Solar Mounting Structure Types: Roof, Ground, Tracker

Picking a mounting structure is one of the first design choices on a solar project, and it is hard to change later. The structure holds your panels at the right angle and keeps them in place in wind and snow. It also decides how the system is installed and what an engineer must check.

This guide covers roof, ground, tracker and specialty systems, when each fits, and what to check before you choose. The mounting structure glossary entry gives the short definitions.

Last updated: November 2026

PV Mounting Structures at a Glance

Mounting cost depends on your site, local steel and labor prices, and the design. This guide does not list a price per watt for each type. We could not find a public source with a fair figure for every type. Ask installers to quote your site. Then compare the options by payback, not by racking price alone. The solar NPV, IRR and payback guide shows how.

Roof-Mounted Structures

Roof mount uses the existing building, so you need no extra land. The roof sets some limits, so check it first.

Pitched Roof Rail Systems

Rails are fixed to the roof structure, usually through the roofing material. Flashings keep water out at each fixing. The panels clamp onto the rails. Rail kits are made for many roof coverings. Check the maker’s list for yours.

Every hole through the roof is a possible leak. Seal each one well.

Rail-Less Systems

Panels fix straight to the roof structure at separate points. There are no long rails. You use fewer parts and do less cutting. You also have less room to adjust the panel spacing.

Flat Roof Ballasted Systems

Panels sit in angled trays or frames. Weight, usually concrete blocks, holds them down. This often means fewer holes in the roof, or none. It is called ballasted racking.

The weight is the limit. A structural engineer must confirm the roof can carry it, especially where snow loads are high.

Flat Roof Tilt-Up Systems

Tilt-up frames raise the panels to a steeper angle than a flat layout. More tilt can raise yield. Tilted rows also shade each other, so you need more space between rows and fewer panels fit. See the inter-row spacing guide for the method. The balance between tilt and panel count is a core design choice. Solar design software lets you compare layouts.

Metal Roof Clamp Systems

On standing-seam metal roofs, clamps grip the raised seams. You do not drill through the roof sheet. Corrugated metal roofs usually need through-fasteners with rubber seals instead. These make holes, but you can seal them.

Rooftop Solar Mounting Structure Design: What to Check

Rooftop mounting design starts with the roof, not the panels. Check these points before you pick a system:

1. Roof structure. Ask for the building’s original structural drawings. If there are none, an engineer must survey the roof.
2. Added weight. Panels, racking and any ballast add load. The engineer compares it with what the roof can carry.
3. Wind. Uplift depends on your location, building height, roof edge and tilt. Engineers use local codes. In the US, that is ASCE/SEI 7-22. In Europe, it is Eurocode EN 1991-1-4 for wind actions.
4. Snow. Snow adds load. The local code gives the design value. Flat and low-tilt panels hold more snow than steep ones.
5. Roof covering. Plan how each fixing keeps the roof waterproof.
6. Row spacing and shade. Tilted rows need space so they do not shade each other.
7. Racking documents. Ask the racking maker for its load tables and an engineering report for your site.

The panels themselves are tested to separate standards. IEC 61215-2 sets the test procedures for module design qualification, and IEC 61730-1 sets module safety construction rules. Both apply to the module, not to the racking.

Ground-Mounted Structures

Ground mount is used for utility-scale solar. It is also an option for commercial and farm sites with little or poor roof space. You control the tilt, the direction and the row spacing.

Fixed-Tilt Driven Pile

Steel piles are driven into the ground. Rails and frames connect the piles, and the panels mount on top. This works in many soil types, but it may not suit solid rock. A geotechnical survey tells you which foundation the soil can take.

Fixed-Tilt Ballasted Ground Mount

Concrete blocks or precast footings replace piles. Panels mount on frames that sit on the ballast. Use this where you cannot drive piles, such as landfills and sites with buried utilities.

Ground Screws

Helical steel screws are twisted into the ground. They hold the frame like piles. They can be removed, so they suit sites that need little ground disturbance or a plan to remove the system later.

Seasonal Adjustable Tilt

Some frames let you change the panel angle by hand a few times a year to follow the sun’s height. This adds labor each time you adjust. Larger projects often use trackers instead.

Tracking Systems

Trackers turn the panels to follow the sun. They add motors and moving parts, but they raise energy output at the right site.

Single-Axis Trackers

A single-axis tracker turns the panels around one axis, usually north to south, so the panels follow the sun from east to west. Motors and controllers do the turning. Plan for regular checks of the motors and bearings.

