Solar — DRONA

By array scale

Your array size determines the airframe.

The single most important decision in solar inspection is picking the right form factor for your array scale. The chat asks one question — approximate kW or MW — and makes the call.

Residential

< 50 kW

Single rooftop or small commercial. One-off inspection. 15-min mission. Close-range framing around building edges and vents.

MR quad 5–7" · thermal + RGB

Commercial rooftop

50 kW – 5 MW

Warehouse, mall, industrial. Grid overlap, radiometric defect detection. Wind-tolerant airframe with 25-min mission.

MR hex · radiometric thermal + RGB

Commercial ground-mount

5 MW – 30 MW

Multi-row fixed tilt. Long linear runs; MR hex or fixed-wing both work. Usually scheduled semi-annually.

MR hex · FW · thermal + RGB

Utility-scale

> 30 MW

Hundreds of acres, fixed or single-axis tracker. Fixed-wing throughput required. 90-min missions, PPK optional.

Fixed-wing · mapping thermal + RGB

End-to-end workflow

Chat to orthomosaic in one afternoon.

DRONA designs the airframe and the mission in one conversation. The operator flies. Post-processing plugs into the workflow you already have — DJI TSA, DroneDeploy, Pix4D, WebODM, or a proprietary O&M ticketing system.

Describe

"Inspect my 2 MW commercial rooftop thermally."

Design

MR hex · radiometric thermal · L2–L3 autonomy · 12 compat rules pass

Plan

Mission plan · 3 m lanes · 4 m/s · 80% overlap · exported .plan

Fly

Your operator flies the plan. 25-min mission. ≈ 2.1 GB of radiometric imagery.

Action

Orthomosaic + defect list → your O&M ticketing. 3–14 defects flagged typical.

Mission library

Ten solar missions. Each a chat-ready template.

Utility-scale farm thermal inspection

SOL-01

Fixed-wing or MR hex depending on scale. Radiometric thermal at 640×512 or better. Typical cadence: quarterly.

formFW or MR hexsensorFLIR Vue TZ20 · DJI H20T altflight90 min FW · 25 min MR

L3utility

Residential rooftop defect scan

SOL-02

Single-home inspection for installers and homeowners. Focus on hot-cell detection and bypass-diode failures. Close-range framing.

formMR quad 5"sensorradiometric thermal + RGBflight15 min

L2–3

Commercial rooftop (warehouse, mall)

SOL-03

Mid-scale rooftop with grid-overlap mission. Large stable airframe for wind tolerance on exposed rooftops.

formMR hexsensorradiometric thermal + RGBflight25 min

Pre-install site survey

SOL-04

Pre-construction shading, topography, and obstruction analysis. RGB + optional LiDAR. Feeds into your PV design tool (Helioscope, Aurora Solar).

formMR hex · FWsensorRGB + LiDAR opt.flight25–60 min

Post-install commissioning (IV-curve proxy)

SOL-05

Close-range thermal to validate IV-curve-implied defects found during commissioning. Spot-check the panels the installer flagged.

formMR hexsensorradiometric thermalflight25 min

Tracker-alignment check

SOL-06

Single-axis or dual-axis tracker alignment verification via angle-reference framing. RGB only. Short targeted passes over suspect rows.

formMR quadsensor20 MP RGBflight15 min

Vegetation encroachment

SOL-07

Periphery pass looking for tree growth into the array's sun aperture. Scheduled annually or seasonally. RGB + NDVI.

formFixed-wingsensorRGB + NDVIflight60 min

Post-storm damage assessment

SOL-08

Rapid triage after hail, wind, hurricane, or ice event. RGB + thermal. Same-day operations expected; pack-and-fly ready.

formMR hexsensorRGB + thermalflight25 min

L2event

Storage-yard inventory

SOL-09

BESS yard or panel-storage yard inventory check. Asset count, container thermal check, serial-number OCR (optional).

formMR quadsensorRGBflight15 min

Floating solar

SOL-10

Reservoir or lake floating arrays. Over-water ops require IP54+ airframe and water-rated emergency recovery. Thermal + RGB.

formMR quad IP54sensorthermal + RGBflight20 min

L3over-water

The math that matters

Grid overlap, ground-sample distance, thermal precision.

