Reduce your biggest operating cost with commercial solar that pays its way

Commercial and industrial solar operates on the same fundamental principles as residential solar — photovoltaic panels convert sunlight to electricity — but the scale, engineering complexity, and financial structure are quite different. A business might install anywhere from 30 kilowatts (enough for a small office or café) to several megawatts for a manufacturing facility or logistics centre. The design must account for three-phase power, demand tariffs, structural engineering of commercial rooftops, and sometimes ground-mount or carpark canopy configurations.

The financial case for commercial solar is compelling precisely because businesses typically consume most of their electricity during daylight hours — the exact same window when solar panels are generating at their peak. That alignment between generation and consumption means self-consumption rates of 70–95% are routinely achievable, which is far higher than a typical home where occupants are often away during the day.

Understanding your commercial electricity tariff

Before designing a system, we always start with a deep dive into your electricity bills. Commercial tariffs are more complex than residential ones. Most businesses are on time-of-use rates, where you pay different prices depending on when you consume electricity — peak rates (often 35–50c/kWh) typically apply from 7am to 10pm on weekdays, which is precisely when solar is generating. Many commercial customers also face demand charges — a separate fee based on your single highest 15-or-30-minute consumption peak in the billing period. Solar can reduce demand charges significantly when the system is sized and managed correctly.

• Time-of-use savings: consuming your own solar generation during peak-rate windows means every kilowatt-hour produced is worth the full peak tariff — typically 35–50c/kWh.
• Demand charge reduction: solar generation directly reduces your consumption peak during daylight hours, which can knock hundreds of dollars off your monthly demand charge.
• Feed-in credits: surplus generation exported to the grid earns a feed-in credit, though commercial feed-in tariffs are modest (2–8c/kWh), so maximising self-consumption is the priority.
• Network tariff reclassification: some businesses generate enough solar to qualify for a lower network tariff category, delivering further ongoing savings.

Large-scale Generation Certificates and commercial rebates

Commercial systems under 100kW still qualify for the Small-scale Technology Certificate (STC) federal rebate, applied as a point-of-sale discount just like residential systems. Systems above 100kW instead generate Large-scale Generation Certificates (LGCs) over time as electricity is produced — these are sold on the market or surrendered to meet renewable energy targets, creating an additional revenue stream that improves your system's financial return. State-based business incentives also exist: Victoria's Business Energy Upgrades, NSW's Energy Savings Scheme, and various network rebates add further layers of support.

For businesses that prefer not to use capital for an upfront purchase, Power Purchase Agreements (PPAs) are an increasingly popular structure. Under a PPA, a solar finance company installs the system on your property at no upfront cost, and you purchase the electricity it generates at a fixed, below-market rate for a contracted term (typically 10–20 years). You get immediate savings without the capital outlay; the financier earns a return through the electricity payments. It's a legitimate structure used by some of Australia's largest companies.

Engineering considerations for commercial installations

Commercial rooftops present different engineering challenges to residential ones. Flat roofs — common on warehouses, factories, and retail centres — require ballasted or penetrating tilt-frame mounting systems designed to withstand wind loads specific to the building's location. The structural engineer of record must sign off on the additional load, and for older buildings a roof survey is essential. Three-phase inverters are standard at commercial scale, and switchboard upgrades or additional protection equipment may be required to meet AS/NZS 4777 grid connection standards.

• Rooftop systems: most cost-effective for buildings with large, unshaded roof areas. Minimum viable roof is roughly 150 square metres for a 30kW system.
• Carpark canopies: solar carport structures generate electricity while providing vehicle shade — ideal for retail centres, hospitals, and large commercial sites with expansive car parks.
• Ground-mount arrays: where roof space is limited or structurally challenged, ground arrays in adjacent land can be cost-competitive, particularly for industrial sites.
• Monitoring and SCADA: commercial systems benefit from advanced monitoring platforms that track performance at the string or panel level, flag underperformance early, and provide data for your accountants' depreciation schedules.

Tax incentives and depreciation

Beyond the direct energy savings, commercial solar delivers meaningful tax benefits. The Australian Taxation Office allows businesses to depreciate solar assets, and the instant asset write-off provisions (thresholds vary by year and business size — check with your accountant for the current rules) have allowed many businesses to write off a significant portion of the system cost in the year of installation. This effectively brings forward your tax saving, improving the net present value of the investment considerably.

SolBuddy works alongside your financial advisers to structure the investment correctly. We provide detailed asset registers, installation certificates, and performance documentation to support your depreciation claims. Our commercial proposals always include a detailed financial model showing after-tax, after-rebate payback period, internal rate of return (IRR), and net present value (NPV) over the system's 25-year life — the same metrics your finance team will use to evaluate any capital expenditure.

Frequently asked questions