Solar Power for a Rural Cabin or Off-Grid Shed: What Size Do You Really Need?
Short answer: A rural cabin with a fridge, lights, TV, and basic tools needs 2,000–4,000 Wh daily. Without solar recharge, you need 4,000–8,000 Wh stored capacity for a 2-day buffer. With a 400W solar panel in good conditions, a 2,000–3,000 Wh system runs indefinitely for basic loads. A well pump changes the equation significantly.
Cabin Loads vs Camping Loads
A rural cabin or off-grid shed is fundamentally different from camping. The loads are higher, the runtime expectations are longer, and reliability matters more. You’re not trying to survive one night — you’re trying to run a functional space indefinitely.
Typical Cabin Daily Loads
| Load | Watts | Hours/day | Duty cycle | Daily Wh |
|---|---|---|---|---|
| Refrigerator | 120W | 24h | 40% | 1,152 Wh |
| LED lights ×6 | 60W | 5h | 100% | 300 Wh |
| TV / screen | 80W | 3h | 100% | 240 Wh |
| Laptop | 65W | 4h | 100% | 260 Wh |
| Router | 15W | 12h | 100% | 180 Wh |
| Phone charging ×2 | 20W | 2h | 100% | 40 Wh |
| Total (no pump) | 2,172 Wh/day |
The Well Pump Factor
If your cabin has a well pump, it adds 500–2,000 Wh/day depending on usage and pump size. More importantly, the startup surge requirement (2,000–5,000W for a ½–1 HP pump) determines which power station you can use. A unit with less than 3,000W surge cannot reliably start most well pumps.
Sizing with Solar Recharge
The key advantage of pairing a solar generator with panels: you don’t need to store multiple days of energy — you recharge daily. With 400W of solar panels and 5 peak sun hours, you generate ~2,000 Wh/day — enough to run the cabin indefinitely in good weather.
For cloudy days, size your battery to cover 2–3 days without sun. At 2,172 Wh/day, that means 4,344–6,516 Wh of storage. The EcoFlow Delta Pro (3,600 Wh) covers 1.5 cloudy days; the Bluetti AC300+2×B300 (6,144 Wh) covers nearly 3 days.
Recommended Systems by Cabin Size
| Cabin type | Daily Wh | Recommended storage | Recommended solar | Best unit |
|---|---|---|---|---|
| Small shed / workshop | 500–800 Wh | 1,000–1,500 Wh | 200W panel | EcoFlow Delta 2 |
| Basic cabin (no pump) | 1,500–2,500 Wh | 2,500–4,000 Wh | 400W panels | EcoFlow Delta Pro |
| Cabin with well pump | 2,500–4,000 Wh | 4,000–7,000 Wh | 600W+ panels | Bluetti AC300+2×B300 |