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Click "Calculate Wire Gauge" after the system calculator has run.
Fuse/breaker recommendations appear after calculation.
Size the perfect solar system for your off-grid cabin. Enter your appliances and get exact recommendations for panels, batteries, inverter, and charge controller.
Pre-loaded with typical off-grid cabin appliances. Adjust for your actual setup — seasonal or year-round.
Pick a preset to load typical appliances, or skip and add your own below.
The duty cycle accounts for appliances that don't run at full power continuously. A refrigerator compressor cycles on/off (~35% of the time); a lamp stays on 100%.
| Appliance | Peak Watts | Duty Cycle % | Hours/Day | Wh/Day | |
|---|---|---|---|---|---|
| Daily Total: | 0 Wh | ||||
Cabins have the luxury of space. Ground-mounted panels are easier to install, clean, and tilt for optimal angle. They also stay cooler than roof-mounted panels (heat reduces efficiency). If your cabin has tree shading on the roof, ground mounting lets you place panels in the sunniest spot on your property.
Off-grid cabins in northern states get as little as 2–3 peak sun hours in December. Use the Winter season toggle above for realistic sizing. Many cabin owners combine solar with a backup generator for the worst winter weeks rather than oversizing the solar array for a month of bad weather.
If your cabin uses more than 5 kWh/day (well pump, refrigerator, washing machine, power tools), go with a 48V system. It reduces wire size requirements, allows longer cable runs from a ground array to the cabin, and gives you access to more powerful all-in-one inverter/chargers.
A weekend cabin running LED lights, fridge, and water pump uses roughly 2 kWh/day and needs ~600 W of solar with 5–8 kWh of LiFePO4 storage. A year-round small cabin (5 kWh/day) wants 1.5–2 kW of solar with 15–20 kWh of storage. A full-time off-grid homestead at 15 kWh/day needs 5–8 kW of solar and 35–50 kWh of storage. Use the calculator above with your actual appliance list for an exact recommendation.
Plan for 2–3 days of autonomy (battery covers usage with no solar input). For a small cabin using 2 kWh/day, that’s 5–8 kWh of usable LiFePO4 storage (or about 400–600 Ah at 12V). For a homestead using 15 kWh/day, plan 35–50 kWh (typically 48V × 600–1,000 Ah). Northern climates with long winter cloudy stretches benefit from generator backup instead of oversizing the bank.
Ground mount is usually better for cabins. You can tilt seasonally for 15–25% more winter output, place panels in the sunniest spot regardless of cabin location, sweep snow off easily, and benefit from cooler operation. Roof mount makes sense only if you have ideal solar exposure on the roof and limited yard space, or want to avoid running long DC wire to the cabin.
Yes, but plan for 50–70% less production December–February in northern states. Northern Wisconsin, Minnesota, and Maine see only 2–3 peak sun hours in December vs 5–6 in summer. Most off-grid cabin owners install a generator (3–6 kW propane or dual-fuel) for the worst 2–4 weeks of winter rather than oversizing the solar array year-round.
For weekend or summer cabins in sunny areas, no — solar plus adequate battery handles everything. For year-round cabins in northern climates, a generator backup is the cheaper choice than 2× solar/battery sizing. Modern inverter/chargers (Victron Multiplus, Schneider XW Pro) automatically start a generator when batteries get low and recharge them efficiently.
Use 12V for tiny cabins under 1 kWh/day. Use 24V for small cabins 1–4 kWh/day with modest 1,500 W loads. Use 48V for any cabin over 4 kWh/day or with heavy loads (well pump, washing machine, electric range). 48V allows long DC wire runs from ground arrays to the cabin without huge cables.