Commercial solar buyers have more choice than households, and the choice changes who carries risk, who claims the tax benefit and who owns the certificates. This page outlines the main options. Tax advice belongs with your accountant.
The main options
Cash purchase. You pay the post-discount price. It has the lowest total cost and the simplest paperwork, and you keep the STCs benefit, usually as an upfront discount.
Equipment loan or chattel mortgage. You own the system from day one and the lender takes security over it. Repayments are fixed, interest and depreciation may be deductible, and GST is usually claimed up front where eligible. Make sure the loan is sized on the post-discount invoice. See STCs with solar finance.
Lease or hire-purchase. Payments over a set term, with ownership at the end in some structures. It keeps cash free but total cost is higher than a loan.
Power purchase agreement (PPA). A third party owns and maintains the system and sells you the power at a set rate per kWh. No upfront cost, but you carry a long contract, and the owner usually keeps the certificates. See PPA rates and PPA versus buying outright.
Green or asset finance products. Some lenders offer lower rates for energy-efficient equipment. Ask for the comparison rate and fees.
How certificates change the finance
- Up to 100 kW: the STC discount lowers the price at install. Zone ratings and the deeming period drive the number: 5 years for 2026 installs, 4 for 2027. Use the STC calculator.
- Above 100 kW up to 1 MW: from 1 October 2026 the system creates STCs with a fixed five-year deeming period (CER says applications open mid to late November 2026). See mid-scale solar STCs. That makes a larger upfront discount possible and changes the financing amount.
- Above 1 MW: LGCs create a revenue stream over time. Prices are low in 2026, so do not base borrowing on them.
Cash flow timing
If the installer assigns STCs to a trader, the discount comes off the invoice and the installer waits for settlement. If the business owns the STCs, it must sell them itself. Whichever applies, align the loan drawdown with the invoice date. Our guide to how installers manage cash flow shows the other side of the transaction.
What this means for businesses and installers
Installers who can present two or three finance paths close more commercial jobs. Check customers’ ownership structure, because rebates differ for leased systems and PPAs. If you also need the numbers, see commercial solar rebates in Australia. To turn certificates into cash quickly, see pricing and how it works.