Selecting the right material is one of the most important decisions in the design and construction of a Ground Mounted Solar Module Mounting Structure (MMS). A properly selected material improves structural strength, increases service life, reduces maintenance costs and provides better resistance against corrosion and environmental conditions.
Solar MMS structures are expected to perform continuously for more than 25 years under varying weather conditions including sunlight, rain, wind, humidity and temperature fluctuations. Therefore, every structural member should be manufactured using suitable materials that comply with the project specifications and applicable standards.
In this article, we will understand the materials commonly used in Solar MMS structures, their applications, corrosion protection methods and selection criteria.
PROJECT DETAILS
- Project Type
- Ground Mounted Solar Power Plant
- Structure Type
- Fixed Tilt Solar MMS
- Module Configuration
- 2P × 28
- Total Modules
- 56 Nos
- Module Size
- 2382 × 1134 × 35 mm
- Tilt Angle
- 11°
- Design Life
- 25 Years
OBJECTIVES OF MATERIAL SELECTION
The primary objectives of selecting suitable materials are
- High structural strength.
- Long service life.
- Better corrosion resistance.
- Easy fabrication.
- Easy transportation.
- Faster installation.
- Lower maintenance.
- Cost-effective construction.
MAIN STRUCTURAL MEMBERS
A typical Solar MMS consists of the following members.
- Columns
- Rafters
- Hat Purlins
- Front Bracing
- Rear Bracing
- Wind Bracing
- Cleats
- Connection Plates
- Bolts, Nuts and Washers
Every component should be manufactured using suitable structural materials.
STRUCTURAL STEEL
Cold-formed structural steel is widely used in Ground Mounted Solar MMS because of its excellent strength-to-weight ratio.
Advantages
- High strength.
- Lightweight.
- Easy fabrication.
- Faster installation.
- Better dimensional accuracy.
- Suitable for hot dip galvanizing.
STEEL GRADE
The steel grade should satisfy the structural design requirements specified in the approved engineering drawings.
Higher strength steel allows the use of lighter sections while maintaining structural performance.
Selection of the steel grade should always be verified during procurement.
HOT DIP GALVANIZING
Hot Dip Galvanizing is the most commonly used corrosion protection method for Solar MMS structures.
The steel members are completely immersed in molten zinc, forming a protective coating on the surface.
Benefits
- Excellent corrosion resistance.
- Long service life.
- Low maintenance.
- Suitable for outdoor applications.
WHY GALVANIZING IS IMPORTANT
Ground Mounted Solar Plants are continuously exposed to
- Rain.
- Humidity.
- Dust.
- UV Radiation.
- Temperature Changes.
- Industrial Pollution.
Galvanizing protects the steel against corrosion throughout the design life of the plant.
FASTENERS
Bolts, Nuts and Washers are equally important as the primary structural members.
Fasteners should
- Match the approved project specification.
- Be compatible with the structural members.
- Have suitable corrosion protection.
- Be free from visible damage.
CONNECTION PLATES
Connection Plates should
- Be fabricated accurately.
- Have proper hole alignment.
- Be free from distortion.
- Receive the specified corrosion protection.
CLEATS
Cleats are fabricated components used to connect structural members.
Before installation, verify
- Dimensions.
- Hole positions.
- Flatness.
- Surface condition.
- Galvanized coating.
MATERIAL STORAGE
Proper storage helps maintain material quality before installation.
Recommended practices
- Store members above ground level.
- Keep materials dry.
- Avoid direct contact with standing water.
- Prevent mechanical damage.
- Separate different member types.
MATERIAL HANDLING
Improper handling may damage structural members.
Follow these practices
- Lift members carefully.
- Avoid dragging steel sections.
- Prevent impact damage.
- Protect galvanized surfaces.
- Stack members properly.
INSPECTION OF RECEIVED MATERIAL
Before accepting the material at site, verify
□ Member Identification.
□ Correct Section Profile.
□ Correct Member Length.
□ Correct Quantity.
□ No Visible Damage.
□ No Twisting.
□ No Bending.
□ Galvanized Coating Intact.
CORROSION INSPECTION
Inspect structural members for
□ Rust.
□ Scratches.
□ Peeling Coating.
□ White Rust.
□ Surface Damage.
Any damaged coating should be repaired according to the approved project procedure.
COMMON MATERIAL DEFECTS
The following defects should not be accepted without proper evaluation.
- Bent members.
- Twisted members.
- Damaged galvanizing.
- Deep scratches.
- Corrosion.
- Distorted holes.
- Fabrication defects.
MATERIAL TRACEABILITY
Every structural member should be traceable throughout the project.
Maintain records for
- Material Receipt.
- Inspection Reports.
- Identification Marks.
- Installation Location.
- Replacement History.
Proper traceability improves quality control and simplifies future maintenance.
QUALITY CONTROL CHECKLIST
Before installation, verify
□ Correct Material.
□ Correct Section.
□ Correct Quantity.
□ Proper Identification.
□ No Damage.
□ Proper Storage.
□ Galvanized Surface Intact.
□ Approved for Installation.
BEST PRACTICES
- Purchase materials only from approved suppliers.
- Inspect every delivery before unloading.
- Protect galvanized coatings during transportation.
- Replace damaged members immediately.
- Maintain proper storage conditions.
- Keep complete material inspection records.
BENEFITS OF PROPER MATERIAL SELECTION
Proper material selection provides
- Better Structural Performance.
- Improved Corrosion Resistance.
- Longer Service Life.
- Lower Maintenance Cost.
- Better Project Quality.
- Improved Installation Efficiency.
- Higher Reliability.
CONCLUSION
The performance of a Ground Mounted Solar Module Mounting Structure depends not only on good engineering design but also on selecting high-quality materials. Proper structural steel, corrosion protection, fasteners and quality control procedures ensure that the Solar MMS performs safely and reliably throughout its design life. Careful material selection during procurement and inspection during construction are essential for achieving a durable and maintenance-friendly solar power plant.
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Part 15 – Complete Solar MMS Design Workflow – From Site Survey to Final Commissioning (A Step-by-Step Guide for Engineers)