-Induced Degradation (PID) might seem complicated, but knowing its causes and how to prevent them helps you make better decisions when choosing a solar panel system. PID happens when there are voltage differences between solar cells and the frame. This causes power loss, which reduces the efficiency and lifespan of solar panels. PID is mainly caused by high voltage stress, environmental factors like high humidity and temperature changes, and poor-quality materials used in making the panels.

To prevent PID, invest in high-quality solar panels with built-in PID resistance. These panels handle voltage stress and environmental factors better.

Make sure your solar panels are installed correctly, with proper grounding and insulation to minimise voltage differences. Regular maintenance is also important to catch and fix any PID issues early. You can also use PID recovery solutions to reverse PID effects and restore panel performance.

By choosing quality panels and following best practices for installation and maintenance, you can protect your investment. This way, your solar panels will keep generating clean energy efficiently for many years, saving you money and benefiting the environment.

Understanding and preventing Potential Induced Degradation is essential for anyone investing in solar energy. By taking steps to avoid PID, you can make your solar panel system last longer and work better. Choose reliable manufacturers, ensure properly installed solar panels, and keep up with maintenance to enjoy the benefits of renewable energy while protecting your investment.

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