Small-scale Technology Certificate

How STCs work

The Australian federal government’s Small-scale Renewable Energy Scheme (SRES) creates a financial incentive for households and small businesses to install eligible renewable energy systems. The mechanism is indirect: instead of paying a rebate directly, the scheme creates tradeable certificates that installers receive on your behalf and discount from the upfront cost.

Each STC represents 1 megawatt-hour (1,000 kWh) of electricity either generated or displaced over the system’s deeming period. A larger system in a sunnier location generates more STCs - and therefore a larger discount.

Calculating your STCs

The number of STCs you receive depends on:

System size (kWp). More panels, more certificates.

Location zone. Australia is divided into four climate zones based on solar irradiance. Zone 1 (Darwin, far north Queensland) receives the most sun and generates the most STCs per kW. Zone 3 (Sydney, Brisbane, Adelaide) is in the middle. Zone 4 (Melbourne, Hobart) generates the fewest.

Deeming period. The SRES scheme is designed to wind down to zero by 2030. Each year the deeming period - the number of years of future generation certificates are issued for - shrinks by one year. In 2026, the deeming period is around 5 years. A system installed in 2027 receives fewer STCs than the same system installed in 2025 because there are fewer years left in the scheme.

What they’re worth

STCs are traded on a market. The price fluctuates but is often supported by a clearing house mechanism at $40 per STC. A typical 6.6 kWp system in Sydney might generate around 80–90 STCs, worth $3,200–$3,600 - applied directly as a discount at the point of sale.

In practice, you sign over your rights to create the STCs to the installer at purchase. They create the certificates, claim the value, and pass most of it to you in the form of a lower quoted price. You never see the certificates themselves.

What qualifies

Solar PV systems, solar water heaters, air-source heat pumps, and small wind and hydro systems all qualify under the SRES. The installer must be Clean Energy Council accredited and use CEC-approved products.

The scheme ends in 2030

The SRES phases out completely on 1 January 2031. Systems installed before that date receive STCs calculated on the remaining deeming period. A system installed on 1 January 2030 would receive just one year’s worth. This is baked into the declining incentive structure, but it means the financial case for installation gets incrementally weaker each year as the upfront discount shrinks.