Case Study: 800kW Cyclone-Resistant Solar Mounting on Factory Shed in Chennai
Project Overview
- Capacity: 800 kWp
- Location: Ennore Industrial Belt, Chennai, Tamil Nadu (within 4km of coastal bay)
- Roof Type: Trapezoidal sheet metal factory shed (10m height, Category 3 terrain)
- Target Wind Speed: 50 m/s (Zone 5, Extreme Cyclonic Wind Zone)
- Structural Solution: Heavy-duty hot-dip galvanized steel (GI) purlins in compliance with IS 2629 / IS 4759 standards with SS304 clamping hardware.
The Engineering Challenge
The project site is located in coastal Ennore, Chennai, where high humidity and salt spray accelerate corrosion. Standard hot-dip galvanized steel frames with lightweight coating rust within 3 to 5 years.
Furthermore, the site resides within a high-wind cyclonic zone. Design wind calculations had to incorporate a cyclonic risk multiplier under IS 875 Part 3, resulting in design wind speeds exceeding $200\text{ km/h}$. The racking structures had to withstand massive wind lift forces without tearing the thin corrugated sheet roofing off the factory purlins.
Structural Design & Solution
The SOLBE engineering division designed a Heavy-Duty Cyclone-Resistant GI Racking System:
800kW CHENNAI CYCLONIC MOUNTING PROFILE
[ PV Module Table ]
[ SS304 Mid/End Clamps (A2-70 Grade) ]
[ Heavy-Duty GI C-Channels (IS 2062 E350 steel) ]
[ IS 4759 Compliant Post-Fabrication Hot-Dip Galvanizing ]
[ EPDM Vibration Pads ]
[ Factory Structural Purlins ] <- Anchored using high-shear fasteners- Cyclonic Wind Engineering: Using IS 875 Part 3 calculations, we applied a cyclonic importance factor of $k4 = 1.15$. The design wind speed ($Vz$) was calculated at $43.5\text{ m/s}$, translating to a design wind pressure ($Pz$) of $1,135\text{ N/m²}$.
- Structural Thickness & Material: We fabricated racking columns and purlins using raw IS 2062 E350 (YS 350 MPa) high-tensile steel, maintaining a profile wall thickness of $2.5\text{mm}$.
- Marine Corrosion Barrier: Fabricated steel profiles were treated with post-fabrication hot-dip galvanizing in compliance with IS 2629 and IS 4759 standards. Punched joint connections were isolated using EPDM gaskets, and clamped using stainless steel SS304 (A2-70) fasteners to prevent galvanic battery corrosion.
Key Performance Metrics
- Zinc Coating Weight: Verified compliance with IS 4759 standards across all columns and purlins.
- Pull-Out Safety Margin: On-site anchor pull-out tests verified holding capacities exceeding $7.5\text{ kN}$ (exceeding the design uplift limit of $4.8\text{ kN}$ by 1.56x).
- Storm Durability: The array successfully withstood regional cyclonic storm gusts exceeding 165 km/h with zero component shifting or structural damage.
🚀 Secure Your Coastal Solar Investment
Need structural engineering assistance for high-wind cyclonic zones? Contact our engineering team in Trichy for certified STAAD.Pro load analysis.