Solar pumping is common on farms: a panel array, a controller and a submersible or surface pump, with no inverter and no grid. This is where search results on “off-grid solar STCs” start to contradict each other. The reason is a distinction the scheme draws between a solar power station and a solar-powered appliance.
The distinction that decides it
The STC scheme is built around small generation units that produce electricity as a system: panels, an approved inverter and, where relevant, an installation that supplies loads through a switchboard. A direct-drive pump has panels connected to a DC pump controller. There is no inverter on the approved list and the panels are part of the pump, not a power system. Reports from the industry say these are generally not eligible, and the CER’s guidance is the final word.
A conventional system is different. If you install a panel array, an approved off-grid or grid-connected inverter and wire the pump load from the switchboard, the system is an ordinary generation unit and the pump is simply one of its loads. For off-grid systems the installer needs SAA accreditation; see off-grid solar STCs.
Irrigation
The same logic holds for irrigation. Solar that runs an irrigation pump through an inverter and switchboard can earn STCs, within the 100 kW limit. At 30 kW in zone 3 and a 2026 install, certificates would be 30 x 1.382 x 5 = 207. A direct-drive irrigation pump with no inverter would not. Anything above 100 kW and up to 1 MW, installed from 1 October 2026, falls under the new mid-scale solar STC rules.
Do other rebates apply
State and regional programs have funded solar pumping at various times, typically as grants and not certificates. Names and amounts change, so ask the state agriculture or water department. We do not list amounts here.
What this means for installers
Decide at the quote stage which side of the line the job sits on. If the customer wants an STC discount, design it as a switchboard-connected system with approved components. If the pump is direct-drive, do not include an STC discount in the quote. The STC calculator is only valid for eligible systems.
For the farm context, see farm and rural solar STCs. For how STC trading works once the system is eligible, read STC trading and see current rates.