Solar for a small business, a warehouse roof or a farm shed is covered by the same Small-scale Renewable Energy Scheme as a rooftop on a house. If the system is 100 kW or under (and within the scheme’s annual output limit), the installer or owner creates STCs for the electricity the system is deemed to produce over its deeming period.
The formula, with a worked example
STCs = system size in kW x zone rating x deeming years, rounded down. For a 2026 install the deeming period is 5 years, and the zone ratings are 1.622, 1.536, 1.382 and 1.185.
| System | Zone | Working | STCs |
|---|---|---|---|
| 99 kW warehouse, Sydney | 3 | 99 x 1.382 x 5 | 684 |
| 99 kW warehouse, Melbourne | 4 | 99 x 1.185 x 5 | 586 |
| 30 kW farm shed, Darwin | 2 | 30 x 1.536 x 5 | 230 |
At STC spot of roughly $38 to $40 at the time of writing, the Sydney example is about $26,000 to $27,400. Check your postcode in the STC calculator. The deeming period falls to 4 years for 2027 installs, so timing matters on large jobs.
How a commercial claim runs
The steps are the same as residential: the system is installed and commissioned by a CEC-accredited installer, the owner signs an STC assignment form, and a registered agent lodges the claim. Commercial jobs add three details worth getting right.
- Owner name and ABN. The system owner is whoever owns the asset, which may be the business, a landlord or a finance company.
- GST. The STC value is normally reflected as a discount on the invoice. RCTI, GST and ABN rules matter more at this scale.
- Evidence. Larger systems mean more photos (strings, inverters, array layout), and the photo requirements apply in full.
Warehouses, small business and farm sheds
A leased warehouse needs the building owner’s consent and a clear record of who owns the panels, because the owner is the one assigning the STCs. See the rental property page for how that plays out. Farm sheds are eligible on the same terms whether grid-connected or not. A small business operating as a sole trader or company assigns in the entity’s name.
Above 100 kW
The 100 kW line has always been the cap on small-scale STCs. From 1 October 2026, systems above 100 kW and up to 1 MW can create STCs with a fixed five-year deeming period, with CER saying applications open mid to late November 2026. Above 1 MW remains LGCs. The details are on mid-scale solar STCs. Splitting a larger system artificially to stay under 100 kW is not allowed.
If you are pricing commercial jobs, how it works shows our claim flow and pricing has the current published rate.