The Assumptions
Every input behind the figure.
Production yieldtypical for the state
CertificatesSTCs by zone, VEECs in Victoria
Electricity rateone average rate, yours
Installed costyour quoted $ per kW
LGC revenuenot in the payback
For Australian businesses · free, no signup
Commercial solar payback calculator: years to pay back, by state
Set your state, system size, electricity rate and installed cost. You'll see the payback after STC and VEEC incentives, the net cost and the annual saving straight away, with the maths shown.
- Payback after STCs and VEECs
- Net cost and annual saving
- Live certificate prices
Your System
Defaults are a 50 kW system in New South Wales at $0.30/kWh and $1,200 a kW installed. Change anything and the figures update.
Covers NSW, VIC, QLD, SA and WA.
System size50 kW
10 kW200 kW
The average rate on your bill, not the peak.
Installed price before incentives.
Get a payback figure built from your own bill
The free Solar Insight estimate works from your own bill, demand charges included. No account needed, about two minutes.
Get my free estimateFor Australian businesses. See what is included.The maths
How Solar Payback Is Worked Out
It takes the certificate value for your state off the quoted cost, then divides what is left by the electricity you stop buying each year. The answer is the years to pay the system back.
What It Does Not Model
What your own bill would add.
Demand chargesnot modelled
Time‑of‑use windowsnot modelled
Self‑consumption shareall production at your rate
Degradation, price risesnot modelled
What This Calculator Works Out
It needs four inputs: your state, the system size you are quoted, the rate you pay for power and the installed cost per kW. That is enough for a first-pass payback.
How To Read Your Own Number
Two things move payback most: what you pay per kWh and how much of the generation you use on site. If a quote shows a payback far shorter than this figure, check its rate, its self-consumption share and how it values exports.
Why The State Matters
Incentive zones, feed-in tariffs and electricity prices vary by state, which can shift payback by one to three years for an otherwise identical system. The STC zone comes from your postcode; Victorian sites also claim VEECs.
What The Estimate Leaves Out
Demand charges, time of use windows and your load shape through the year. Ongoing LGC revenue on capacity above the STC ceiling is also left out. The free Solar Insight estimate works from your actual bill.
A Rough Guide
Most commercial systems in Australia land somewhere between three to seven years, after which the power is close to free for the remaining twenty-plus year life of the panels. Rather than lean on a national average, the calculator above uses your own state, rate and system size to estimate a figure for your site.
Questions
Frequently Asked Questions
How do I calculate solar payback for a business?
Take the installed cost, subtract the incentives, then divide that net cost by the value of the electricity the system saves in a year. The result is the payback in years. The calculator does this with the typical yield and the certificate values for your state.
What is a typical commercial solar payback period in Australia?
Most commercial solar systems pay back in 3 to 7 years, depending on the state, system size, electricity rate and the incentives available (STCs, VEECs or LGCs). Under 3 years usually means a high electricity rate and strong daytime use. Past 7 years is worth checking, because it often points to an oversized system exporting at a low feed-in rate.
Does the state I am in change my solar payback period?
Yes. Incentive zones, feed-in tariffs and electricity prices vary by state, which can shift payback by one to three years for an otherwise identical system. Pick your state above and the calculator applies its yield and certificate values.
Do solar incentives change the payback period?
Yes, 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. STCs cover up to 1 MW of site capacity for installs from 1 October 2026 (100 kW before). Capacity above that creates Large-scale Generation Certificates instead, paid as annual revenue rather than an upfront discount.
How do STCs reduce the upfront cost?
STCs are created at installation and assigned to your solar company as a point-of-sale discount. The number of certificates depends on your system size, postcode zone and the deeming period remaining to 2030. The calculator applies your zone automatically.
Does the calculator include demand charges?
No. It covers the energy you stop buying, not the demand part of your bill. Solar can trim a peak demand charge when your peak falls in daylight, which shortens payback further. Modelling that needs your interval data or a bill, which is what the free Solar Insight estimate uses.
Related
Related Calculators And Guides
STC Calculator for AustraliaSTCs and their upfront value by postcode.VEEC Calculator for VictoriaVEECs for commercial solar in Victoria.LGC Calculator for AustraliaLGC revenue above the STC line.NSW Battery Rebate Calculator (PDRS)PRCs and the upfront discount for NSW batteries.Cheaper Home Batteries CalculatorBattery STCs under the federal program.Commercial Solar CalculatorSize, incentives and savings from your spend.Solar System Size CalculatorThe kW that fits a warehouse, office or shop.
Guides
Quoting commercial solar?
Model the whole site.
For solar professionals: bill in, every solar and battery size on one grid, demand charges and time-of-use windows in the payback, a branded proposal out. About 10 minutes to a credible estimate.