Commercial solar calculator for Australian businesses
Enter your electricity spend, state, and business type to estimate the system size, incentive value, and annual savings for your site.
Recommended system size
140–170 kW
Estimated upfront incentives
$41,771
Estimated annual savings
$60,117/yr
Based on $5,000/month electricity spend in NSW.
How this size is built
Estimated annual consumption
200,000 kWh
Recommended system size
155 kW
Annual production
200,389 kWh
Estimated upfront incentives
$41,771
Estimated annual savings
$60,117/yr
Offices have consistent 9-5 consumption, so solar self-consumption is high.
New rule. This size sits above 100 kW, so the incentive value uses the SRES 1 MW expansion, which applies to systems installed from 1 October 2026: the whole system earns upfront STCs at a fixed 5-year deeming instead of LGCs, up to the first 1 MW; capacity above that still earns LGCs. What changes.
Estimate only. Assumes an average rate of $0.30/kWh, a typical production yield for your state, and 0.15 kW of panels per m² of roof. Interval data replaces every one of those assumptions.
The most useful first number is not how many panels fit on your roof. It is how much power your business buys, and when. The calculator above starts from your monthly electricity spend and your business type, converts that into an annual consumption figure, and works back to the system size that covers the daytime share of it.
Roof area only enters as a ceiling. If the space you have caps the system below what your consumption justifies, the estimate falls back to what the roof can carry and says so.
What the numbers mean
Recommended size is the kW of panels that fits your load. Annual production is what that array should generate in your state across a typical year. Incentive value is the up front certificate discount your postcode zone qualifies for, which comes off the installed price rather than arriving later. Annual savings is the grid power you stop buying at a typical commercial rate.
Where a quick calculator stops
Any calculator working from a single spend figure has to assume an average rate and an average load shape. Two businesses with identical bills can have very different results once time of use windows, demand charges, and shift patterns are taken into account. That is the point where an estimate built from your actual bill is worth more than a better rule of thumb.
Frequently asked questions
How much does commercial solar cost in Australia?
Installed commercial systems commonly land between about $900 and $1,500 per kW before incentives, so a 50 kW system sits in the tens of thousands. Small-scale Technology Certificates come off that price at the point of sale, and the calculator above shows the certificate value your postcode zone qualifies for.
What size solar system does my business need?
Size to the power you use during daylight rather than to your total bill. As a rough guide, each 1 kW of panels generates around 1,300 to 1,600 kWh a year in Australia, but the share you can use on site matters more than the headline figure. The calculator adjusts for business type because a retail store, an office, and a cold store consume on very different schedules.
How much can a business save with solar?
Savings are the grid power you stop buying, plus a smaller credit for anything you export. A site that runs its load through the middle of the day captures most of the generation and saves the most. The calculator estimates annual savings at a typical commercial rate, so a site on a high rate will do better than the figure shown and a site on a low rate worse.
Do Australian businesses get a solar rebate?
There is no cash rebate, but there are certificates. Solar up to 1 MW of site capacity creates Small-scale Technology Certificates that reduce the installed price up front (up to 100 kW for installs before 1 October 2026). Victorian businesses can also claim VEECs, New South Wales runs the Peak Demand Reduction Scheme for batteries, and capacity above that ceiling creates Large-scale Generation Certificates as ongoing revenue.
How accurate is a commercial solar calculator?
Accurate enough to tell you whether solar is worth pursuing and roughly what scale to plan for. It is not accurate enough to quote from, because it assumes an average electricity rate and an average load shape. An estimate built from your own bill closes most of that gap, and a site inspection closes the rest.
Solar Insight takes your electricity spend and state, and optionally your bill, and returns a system size, savings, and payback estimate for your site.