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. Victoria, NSW, South Australia, Tasmania

5 hours/day

Average peak sun hours for Australia (South)

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 AUD as of 2026-06-19. AUD placeholder prices — verify against Australian retail (Solar Quotes, manufacturer portals) before production use.
  • 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

880

W

Panels

2

× 440W

Battery

250

Ah @ 24V

Inverter

1,500

W

Solar Array

2 panels

440W × 2 = 880 W total

Min required: 534 W (at 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 panelsA$748
Battery bankA$2,400
InverterA$525
Charge controllerA$390
Wiring & mountingA$609
Total EstimateA$4,672

Estimates based on AUD placeholder prices — verify against Australian retail (Solar Quotes, manufacturer portals) before production use. Prices as of 2026-06-19. Does not include installation labor or permitting.