What is a solar mounting structure
A solar mounting structure is the mechanical framework that supports PV modules at the designed tilt angle and azimuth, transferring wind uplift, snow and gravity loads from the modules to the building roof or the ground. The structure also provides the bonding path for module frames to earth.
Indian solar mounting structures are most commonly fabricated from hot-dip galvanised iron (GI) with zinc coating between 80 and 300 g/m² depending on environment. Aluminium structures appear in premium rooftop installations where weight matters. Stainless steel is used in highly corrosive coastal environments.
Mounting design must account for site-specific wind loads (per IS 875 Part 3), snow loads (relevant for Kashmir, Himachal, Uttarakhand), seismic considerations and corrosion environment. Properly designed mounting lasts 20 to 25 years with minimal maintenance.
Why mounting structure matters
Structural integrity. The mounting bears 25 years of weather including cyclones, dust storms and heat.
Tilt and orientation. Mounting sets the geometric angles that drive yield.
Earthing path. Structure provides bonding for module frames.
Maintenance access. Walkways and serviceability are designed into the mounting.
Project economics. Mounting accounts for 8 to 15 percent of solar plant capex.
Regulatory compliance. CEIG approval and CEA safety regulations apply.
Mounting structure types
| Type | Use | Cost (₹/Wp) |
|---|---|---|
| Rooftop RCC penetrating | Most common for concrete roofs | 4 to 5 |
| Rooftop ballasted | Concrete roofs without penetration | 5 to 7 |
| Rooftop metal sheet | Industrial sheds | 3.5 to 5 |
| Ground-mount fixed-tilt | Utility, C&I ground | 4.5 to 6 |
| Single-axis tracker | Utility | 7 to 10 |
| Dual-axis tracker | Specialty | 12 to 18 |
| Carport | Commercial parking | 6 to 9 |
| Floating | Reservoirs | 8 to 14 |
| Agrivoltaic | Crop overhead | 8 to 12 |
Technical deep dive
Materials and coatings
| Material | Zinc coating | Service life | Use |
|---|---|---|---|
| Hot-dip GI 80 g/m² | Light | 15 to 20 years | Dry inland |
| Hot-dip GI 120 g/m² | Medium | 20 to 25 years | Standard |
| Hot-dip GI 200 g/m² | Heavy | 25 to 30 years | Humid, semi-coastal |
| Hot-dip GI 300 g/m² | Heavy | 30+ years | Coastal |
| Powder-coated aluminium | n/a | 25 to 30 years | Premium rooftop |
| 316L stainless steel | n/a | 30+ years | Highly corrosive |
Wind load (IS 875 Part 3)
| Region | Basic wind speed (m/s) |
|---|---|
| Coastal (Andhra, Tamil Nadu, Odisha, Gujarat coast) | 47 to 55 |
| Plains (most of central India) | 39 to 44 |
| Northern plains | 39 to 44 |
| Hills (lower) | 30 to 39 |
| Hills (upper) | varies |
Roof attachment types
| Type | Description |
|---|---|
| L-foot bolted to rafter | Most common RCC |
| Tile hook for clay tile roofs | Specialty residential |
| Standing seam clamp | Metal sheet |
| Trapezoidal sheet bracket | Metal sheet industrial |
| Ballasted weights | Non-penetrating ballast |
Hardware components
| Component | Function |
|---|---|
| Rail | Horizontal member supporting modules |
| Mid-clamp | Holds modules between adjacent positions |
| End-clamp | Holds modules at row ends |
| L-foot or bracket | Attaches rail to roof or post |
| Cross-bracing | Stiffens the structure |
| Earth lug | Bonds module frame to earth |
| Anti-theft hardware | Tamper-resistant fasteners |
Foundations for ground-mount
| Type | Use |
|---|---|
| Concrete cast-in-place | Highest load |
| Pre-cast concrete | Faster install |
| Driven piles | Soft soil |
| Helical screw piles | Soft or rocky soil, fast install |
| Surface ballast | Non-penetrating, limited tilt |
Real-world applications
PM Surya Ghar rooftop installations, the kind covered in our Lucknow 3BHK hybrid solar case study.
C&I rooftop on industrial sheds, typically delivered under industrial solar installation scope.
