Welcome to Mid-scale Solar STCs

Every requirement for a compliant mid-scale solar STC claim under the expanded Small-scale Renewable Energy Scheme — who owns it, what evidence proves it, and how the claim moves through Formbay to the Clean Energy Regulator.

The Government has announced that from 1 October 2026 the maximum system size to be eligible to claim STCs will increase from 100kW to 1000kW. Until now systems above 100 kW could be accredited as a Power Station and claim LGCs; from 1 October 2026 they can create STCs up front, like small-scale systems under 100kW, but with a fixed five-year deeming period until the end of 2030. These will be known as mid-scale solar devices.

To determine whether an installation is mid-scale, look at the total solar capacity connected at the site at the time of installation.

This means you may need to consider more than just the size of the new system. The total can include:

If the combined capacity is more than 100 kW and no more than 1,000 kW (1 MW), the new installation may be treated as a mid-scale solar system.

If the combined capacity is more than 1 MW, the installation falls outside the mid-scale STC pathway, even where the new system being installed is less than 1 MW.

Before quoting or commencing a job, check what solar generation already exists at the site and whether any other related systems need to be included in the size calculation.

Two or more PV systems are related if any one of these applies. Ownership does not decide it metering and wiring do.

A related power station is an accredited power station whose accreditation listed solar as an energy source and that sits on the same site or adjoining sites in the same area. A commercial meter is one used to bill electricity between unrelated parties — internal or divisional meters do not create a boundary. The Regulations also treat off-grid and microgrid installations as one device across all interconnected components.

The Clean Energy Regulator view the installation date as the date the system was first capable of producing power. This means that to prove this a certificate of testing with the date the system was tested would be used to verify the correct date has been selected.

It's important to make sure that the SAA Accredited installer is physically onsite during the commissioning of the system as this is the time that the system would be capable of producing power and should be listed on your testing document.

To claim STCs you will need to ensure the installation date on the STC claim, your date of test on the Certificate of Testing, and your final onsite selfie are all the same date. There is also a limit of maximum 2 systems (PV and battery are included as 2 systems) commissioned in a single day by a single installer so ensure you aren't completing more than 2 installations per day even if spread across multiple dates.

Finally, you will need to ensure that your STC claim is submitted for processing within 12 months from the installation date. If you don't submit the claim within 12 months it will expire and you will not be able to claim at all.

The amount of STCs most systems are eligible for is based on:

Mid-scale STCs will be eligible at 5 years deeming period until 2030 and therefore will not be impacted by the usual deeming period drop each year.

You can estimate your Mid-scale STCs using the CER calculator here.

Mid-scale solar has been drafted to have very similar requirements to small-scale solar installations. Product and installer accreditation still applies, and onsite data capture will be the same. The key differences are in the approvals and connections. Mid-scale solar will not require an SAA accredited designer or retailer to sign mandatory written statements. Instead, documented evidence of all the necessary approvals will be required before submitting STCs which includes DNSP approval, DA approval, and any Engineering approvals that may be required.

Mid-scale solar has additional evidence requirements before STCs can be created.

Before a claim is submitted, all relevant Commonwealth, state, territory and local government planning and approval requirements must be met. Formbay will need evidence that these requirements have been satisfied before the job can proceed to STC creation.

Depending on the project, this may include:

The installer must also confirm in writing that all applicable Commonwealth planning and approval requirements have been met and that supporting documents are held.

All information provided as part of the claim must be true, complete and accurate. Missing or incorrect information may prevent the STCs from being created and can result in regulatory action.