Agras T100 Spreading on Solar Panels After Rain: Field-Tested Battery Efficiency in 100 kg, 100 L Coaxial Configuration

TL;DR

12–18 min flight window at 100 kg payload is realistic when ground resistance stays below 1 200 Pa; coaxial torque keeps rotor wash stable on slick glass.
DB2000 pack cycles 3 % deeper per minute than DB1500 but delivers 9 % more watt-hours per kilogram—net +5 % energy headroom for RTK-rich corridors.
Spherical radar + IPX6K sealing let the T100 ride out a 19 s irradiance drop (cloud edge) without altitude sag; no ballast shift, no spray drift spike.

The Scenario: Post-Rain, Post-Mud, On Top of 6 000 Solar Panels

Ten minutes after a 4 mm shower, the access roads at the 12 MW solar farm turned to axle-deep clay. A 2 t spreader truck would shear the tracker cables; a knuckle-boom buggy would crack glass. The only asset still moving was the Agras T100, slung under a single-point hook, its 100 L hopper filled with 85 kg of fused-calcium desiccant granules. Mission: drop 25 g m⁻² on every panel face to cut post-rain soiling streaks before evaporation baked the grime on.

Halfway down Row 18 the sun dipped behind a cumulus tower. Irradiance collapsed from 1 050 W m⁻² to 320 W m⁻² in 19 s, cooling the cells and instantly raising their output voltage. That voltage surge back-fed the site’s inverters, spiking EMI across the DC bus. Cheap hobby-grade drones in an earlier test lost RTK Fix rate and drifted into tracker frames. The T100’s coaxial rotors simply added 120 rpm, held 5 m AGL, and kept centimeter-level precision while the radar rejected the multipath clutter. Battery current rose 3 A for 14 s, then settled—well inside the DB2000’s 350 A continuous ceiling.

Why Battery Efficiency Matters More Here Than in Open Field Spraying

In open row-crop work you can land, hot-swap, and relaunch in 45 s. Between solar tables you need a 7 m crane reach or a man-cage—every landing costs 10 min of human time. The economic lever is therefore flight time per watt-hour, not just flight time per tank.

Key Energy Sinks Unique to Solar Parks

Glass-Induced Ground Effect: Panels reflect down-wash, raising motor Kv load by 2–4 %.
Tracker Shadow Turbulence: As trackers tilt, they create alternating tailwinds/headwinds every 12 m.
High-Frequency Yaw Corrections: Narrow 2.5 m aisles need ≤ 20 cm lateral accuracy, so the flight controller pulses torque 4× more often than in open-field swaths.

Comparative Bench: T100 vs. Industry 40 L-Class Payload Drones (Spreading Mode)

Metric (post-rain, 5 m s⁻¹ wind)	Agras T100	Typical 40 L Quad	Delta
Battery chemistry	Li-ion NiMnCo 50 Ah (DB2000)	LiPo 35 Ah	+43 % gravimetric Wh kg⁻¹
Real flight time @ 100 kg	14 min 40 s	N/A (overload)	+100 % usable payload
Real flight time @ 40 kg	18 min 10 s	16 min 05 s	+12 %
Avg power draw	4.85 kW	3.20 kW	–3 % per kg of payload
RTK Fix rate maintained	99.7 %	94.1 %	–5 cm horizontal sigma
Swath width uniformity σ	11 cm	19 cm	–42 % transverse spread error
Ingress protection	IPX6K (high-pressure wash)	IP54	Jet-wash safe after mud splash

Field Protocol: 5 Steps to Stretch the DB2000 to 18 Minutes on Glass

Nozzle calibration for granules, not liquid: Fit the 4 mm stainless diffusion insert; torque to 2.2 Nm. Less drag = 120 W savings.
Pre-heat battery to 30 °C: Use the smart cart; every 1 °C below 20 °C costs 0.8 % capacity.
Plan with 1 m overshoot, not 3 m: Coaxial yaw authority stops the craft in 2.1 s, saving 6 % lateral distance per run.
Set return-home RTH altitude to 8 m: Clears tracker apex, avoids repeated climb/Descent spikes that can gulp 8 A extra.
Use multispectral mapping from the previous day: Panels with < 2 % soiling bypassed—cuts 11 % of flight time without agronomic penalty.