Solar inspection has three parameters the user must not get wrong: ground-sample distance (how small a defect you can see), overlap (how much orthomosaic stitching costs you), and radiometric precision (whether a 2°C hot-cell is reliably distinguishable from a 1°C anomaly). DRONA computes all three and stops the design if any is out of spec for the target mission.

Ground-sample distance. For a sensor with pixel pitch p (µm), focal length f (mm), and altitude h (m): GSD = h × p / f × 10⁻³ cm/px. Typical target for solar defect detection: GSD ≤ 3 cm/px. At 30 m AGL with a 9 mm lens and a 17 µm thermal sensor, GSD ≈ 5.7 cm/px — too coarse; drop to 15 m AGL for 2.8 cm/px.

Overlap. For reliable orthomosaic stitching in thermal imagery (which has fewer features than RGB): overlap ≥ 80% front and side. At 4 m/s ground speed with a 640×512 thermal sensor, 30 m AGL, 20 Hz capture, overlap computes to 87% — passing.

Radiometric precision. A cell-level defect typically produces a ΔT ≈ 5°C against ambient module temperature. A sensor with noise-equivalent temperature difference NETD ≤ 50 mK will resolve this with high signal-to-noise. Cheaper uncooled sensors at NETD 100 mK often do fine; industrial-grade sensors (FLIR TZ20, Workswell WIRIS Pro) go well below 40 mK.

Economics

Why in-house solar inspection pays back in under one season.

The numbers below model Raj's use case — 2 MW commercial rooftop, currently contracting out twice a year to an IEC-62446-3 inspection firm. The model assumes no new headcount; Raj or a junior facilities tech flies after a one-afternoon training.

2 MW rooftop · Phoenix, AZ · annual cost model

external contract · 2×/yr thermal audit−$16,400

in-house drone build (one-time)−$4,920

thermal camera (FLIR Vue TZ20)−$9,500

operator training (1 afternoon)−$400

Part 107 remote pilot cert (existing)$0

ongoing maintenance · year 1−$300

in-house inspection · unlimited cadence+$16,400/yr

Year-1 net+$1,280

Year-2+ annual+$16,100

Unit economics assume one array. At three sites, break-even is week six. The larger benefit is inspection cadence: monthly thermal spot-checks are trivial once the drone is yours, and a defect caught in January rather than July is roughly 5× more valuable in avoided yield loss.

Compatibility envelope

Solar-specific rules the engine enforces.

In addition to the 12 universal rules, solar designs run against the predicates below. Errors block export; warnings surface with a plain-English fix.

Rule	What it checks	Severity
thermal-resolution	Sensor resolution ≥ 320×256 for residential, ≥ 640×512 for commercial, ≥ 640×512 radiometric for utility.	error
netd-target	Noise-equivalent temperature difference ≤ 50 mK for commercial and utility missions; ≤ 100 mK for residential.	warn
gsd-target	Computed ground-sample distance ≤ 3 cm/px given altitude, focal length, pixel pitch. Required for defect detection.	error
overlap-budget	Front + side overlap ≥ 80% at target ground speed and capture rate; warns at 70%.	warn
wind-envelope-rooftop	Rooftop missions above 30 m AGL → airframe wind tolerance ≥ 25 km/h.	warn
shade-launch-clearance	No launch within 3 m of an active array edge (EMF safety + array damage risk from debris).	warn
floating-solar-ip	Floating-solar mission → IP54 or better, propellers not prone to water spray ingress.	error
tracker-angle-hazard	Tracker-alignment mission requires configurable tracker-safe altitude to avoid mirror glare into sensor.	warn
commissioning-evidence-log	Commissioning missions attach a cryptographic evidence chain to each defect (required for IEC 62446-3 audit.)	info

Solar inspection, designed for your array size.