Solar Panel Sizing Calculator
Portable amateur radio stations often rely on solar charging to extend operating time during field deployments, emergency communications, and off-grid operations. This calculator estimates the recommended solar panel size needed to replace the energy consumed during daily operation while accounting for sunlight hours and typical charging system losses.
Actual charging performance varies with weather, season, panel orientation, battery chemistry, and charge controller efficiency.
Typical range: 70–85%. Accounts for charge controller and battery charging losses.
| Station Type | Typical Panel |
|---|---|
| HT Charging | 20 – 40 W |
| QRP Portable | 50 W |
| Mobile Radio | 100 W |
| HF Field Station | 100 – 200 W |
| Emergency Communications | 200 – 400 W |
| Base Camp | 400 W+ |
| Equipment | Approx. Daily Energy |
|---|---|
| HT Charger | 10 – 20 Wh |
| QRP HF Radio | 50 – 120 Wh |
| 100 W HF Radio | 150 – 400 Wh |
| Laptop | 50 – 100 Wh |
| LED Lighting | 20 – 40 Wh |
| Starlink Mini | 250 – 400 Wh |
Values are approximate and vary with equipment settings and operating mode.
- Cloud cover
- Tree shading
- Panel orientation
- High temperatures
- Dirty panels
- Charge controller losses
- Battery charging losses
- Seasonal sunlight variation
- Cable voltage drop
Always size solar systems with reserve capacity. A solar panel that only meets the minimum calculated requirement may perform poorly during cloudy weather or winter conditions.
Selecting the next larger standard panel size generally improves long-term reliability.