Cabin Solar Calculator

Solar sizing for off-grid cabins. Select your cabin type, check off your appliances, pick your location — get a complete system recommendation in seconds.

How to Use This Calculator

Select your cabin type

Choose from Weekend (occasional use, 1-2 days/week), Seasonal (spring through fall, 3-5 days/week), or Full-time (year-round, daily use). This sets the default hours-per-day for each appliance — a fridge in a weekend cabin is off most of the week, while a full-time cabin needs continuous refrigeration. You can adjust individual appliances as needed.

Check the appliances you'll use

Check every appliance you plan to power from solar. The calculator shows each appliance's wattage, daily hours for your cabin type, and kilowatt-hours contributed. You'll see the daily total update in real time. The appliance list covers the most common cabin loads — for unusual loads, use the Off-Grid Solar Calculator where you can enter custom wattages.

Select your location

Pick the region closest to your cabin's location. This sets the peak sun hours for solar energy calculations. If you're between regions, use the lower value for a conservative system — it's much better to produce more than needed than to run short on cloudy days.

Cabin Solar Sizing by Type

Weekend cabin (minimal)0.5–1.5 kWh/day → 200–600W panels + 2–5 kWh battery

Weekend cabin (comfortable)1.5–3 kWh/day → 600W–1.2 kW panels + 5–10 kWh battery

Seasonal cabin2–5 kWh/day → 1–2 kW panels + 8–15 kWh battery

Full-time cabin (modest)3–6 kWh/day → 1.5–2.5 kW panels + 12–20 kWh battery

Full-time cabin (comfortable)6–12 kWh/day → 2.5–5 kW panels + 20–40 kWh battery

FAQ

What is the minimum solar system for a cabin? ▼

For a very basic weekend cabin (lights, phone charging, small fan): 200-400W of panels, a 2-5 kWh LiFePO4 battery, a 20-30A MPPT charge controller, and a 300-500W pure sine wave inverter. This covers the basics for a couple days without sun. Expect to spend $1,500-$3,000 for quality components. Don't skimp on battery capacity — running low on power is frustrating. Size up at least 30% from your calculated minimum.

Can I run a refrigerator in a remote cabin on solar? ▼

Yes — a refrigerator is the most common load in cabin solar systems and very manageable. A standard 15-20 cubic foot refrigerator uses 150-200W running and typically consumes 1-1.5 kWh per day (it cycles on and off, not running continuously). Energy-efficient cabin refrigerators (like Unique, SunFrost, or DC-direct 12V fridges) use 0.5-0.8 kWh/day. Propane refrigerators are an alternative for extremely remote locations but cost more to operate long-term.

Should I use a 12V or 24V system for a cabin? ▼

For systems under 1,500W, 12V is simple and 12V accessories are widely available. For 1,500-4,000W systems (the typical full-time cabin range), 24V is significantly better — half the current of 12V means cheaper wiring and lower losses. The calculator defaults to 24V for most cabin systems. Only go to 48V if your total panel array exceeds 3 kW or if your inverter choice requires it.

How do I handle power in winter when sun hours are lower? ▼

Winter design requires either oversizing for worst-case sun hours or adding a generator backup. Size your system for your location's December/January average peak sun hours (typically 30-50% lower than the annual average). For full-time cabins in northern climates, a propane or diesel generator as backup charger is standard — size the generator to match your inverter-charger's AC input amperage so it can fully charge the battery bank in 4-6 hours. Energy conservation in winter (less heating, more efficient lighting) also dramatically reduces the required system size.

Do I need permits for a solar system on a remote cabin? ▼

Permit requirements vary widely by location. Many remote rural areas have no AHJ (authority having jurisdiction) and no permit requirements for off-grid systems. Other jurisdictions require electrical permits and inspections for any solar installation. Check with your county building department. The NEC (National Electrical Code) provides the standard even where not strictly enforced — following it ensures a safe installation regardless of permit requirements.