STCs are created for the right to claim deemed generation, not for measured output. That is why the choice of mounting hardware does not change the certificate count. Whether panels sit on a pitched roof, a flat roof, a tilt frame, a ground rack or a single-axis tracker, the formula is the same.
The formula ignores mounting
Certificates = rated system kW x zone rating x deeming years, rounded down. For a 10 kW ground-mount array in zone 3 installed in 2026, that is 10 x 1.382 x 5 = 69 STCs. A tracker on the same 10 kW array also earns 69, even though it will produce more electricity over a year. The extra yield belongs to the owner as lower bills or more exports, not as extra certificates.
Ground mount
Ground-mounted systems are common on acreage and farms. Eligibility rests on the same points: approved panels and inverter, an installer with the right accreditation, and installation to the relevant standards. The photo evidence should show the array, the mounting, the inverter, the isolators and the labels. If the array is ground-mounted and off-grid, SAA accreditation applies; see off-grid solar STCs.
Tracking systems
Trackers add moving parts and inverter considerations, but they are still rated by panel capacity. Check the tracker manufacturer’s design with the installer’s standards obligations. A tracker does not change the zone or the deeming period.
Flat roofs and tilt frames
Flat roofs commonly use tilt frames to angle the panels. The frames, ballast and wind loading are an engineering matter. For the CER, what counts is the panel capacity and a clear evidence set. For a commercial flat-roof array above 100 kW, see commercial solar over 100 kW and the mid-scale solar page.
What this means for installers
Build the evidence around the mounting type. For tilt frames and ground racks, photograph the frame fixings and the array from a distance that shows the whole installation, then close-ups of the labels and serial numbers. The photo requirements guide lists the standard shots. Quote the STC discount from the rated kW, not from expected tracker yield.
If you have the paperwork, start trading or see current rates. The STC trading overview explains the process end to end.