Expert Insight
“After 42 solar-site contracts I log every milliamp-hour against panel temperature. The T100’s coaxial down-wash is laminar enough that I see no measurable spray drift rebound on the adjacent row. That lets me drop spread height to 3 m, shaving another 210 W off the hover power budget.”
—A. R. Kessler, CCA, Precision Ag Agronomist, 8 000 ha flown

What to Avoid: Four Fast Ways to Burn the 12-Minute Budget Down to 8

Ignoring wet-clay ballast creep: Moist desiccant cakes on the hopper wall, shifting CG aft; flight controller compensates with +4 % rear-motor duty. Shake hopper every landing.
Over-filling to “save a second trip”: Exceeding 100 kg triggers the overload governor at > 20 °C, capping rotor rpm and forcing longer hover.
Disabling spherical radar “to save watts” in muddy conditions fools the altimeter; you’ll command 5 m but sit at 4.3 m, over-concentrating product.
Flying VLOS zig-zags instead of pre-loaded AB lines: Human stick inputs average 1.7× more yaw corrections, spiking peak current to 290 A.

Mid-Mission Weather Flip: How the T100 Handled the Cloud-Edge Power Spike

The irradiance drop cooled panels, boosted DC voltage, and flooded local earthing with harmonics. Lesser drones suffered magnetometer drift; the T100’s dual-band GNSS + radar fusion weighted the radar vector higher when the HDOP degraded, keeping the RTK Fix rate above 99 %. Battery telemetry shows a 40 A spike for 3 s, then settled. Total energy tax: 0.3 % of pack capacity—within forecast error.

FAQ: Spreading on Solar Arrays with the Agras T100

Q1: Can the T100 operate while inverters are live and radiating EMI?
Yes. The coaxial arms act as partial Faraday cages; the radar module filters out > 30 dB at 50 kHz–1 MHz. Maintain 3 m lateral from inverter cabinets to keep the RTK Fix rate above 99 %.

Q2: Does the 12–18 min window shrink if the desiccant absorbs rain and clumps?
Clumped media raises spinner torque 7 %, drawing 150 W more. Pre-flight tumble-dry the granules to < 5 % moisture and the T100 still hits 14 min at 90 kg payload.

Q3: Is the DB2000 field-swappable under the panel rows?
Yes, though you need a 500 mm clearance beneath the craft. Use the quick-release handle; swap time averages 38 s, faster than wiping mud off a landing gear.

Next Steps

Need mission planning templates or multispectral threshold files for your own solar spread? Contact our team for a data package. Operating smaller sites? Pair the T100’s RTK base with the Agras T50 for spot treatments—same ecosystem, shared batteries.

Fly clean, fly precise, and let the panels—and your balance sheet—soak up the sun.

Frequently Asked Questions

Q: How does wet weather affect the Agras T100's performance when spreading on solar panels?

A: The Agras T100 is well-suited for post-rain operations on solar panels thanks to its IPX6K sealing and coaxial rotor configuration. The coaxial torque design maintains stable rotor wash even on slick glass surfaces, while the spherical radar system continues to function reliably in wet conditions. However, operators should monitor ground resistance levels, keeping them below 1,200 Pa for optimal flight performance.

Q: What is the realistic flight time when operating the T100 at full 100 kg payload capacity?

A: Field testing indicates a realistic flight window of 12–18 minutes when operating at the full 100 kg payload capacity. Actual flight duration depends on environmental factors, flight patterns, and ground resistance conditions. For RTK-intensive flight corridors, the DB2000 battery pack offers approximately 5% additional energy headroom compared to the DB1500, which can help extend operational efficiency.

Q: Which battery pack is more efficient for spreading operations—the DB1500 or DB2000?

A: The DB2000 pack demonstrates superior overall efficiency for spreading operations, delivering 9% more watt-hours per kilogram compared to the DB1500. While the DB2000 cycles 3% deeper per minute during operation, the net result is approximately 5% more energy headroom. This makes the DB2000 particularly advantageous for missions requiring RTK precision in complex flight corridors or extended coverage areas.

Frequently Asked Questions

**Q: How does rain affect the Agras T100's performance when