Hey everyone,
I wanted to share a tool I built for the ArduPilot community — a Solar-Powered UAV Endurance Calculator, designed specifically for engineers and hobbyists working on solar UAV platforms with ArduPlane.
As someone working in UAV integration and systems engineering, I kept running into the same problem: there was no quick, accessible way to determine whether a solar UAV configuration could sustain flight indefinitely, or how long the battery reserve would last when solar input wasn’t enough.
So I built one.
GitHub: What it does:
The calculator answers the core question every solar UAV designer needs to answer:
Is solar energy input ≥ total power consumption?
Solar geometry engine — computes real sun position for any latitude, month, and time of day using declination angle, hour angle, and solar elevation angle (no external API — all pure math)
Solar cell presets — SunPower Maxeon, Alta Devices GaAs, MiaSole CIGS Flexible, SolarWorld Mono and more — one click loads all datasheet values
Full power budget — propulsion, avionics, flight controller, payload, telemetry/C2 radio
Battery system modelling — capacity, chemistry (LiPo/Li-Ion/LiFePO4), minimum SOC reserve, charge efficiency
MPPT efficiency and temperature coefficient correction applied to solar output
Altitude correction — solar irradiance increases above sea level (relevant for HALE platforms)
Solar Power vs Time of Day chart — shows surplus zone where P_solar > P_total with a red threshold line
Power breakdown bar chart — visualises propulsion vs avionics vs solar generated
Season comparison — plots June vs December on the same chart for worst-case winter analysis
Cloud cover survival calculator — input cloud duration, get battery SOC remaining
PDF report export — full results with all inputs and verdict
Verdict system:
SUSTAINABLE — solar covers 100% of consumption
MARGINAL — positive balance but less than 15% headroom- BATTERY ASSISTED — deficit but endurance > 4 hours
INSUFFICIENT — deficit and endurance < 4 hours
Who it is for:
This tool is particularly useful if you are:
- Designing a solar-assisted ArduPlane build and want to know minimum panel area before you buy cells
- Planning a long-endurance surveillance or relay mission and need to check power balance at your location and season
- Sizing a battery pack to survive cloud cover or a night segment
- Comparing solar cell types (GaAs vs CIGS vs monocrystalline) for a given wing area
How to use it:
Fully browser-based — no installation, no server, no dependencies. Download the HTML file from GitHub and open it in any browser. Works offline.
Validation reference points:
At Latitude 0° (equator), June, 12:00 noon, clear sky, sea level:
→ Solar irradiance ≈ 1060 W/m²
→ With 22% efficiency, 2.5 m² panel, 93% MPPT → P_solar ≈ 542 W
Real-world reference included in the tool:
| Aircraft | Endurance |
|---|---|
| Airbus Zephyr S | 64 days (world record) |
| AeroVironment Puma AE Solar | 9 hours |
| Silent Falcon | 12+ hours |
I would really appreciate feedback from anyone flying solar-assisted ArduPlane builds — especially if you can compare the calculator output against your actual measured flight data. That would be the best real-world validation.
If you find any bugs or want a feature added, please open an issue on GitHub or reply here.
Built using vibe coding with Claude (Anthropic) — iteratively designed, debugged, and validated through AI-assisted engineering.
Results are indicative engineering estimates only. Always validate with actual solar measurements and ground testing before flight operations.
Thanks!
Nagasurya