Millions of Rooftop Systems, One Simple Truth — Proper Earthing Can Save Crores in Lost Solar Energy

Let’s be honest — when we think of solar installations, we mostly focus on the panels, the inverter, or maybe the subsidies we get under schemes like PM Surya Ghar Yojana. But there’s one silent hero that often gets ignored — earthing. It doesn’t shine on your rooftop, doesn’t generate power, but without it, your solar system might start losing its strength month after month.

Across lakhs of rooftop solar systems installed under government subsidy programs, many homeowners have unknowingly lost 10–30% of generation over the years. The reason? A slow, invisible phenomenon called Potential Induced Degradation (PID) — and surprisingly, a big part of that story begins deep in the ground, with how your solar system is earthed.

What Exactly Is Potential Induced Degradation?

Think of your solar panel as a hardworking employee who performs best when stress-free. Now imagine that panel continuously working under electrical tension — voltage differences between its cells and its grounded metal frame. Over time, this electrical imbalance pushes charged particles (like sodium ions) to move into the cell structure. That’s PID in action — slow, silent, and damaging.

It usually starts showing up as reduced generation, sometimes 5–10% in a year. If not addressed, it can eat away up to 30% of your power output over time — meaning your expected ROI from a ₹1 lakh system might actually perform like a ₹70,000 one.

The Hidden Link Between Earthing and PID

Now here’s the interesting part. PID doesn’t just happen because of the panels — it happens because of the potential difference between the negative side of the module and the earth. If your solar system’s earthing is not proper, this potential difference grows larger. The more the voltage difference, the stronger the “pull” that drags ions inside the cell. That’s how poor earthing directly fuels PID.

Imagine this: Two identical solar systems are installed on neighbouring terraces in Pune. One has proper copper-bonded earthing rodsconnected to each array frame, and a low earth resistance below 2 ohms. The other has a loosely connected GI strip, half-rusted, with no proper chemical treatment. After a couple of monsoons, the second system starts underperforming — even though both have the same panels and inverter.

The reason? Poor earthing allowed leakage currents to find alternate paths through the panel glass and frame, initiating PID. Meanwhile, the first system’s tight grounding kept everything balanced — no ion migration, no hidden losses.

Types of Earthing and Their Role in PID Prevention

Not all earthing systems are equal. Let’s look at how each type plays its role in protecting your solar investment:

Copper-Bonded Earthing Rods: These are among the most reliable for solar systems. Copper’s low resistivity ensures a strong, consistent path for fault and leakage currents, keeping voltage potential stable. When used with chemical backfill compounds, they maintain low resistance even in dry or rocky soil.
GI (Galvanized Iron) Strip-in-Rod Electrodes: This is a modern type of chemical earthing where a GI strip is placed inside a pipe or rod filled with conductive chemical compounds. The chemical backfill maintains moisture and conductivity around the electrode, while the strip provides a larger surface area for current dissipation. This combination ensures a much lower and more stable earth resistance over time compared to traditional rods.

In simple terms, the strip-in-rod electrode allows leakage and fault currents to pass smoothly into the ground, keeping your system’s potential balanced. This stable grounding minimizes voltage stress on solar panels — effectively reducing the chances of Potential Induced Degradation (PID).

Whether it’s copper-bonded or chemical earthing, the goal is the same — to keep the potential between your solar cells and ground as low and stable as possible. When that happens, PID simply doesn’t find room to grow.

Why It Matters for PM Surya Ghar and Other Subsidy Projects

Let’s connect this to what’s happening across India. Under the PM Surya Ghar Muft Bijli Yojana, the government is subsidizing lakhs of rooftop solar systems. But imagine if even 10% of those systems lose 20% efficiency due to PID caused by poor earthing — that’s crores worth of lost energy and subsidy benefit.

For many DISCOMs, the expected generation data doesn’t match the real numbers on the ground. Often, it’s not the panels or inverters that are at fault — it’s the grounding. A small compromise at installation time can turn into massive loss for both homeowners and the subsidy program itself.

Simple Checklist for Proper Solar Earthing

Use copper-bonded or chemical earthing rods with resistance below 2 ohms.
Connect inverter body, module frames, DC and AC distribution boxes, and array structures to separate earth pits.
Test earth resistance every 6 months — especially before monsoon.
Avoid makeshift GI strips without chemical treatment in the long term.
Ensure all connections are tight, rust-free, and tagged properly.

In Simple Words — Earthing Is Like Insurance

You may not see its benefit every day, but when it matters, it saves your system. Just like how an insurance policy quietly protects your car from future damage, proper earthing silently guards your solar panels from PID-related degradation. It’s a one-time investment that ensures years of consistent power generation.

In India, where temperature and humidity vary drastically from Rajasthan to Kerala, this single practice can make the difference between a long-lasting solar plant and one that fades early.

Conclusion

The next time you see a rooftop solar system shining under the sun, remember — its true strength lies not just in the panels, but also in the ground beneath them. Proper earthing, especially with copper-bonded or chemical electrodes, can stop PID before it even begins.

As India moves towards 1 crore+ solar rooftops, let’s ensure that every installation — big or small — is backed by solid grounding. Because when your system is earthed right, it performs right, year after year.

Strong earthing = PID-free solar = Peace of mind for 25 years.