Ground-mounted solar panels: when to use them and what they cost

Table of contents

Ground vs roof: when ground mount wins

Rooftop solar is the default choice because it uses existing structure, minimizes ground footprint, and typically costs less to install. But ground mounts are the better option in several situations:

If your roof is south-facing, unshaded, and in good condition, rooftop solar is usually the right call. If any of those conditions don't apply, a ground mount is worth the extra planning.

Types of ground-mount structures

Standard ground mount (fixed tilt)

The most common type. Steel posts are driven or set in concrete footings. Racking rails are attached to the posts, and panels mount on the rails at a fixed angle — typically the latitude of your location for optimal year-round production.

• Pros: Lowest cost, simple, minimal maintenance
• Cons: Fixed angle; not optimized for seasonal variation
• Best for: Residential and small off-grid systems

Pole mount (top-of-pole or side-of-pole)

A single large pole set in concrete supports multiple panels on a rack above it. Popular for small off-grid and cabin installations where a compact footprint matters.

• Pros: Small ground footprint, elevated above snow and vegetation, often easier to manually adjust tilt seasonally
• Cons: Limited to smaller arrays (typically 2–6 panels per pole for residential)
• Best for: Off-grid cabins, remote outbuildings, small systems needing minimal ground space

Single-axis tracker

Motorized system that rotates panels east-to-west throughout the day to follow the sun. Can increase production by 20–35% compared to fixed tilt. However, cost and maintenance requirements make them rare for residential use.

• Pros: Highest production per panel
• Cons: 2–3x higher cost, mechanical parts that can fail, requires level ground
• Best for: Commercial installations, large off-grid systems where maximizing production matters more than minimizing cost

Sizing a ground-mount system

Sizing a ground-mount system uses the same process as any solar array — calculate your daily energy needs, then work backward to panel watts and battery capacity (if off-grid). What's unique to ground mounts is physical space planning.

Space requirements

A standard 400W residential solar panel is approximately 6.7 ft × 3.4 ft (2.05m × 1.04m). When installed at an angle and with recommended row spacing to minimize shading, plan for:

Row spacing is typically 1.5–2× the height of the array (measured at the top edge) to prevent one row from shading the next during winter when sun angles are lower.

Optimal tilt angle

For fixed-tilt ground mounts, the rule of thumb is to set the tilt angle equal to your latitude for year-round optimization. If you want to favor winter production (when sun is lower), add 15°; for summer production, subtract 15°. For most residential and off-grid installations, latitude angle is the practical starting point.

Examples:

• Phoenix AZ (33°N): tilt at ~33°
• Denver CO (40°N): tilt at ~40°
• Seattle WA (47°N): tilt at ~47°
• Miami FL (26°N): tilt at ~26°

Orientation

True south (not magnetic south) is ideal in the northern hemisphere. A ground mount lets you achieve this regardless of how your house faces — a significant advantage over rooftop solar on non-south-facing roofs. Up to 15° east or west of true south has minimal production impact.

Ground-mount cost breakdown

Ground-mounted systems cost more to install than rooftop systems of the same capacity — primarily because of the structural work, concrete, and wiring run to the building. Budget 10–25% more than an equivalent rooftop installation.

Rough total installed cost for a 6 kW ground-mount system: $15,000–$24,000 before incentives.

After the 30% federal Investment Tax Credit (ITC): approximately $10,500–$16,800. State and utility incentives may reduce this further.

For comparison, a 6 kW rooftop system typically costs $12,000–$18,000 installed before incentives.

DIY vs professional installation

Ground mounts are more DIY-accessible than rooftop solar in some ways (no working at height, more control over placement) but add complexity in others (concrete work, longer wire runs, permitting).

What DIYers can reasonably handle

• Purchasing and assembling pre-engineered racking kits (available from IronRidge, Unirac, and similar suppliers)
• Setting posts in concrete (with proper depth for local frost line)
• Mounting panels on the racking structure
• Wiring the array and running conduit to the building

Where professional help is usually necessary

• Electrical panel connection: In most jurisdictions, the final connection to the main panel requires a licensed electrician
• Permitting: Structural engineering stamps may be required for the mounting structure
• Utility interconnection: Grid-tied systems require utility approval and inspection; this process varies by state and utility

Many off-grid DIY installers handle their entire ground-mount systems without a contractor — but if you're planning a grid-tied system, budget for at least electrical inspection and permitting assistance. See our guide to DIY vs professional solar installation for a deeper breakdown.

Permitting and setbacks

Ground-mount solar systems require permits in most US jurisdictions. Requirements vary, but typically include:

• Building permit: Required for the structural installation (posts, concrete, racking)
• Electrical permit: Required for the wiring and any grid connection
• Setbacks: Your array must be set back from property lines. Typical setbacks are 5–10 feet from side and rear property lines. Check your local zoning code; agricultural and rural zones often have more permissive setbacks than residential zones.
• Height limits: Some zones limit structure height. Standard ground mounts peak at 7–10 feet, usually within residential limits.
• HOA rules: If you have an HOA, review solar installation rules. Some HOAs restrict placement to rear yards or require visual screening.

Pull permits before breaking ground. Unpermitted solar installations can complicate home sales and may require costly removal or retrofitting to pass inspection later.

Frequently Asked Questions

Is a ground-mount system more efficient than rooftop?

Potentially yes — because you can set the optimal tilt angle and orientation, rather than being constrained by your roof angle. Ground mounts also typically run cooler than roof-mounted panels (better airflow underneath), and solar panel efficiency decreases slightly at higher temperatures. In practice, a well-sited ground mount may produce 5–15% more energy per panel than a non-optimally oriented rooftop system.

Do I need a concrete foundation for ground-mount solar?

It depends on soil conditions and local wind loads. In most residential installations, posts are either driven into the ground with a post driver (helical piers) or set in poured concrete footings. The depth must extend below the local frost line to prevent frost heaving. In soft or sandy soils, concrete footings are usually required. Pre-engineered racking kits come with engineering specifications that guide footing requirements.

How far can the solar array be from the house?

There's no firm maximum distance, but energy loss in the DC wiring run increases with distance. Long runs require larger gauge wire to stay within acceptable voltage drop (typically less than 2–3%). For most residential situations, keeping the array within 100–200 feet is practical. Beyond 200 feet, the additional wire cost and potential voltage drop calculations become significant. Use a voltage drop calculator for your specific run length and wire gauge.

Can I expand a ground-mount system later?

Yes — this is one of the advantages of ground mounts. You can extend the racking structure and add panels in the future, as long as your inverter capacity supports it or you upgrade the inverter. Plan the physical racking to allow for future expansion from the beginning — it's much easier than retrofitting later.

Does a ground-mount system need to be fenced or protected?

Utility-scale installations are always fenced. For residential, it depends on your situation. If you have children, animals, or livestock, a low fence around the array prevents damage and keeps people away from energized wiring. In rural settings with deer or other wildlife, a fence also prevents animals from rubbing against and damaging the structure. Check your local permitting requirements — some jurisdictions require fencing for ground-mount arrays above a certain size.