STC glossary

Short for registered agent: a registered person who can create certificates on behalf of the owners of eligible small-scale systems.

STC registered agents

Source: REC Registry glossary, registered agents page

The system owner giving their right to create STCs to a registered agent, usually in return for an upfront discount on the system. An owner can assign the right to only one agent at a time.

The STC assignment form

Source: registered agents page

The form the owner signs to make the assignment. The regulator says an agent must get one signed, and that it must include a declaration that the owner assigned the right to create STCs to that agent.

What the form does

Source: registered agents page

The regulator's check of a claim before it registers the certificates. It usually takes 4 to 6 weeks, and longer if documents are incomplete or it finds a compliance issue. It may fail a claim that is incorrect, incomplete or for an ineligible system, and it can ask for the documents for up to 5 years after creation.

How STC trading works

Source: create STCs page

The regulator's STC factor: the number of STCs a battery earns per kWh of usable capacity. It steps down over time to follow falling battery costs, and it applies in full to the first 14 kWh, at 60% for the next 14 kWh and at 15% for the next 22 kWh, up to 50 kWh.

Battery STCs, by date

Source: STC entitlements page

The Clean Energy Council's list of approved products. The regulator says retailers must make sure the systems and components they sell are on it.

What makes a system eligible

Source: solar retailers page

The STC clearing house is a facility in the REC Registry where STCs are sold at a fixed $40 per certificate, before GST. Buyers and sellers meet in one place with no negotiation, and there is no guarantee how long STCs take to sell.

The STC clearing house

Source: certificate markets page, buy and sell STCs page

The regulator's estimate of how many years a system will generate renewable energy, which sets how many years of output are claimed up front. For small-scale solar, hydro and wind systems up to 100 kW, solar water heaters and heat pumps it falls by one year each year until the scheme ends in 2030. Mid-scale solar has a fixed five-year period.

The STC deeming period to 2030

Source: STC entitlements page

A system owner who is registered, or required to be registered, for GST and uses the system in their business. Their assignment of STCs is a taxable supply, so GST is added and they issue a tax invoice. For a home system not used for business, no GST applies to the assignment.

GST on STCs

Source: ATO page on GST and the scheme

A large-scale generation certificate: 1 MWh of renewable electricity generated by an accredited power station. LGCs are a separate certificate from STCs, and liable entities surrender both.

STCs and LGCs compared

Source: large-scale generation certificates page, liable entities page

A person or company that makes a relevant acquisition of electricity. Liable entities must surrender LGCs each year and STCs each quarter. The regulator calls them the main demand for certificates, and the Australian Government also buys STCs equal to the battery STCs created: 98,769,427 in 2025-26.

Who buys STCs

Source: liable entities page, certificate markets page, department page on battery STCs

Solar PV systems from 100 kW to 1 MW, which the regulations brought into the Small-scale Renewable Energy Scheme for systems installed from 1 October 2026. At its last update the regulator expected applications to open in mid to late November 2026.

Mid-scale solar STCs

Source: mid-scale solar page

The number used to work out STCs for solar water heaters and heat pumps. The register's 10-year STC figure for the model and zone is multiplied by the factor for the deeming period and rounded down. The factor falls by 0.1 as the deeming period falls by a year: 0.7 for a seven-year period and 0.1 for a one-year period.

STCs for heat pumps and solar hot water

Source: STC entitlements page

Buying and selling STCs outside the clearing house. The price depends on supply and demand and has no maximum. The buyer and seller negotiate it and arrange payment under a contract, and the regulator does not regulate this market.

The open market and the clearing house

Source: certificate markets page, buy and sell STCs page

The Clean Energy Regulator's online system for creating, transferring and surrendering STCs and LGCs. All certificates must be created in it before they can be bought, sold, traded or surrendered. This website is not the REC Registry.

The REC Registry explained

Source: REC Registry glossary, certificate markets page

A business that holds a registered agent account in the REC Registry and can create STCs for system owners who assign the right to it. To become one it completes the regulator's SRES Smart course, applies, declares it is fit and proper and pays a one-off fee.

STC registered agents

Source: registered agents page, become a registered agent page, REC Registry accounts page

A person registered under section 11 of the Act and listed in the Register of Registered Persons. Only a registered person can create LGCs and STCs.

The REC Registry explained

Source: REC Registry glossary

The Renewable Electricity Guarantee of Origin: digital certificates of 1 MWh each that track and verify where renewable electricity came from. It is part of the Guarantee of Origin Scheme, separate from the Renewable Energy Target, and it continues past 2030. Owners of mid-scale solar choose between STCs and REGO certificates.

STCs or REGO for mid-scale solar

Source: REGO page, mid-scale solar page

If there are no STCs for sale in the clearing house, the regulator can create STCs so that buyers can still purchase them. They can be traded and surrendered as ordinary STCs.

The STC clearing house

Source: REC Registry glossary, certificate markets page

The written statement a solar retailer completes for each solar PV or battery system, signed by a representative with authority to act for the business and given to the registered agent or system owner. The system is not eligible for STCs without it. Mid-scale systems do not need one.

The retailer's statement

Source: solar retailers page

The regulator's term for small-scale solar panel, wind and hydro systems, which for the deeming period means systems up to 100 kW. Often shortened to SGU.

What is an STC?

Source: REC Registry glossary, STC entitlements page

A target the Australian Government sets each year. The regulator uses it to work out how many STCs liable entities must surrender, which creates the market that STC sellers rely on. Battery STCs are not included, because the Department of Climate Change, Energy, the Environment and Water buys them. The 2026 percentage is 11.67%.

Who buys STCs

Source: small-scale technology percentage page, small-scale technology certificates page

The body that accredits solar installers and designers. An installer must be accredited by it and, with limited exceptions, hold an unrestricted electrical licence in the state or territory of installation. An accredited designer is not required for mid-scale systems.

What makes a system eligible

Source: installers and designers page

The regulator's initiative for checking panels on site. Installers scan panel serial numbers in an app, which checks them against manufacturers' databases, and a verified install produces a signed data package for the agent. The regulator says it can process such claims faster, unless it finds other compliance risks.

Why panel validation matters

Source: Solar Panel Validation page

A small-scale technology certificate, equal to 1 MWh of renewable electricity generated, stored or displaced by an eligible system. The regulator calls it an incentive, and says it is not a rebate and that it pays no money to owners or agents.

What is an STC?

Source: small-scale technology certificates page, registered agents page

Giving certificates to the regulator, which takes them out of the market. Liable entities surrender STCs each quarter to meet their obligations. Anyone with the permission can also surrender voluntarily, and a certificate accepted for voluntary surrender is permanently removed.

Who buys STCs

Source: certificate surrender page, REC Registry glossary

The queue of STCs offered in the clearing house while there are more sellers than buyers. It is first in, first served, and new offers join the end. When buyers outnumber sellers, a seller's STCs sell immediately.

The transfer list

Source: REC Registry transfer list page, certificate markets page

One of four areas that decide how much a solar panel system earns. The zone for a system is the one listed for the postcode where it is installed, and the boundaries do not follow state lines. Solar water heaters and heat pumps have their own postcode zones.

STC zones by postcode

Source: zone ratings instrument, STC entitlements page

The number the regulator sets for each zone, which feeds into how many STCs a solar panel system earns. For solar PV, zone 1 is 1.622, zone 2 is 1.536, zone 3 is 1.382 and zone 4 is 1.185. A higher rating means more STCs per kW.

The four zones and their ratings

Source: zone ratings instrument