Why Are Grounding Washers Essential in Solar Mounting Systems?

When installing solar PV systems, we often focus on module efficiency, mounting strength, and cable routing. But what about electrical grounding? Specifically, have you ever asked:

How do you ensure a reliable, long-lasting ground path between solar modules and mounting rails—especially in outdoor, corrosive environments?

The answer lies in one small but powerful component:

The Grounding Washer.

What Is a Grounding Washer?

A grounding washer is a thin metal disc inserted between the solar module frame and the pv mounting rail. While it may look simple, this small part plays a critical role in the electrical integrity of the entire PV system.

Why Stainless Steel SUS304?

The grounding washer we use is made from SUS304 stainless steel, a material known for:

Excellent corrosion resistance, ideal for long-term outdoor exposure

High mechanical strength, maintaining pressure over time

Natural silver finish, with no added coatings to degrade or peel

By using raw stainless steel, we avoid surface treatments that might interfere with metal-to-metal conductivity.

How Does It Work?

When inserted between the anodized aluminum frame of the solar module and the solar mounting rail, the grounding washer’s teeth bite through the anodized layer. This creates a metallic connection that:

Enables efficient current flow

Prevents oxidation or corrosion at the contact point

Unifies the module and rail into a single conductive structure

This effectively establishes a grounding electrical path without requiring additional wires or bonding jumpers.

Why Is This Important?

A reliable ground connection ensures:

Electrical safety during operation

Protection against static buildup

Reduced risk of current leakage or arc faults

Compliance with international electrical codes (e.g. NEC, IEC)

In environments prone to humidity, dust, or salt air—such as coastal or desert regions—the grounding washer becomes even more critical.

What Happens Without Proper Grounding?

Ground faults may not trip properly

Electrical surges could damage equipment

Modules may fail compliance checks during inspection

Long-term degradation could cause system instability or safety risks

Final Question: Are You Grounding Your PV System the Right Way?

The humble grounding washer may not make headlines, but it’s one of the unsung heroes of a safe and efficient solar installation. Choosing the right material and design—like our SUS304 stainless steel washer—can make the difference between a reliable system and an unpredictable one.

Need grounding solutions for your solar projects?
Contact our business team to learn more about our PV accessories and how to build safer, smarter systems.