Utility solar parks.
Carports for commercial parking.
Floating solar reservoirs.
Agrivoltaics over crops.
Solar pumps under PM-KUSUM.
Common mounting problems
Corrosion in coastal areas with light galvanising.
Loose hardware after thermal cycling.
Roof leakage from improper waterproofing of penetrations.
Inadequate wind load design failing in cyclones.
Ballast moving on flat roofs.
Bird nesting under modules.
Earthing continuity lost over years.
Best practices
Specify galvanising mass per environment (IS 2062 grade and IS 4759 specifications).
Use IS 875 for wind load calculations.
Engineer-sealed structural calculations for roof load.
Stainless steel hardware (not plain steel) for fasteners.
Anti-theft hardware in unattended sites.
Annual visual inspection and torque check.
Document mounting structure on the single line diagram.
Comparison: mounting types
| Type | Capex | O&M | Yield | Best for |
|---|---|---|---|---|
| Fixed-tilt rooftop | Lowest | Lowest | Baseline | Rooftops |
| Fixed-tilt ground | Low | Low | Baseline | Cost-sensitive utility |
| Single-axis tracker | Medium | Medium | +15 to 25% | Modern utility |
| Carport | Higher | Low | Baseline | Commercial |
| Floating | Higher | Higher | +5 to 10% (cooling) | Reservoirs |
Indian market context
Major Indian mounting structure brands: Tata BlueScope, Mahindra Susten, Esennar, Hexa Power, NextMSC, Mounting Systems India — the same category of mounting structure products sold through solar equipment suppliers.
ALMM does not certify mounting structures separately. MNRE technical specifications apply.
CEIG drawing approval verifies structural compliance, backed by structural and civil engineering calculations for larger projects.
PM Surya Ghar residential typically uses GI rail-and-clamp systems.
Utility plants under SECI tenders increasingly specify tracker mounting for higher yield.
Standards and certifications
| Standard | Scope |
|---|---|
| IS 875 Part 3 | Wind load on structures |
| IS 800 | Code of practice for structural steel |
| IS 2062 | Structural steel grades |
| IS 4759 | Hot-dip zinc coating |
| MNRE Technical Specifications | Solar mounting requirements |
| CEA Measures Relating to Safety 2023 | Structural safety |
Common mistakes
Light galvanising in coastal locations.
Using plain steel hardware instead of stainless.
Inadequate roof waterproofing at penetration points.
Skipping structural engineering for old or sheet metal roofs.
Ballast undersized for cyclone wind loads.
Missing earthing bond on every metallic element.
Key takeaways
Mounting structures hold solar modules at design tilt and orientation, transferring loads to the supporting building or ground. Indian mounting uses hot-dip GI with zinc coating sized for local environment. Wind load design per IS 875, structural compliance per IS 800, and earthing continuity are the key design criteria. Trackers add yield but increase capex and O&M. Mounting accounts for 8 to 15 percent of total solar capex.
Further reading
For how Mounting Structure plays out in real projects, these guides go deeper:
- Utility-Scale Solar Design Software Compared
- PVcase Review 2026: Terrain-Aware Ground Mount Design, Assessed
Sources
- IS 875 Part 3, Wind load on structures.
- IS 800, Code of practice for structural steel.
- IS 2062, Structural steel grades.
- IS 4759, Hot-dip zinc coating.
- MNRE Technical Specifications for Solar PV Mounting.
- CEA Measures Relating to Safety and Electric Supply Regulations 2023.
- IEC 61730, Module safety (mounting requirements).
- Manufacturer documentation from Tata BlueScope, Mahindra Susten and other Indian brands.
- IEA PVPS Task 14 Report on PV mounting systems.
Frequently Asked Questions
What is a mounting structure in simple words?
What materials are used?
What are the main types?
How long do mounting structures last?
What is GI grade?
How much does mounting cost?
Do mounting structures need certification?
What is the typical wind load design?
Are roof penetrations needed?
What is L-foot mounting?
What is mid-clamp and end-clamp?
How are structures earthed?
What is the typical Indian tilt for mounting?
Do trackers need maintenance?
Can mounting structures be removed and reused?
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Co-founder & CEO driving Qbits Energy's product strategy and growth across India.