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Solar Payback Calculator for Australian Businesses

See how many years a commercial solar system takes to pay for itself. Set your state, system size, electricity rate, and installed cost for a live estimate.

System Size50 kW
10 kW200 kW
Estimated Payback Period
2.4 years
Net cost of $46,526 offset by $19,392/yr in savings
System Cost
$60,000
Total Incentives
$13,475
Net Cost After Incentives
$46,526
Annual Electricity Savings
$19,392/yr
Annual Production
64,641 kWh

How Solar Payback Is Worked Out

What This Calculator Works Out

Enter your state, the system size you are being quoted, the rate you pay for power, and the installed cost per kW. The calculator applies the certificate value your postcode zone qualifies for, subtracts it from the quoted cost, and divides what is left by the electricity your business stops buying each year. The answer is the number of years before the system has paid for itself.

How To Read Your Own Number

Payback is a ratio, so only two things move it far: what you pay per kilowatt hour, and how much of the generation you use on site instead of exporting. A business that runs its load through the middle of the day, such as a factory, a cold store, or a busy office, keeps more of what the panels make and pays the system back sooner than a site that only gets going after dark.

If a quote you are holding shows a payback far shorter than the figure here, look at the assumptions behind it. The usual culprits are an electricity rate that ignores discounts, an assumed self-consumption share that no one measured, and savings that quietly include export credits at full retail value.

What The Estimate Leaves Out

This is a first-pass number from four inputs, so it does not model your demand charges, your time of use windows, or the shape of your load through the year. It also excludes ongoing certificate revenue for systems above 100 kW, which is treated separately. For a figure built from your actual bill rather than a typical rate, run the free Solar Insight estimate below.

Frequently Asked Questions

How do I calculate solar payback for a business?
Take the installed cost of the system, subtract the incentives it qualifies for, then divide that net cost by the value of the electricity the system saves you in a year. The result is the payback period in years. The calculator above does this with the certificate values that apply to your state and postcode zone.
What is a good solar payback period for an Australian business?
Commercial systems in Australia commonly pay back in three to six years. Anything under three years usually means a high electricity rate combined with strong daytime consumption. Anything past seven years is worth checking, because it often points to an oversized system exporting power at a low feed-in rate.
Do solar incentives change the payback period?
Yes, and by a lot. Small-scale Technology Certificates come off the installed price up front, so they shorten payback directly. Victorian sites can also claim VEECs. Systems above 100 kW create Large-scale Generation Certificates instead, which arrive as annual revenue rather than an upfront discount.
Does the calculator include demand charges?
No. This estimate covers the energy you stop buying, not the demand component of your bill. Solar can trim a peak demand charge when your peak falls in daylight hours, which shortens payback further. Modelling that properly needs your interval data or a bill, which is what the free Solar Insight estimate uses.
Is this different from the payback period guide?
Yes. This page is the tool. The commercial solar payback guide compares a reference system across every state and explains why the answer moves between them. Use the calculator for your own numbers, and the guide for context on where your state sits.

Go Deeper On Payback

Payback Period Guide
How payback works, and what a reference system returns in each state.
Payback By State
Live state-by-state comparison on a 50 kW reference system.
Demand Charges And Solar
The bill component this calculator does not model, and when it matters.

Get A Payback Figure Built From Your Own Bill

The calculator above uses a typical rate. Solar Insight uses your electricity spend, your state, and your business type to size a system and estimate the savings behind the payback.

No account or password needed. The free estimate takes about 30 seconds.

See Amperage model this for your clients

Every size, payback, and a branded proposal.

Prefer a live walkthrough? Book a demo

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