Solar Mounting Structures: Why Structural Design Matters as Much as the Panels

Solar panels may receive most of the attention in a solar project, but they depend entirely on the structure holding them in position.

A premium photovoltaic module installed on a poorly designed mounting structure can still become part of an unreliable or unsafe system.

Solar mounting structures must support the weight of the modules, maintain the intended orientation and tilt, withstand environmental forces, protect the building or foundation they are attached to and remain durable for years outdoors.

The U.S. Department of Energy states that photovoltaic arrays need stable, durable mounting structures capable of supporting the array while withstanding wind, rain, hail and corrosion over decades. (energy.gov)

That makes structural engineering an important part of solar design rather than a secondary fabrication task.

What Is a Solar Mounting Structure?

A solar mounting structure is the mechanical framework that supports photovoltaic modules.

Depending on the project, the system may be installed on:

• A residential rooftop.
• A commercial building.
• An industrial shed.
• An elevated steel structure.
• Open ground.
• A solar carport.
• An agricultural site.

The structure determines where the panels sit, their orientation, tilt and height, and how mechanical forces are transferred into the roof, building or foundations.

The correct structure therefore depends on the actual site.

Why Solar Structure Design Matters

A solar array remains outdoors for years.

During that period, the mounting system may experience:

• Wind.
• Rain.
• Temperature changes.
• Corrosion.
• Structural movement.
• Maintenance loads.
• Environmental exposure.

The structure must support these conditions while keeping the modules securely positioned.

Solar design standards also recognize mounting as a formal engineering requirement. IEC 62548-1:2023 revised its provisions relating to photovoltaic mounting structures as part of the international requirements for PV-array design. (webstore.iec.ch)

This is why selecting the structure only from its appearance or steel weight is insufficient.

The Roof Must Be Assessed First

Before adding solar to a building, the existing roof should be evaluated.

Important considerations can include:

• Roof type.
• Existing structural condition.
• Available load capacity.
• Age of the roof.
• Corrosion or deterioration.
• Waterproofing.
• Existing equipment.
• Maintenance access.

A concrete rooftop, pre-engineered industrial shed and lightweight metal roof cannot automatically use the same mounting solution.

The structure needs to transfer loads safely into the building rather than concentrating force in unsuitable areas.

Solar Panels Add More Than Their Own Weight

The structure is not designed only for the static weight of the panels.

Engineers may need to consider the combined effect of:

• PV modules.
• Structural steel or aluminum.
• Rails and fasteners.
• Electrical equipment where mounted.
• Maintenance loads.
• Environmental forces.

A structure that appears strong enough to hold the panels while stationary may behave differently during severe weather.

That is why load calculations should be completed before fabrication.

Wind Load Can Be a Major Design Factor

Solar modules form large exposed surfaces.

Wind flowing around and underneath the array can create uplift, lateral forces and pressure on the mounting structure.

These forces must ultimately be transferred through:

Panels → mounting system → structural supports → roof or foundations.

NREL engineering guidance has long treated array wind loading as an important mechanical-design consideration when evaluating photovoltaic mounting and structural support. (nrel.gov)

The required design depends on location, structure height, array geometry, exposure and applicable structural criteria.

A mounting structure should therefore not be copied from another project simply because the solar capacity is similar.

Elevated Solar Structures Need Additional Attention

Elevated structures are common where owners want to retain usable rooftop space or raise panels above obstacles.

However, increasing height changes structural behavior.

An elevated solar shed may experience different:

• Wind forces.
• Structural moments.
• Column loads.
• Bracing requirements.
• Foundation or anchoring loads.

The design should therefore be engineered as a complete steel structure.

E&E Industries currently lists custom elevated solar structures and structural mounting systems among its fabrication capabilities, supported by stress analysis, wind-load planning and steel fabrication. (eneindustries.com)

Tilt Angle Affects Both Energy and Structure

Panel tilt influences solar-energy production, but it also affects structural design.

Increasing tilt can change:

• Wind exposure.
• Structural forces.
• Required row spacing.
• Panel height.
• Steel quantity.
• Roof utilization.

Therefore, the theoretical angle that maximizes solar irradiation may not always be the best overall engineering solution.

Our guide to solar panel direction, tilt and shading explains how energy production and site constraints need to be considered together.

Row Spacing Matters

Tilted arrays installed in multiple rows require enough spacing to reduce unnecessary row-to-row shading.

Spacing also affects:

• Rooftop capacity.
• Maintenance access.
• Cleaning access.
• Cable routing.
• Structural layout.

Trying to fit the maximum number of panels into the smallest possible space can create shading and make future maintenance difficult.

A good structural layout therefore considers both energy generation and physical accessibility.

Corrosion Protection Is Essential

Solar mounting structures remain outdoors continuously.

Steel exposed without adequate protection can corrode over time, particularly where moisture, pollution or harsh environmental conditions exist.

Structural protection may include methods such as:

• Hot-dip galvanization.
• Suitable protective coatings.
• Corrosion-resistant materials.
• Appropriate fasteners.

E&E Industries currently describes hot-dip galvanization, weather-resistant coatings and other corrosion-protection treatments as part of its structural fabrication process. (eneindustries.com)

The appropriate protection should reflect the site environment and expected service life.

Ground-Mounted Solar Requires Foundation Design

Ground-mounted solar avoids some rooftop limitations but introduces foundation requirements.

The structure must transfer wind and other structural forces into the ground.

Depending on the project, foundations may involve:

• Concrete footings.
• Driven piles.
• Ground screws.
• Other engineered foundation systems.

Selection depends on factors such as soil conditions, structure geometry and project scale.

Foundation design should therefore be coordinated with the mounting structure rather than decided after fabrication.