The best public data is from the US. The Lawrence Berkeley National Laboratory (LBNL) tracks utility-scale solar projects. Its October 2025 data update reports these results. The share and cost rows are for projects that came online in 2024. The capacity factor row covers all projects in the LBNL sample, not only 2024:

LBNL says the cost figures do not control for other factors, such as project size, labor and land. LBNL also says tracking helps more in regions with strong sun. It says fixed tilt was used in 2024 only at particularly challenging sites, such as windy regions, brownfields, landfills and hard terrain. Source: LBNL, U.S. Utility-Scale Solar, 2025 Data Update. Capacity factor is the share of its maximum possible output that a plant actually delivers over a year.

These numbers come from large US ground projects. Your result depends on your site’s sun, terrain and wind. Model your own site before you decide. For a side-by-side view, see tracker vs fixed-tilt solar.

Dual-Axis Trackers

A dual-axis tracker turns on two axes to keep the panels facing the sun more closely. It has more moving parts and more to maintain. The LBNL data above covers single-axis trackers, so this guide gives no yield figure for dual-axis systems.

Specialty Mounting Systems

Solar Carports and Canopies

A carport is a steel or aluminum structure over a parking area, with panels as the roof. It makes power and gives cars shade and rain cover. It uses space that would otherwise make no power. It is a bigger structure than a roof or ground frame, so ask for a full structure quote. See the commercial solar carport design guide and the solar carports hub.

BIPV (Building-Integrated Photovoltaics)

BIPV puts solar cells into building parts, such as roof tiles, facade panels and windows. The solar part replaces a normal building material. It can suit new buildings with strict design rules, or heritage buildings where standard panels are not allowed.

Floating Solar

Floating solar mounts panels on floats on a reservoir, lake or pond. A study by the US National Renewable Energy Laboratory (now the National Laboratory of the Rockies) lists three possible benefits over ground-mount PV. They are higher panel efficiency from cooling and low shading, co-location with hydropower, and possible cuts in water evaporation. The same paper says the global floating PV market passed 13,000 MWdc of cumulative capacity in 2022. Source: Rosenlieb, Rivers and Levine, Solar Energy 287 (2025). Anchoring for changing water levels and keeping connections dry are the main design tasks. See floating solar.

Pole-Mounted Systems

A pole mount holds a few panels on a single steel pole. It suits small off-grid loads, such as signs, cameras, weather stations and gate openers.

How Mounting Type Affects System Design

The mounting structure shapes every later design step.

Tilt and Azimuth

A pitched roof fixes the tilt and the direction (azimuth) the panels face. Flat roofs and ground sites give you more choice. The best tilt and azimuth depend on latitude, how much power you use on site, and the row spacing. The solar angles guide explains how to choose.

Row Spacing

Any system with tilted rows needs space so the rows do not shade each other. A steeper tilt and a higher latitude need more space. The inter-row spacing guide shows the formulas.

Energy Yield

Mounting type changes yield. Tilt and direction matter, and so does how well air cools the back of the panels. For bifacial panels, mounting height and the ground surface matter too. Read bifacial solar gain by mounting type for details.

Design Workflow

The steps are the same for every mounting type:

1. Bring in site imagery and mark the mounting area. See the solar panel layout design guide.
2. Choose the mounting type and the panel direction.
3. Place the panels with the right setbacks and spacing.
4. Run shadow analysis to find shaded panels.
5. Assign strings and inverters.
6. Produce the bill of materials and a proposal.

The mounting type changes the spacing rules and the structural checks. The workflow stays the same. For the full process, see the residential solar system design guide and the solar panel installation guide. The solar installation hub has more chapters on site surveys, permits and commissioning.

Frequently Asked Questions

What are the different types of solar panel mounting systems?

The main types are roof mounts, ground mounts, trackers and specialty systems. Roof mounts include pitched rail, rail-less, flat ballasted, flat tilt-up and metal roof clamp. Ground mounts use driven piles, ballast or ground screws. Trackers are single-axis or dual-axis. Specialty systems include carport, BIPV, floating and pole mount.

What is a PV mounting structure?

A PV mounting structure holds solar panels at a set angle and keeps them in place in wind and snow. It can be a frame, rails, a foundation or a float. Roof systems fix to the building. Ground systems fix to the earth. Floating systems sit on water.

Which solar mounting system is best for a home?

For a sloped roof, a rail system or a rail-less system is the usual route. For a flat roof, ballasted or tilt-up frames avoid drilling, but the roof must carry the weight. Ask a structural engineer to check the roof first.

Are solar trackers worth the cost?

For large US ground projects, LBNL reports that 99% of new capacity in 2024 used single-axis trackers. It also reports that tracking adds about 5 percentage points to median capacity factor on average. For homes and most rooftops, trackers do not apply. Check your own site before you decide.

How do you choose between roof mount and ground mount solar?

Choose roof mount when the roof is strong enough and has enough unshaded space. Choose ground mount when the roof is not suitable or you need a larger system. Choose it also when you want to pick the best tilt and direction. Ground mount needs land and a foundation.