How Much Do Commercial Solar Panels Cost in Australia?

Notice how the cost per watt drops as you go bigger. A 10kW system might cost $1.10/W, while a 100kW system can come in under $0.80/W. This is because a lot of the costs (design, paperwork, site setup, scaffolding) are fixed regardless of how many panels go on the roof. Spreading those fixed costs across more panels brings the per-watt price down significantly.

The wide ranges in the table above are not there to be vague. Commercial solar pricing genuinely varies a lot depending on a handful of factors. Understanding these will help you figure out where your business is likely to land within each range.

Panel and inverter selection

The equipment itself accounts for roughly 50–60% of the total cost. Budget tier panels and a basic string inverter will sit at the low end. Choosing a premium panel brand like SunPower, REC, or Q CELLS with a commercial-grade three-phase inverter from Fronius or SMA will push you towards the upper end. For most commercial installations, mid-range panels from Trina, Longi, or JA Solar paired with a quality inverter offer the best balance of performance and cost.

Roof type and accessibility

This is where commercial solar has a natural advantage over residential. Most commercial buildings have large, flat or low-pitch metal roofs, which are the fastest and cheapest surface to install panels on. No tile hooks, no steep pitches, no multiple roof planes to work around. However, if your building is multi-storey, has limited roof access, or requires a cherry picker or crane, installation costs will increase. Older buildings may also need a structural engineering assessment to confirm the roof can handle the additional weight.

Electrical infrastructure

Many commercial buildings, particularly older ones, need electrical upgrades to support solar. Your main switchboard might need additional circuit breakers, or the board itself might need replacing to meet current standards. Three-phase power is standard for commercial solar over about 10kW, and if your site only has single-phase, the upgrade cost can be substantial. Your installer should flag all of this during the site assessment.

Metro vs regional pricing

Location matters more for commercial solar than residential. Metro areas have more commercial installers competing for work, which keeps prices lower. Regional and rural installations carry extra costs for travel time, accommodation, and sometimes freight for equipment. The difference can be 10–25% compared to a comparable metro install. On the flip side, regional areas often have higher electricity rates, which means the payback can still be competitive.

The lesson here: always ask what is and is not included in the quoted price. A quote that looks cheap but excludes switchboard work and scaffolding is not actually cheap. Our guide on how to vet a solar installer covers this in more detail.

The per-watt savings come from bulk equipment purchasing, simpler roof mounting on commercial buildings, and fixed costs being spread across more panels. When you add tax deductions on top, commercial solar is one of the strongest returns on investment available to Australian businesses right now.

Small-scale Technology Certificates (STCs) are the federal government incentive that reduces the upfront cost of solar systems under 100kW. Your installer creates the certificates on your behalf and applies the value as a discount on your invoice. You do not need to deal with the paperwork yourself.

In 2026, the STC rebate is worth approximately $2,800 for a 10kW system, $8,500 for a 30kW system, and $13,500 for a 50kW system (exact figures depend on your postcode zone and the current certificate trading price). All the prices in our table above already have the STC discount applied.

The important thing to know: the STC rebate shrinks every year and the scheme ends in 2030. Every year you wait, the discount gets smaller. Our STC rebate phase-out guide explains the year-by-year decline in detail.

For systems over 100kW, STCs do not apply. Instead, these larger systems fall under the Large-scale Generation Certificate (LGC) scheme, which works differently. LGCs are earned over time based on actual generation rather than being claimed upfront.

This is where commercial solar really pulls ahead of residential. Australian businesses can claim the cost of solar as a tax deduction, which effectively reduces the real cost by your marginal tax rate. For a company paying the standard 25% corporate tax rate, a $30,000 system after STCs has an effective cost of $22,500 after the tax benefit.

Under the instant asset write-off provisions, eligible businesses can deduct the full cost in the year of installation rather than depreciating it over time. This front-loads the tax benefit and improves cash flow. If your business turns over less than $10 million per year, you are almost certainly eligible.

For a detailed breakdown of how this works and the current thresholds, see our guide on the instant asset write-off for solar. And always confirm the specifics with your accountant before relying on tax savings in your ROI calculations.

For systems above the write-off threshold, you will use ATO depreciation rates instead. The simplified depreciation pool for small businesses is often the fastest way to claim the deduction.

Not every business wants to pay $30,000 or more upfront, even if the returns are strong. There are several ways to spread the cost.

Chattel mortgage and equipment finance are the most common options. You borrow the funds, own the system from day one, and claim both depreciation and interest as tax deductions. Typical terms are 3–7 years, and in many cases the monthly repayment is less than the electricity savings from day one, making the system cash-flow positive from the start.

Operating leases and Power Purchase Agreements (PPAs) are also available, particularly for larger systems. With a PPA, a third party owns and maintains the system on your roof, and you simply buy the electricity it produces at a fixed rate below your current grid price. This means zero upfront cost, but you do not own the asset and you miss out on the tax deductions.

For most small to medium businesses, outright purchase or equipment finance gives the best overall return. PPAs make more sense for businesses that cannot utilise the tax deductions or prefer to keep the capital expenditure off their balance sheet.

Getting three quotes is good advice. Getting three quotes you can actually compare is better. Commercial solar quotes are notoriously inconsistent in format and what they include, which makes it easy to accidentally compare a complete, detailed proposal against a bare-bones lowball price.

When reviewing quotes, make sure each one specifies the exact panel make and model (not just “Tier 1 panels”), the inverter brand and model, total system capacity in kW, whether switchboard upgrades are included or excluded, whether network application fees are included, the warranty terms for panels, inverter, and workmanship separately, and the projected annual generation in kWh. If any of these details are missing, ask for them before comparing.

The cheapest quote is rarely the best value. A $22,000 quote with budget panels, a 5-year workmanship warranty, and no switchboard work included will almost certainly cost more over 25 years than a $28,000 quote with quality components, a 10-year workmanship warranty, and everything included. Our guide on how to read solar quotes walks through exactly what to look for line by line.