Off Grid Collective
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Solar System Calculator

Size your solar panel array, battery bank, and inverter based on your energy needs and location.

New to off-grid? Start with our 3-question path finder for a personalized off-grid guide.

Energy Needs

Enter your daily energy consumption. Use the Home Load Calculator to find your exact daily usage.

2.00 kWh/day

Inverter must handle at least 1,250 W

Location & Sunlight

Peak sun hours determine how much power your panels can generate each day.

e.g. Illinois, Ohio, Kansas

4.5 hours/day

Average peak sun hours for Midwest US

System Configuration

Configure your system preferences to get accurate sizing recommendations.

2 days
1 day7 days

Calculation Assumptions

  • 75% overall system efficiency (wiring, temperature derating, charge controller, battery round-trip)
  • LiFePO4: 80% depth of discharge · Lead-acid: 50% depth of discharge
  • 20% battery safety margin for capacity headroom
  • Prices in USD as of 2026-06-19. USD base prices, typical US retail market. Verify quarterly on manufacturer sites, Amazon.com, or Home Depot.
  • Inverter sized at 1.25× peak load; MPPT controller sized at 1.25× array watts ÷ system voltage

System Summary

Updates live as you adjust inputs.

Solar Array

800

W

Panels

2

× 400W

Battery

250

Ah @ 24V

Inverter

1,500

W

Solar Array

2 panels

400W × 2 = 800 W total

Min required: 593 W (at 4.5 peak sun hrs)

Battery Bank

6,000 Wh

250 Ah at 24V · LiFePO4

2 days autonomy · 20% safety margin

Inverter & Charge Controller

Inverter

1,500 W

pure sine wave

MPPT Controller

60 A

charge controller

Estimated Cost

Solar panels$640
Battery bank$1,800
Inverter$375
Charge controller$280
Wiring & mounting$464
Total Estimate$3,559
Est. cost after Federal ITC (expired 2025)$3,559

Estimates based on USD base prices, typical US retail market. Verify quarterly on manufacturer sites, Amazon.com, or Home Depot. Prices as of 2026-06-19. Does not include installation labor or permitting.