Commercial Solar Brisbane: Costs, ROI and Payback for Business

The first question every business owner asks us about solar is the same one: what does it cost, and how long before it pays for itself? The honest answer is that commercial solar in Brisbane is cheaper per watt than the system on your house, and the payback is usually faster — but the sticker price on a quote rarely tells the whole story.

Here is what a commercial system actually costs in Brisbane right now, how the payback maths works, and the two things that most often move the number.

What commercial solar costs in Brisbane in 2026

These are current installed prices for the Brisbane market, after the federal STC discount is applied and including GST. They come from the Solar Choice national price index, updated 1 September 2026.

For comparison, a 10kW residential system in Brisbane sits around $9,480, or roughly $0.95 per watt. Scale is what makes the difference: commercial installs typically land 15–30% cheaper per watt than residential, because the fixed costs of design, approvals and getting a crew on site are spread across far more panels.

Treat these as a planning range, not a quote. Roof type, switchboard condition and access can move a real price by several thousand dollars in either direction, which is the next thing worth understanding.

What the headline price does not include

Most commercial quotes cover panels, inverters, mounting and installation. The costs that catch businesses out sit outside that scope, and they are site-specific rather than system-specific:

• Switchboard upgrades — $1,500 to $5,000. Older commercial boards frequently lack the capacity or protection devices a solar connection requires. This is the single most common addition on Brisbane commercial jobs.
• Structural engineering sign-off — $800 to $2,000. Required on many commercial roofs to certify the structure carries the additional load and wind uplift.
• Access equipment — $1,000 to $3,000 per day. Cherry pickers or cranes where the roof cannot be safely reached and loaded by ladder.
• Network connection upgrades — $2,000 upwards. Applies where your Energex connection needs work to accept the export capacity.
• Asbestos testing or removal — $500 upwards. Relevant on older industrial sheds, and it must be resolved before anyone works on the roof.

None of these are universal. A modern tin-roofed shed with a recent switchboard may need none of them. A 1980s brick industrial unit may need three. This is precisely why we inspect the site before quoting rather than pricing off a satellite image.

How the payback maths actually works

Payback on commercial solar is driven far less by how much power you generate and far more by how much of it you use yourself. Electricity you consume on site displaces a retail rate. Electricity you export earns a feed-in rate that is a fraction of it.

Queensland business rates on the Energex network currently run from about 24c to 42c per kWh on flat tariffs, with time-of-use peak rates reaching 50c. Commercial feed-in rates are typically a few cents. So a business that runs its load during daylight hours — a workshop, a cafe, cold storage, anything with refrigeration or machinery — gets dramatically better returns than a site that sits empty until 4pm.

Here is the same calculation run across the three sizes above, using deliberately conservative assumptions: 4.0 kWh generated per kW per day for Brisbane, 70% of that consumed on site, 26c per kWh avoided, and 5c per kWh for exports.

That lands in the 3 to 5 year band typical for Australian commercial installations. Push self-consumption to 90% on a site with strong daytime load and the payback moves under three years. Drop it to 40% because the business runs evenings, and it stretches past six — which is usually the point at which we start discussing whether battery storage makes the numbers work instead.

After payback, the system keeps producing. Panels carry 25-year product and 30-year performance warranties, so the back half of that lifespan is effectively free generation against electricity prices that have not historically fallen.

The tax position, stated accurately

Commercial solar is a depreciating business asset, and there is a persistent myth that it can simply be written off in full. For most systems, it cannot.

The instant asset write-off threshold is $20,000 per asset for businesses with aggregated turnover under $10 million. A 30kW system at $27,460 sits above that threshold, so it does not qualify for immediate deduction. Instead it goes into the general small business pool and depreciates at 15% in the first income year and 30% each year after.

That is still a meaningful benefit — it just arrives over several years rather than all at once. Smaller systems under $20,000 may qualify outright. Either way, the depreciation treatment materially improves the real-world return, and your accountant is the right person to confirm how it applies to your structure. We are installers, not tax advisers, and any solar company that tells you the whole system is instantly deductible without asking what you paid for it is guessing.

What changes above 100kW

Systems up to 100kW receive Small-scale Technology Certificates, which is the upfront discount already reflected in the prices above. Above 100kW the incentive shifts to a different mechanism based on Large-scale Generation Certificates, which are earned over time rather than deducted at purchase. The economics can still be strong, but the cash-flow profile is different and the approval process with Energex is longer. If you are considering something in that range, it needs modelling specific to your site rather than a price-per-watt estimate.

Export limits matter at this scale too. Energex may cap how much you can send back to the grid, which makes self-consumption — and sometimes storage — the deciding factor rather than array size.

What Brisbane systems at this scale look like in practice

Our 30kW commercial install at Acacia Ridge pairs a 30kW array with 36.2kWh of battery storage, specifically because grid outages were costing the business productivity several times a year — a cost that never appears in a simple payback calculation but was the deciding factor for that owner.

At the larger residential-to-light-commercial crossover, the 37.05kW system in Bardon and a 22kW array in Brisbane show how the per-watt cost improves as arrays scale. Every one of our case studies lists the real system specification and output figures rather than rounded marketing numbers.

If you are weighing up the ongoing side of ownership, our guide to commercial solar maintenance in Brisbane covers what servicing a commercial array actually involves, and our Milton commercial write-up looks at the same question for an inner-suburb business.

What we need to quote your site properly

A commercial quote worth comparing is built from your actual consumption, not a rule of thumb. To price a system for your business we need twelve months of electricity bills — interval data if your meter provides it — along with your roof type and age, switchboard details, and a sense of when your load actually occurs through the day. That last point is what determines whether a 30kW system pays back in three years or six.

You can see the full scope of what we install on our commercial solar page, or request a quote and we will assess the site properly before putting a number in front of you. We are SAA accredited and a Master Electrician, licence 89059, and every commercial job is designed against your consumption profile rather than sold from a price list.

Prices cited are current as at September 2026 and will change. Figures in this article are indicative planning estimates, not a quotation, and the tax commentary is general information rather than financial advice.