Solar credits, introduced by the Australian Federal Government in 2009, were a key component of the Renewable Energy Target to incentivize renewable energy adoption.^[1] This initiative, replacing the Solar Homes and Communities Plan, applied a multiplier to small-scale technology certificates (STCs) for solar, wind, and hydro systems.^[2]

In this scheme, STCs, representing 1 megawatt-hour of renewable energy, are allocated based on location, installation date, and energy output of the system. Managed by the Renewable Energy Certificate Registry, these certificates contribute to the reduction of initial costs for renewable installations. The number of STCs each system can generate is calculated using established parameters.^[2]

Australia is divided into 4 zones based on solar irradiance patterns.^[3] The more irradiance, the larger the multiplier applied.

Since 2022 the STC scheme is slowly being phased out, it will end in 2031. There is a multiplier that reduces by 0.1 every year, from 0.9 in 2022 to 0.1 in 2030.^[4]

The Small-scale Renewable Energy Scheme (SRES), updated in April 2022, revises standards for solar business operations and small-scale technology certificate (STC) claims. It incentivizes renewable energy installations, granting one STC per megawatt hour of energy generated. System owners can sell STCs themselves or via agents, while electricity retailers are obligated to annually surrender STCs as per the small-scale technology percentage. This scheme, promoting renewable energy use, is set to run until 2030.^[5]

• Small generation unit STC calculator