What Are Steel Ground-Mounted Solar Racks?

Steel ground-mounted solar racks are structural support systems designed to secure photovoltaic modules to the ground. Constructed primarily from carbon steel (Q235B, Q355B) or galvanized steel, these racks are the preferred choice for utility-scale solar farms, agrivoltaics, and large commercial ground-mount installations due to their high strength, cost-effectiveness, and durability.

Unlike aluminum racks which are lighter but more expensive, steel racks offer superior load-bearing capacity, making them ideal for regions with high wind speeds, heavy snow loads, and challenging terrain conditions.

1. Key Advantages of Steel Ground-Mount Systems

2. Main Types of Steel Ground-Mount Racks

3. Material Specifications

Common Steel Grades:

Corrosion Protection:

4. Structural Profiles

5. Foundation Options for Steel Racks

6. 2024-2025 Technology Trends

1. High-Strength Steel Adoption

The use of Q355B and S420GD grades has increased significantly, allowing for thinner sections and reduced material consumption without compromising strength. Some manufacturers now offer racks with 20-30% less steel compared to traditional Q235B designs.

2. Zn-Al-Mg Coated Steel Mainstream

Zinc-aluminum-magnesium (Zn-Al-Mg) coated steel has become the standard for high-corrosion environments. With 5-10 times the corrosion resistance of traditional hot-dip galvanizing and self-healing properties at cut edges, Zn-Al-Mg extends service life to 35+ years.

3. Large-Span Designs for Agrivoltaics

As agrivoltaics expands, steel racks with spans of 8-12 meters and column heights of 3-4 meters have become standard. These designs accommodate standard farming equipment while maintaining generation capacity. Single-pole racking systems minimize land occupation and reduce interference with crop growth.

4. Screw Pile Integration

Steel racks are increasingly designed with integrated screw pile interfaces, eliminating the need for concrete foundations. The Nextracker NX Anchor system, for example, achieves 50% steel savings and 70% depth reduction compared to conventional pile foundations, with installation times of 2-3 minutes per pile.

5. Prefabricated and Modular Systems

Factory pre-assembled steel rack sections reduce on-site labor by 30-50%. Pre-punched holes, pre-cut lengths, and pre-installed connection hardware simplify field assembly and improve quality consistency.

6. Terrain-Following Designs

For mountainous and reclaimed land sites, articulated steel rack systems with ±15° to ±20° tilt compensation eliminate the need for extensive grading, preserving topsoil and reducing environmental impact.

7. Engineering Considerations

Load Design:

Corrosion Environment Classification:

8. Application Examples

Example 1: Large-Scale Fixed-Tilt Plant (100 MW)

Location: Flat terrain, moderate wind zone

Structure: Q355B C-channel, 25° fixed tilt

Foundation: Driven piles, 2.5 m depth

Coating: Hot-dip galvanized, 85 μm

Result: 25-year design life, 60 m/s wind resistance

Example 2: Agrivoltaics Project (10 MW)

Location: Rolling farmland, high snow load

Structure: Q355B large-span H-beams, 3.5 m height

Span: 10 m between columns

Foundation: Screw piles, double-helix

Result: Farming equipment access maintained, 30-year service life

Example 3: Tracker System (50 MW)

Location: High-irradiation region, moderate terrain

Structure: Q355B torque tubes + C-channel purlins

Drive: Single-axis, 60° tracking range

Foundation: Precast concrete piles

Result: 18-22% generation gain over fixed-tilt

9. Comparison: Steel vs. Aluminum Ground Mounts

10. 2024-2025 Industry Developments

Material Innovations:

Baosteel Danxia Steel: A high-strength weathering steel specifically developed for PV mounts, achieving monthly orders of 12,000 tonnes in mid-2024. Over 45,000 tonnes have been supplied for 1.5 GW of PV projects across diverse terrains including mountains, coal mine backfill sites, deserts, and coastal tidal flats.

Shangang Group: Successfully developed and rolled out a new high-strength steel for PV mounting structures in late 2024, meeting stringent customer requirements for load capacity and corrosion resistance.

Production Capacity:

Inner Mongolia Energy Group: Commissioned a fully automatic PV mount production line in February 2024 with a design capacity of 100,000 tonnes/year (sufficient for 3.5 GW of PV plants). From equipment arrival to commissioning took only 12 days.

Standardization:

The YB/T “Photovoltaic Mounting Steel Sections” industry standard was reviewed in November 2024, specifying structural types, chemical composition, mechanical properties, and anti-corrosion requirements for C-channel, angle steel, and H-beam sections used in PV mounts.

In a Nutshell

Steel ground-mounted solar racks remain the backbone of utility-scale PV due to their strength, cost-effectiveness, and proven reliability. Key developments in 2024-2025 include:

High-strength steel grades (Q355B, S420GD) reducing material consumption

Zn-Al-Mg coated steel offering 35-year corrosion protection with self-healing properties

Large-span designs enabling agrivoltaics and equipment access

Screw pile integration eliminating concrete and accelerating installation

Prefabricated systems reducing on-site labor by 30-50%

For large-scale projects requiring durability, cost control, and long-term reliability, steel ground-mount systems remain the industry standard.