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Solar Payback Calculator

Calculate how long it will take for your solar system to pay for itself and see your 25-year ROI.

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Your details

3kW15kW
$3,000$20,000
20% (mostly export)80% (home during day)
Advanced options

Estimated payback period

4.0years

Break even in year 5

Estimated annual savings
$1,730
Estimated 25-year ROI
518%

Annual savings breakdown

Estimated daily production
26.9 kWh
Estimated annual production
9,829 kWh
Self-consumption savings
$1,258
Export income
$472
Total annual benefit
$1,730

Assumes 4.8 peak sun hours a day, the NSW average, and a 15% allowance for inverter, heat, dust and wiring losses. Savings use your self-consumption share, electricity rate and feed-in tariff as entered, with no panel degradation or price changes over the 25 years.

25-year projection

Cumulative savings less the system cost.

Year 5
+$1,650
Year 10
+$10,299
Year 15
+$18,949
Year 20
+$27,598
Year 25
+$36,248

How to improve your payback

  1. Increase self-consumption

    Run appliances during the day when your solar is producing. Use timers for dishwashers, washing machines, and pool pumps.

  2. Add a battery

    Store excess solar for evening use. This increases self-consumption to 70 to 80% and reduces reliance on grid electricity.

  3. Time-of-use tariffs

    Switch to a time-of-use plan. Solar offsets the most expensive peak rates, maximising your savings per kWh.

  4. Compare retailers

    Shop around for the best feed-in tariff and electricity rates. Even small differences add up over 25 years.

See your real payback, on a real quote

Start with the rebate your home could get. One Why Solar Approved installer, one free written quote, and fifteen minutes with a solar expert before you sign.

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How this payback calculator works

Enter your system size, installed cost (after STC rebate), state, and self-consumption percentage. The calculator uses state-specific sun hours, electricity rates, and feed-in tariffs to project your annual savings and cumulative return over 25 years.

The payback period is when your cumulative savings exceed your system cost. After that point, your solar system is generating pure profit. Most Australian systems reach payback in 3 to 5 years, with 20+ years of savings remaining.

Brick house with rooftop solar panels on a suburban street

Common questions

How long does solar take to pay for itself in Australia?
Most residential solar systems pay for themselves in 3 to 5 years in Australia. South Australia averages the fastest payback (under 3 years) due to high electricity prices. Victoria and Tasmania tend to be slower (4 to 6 years) due to lower sun hours. System cost, self-consumption rate, and electricity tariff are the biggest factors.
What is a good ROI on solar panels?
A typical 6.6kW solar system in Australia delivers a 20 to 30% annual return on investment, far exceeding term deposits or shares. Over 25 years, a system costing $6,000 to $7,000 can save $40,000 to $70,000 in electricity costs, depending on tariff inflation and self-consumption.
Does self-consumption affect payback period?
Yes, significantly. Every kWh you use directly from your panels saves you the full retail tariff (28 to 42c/kWh), while exporting only earns the feed-in tariff (3 to 10c/kWh). Increasing self-consumption from 30% to 60% can cut your payback period by 1 to 2 years.
Up to $8,000+ in solar and battery rebates · Federal rebates step down in 80 daysSee how we calculate this