Over the 25-year or longer lifecycle of a photovoltaic power plant, the mounting structure continuously withstands environmental forces. Among all external loads, wind load plays the most critical and complex role in solar mounting system design.

A robust, code-compliant wind load calculation directly supports structural safety, asset protection, and long-term energy yield. From the perspective of a solar mounting structural engineer, this article explains how engineers calculate wind load in solar mounting design, outlines the key influencing factors, and summarizes common industry practices.

Why Wind Load Matters in Solar Mounting Systems

Solar power plants operate in open environments, whether in deserts, hilly terrain, or dense commercial rooftops. Wind acts on every PV system and directly influences material selection, member sizing, and overall structural integrity.

Typical Wind-Induced Failure Risks

• Structural deformation
  Continuous strong winds can bend rails or twist posts, affecting module alignment and increasing the risk of hotspots.
• Structural collapse
  Extreme wind suction or pressure may exceed design limits and cause array overturning or system failure.
• Module damage
  Under severe wind conditions, PV modules may bend, crack, or detach from the mounting structure.

Sensitivity Across Different Applications

• Rooftop systems
  Building height, geometry, and surrounding obstacles create highly uneven wind load distribution. Edge and corner zones experience the most critical effects.
• Ground-mounted systems
  Large array fields may amplify wind effects, making foundation uplift resistance a primary design concern.
• Solar carports
  As open or semi-open structures, carports allow wind to pass through, which can generate vortex-induced vibration and torsional effects.

What Wind Load Means in Solar Mounting Design

Wind load refers to the force that wind exerts on the surface of a PV array. Engineers treat it as a dynamic and non-uniform pressure field rather than a simple horizontal push.

Basic concept:
Wind load equals wind pressure acting on a surface multiplied by the effective exposed area. Wind speed, array geometry, orientation, and exposure conditions all influence its magnitude and direction.

Pressure, Suction, and Lift

• Wind pressure
  Wind striking the front surface of a PV module generates direct compressive force.
• Wind suction
  As airflow accelerates over or beneath the array, it creates negative pressure on leeward surfaces. In many PV designs, uplift from suction governs structural checks.
• Lift
  At certain tilt angles, airflow generates an upward force similar to an airfoil effect.

Why uplift often governs design:
PV modules usually install at a tilt angle. When wind flows beneath or over the array, it creates a low-pressure zone behind the modules, producing strong uplift forces. In specific wind directions, higher tilt angles can intensify this effect.

Key Factors That Influence Wind Load Calculations

Accurate wind load calculations require engineers to evaluate several interrelated parameters.

Basic Wind Speed

Engineers start all calculations with basic wind speed, which local meteorological data and defined return periods (such as a 50-year event) determine. Coastal regions, typhoon corridors, and inland areas show significant differences.

Terrain and Exposure Category

• Open terrain (grasslands, water bodies)
  Minimal surface obstruction allows higher wind speeds and increases wind load.
• Urban or suburban areas
  Buildings increase surface roughness, which creates turbulence but may reduce wind speed in sheltered zones.
• Mountainous terrain
  Ridges and valleys accelerate wind or change flow direction, requiring terrain amplification factors.

Installation Height and Elevation

Wind speed increases with height due to the wind profile effect. Rooftop elevation and ground clearance therefore have a direct impact on design wind pressure.

Tilt Angle and Array Layout

• 傾斜角度
  Tilt directly affects exposed area and force lever arms. Designers balance energy yield against increased wind load.
• Row spacing and layout
  Upwind rows can shield or disturb airflow to downwind rows. This array effect becomes critical in dense ground-mounted systems.

Structural System Type

• Fixed-tilt vs. tracking systems
  Trackers experience very different wind loads in operating mode and storm stow mode, and designers must also consider dynamic effects.
• Single-row, double-row, and cantilever structures
  Support configurations change load paths and influence critical failure modes.

Wind Load Design Standards and Codes

Global PV projects must comply with local structural design standards.

• ASCE 7 / IBC
  Widely used in North America and many regions in Asia and the Middle East, these standards calculate wind load using velocity pressure and multiple coefficients.
• EN 1991-1-4 (Eurocode)
  Common across Europe, this standard relies on regional wind maps and detailed external and internal pressure coefficients.
• Other regional standards
  Including AS/NZS 1170.2 (Australia and New Zealand) and JIS standards (Japan).

Key principle:
Local mandatory codes always take priority over internal guidelines or foreign standards. Projects rely on code compliance for permitting, financing, and insurance approval.

How Engineers Calculate Wind Load

Although calculation methods vary by standard, engineers generally follow the same logic.

From Wind Speed to Wind Pressure

Engineers derive design wind pressure from basic wind speed, exposure category, installation height, and terrain factors.

Application of Key Coefficients

• Pressure or shape coefficients
  These coefficients describe how wind interacts with inclined PV surfaces.
• Gust response factors
  They account for turbulence and dynamic amplification effects.
• Area reduction factors
  Large module surfaces do not experience fully synchronized pressure, allowing partial reduction.

Load Combinations and Structural Analysis

Designers evaluate structures under multiple wind directions and load combinations, including wind with self-weight, snow, or construction loads. During extreme wind events, engineers typically exclude other live loads.

They then convert surface loads into forces at support points to assess:

• Uplift forces, which govern anchoring or ballast design
• Sliding forces, which govern anti-slip requirements
• Overturning moments, which govern post and foundation strength

Wind Load Considerations by Installation Type

Rooftop Solar Systems

• Wind pressure zoning
  Edge, corner, and ridge zones often experience suction several times higher than central roof areas.
• Uplift resistance
  Designers focus on the tensile capacity of mounting connections and the load-bearing capability of the roof structure.

Ground-Mounted Solar Systems

• Array height
  Taller structures generate higher wind loads and overturning moments.
• Foundation design
  Engineers size driven piles, screw piles, or concrete foundations based directly on calculated uplift forces.

Solar Carports

• Wind channel effects
  Wind can act simultaneously on the upper and lower surfaces, creating pressure differentials.
• Overall stability
  Designers emphasize lateral stiffness, torsional resistance, and performance under asymmetric wind loads.

Engineering Accuracy Ensures Long-Term Safety

Wind load calculation goes far beyond inserting values into formulas. Engineers integrate meteorology, fluid mechanics, structural analysis, and local design codes into a single, comprehensive process.

At SOEASY, we fully understand this complexity. We operate not only as a solar mounting system manufacturer, but also as an engineering-driven solution provider. By combining international code expertise with extensive project experience, our engineering team delivers mounting solutions that achieve both structural safety and economic efficiency.

Choosing SOEASY means relying on systems supported by rigorous calculations, simulations, and full-scenario testing. From precise wind load analysis to customized structural design, our team provides end-to-end technical support to protect your assets and ensure stable PV performance throughout a 25-year lifecycle.