How much does an off-grid solar system cost?

Typical 2-3 kW off-grid system with lithium batteries runs $15,000-$30,000 installed. DIY brings it to $8,000-$15,000. Larger systems for full-house with HVAC run $30,000-$75,000+.

Can solar alone power a full off-grid home?

Yes — but you'll need a properly sized battery bank for cloudy stretches plus often a small generator for 2-3% of the year (worst winter weeks). Most full off-grid setups are hybrid solar + generator.

What's the best battery for off-grid solar?

LiFePO4 lithium is the current standard — 10x the cycle life of lead-acid, deeper discharge, no maintenance. Top brands: Battle Born, EG4, SOK, Victron Smart, Discover AES. Avoid lead-acid for new builds.

Do I need permits for off-grid solar?

Depends on local jurisdiction. Off-grid systems not connected to utility grid often have fewer permit requirements than grid-tied. Check with your county building department before purchase.

How to Size a Solar System for Off-Grid Living

Sizing an off-grid solar system means matching three numbers: your daily energy use (kWh/day), local peak sun hours, and battery autonomy days. Get any one wrong and you'll either over-spend or run out of power in winter. Here's the math, simplified.

1. Calculate daily kWh load

List every appliance, find its watt rating (label or manual), multiply by hours used per day. Add 20% headroom. A typical 2-person off-grid cabin runs 4-8 kWh/day. A full house with electric heat can hit 30+ kWh/day.

2. Find your peak sun hours

Use NREL's PVWatts calculator (free) for your zip code. US ranges from 3 (Pacific Northwest winter) to 7+ (Southwest summer). Average for design = lowest month, not annual average.

3. Size your solar array

Array wattage = (Daily kWh × 1000) ÷ (peak sun hours × 0.75 efficiency). Example: 6 kWh/day in a 4-hour zone = 6,000 ÷ (4 × 0.75) = 2,000W or 2 kW array.

4. Size your battery bank

Battery capacity (kWh) = daily load × autonomy days × 1.25 (depth of discharge). For 6 kWh/day with 2 days autonomy in LiFePO4 = 6 × 2 × 1.25 = 15 kWh. That's ~12 × 100Ah Battle Born 12V batteries in 48V config.

5. Size your inverter

Inverter wattage = peak simultaneous load + 20%. If your worst-case is microwave (1500W) + lights (200W) + fridge (300W) running together = 2000W min. Get a 3000W pure sine wave to be safe.

6. Pick your charge controller

MPPT controllers maximize array output. Sizing: array wattage ÷ battery voltage = amps. For a 2000W array on 48V system = ~42A. Round up to 60A MPPT (Victron, Outback, Schneider).

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Frequently Asked

How much does an off-grid solar system cost?: Typical 2-3 kW off-grid system with lithium batteries runs
5,000-
0,000 installed. DIY brings it to $8,000-
5,000. Larger systems for full-house with HVAC run
0,000-$75,000+.
Can solar alone power a full off-grid home?: Yes — but you'll need a properly sized battery bank for cloudy stretches plus often a small generator for 2-3% of the year (worst winter weeks). Most full off-grid setups are hybrid solar + generator.
What's the best battery for off-grid solar?: LiFePO4 lithium is the current standard — 10x the cycle life of lead-acid, deeper discharge, no maintenance. Top brands: Battle Born, EG4, SOK, Victron Smart, Discover AES. Avoid lead-acid for new builds.
Do I need permits for off-grid solar?: Depends on local jurisdiction. Off-grid systems not connected to utility grid often have fewer permit requirements than grid-tied. Check with your county building department before purchase.