Does Commercial Solar Stack Up for Small Business in QLD?
Most articles about small business solar answer this question with “yes, absolutely” and a picture of a roof. The honest answer is that it depends almost entirely on one thing, and for a meaningful minority of Queensland businesses the answer is no — or at least not yet.
Here is how to work out which group you are in before you spend anything.
The one number that decides it
Solar pays a business back in two different ways, and they are worth very different amounts.
Power you generate and use on site offsets your retail tariff. In South East Queensland small business rates commonly sit somewhere in the 25 to 35 cents per kilowatt hour range, depending on your tariff and retailer. Every unit you self-consume saves you that full amount.
Power you generate and export earns a feed-in tariff, which for commercial customers is typically a fraction of the retail rate.
So the question is not “how much sun does my roof get”. It is what proportion of your generation you will actually consume. A business self-consuming 85% of its solar and one self-consuming 35% can have identical roofs, identical systems and wildly different returns.
That proportion is decided by when your business uses power, not how much.
What a small commercial system costs
For most small businesses the useful range is 10kW to 30kW. At the top of that range:
| System size | Estimated cost | Annual saving | Typically suits |
|---|---|---|---|
| 30 kW | $22,000 | up to $7,800 | Small offices, retail, light trade premises |
| 50 kW | $34,500 | up to $13,500 | Warehouses and workshops |
A 30kW system at $22,000 saving up to $7,800 a year pays for itself in roughly three years, then keeps producing for two decades or more. Commercial payback across the systems we install generally runs 2.4 to 3.2 years.
Those figures assume the instant asset write-off applies. Thresholds and eligibility change between financial years, and the treatment depends on your business structure and turnover, so confirm your position with your accountant rather than relying on a number from a website.
It is also worth noting that systems up to 100kW qualify for small-scale technology certificates, claimed upfront and applied as a discount to the installed price. Every system in the small business range comfortably qualifies, and the prices above already reflect it.
The businesses it works best for
Solar suits businesses whose demand curve looks like the sun’s. In practice, across Brisbane, that means:
- Trades and workshops — compressors, welders, extraction and lighting, all running through the working day
- Retail and hospitality with daytime trade — refrigeration and air conditioning peak on exactly the hottest, brightest days
- Offices and professional services — HVAC and equipment load during business hours, close to zero overnight
- Medical and veterinary practices — sterilisation, imaging, climate control and refrigeration during opening hours
- Light manufacturing on day shift — steady, predictable, high self-consumption
What these have in common is that the load is already there when the sun is up. Nothing needs to change operationally for the system to pay.
When it does not stack up
This is the part most solar articles skip. Some businesses genuinely should not install solar yet:
If most of your load is after dark. Evening restaurants, bars, late-trade venues and night-shift operations will export most of their generation at low feed-in rates. The system still works — it just pays back far more slowly. Storage changes this calculation, but it also changes the capital cost, and the combined payback needs modelling rather than assuming.
If you are on a short lease. Solar is a fixture, and a three-year payback on a two-year lease is a loss. Some landlords will contribute or amortise the cost through rent — worth asking before ruling it out — but installing at your own expense on a lease you may not renew rarely makes sense.
If your roof needs work. Installing on sheeting that needs replacing within five years means paying to remove and reinstall the array later. Sequence the roof first; the solar can wait a few months.
If your bill is genuinely small. Below roughly $800 a month, the fixed costs of a commercial installation — design, approvals, project management — start to dominate the economics. A residential-scale system may be the better fit.
An installer who tells you solar works for every business is telling you something they cannot know without seeing your bills.
What actually moves your number
Beyond self-consumption, the variables that most change a small business quote are roof access and height, whether tilt frames are needed on a flat roof, the condition and capacity of your existing switchboard, cable run length from array to board, and any export limiting the network imposes on your connection.
Network approval matters here too. Systems in South East Queensland need connection approval from Energex, and depending on your site and local network capacity, that approval may come with a cap on exports. For a business with strong daytime self-consumption this changes very little. For one planning to export heavily, it changes everything.
How to get a real answer
You do not need a site visit to get most of the way there. Your interval data — available from your retailer — shows your consumption hour by hour. Read against your current tariff, it answers the self-consumption question directly, and from there the system size and payback follow.
That is where any serious commercial quote should start. A proposal built from your roof area rather than your load profile is a guess dressed up as a number.
If you want that worked through for your site, see our commercial solar service, or look at the full commercial cost breakdown for pricing across system sizes. For businesses considering the larger end, our article on commercial solar costs, ROI and payback in Brisbane covers the wider picture.
