Solar PV inspection

Thermal pass over a utility-scale ground-mount solar array

thermal pass · 30–40 m AGL · 9.3 MWp ground-mount

§ 01 · Solar PV

Thermographic survey of crystalline-silicon arrays. Two-pass capture: nadir thermal at 30–40 m AGL for anomaly mapping, oblique RGB for context and module-ID confirmation. Anomalies classified by ΔT against ambient and string-baseline, severity-ranked S1–S4, returned as GeoJSON tied to module geometry.

Standard reference: IEC TS 62446-3 for thermography, IEC 61724-1 for environmental conditions during the flight window.

Open Cat A3 ≤ 5 MWp · single-day String-level resolution

Solar inspection procedure

How a flight runs, end to end.

Compliant with IEC TS 62446-3 (outdoor IR thermography of PV) and IEC 61724-1 (PV performance monitoring). EU 2019/947 Open Category A1/A3. GDPR-compliant data handling — site imagery stored encrypted, deleted on client request.

01 Pre-flight planning remote · 1–3 days before ▸

Site briefing call — plant layout, MW, string/inverter map, access, on-site contact.
Review of prior reports and current performance-ratio anomalies, if available.
Flight window scheduled for clear-sky conditions, irradiance ≥ 600 W/m² (IEC TS 62446-3 minimum).
NOTAM / airspace clearance filed with Slovenia CAA (or competent authority for IT, ES, SI, AT or HR).
Operator registration, A1/A3 certificate, €1M liability and hull cover verified for the flight date.
Pre-flight checklist sent to client: gate access, livestock notice, inverter status, on-site duration.

02 On-site setup 30–45 min ▸

Site walk with plant contact; confirmation that all strings are energised and inverters operational.
Irradiance measurement with calibrated pyranometer / reference cell — logged for the report.
Ambient temperature, wind speed, cloud cover recorded.
Mission upload: automated grid pattern, ~30–40 m AGL, nadir orientation, 80% front / 70% side overlap.
Safety perimeter established; ground crew briefed.

03 Aerial thermal + RGB capture 1-2 hours / 5 MW ▸

DJI Mavic 3 Thermal — radiometric thermal (640×512, ±2 °C) + 4/3 CMOS RGB, synchronised capture.
Automated mission with manual override available.
Live anomaly check on a second screen; obvious hotspots flagged for a low-altitude verification pass.
Coverage of full array plus combiner boxes, inverter housings, and transformer enclosures where line-of-sight permits.
Battery swaps pre-planned to avoid interrupting a string row mid-capture.

04 Post-processing and analysis 3–5 working days ▸

Radiometric mosaic stitched in DJI Terra / DroneDeploy.
Anomaly classification per IEC TS 62446-3:
- Category 1 — single cell / hotspot (ΔT 5–20 °C)
- Category 2 — multi-cell / substring fault
- Category 3 — full module / bypass diode / disconnected string
- Category 4 — junction box, connector, or interconnect fault
Each defect geo-tagged, photographed (thermal + RGB), and cross-referenced to string ID.
Severity prioritisation: critical (immediate revenue / safety impact), major (within 30 days), minor (next maintenance cycle).
Operator QC pass before report release.

05 Deliverables — ▸

PDF report — executive summary, methodology, weather log, full defect list with images, severity ranking, recommended action.
Interactive web map — clickable defects with thermal + RGB images and GPS coordinates.
CSV / GeoJSON export of all anomalies for CMMS / SCADA integration.
High-resolution orthomosaic (RGB + thermal) on request.
Raw radiometric data available for client archival.

06 Follow-up — ▸

30-minute debrief call to walk through findings and prioritisation.
Optional re-inspection of repaired defects.
Annual or semi-annual cadence available under framework retainer.

Typical timelines

Plant size	On-site	Report delivery
Up to 1 MW	2–3 h	3 working days
1–5 MW	4–8 h	4 working days
5–20 MW	1-2 days	5 working days
20 MW+	2–4 days	7–10 working days

Equipment

Standard plus a named upgrade path.

One aircraft on day one. The upgrade unit isn't on a shelf — it's named so you can see how the operation scales without surprise.

Standard equipment · day-1

DJI Mavic 3 Thermal

Open Cat A3

ClassEU C1 · CE marked
Thermal640 × 512 · ±2 °C · radiometric
RGB4/3 CMOS · synchronised
MTOWSub-1 kg · transponder-equipped
Operator weight classBelow 25 kg, Open A3 compliant

Upgrade path · on request

DJI Matrice 400 · Zenmuse H30T

Specific Cat

ClassSpecific Cat · declaration
ThermalH30T · 1280 × 1024 · radiometric
RGBZoom 34× · wide + tele
MTOWHeavy-lift · dual-payload
Lead timeQuoted per site · 2–3 wk planning

Solar PV inspection. One delivery discipline.