On utility-scale solar projects, pile acceptance documentation is the gate between pile driving and racking installation. The EPC contractor will not release the racking crew to begin installation until pile elevation data for the block has been reviewed and accepted. Getting the documentation workflow right — from GPS setup through block sign-off — keeps the racking crew moving and avoids the idle-crew costs that eat project margins.
What documentation is required for solar pile inspection and EPC acceptance?
Solar pile inspection documentation for EPC acceptance requires: GPS setup documentation (base station or network RTK configuration, occupation time, accuracy verification); per-pile records (pile ID, design elevation, measured elevation, deviation, and horizontal offset from design position); block-level pass/fail summary with pass rate calculation; out-of-tolerance pile list with remediation records; and EPC engineer sign-off on the block acceptance form before racking installation begins. Typical tolerance is ±0.02 ft vertical and ±1 inch horizontal from the IFC pile schedule.
Pile elevation tolerances on solar farm projects are set by the racking manufacturer and incorporated into the EPC contract. The tolerance varies by racking system because different tracker designs have different sensitivity to pile height variation:
| Tolerance Type | Typical Range | Impact of Exceedance |
|---|---|---|
| Vertical elevation | ±0.02 ft (±0.24 in) | Out-of-tolerance piles require extension or shortening before racking |
| Horizontal position (row direction) | ±1 in from design centerline | Affects module string alignment and cable management |
| Horizontal position (tracker axis) | ±0.5 in from design on tracker axis | Direct impact on tracker rotation clearance |
| Plumb | ≤0.5 degrees from vertical | Out-of-plumb piles affect torque tube seating and tracker rotation |
| Relative elevation (adjacent piles) | ±0.02 ft between any two adjacent piles | Controls module tilt and tracker mechanical stress |
Use the Pile Elevation Checker to compare your measured pile top elevations to the IFC design elevation and flag any pile outside the tolerance window before generating your block report.
The accuracy of the pile elevation survey depends entirely on the GPS setup. Required documentation:
Each pile in the block requires an individual data record. Required per-pile data:
Unique pile identifier matching the IFC pile schedule — typically row number and pile number within the row (e.g., Row 47, Pile 3 = 47-03).
Elevation from the IFC pile schedule for this pile ID. Must be pulled from the current IFC revision — using a superseded revision is a common source of errors.
GPS-measured elevation at the top center of the pile. This is the actual field elevation.
Measured minus design elevation. Positive = pile is high; negative = pile is low. Flag if absolute value exceeds vertical tolerance.
Distance from the measured pile center position to the design center position. Report in both the tracker axis direction and the row direction.
Clear pass or fail determination for each pile based on vertical and horizontal tolerance criteria.
The block sign-off form summarizes the block-level results: total piles surveyed, piles passing, piles failing, pass rate, and disposition of out-of-tolerance piles (remediated or pending). The EPC engineer signs the block acceptance form when the pass criteria are met and remediated piles are re-surveyed and confirmed within tolerance.
Out-of-tolerance piles must be documented both before and after remediation. Do not delete or overwrite the original out-of-tolerance measurement — the original data is part of the project record.
Required remediation documentation:
Sitemark's solar pile verification platform tracks per-pile elevation data, generates block pass/fail reports, and produces the EPC acceptance package — keeping racking crews moving and eliminating documentation delays.
Start Free Trial →GPS rovers and RTK equipment for utility-scale solar pile elevation verification.
Shop at Express Tools →Required documentation includes GPS setup and accuracy verification records, per-pile records (design elevation, measured elevation, deviation, pass/fail), block-level summary with pass rate, out-of-tolerance pile list with remediation records and post-remediation survey data, and EPC engineer block acceptance sign-off. Racking installation cannot begin until the block acceptance form is signed.
Typical EPC contracts specify ±0.02 ft (±0.24 in) vertical tolerance and ±1 inch horizontal tolerance for driven piles. Tolerances vary by racking manufacturer — check the IFC documents for the project-specific requirement before beginning the pile inspection program.
In some cases, EPCs will issue a written waiver accepting specific piles slightly outside tolerance after engineering review confirming the deviation does not affect racking installation or tracker performance. The waiver must be in writing from the EPC engineer, reference the specific pile IDs, and be retained in the project record. Never remediate or accept out-of-tolerance piles verbally.