Solar Array Thermal Inspection

A failing solar module rarely announces itself in the SCADA dashboard. The string still produces power; the array still hits its number; the underperforming panel just sits there, silently dragging yield down. A drone-mounted radiometric thermal camera finds those panels in hours instead of months: flying a planned grid over the array and surfacing every bypass-diode failure, cell crack, soiling pattern, hot junction, and string-level disconnect as a distinct thermal signature.

What an array inspection actually produces

• Thermal orthomosaic of the array stitched into a single georeferenced map you can scroll, zoom, and click through.
• Per-module anomaly list with GPS coordinates and array address (combiner / inverter / string / module) so your O&M crew knows exactly which panel to look at.
• Classification by defect type and severity: bypass-diode failure, single-cell anomaly, multi-cell anomaly, junction-box heating, string disconnect, soiling pattern, shading.
• Visible-light comparison imagery paired with every thermal frame: thermographer’s job gets easier when the same panel is shown in both spectra.
• Summary report tied to your inverter and string IDs so the findings drop into your existing asset-management platform.

The conditions a valid thermal scan requires

Thermography only works when there’s enough sun loading the modules. Most O&M contracts cite an irradiance floor at or above 600 W/m²: below that, the temperature contrast between a healthy and a failing module is too low to reliably classify. We measure irradiance on site at the start of the flight, and we don’t fly through cloud-cover windows that drop the reading below threshold. If a weather window closes mid-flight, we stop and re-fly. The deliverable’s value depends on this discipline.

Hardware and standards

We fly radiometric thermal sensors at 640×512 resolution or higher with a paired visible-light camera for context. Higher sensor resolution pushes the small-defect detection limit further out: useful on utility-scale arrays where a single failing cell is the size of a fingernail at altitude. Reporting is structured to align with the IEC TS 62446-3 guideline that most O&M contracts reference for PV plant thermography: we confirm your contract’s specific version on the kickoff call so the deliverable matches what your asset team expects.

The questions buyers ask first

• Irradiance and weather windows? ≥600 W/m² is the working floor. Clear or thin-overcast sky preferred. We schedule against your local solar window and re-fly if conditions drop mid-mission.
• What classification scheme do you use? Standard categories: bypass-diode, single-cell, multi-cell, junction-box heating, string-level, soiling, shading. We map each to your contract’s defined categories during scoping.
• How often should we re-inspect? Most O&M cadences run annually for utility-scale, with optional mid-year flights after lightning events or major weather. Smaller commercial/industrial arrays often go on a 12-24 month cycle.
• Will the deliverable integrate with our asset-management platform? Inverter and string IDs are the join key: we name findings against your IDs so ingest is straightforward.
• Who interprets the imagery? Anomaly identification is reviewed by a thermographer; severity and recommended-action calls map to your contract’s defined response thresholds.

Who buys solar thermal inspections

Solar EPCs (commissioning scans pre-acceptance), independent power producers and utility owners (annual yield-protection scans), O&M providers (routine and post-event inspections), and commercial/industrial solar asset owners with rooftop or carport arrays large enough that a manual IV-curve sweep isn’t cost-effective.

How it’s priced

• Per-megawatt for utility-scale arrays: the dominant model
• Per-acre for smaller arrays where AC capacity isn’t the cleanest unit
• Mobilization fee for travel and any required after-hours / pre-dawn arrival
• Fixed report fee covers the thermographer review, classification, and deliverable formatting
• Portfolio programs covering multiple sites are quoted annually with a per-site rate that drops with portfolio size