🌞 Understanding PID in Solar Panels: Causes, Effects, and How to Prevent It

By Whitematter Energy Solutions

As the demand for solar energy continues to rise, ensuring the long-term performance and reliability of solar power plants has become more critical than ever. One of the lesser-known yet significant issues affecting solar systems worldwide is PID — Potential Induced Degradation.

In this blog, we’ll explain what PID is, its causes, how it impacts system performance, and most importantly, how you can prevent and remedy it to protect your solar investment.

🔍 What is PID (Potential Induced Degradation)?

PID is a performance degradation phenomenon that occurs in solar panels due to voltage potential differences between the solar cell and the module frame or the grounded parts of the system.

Over time, this voltage difference causes unwanted leakage currents and ion migration within the module, leading to reduced power output and, in severe cases, permanent damage to solar cells.

⚙️ Causes of PID in Solar Systems

PID usually results from a combination of electrical, environmental, and material factors. Key causes include:

High System Voltage (1000V / 1500V systems):
The higher the operating voltage of a solar array, the greater the potential difference across the cells, increasing the risk of PID.

Poor Module Encapsulation or Quality Issues:
Inadequate insulation or low-quality encapsulant materials (like EVA) allow ions — especially sodium (Na⁺) — to move from the glass surface into the cell.

Humidity and High Temperature:
Hot and humid environments accelerate the ion migration process, worsening PID.

Negative Potential Grounding:
When the negative pole of the inverter is grounded, modules operating at a negative potential are more prone to PID.

Improper System Earthing or Leakage Paths:
Faulty grounding and moisture accumulation in junction boxes or connectors create leakage paths, promoting PID formation.

⚠️ Effects of PID on Solar Performance

PID can have severe financial and technical impacts on solar plants. Common effects include:

Significant Power Loss:
Affected modules can lose up to 30–80% of power output, directly reducing the overall plant yield.

Uneven String Performance:
Some panels degrade faster than others, creating mismatch losses and lower string efficiency.

Reduced Plant ROI:
Customers experience reduced energy generation, lower savings, and a longer payback period.

Warranty Issues:
Many manufacturers may not honor warranty claims if PID prevention guidelines weren’t followed during installation.

💸 How PID Impacts Customers Financially

For a typical 100 kW on-grid plant, even a 10% PID-induced loss can reduce annual generation by 15,000 units (kWh).
At ₹7 per unit, this equals ₹1,05,000 per year — a recurring loss that grows over time.

In large commercial or industrial systems, PID can cause lakhs of rupees in annual revenue loss and affect the project’s overall bankability.

🧩 Remedies for Existing PID Issues

If PID has already affected your solar system, the following steps can help recover performance:

PID Recovery Devices (Reversal Units):
These devices apply an opposite voltage during nighttime to neutralize ion migration and restore module performance.

Rewiring the System Polarity:
Changing the grounding configuration or inverter polarity can reduce further degradation.

Replacing Affected Modules:
Severely degraded modules may need replacement to maintain string performance.

Regular O&M and IV Curve Testing:
Professional operation & maintenance services can detect early signs of PID and minimize its spread.

🛡️ Prevention: How to Protect Your Solar Plant from PID

Prevention is always better (and cheaper) than cure. Here’s how you can avoid PID in your solar installation:

Use PID-Resistant Panels:
Choose modules certified for PID resistance as per IEC 62804 standards. Reputed brands like Waaree, Adani, and Trina offer PID-resistant modules.

Proper System Grounding:
Follow recommended earthing practices and avoid grounding the negative terminal in high-voltage systems.

Use Quality Inverters and Components:
Premium inverters have built-in PID protection and active monitoring systems.

Maintain Clean and Dry Conditions:
Regular cleaning, checking for moisture ingress, and using IP65/IP67-rated junction boxes reduce the risk.

Install Surge Protection and Monitoring:
Real-time monitoring (like SOLAR-MAX) helps detect early PID symptoms through performance analytics.

🌿 Conclusion

PID is a silent performance killer in solar power plants, but with the right knowledge and preventive design, it can be effectively controlled or eliminated.

At Whitematter Energy Solutions, we ensure every solar installation uses PID-resistant technology, quality earthing systems, and advanced monitoring to protect your investment and guarantee maximum generation for years to come.

💬 Got doubts about PID or your plant’s performance?
Contact our technical team today for a free performance assessment or O&M consultation.

📞 Call: +91 99884 32432
🌐 Visit: www.whitematter.in

📍 Address: 1197/2, Jaimal Singh Road, Janta Nagar, Ludhiana, Punjab