Solar Carports Are Structural Projects

Solar carports demonstrate why solar structure design can become a major engineering discipline.

The structure must support the PV array while also maintaining:

• Vehicle clearance.
• Safe column placement.
• Parking usability.
• Wind resistance.
• Drainage.
• Electrical routing.

Our solar carport guide explains why parking-lot systems should be treated as both energy and infrastructure projects.

E&E Industries’ portfolio includes a 200 kW solar parking-lot installation at Ayyub Hockey Stadium using an engineered elevated steel structure. (eneindustries.com)

Industrial Roofs Need Site-Specific Solutions

Factories commonly provide large rooftop areas, but industrial buildings can vary substantially.

The roof may be:

• Reinforced concrete.
• Metal sheet.
• Pre-engineered building.
• Existing steel shed.
• Custom industrial structure.

Before installation, engineers should understand how solar loads will interact with the existing structure.

Our industrial solar guide explains why factories should assess structural conditions along with electrical load and solar capacity before proceeding.

Mounting Should Not Damage the Roof

Poor installation can create problems even when the steel structure itself is strong.

Roof attachment methods should consider:

• Waterproofing.
• Existing roof sheets.
• Structural members.
• Penetration locations.
• Sealing.
• Drainage.

Mounting should transfer loads into suitable structural points without unnecessarily compromising the building envelope.

A roof leak created by poorly installed solar supports can become a long-term maintenance problem.

Fasteners and Connections Matter

A structure is only as reliable as its connections.

Bolts, clamps, welds and other connection points transfer forces through the mounting system.

Poor connections may result from:

• Incorrect hardware.
• Insufficient tightening.
• Weak welding.
• Corrosion.
• Incorrect installation.
• Incompatible materials.

Quality control during fabrication and installation is therefore important.

Structural performance should not be judged only from the thickness of visible steel members.

Fabrication Quality Affects the Final Installation

Accurate engineering drawings need equally accurate fabrication.

Poor fabrication can create:

• Misaligned supports.
• Difficult panel installation.
• Incorrect hole locations.
• Weak connections.
• Uneven module alignment.
• Additional field modifications.

E&E Industries describes its fabrication capabilities as including 3D CAD modeling, stress analysis, precision cutting and punching, beam assembly and modular pre-engineered components intended to reduce field welding. (eneindustries.com)

A repeatable fabrication process can help translate structural engineering into reliable site execution.

Maintenance Access Should Be Designed From the Beginning

Solar panels eventually need inspection and cleaning.

Technicians may also need access to:

• Module connectors.
• Cables.
• Junction equipment.
• Mounting hardware.
• Drainage areas.

If every section of roof is filled with panels, maintenance can become difficult or unsafe.

A professional structural layout should therefore leave suitable access rather than treating every unused centimeter as wasted solar space.

Inspect the Structure During Maintenance

Structural inspection should continue after installation.

Periodic checks may look for:

• Loose fasteners.
• Corrosion.
• Damaged members.
• Structural movement.
• Failed coatings.
• Water accumulation.
• Damaged module clamps.

After severe weather or unusual site events, an additional inspection may be appropriate.

Our solar cleaning and maintenance guide explains why mechanical inspection should be included alongside module cleaning and electrical monitoring.

Mounting Structures Belong in the BOQ

A solar quotation should not describe the structure simply as:

“Complete solar mounting included.”

For significant projects, useful structural information may include:

• Structure type.
• Material.
• Corrosion protection.
• Mounting arrangement.
• Engineering scope.
• Foundation scope where applicable.

Our solar quotation and BOQ guide explains why structural components should be clearly documented before project approval.

Do Not Choose a Structure by Price Alone

Two mounting systems that appear similar may differ significantly in:

• Material quality.
• Member dimensions.
• Galvanization.
• Bracing.
• Fasteners.
• Foundation design.
• Structural calculations.
• Fabrication quality.

Reducing structure cost without understanding these differences can compromise one of the longest-lived physical components in the solar project.

The correct objective is not necessarily the heaviest or most expensive structure.

It is the properly engineered structure for the site.

Structural Design Is Part of Solar EPC

Mounting structures connect the solar-energy design to the physical building or land.

They affect:

• Safety.
• Panel orientation.
• Durability.
• Maintenance.
• Energy performance.
• Long-term reliability.

E&E Industries currently combines solar EPC with in-house structural fabrication and describes its solar mounting designs as incorporating tilt optimization, wind resistance, load calculations and corrosion protection for rooftop and ground-mounted applications. (eneindustries.com)

The panels may generate the electricity, but the structure determines whether those panels remain securely positioned to do their job for years.

Frequently Asked Questions

Why are solar mounting structures important?

They physically support the photovoltaic array, maintain panel orientation and transfer environmental and structural loads into the roof, building or foundations.

Can the same solar structure be used on every roof?

No. Roof type, structural capacity, geometry, wind exposure, panel layout and mounting method can require different structural solutions.

Why does wind load matter for solar panels?

Solar arrays create exposed surfaces that can experience uplift and lateral forces during high winds. The mounting structure and its connections must safely resist and transfer these loads.

Is galvanized steel good for solar structures?

Galvanized steel is widely used because zinc protection can improve corrosion resistance. The required material and coating specification should depend on the site environment and structural design.

Do ground-mounted solar systems need foundations?

Normally yes. The exact foundation system depends on the mounting design, loads, soil conditions and project requirements.

Should solar mounting structures be inspected after installation?

Yes. Periodic inspection can identify loose connections, corrosion, movement, damaged members or other mechanical issues.

Should the mounting structure appear in the solar BOQ?

Yes. Significant structural scope should be documented so the customer understands the structure type, material, protection and other relevant specifications.