Solar carports on ground screws — foundations in parking lots without demolition

A solar carport is a parking space canopy made of photovoltaic panels, whose supporting structure is anchored into a reinforced surface—asphalt, paving, or garage concrete. Ground screws allow the foundation to be installed directly through the asphalt layer into the subgrade within a single night, without tearing up the surface and without multi-day parking lot closures.

Specifics of carport installation

Carport projects differ from greenfield installations (PV systems, timber structures) in several key aspects that influence both the choice of machinery and the work procedure.

Work on the paved area. The screw must drill through the asphalt or concrete surface and anchor into the underlying layers and the soil beneath it. This requires a higher torque than driving into loose soil and often a DTH pilot hole through the hardest layer.

Confined space. Parking spaces and aisles between rows are narrow — the machine must fit between pillars, curbs, and existing street furniture. The width of the machine is therefore a key selection parameter.

Time pressure. Parking lots of hotels, supermarkets, or office parks cannot be closed for weeks. The implementation typically takes place in sectors or at night so that parking is fully functional again by morning.

Noise and traffic near vehicles. The installation takes place in close proximity to parked (and potentially passing) vehicles — it requires temporary signage, clearing the sector, and coordination with the parking lot operator.

Higher wind load on the structure. A carport is an elevated structure with a large surface area exposed to the wind (unlike a low PV mount on the ground) — the foundation must account for higher uplift and lateral loads.

Why ground screws for solar carports

No demolition, no rubble removal. The screw-in machine drills through asphalt or paving stones at the anchor point — eliminating the need for extensive excavation or subsequent restoration of a large surface area.

Overnight installation. Ground screws can be loaded immediately after installation. The parking lot section can be closed in the evening and reopened in the morning — with a concrete foundation, the same section would be out of service for weeks due to curing.

Exact load capacity documentation. The telematics unit records the time and depth of each screw—providing data for the structural engineer and the parking lot operator, who is responsible for the safety of the structure above the vehicles.

Reversibility. For rented parking areas (retail parks, hotel complexes), the carport can be removed after the end of the contract without permanent intervention in the surface.

Recommended machine for solar carports

For carport projects, we recommend two models depending on the surface type and project scope:

Glentor B80 — the primary choice for commercial carports on asphalt. The 8,000 Nm torque handles drilling through both the asphalt surface and the compacted sub-base layer, while remote control enables operation in close proximity to vehicles without requiring an operator on the machine.

Glentor A70 — suitable for smaller projects (hospitality, glamping, individual shelters) where a lower torque is sufficient and low weight (1,700 kg) and compact dimensions for entering confined areas are key.

Glentor C65 — an optional choice for concrete parking garage floors, where the combination of drilling and the MTB36 hydraulic hammer (900 J) can handle a harder concrete overlay that the B80 could not penetrate without pre-drilling.

Carport installation guide — step by step

  1. Project preparation. The structural engineer will design the layout of the screws according to the carport's load-bearing structure, and will supplement this with a survey of the road structure composition (asphalt thickness, base layers) at the locations of the future points.
  2. Setting out and coordination with parking lot operations. A surveyor will stake out the positions of the screw anchors, the operator will provide temporary marking and clear the sector — work is usually scheduled for nighttime hours or outside operating hours.
  3. Drilling through the hardened layer. The machine will drill through the asphalt or concrete surface at the location of each point, using DTH pre-drilling in case of a harder subgrade.
  4. Driving of the screw with telemetry recording. The screw drills into the underlying layers and soil to the prescribed depth, and the torque and depth are recorded for each point.
  5. Surface preparation around the screw and handover for the structure installation. Instead of drilling, it is cleaned up (grouting around the screw, or local asphalt repair), the sector can be reopened to traffic in the morning — the installation of the supporting steel structure and panels then takes place without disrupting the operation of the rest of the parking lot.

Comparison of Glentor models for carport projects

CriterionA70B80C65
Torque7,000 Nm8,000 Nm6,500 Nm
Weight1,700 kg2,480 kg3,050 kg - 3,250 kg
Hydraulic hammer❌ No❌ No✅ 900 J
Controls—Remote—
Suitable forSmaller shelters, hospitalityCommercial parking lot, asphaltConcrete garage floors

B80 is the best choice if:

  • The project is a commercial carport on asphalt or a compacted surface (hotel, supermarket, office park)
  • A higher torque is required to drill through the hardened layer
  • A remote control is required for working near vehicles

Case study: Carport at a hotel resort

The hotel resort operator planned to cover part of the parking lot (approximately 250 spaces) with solar panels without the need to shut down the parking lot for an extended period—guests needed continuous access to their vehicles.

The implementation team divided the area into sectors of approximately 30 to 40 parking spaces. Each sector was closed for the night, the B80 machine drilled through the asphalt surface and screwed in the ground screws according to the project, and in the morning the sector was reopened to traffic. The telemetry record of each screw served as a basis for the structural engineer and for the insurance of the structure above the parking spaces.

The entire foundation for 250 parking spaces was completed within a matter of weeks, but without a single day of the parking lot being completely closed — work took place exclusively by sectors during nighttime hours.

TCO: carport without screws vs. with screws

CriterionConcrete foundationGround screws
Extent of surface interventionExcavation and concreting over the entire foundation areaDrilling at a single point location
Parking closure timeWeeks (incl. concrete curing)Sectors by night
Debris removal and surface remediationExtensiveMinimal (local watering)
Weather dependencyHighLow
Reversibility after lease terminationLimitedHigh

Frequently Asked Questions

Where to continue

Technical and normative requirements for foundation work through asphalt and paving: Foundation on paved areas

Carports often complement larger PV projects: Solar parks on ground screws