How many solar watts do I need?
Panel wattage decides how fast a power station refills from the sun. You don’t need a perfect number, just a sensible range. Three inputs get you there.
1. How much do you want to refill?
Start with your station’s capacity in watt-hours (Wh), or with what you actually use in a day. A 1,024Wh station that you run down to empty needs about 1,024Wh back.
2. How many peak sun hours do you get?
“Peak sun hours” is the number of hours a day that sunlight is roughly equivalent to full midday sun. It varies by location, season and weather; in much of the US it’s commonly somewhere around 3 to 5 hours, lower in winter and on cloudy days. Your local figure is what matters.
3. Allow for real-world losses
Panels rarely deliver their rated watts outdoors. Heat, angle, haze, dust, cable and charging losses all take a cut. A cautious planning figure is about 75% of the label. Partial shade can cut output far more.
The rule of thumb
Panel watts ≈ Wh to refill ÷ (peak sun hours × 0.75)
Example: refilling a 1,024Wh station with 5 peak sun hours → 1,024 ÷ (5 × 0.75) ≈ 273W of panels. With only 3 sun hours, it’s about 455W.
| Wh to refill in one day | 3 sun hours | 4 sun hours | 5 sun hours |
|---|---|---|---|
| 256 Wh | 114 W | 85 W | 68 W |
| 500 Wh | 222 W | 167 W | 133 W |
| 1,024 Wh | 455 W | 341 W | 273 W |
| 1,548 Wh | 688 W | 516 W | 413 W |
| 2,048 Wh | 910 W | 683 W | 546 W |
4. Check the station’s solar-input limit
A station only accepts so many solar watts. Extra panel capacity above that limit is wasted at midday (though it can help on cloudy days or at low sun angles, as long as the voltage stays in range). Examples from official specs: GEYOTO N300 takes up to 140W, GEYOTO N1000 up to 800W, VTOMAN FlashSpeed 1000 up to 300W, Goal Zero Yeti 500 up to 200W, Goal Zero Yeti 1500 up to 900W combined, BLUETTI AC180 up to 500W.
5. Weigh portability
Bigger panels are heavier and need more ground space. GEYOTO’s S100 weighs 8.38 lb and its S200 14.99 lb; VTOMAN’s 400W panel weighs 38 lb. If you carry gear any distance, two smaller panels can be easier than one big one, provided your station’s voltage and connector allow it (see our compatibility guide).
General guidance, not professional electrical advice. Always follow your power station’s and panel’s manuals. Specs quoted here come from the brands’ official product pages, checked Oct 16, 2026.