How Many Solar Panels Do You Need to Recharge Your Power Station Every Day?
Divide your power station's watt-hour capacity by your location's typical peak sun hours (commonly 4-5 hours as a year-round US average, varying by region and season) and by a real-world efficiency factor (typically 75%) to get the solar wattage needed for a full daily recharge — for a 1,000Wh power station with 5 peak sun hours at 75% efficiency, that works out to roughly 267 watts of solar panels, commonly rounded up to a 300W setup using common panel sizes.
This is the same core calculation used across the solar power station industry, and it's simpler than it first appears once each piece is defined clearly.
Why peak sun hours, not total daylight hours
Peak sun hours measure the equivalent hours per day at full-strength sunlight (1,000 W/m²), which is a far more useful planning figure than total daylight hours, since actual sunlight intensity varies throughout the day and by season — a location with 12 hours of daylight might have only 4-5 peak sun hours of that be strong enough to count at full strength.
Checking your specific region rather than using a generic average
Peak sun hours vary meaningfully by region and season — commonly cited figures range from roughly 3 hours in winter in the Pacific Northwest up to 6-7 hours in summer in the Southwest — a solar insolation map for your specific location gives a much more accurate figure than a generic national average.