Case Study: How Our Galvanized Steel Powered Zhejiang University's Game-Changing BIPV Campus

Last Updated: May 30, 2026By the Engineering Team at Shandong Pinjie New Material Co., Ltd.12+ years designing galvanized steel solutions for solar. Our products support over 800MW of projects across 32 countries, including 120+ high-corrosion coastal installations.

Back in 2021, we got a call that would turn into one of our most memorable projects. The team at Zhejiang University Ningbo Institute of Technology (ZJUNIT) had a wild idea: they didn't want to mount solar panels on a roof. They wanted the solar panels to be the roof. And they needed it to survive Ningbo's brutal coastal weather-typhoons, salt spray, heavy rains, the works.

We knew right away this wasn't going to be a standard job. But that's exactly the kind of challenge our team lives for. Today, five years later, that 2,600-square-meter BIPV roof is still going strong, powering the university's General Experimental Building and serving as a model for what integrated solar can do. And at its core? Our CGI Solar Structure (Galvanized Iron Solar Structure).

Project At A Glance

The Problem: Rooftop Solar Wasn't Good Enough

The university's General Experimental Building had a bare concrete rooftop that was going to waste. But a traditional solar installation-roofing material + mounting racks + panels-would have added unnecessary weight, created potential leak points, and cost more than they wanted to spend.

As ZJUNIT's official news release explained, they needed something that could do it all: generate electricity, keep the building dry, support maintenance workers walking on it, and hold up for decades in an environment where salt air eats through steel faster than you'd believe.

The engineering team at ZJUNIT had already rejected aluminum (too expensive, not strong enough) and pre-galvanized steel (too thin, won't last). That's when they reached out to us.

Our Solution: Custom Hot-Dip Galvanized Steel Built for the Coast

We didn't just ship them steel. We worked side-by-side with their engineers for three months to design a system that would meet every single one of their requirements.

The result was a custom Hot Dip Galvanized Steel Solar Mounting Structure that acts as both the roof's structural skeleton and the panel mounting system. Each 2m² unit bonds a monocrystalline solar panel directly to a galvanized steel base-no separate roofing, no extra layers, no leaks.

Why We Insisted on Hot-Dip Galvanizing (And Not Pre-Galvanized)

This was the biggest debate we had with the client early on. Their initial budget had them leaning toward pre-galvanized steel, which is cheaper upfront. But we knew it would be a disaster in Ningbo.

We walked them through the HDG vs Pre-Galvanized Solar Structure data we've collected over 11 years of coastal projects:

Pre-galvanized steel has a zinc coating of only 5-15μm. In Ningbo's salt air, it starts rusting in 3-5 years.

Our hot-dip galvanized steel creates a metallurgically bonded zinc-alloy layer 80-120μm thick. It lasts 10-20 times longer.

We showed them photos of two identical brackets we installed in Qingdao in 2012: one with 80μm HDG coating, one with pre-galvanized. The pre-galvanized one was almost completely rusted through. The HDG one looked almost new.

That settled it. They went with hot-dip galvanizing.

The Custom Tweaks That Made This Project Work

During our site analysis, we discovered something important: Ningbo's salt spray concentration was 20% higher than the standard C3 environment. So we made two critical changes to the design:

Increased Zinc Coating Thickness: We bumped the minimum Zinc Coating Thickness for Solar Mounting from 80μm to 85μm. Our data shows this adds an extra 5-7 years of corrosion protection in high-salt environments.

Reinforced C Channels: We used high-strength Q235B Galvanized Steel C Channel for Solar Mounting to form the structural grid. These channels can support 80kg per square meter-enough for a 160-pound worker to walk safely anywhere on the roof.

We also manufactured every component to ±0.5mm tolerances, so they could bolt everything together on-site without welding. This cut installation time by 40% and eliminated the risk of weld corrosion.

The Results: 5 Years of Flawless Performance

The system went live in April 2021, and it's been exceeding expectations ever since. We do annual inspections, and every time we're impressed by how well it's holding up.

What The Numbers Tell Us

Total generation to date: Over 1.75 million kWh (enough to power 160 average homes for a year)

CO₂ emissions reduced: ~1,200 tons

Zero leaks reported-even during Typhoon In-Fa in 2021, which dumped 400mm of rain in 3 days

2025 inspection: Average zinc coating thickness still 78μm (only 8.2% loss in 5 years)

No structural deformation, no bent brackets, no failed components

Dr. Hu Changxing, Vice Dean of the College of Mechanical and Energy Engineering at ZJUNIT, told us:

"We took a risk with this integrated design, and it paid off big time. Pinjie didn't just sell us steel-they helped us solve the biggest problem we faced: corrosion in our coastal climate. Five years later, this roof still looks and performs like it's brand new. We couldn't be happier."

The project has been so successful that the university is now rolling out the same design across 50,000 square meters of campus rooftops. The expansion will also include a Galvanized Steel Solar Carport Structure and several Galvanized Steel Solar Ground Mount installations. When complete, the system will meet 35% of the university's total electricity needs.

Why Pinjie Is The Right Choice For Your Solar Project

This project taught us a lot about what works in coastal BIPV applications. And it's exactly the kind of expertise we bring to every project we do.

When you work with Shandong Pinjie New Material Co., Ltd., you get:

Proven Quality: All our products meet ISO 9001, ISO 1461, and EN 1090 standards. We test every batch for strength, adhesion, and corrosion resistance.

End-to-End Support: Our engineers work with you from initial design through installation. We don't just ship parts and disappear.

Full Product Range: We make everything you need, from CGI Solar Structure to Galvanized Steel Solar Carport Structure and everything in between.

Best Total Cost of Ownership: Our hot-dip galvanized steel costs only 38% of aluminum, lasts just as long, and requires almost no maintenance.

If you're working on a coastal project or have special durability requirements, we'd love to share what we've learned.

Frequently Asked Questions

Q: How long will hot-dip galvanized steel last in a coastal environment?

A: With proper coating thickness (100-120μm), our hot-dip galvanized steel will last 20-25 years in most coastal areas. In milder inland environments, it can last 30+ years.

Q: Is zinc-aluminum-magnesium coating worth the extra cost?

A: For extreme coastal or offshore sites, yes. It has 10-20 times the corrosion resistance of standard hot-dip galvanizing and can self-repair scratches. For most inland sites, standard HDG is more cost-effective.

Q: Can your C channels handle heavy snow loads?

A: Yes. Our standard Q235B channels can handle up to 0.8kN/m² of snow load. For areas with heavier snow, we offer Q355B channels that have 50% higher yield strength.

Q: How quickly can you deliver?

A: We keep large inventories of standard products, so we can ship most orders in 7 days or less. Custom orders typically take 14-21 days.

Final Thoughts

The ZJUNIT project showed us that solar doesn't have to be an afterthought. When you integrate it into the building itself-using the right materials, designed for the specific environment-it can be more functional, more durable, and more cost-effective than traditional installations.

We're proud to have been part of this groundbreaking project, and we're excited to bring what we've learned to your next solar installation. Whether you're building a rooftop system, a carport, or a utility-scale ground mount, we have the expertise and products to make it a success.

Ready to get started? Contact our engineering team today for a free site assessment, coating thickness recommendation, and no-obligation quote. We'll help you design a galvanized steel solution that's perfect for your project's conditions and budget.