STC supply for 2021 year to date totalled 36.3 million, 5% above the same period in 2020. In addition, 8.6 million
STCs were carried forward from earlier assessment years into the 2021 assessment year.
STC creations have been impacted by the lockdowns across NSW, Victoria and the ACT. Creation trends in previous years
suggest more STCs are created during the second half of the year (see Figure 3.1). In 2021 STC creations in Q3
decreased by 5% from Q2. Weekly creations in the Q3 2021 averaged at 886,000 STCs, down 9% compared to the weekly
average of 963,000 over the first half of 2021.
Figure 3.1: STC creation by quarter, 2019 to 2021
With lockdowns lifting, creations are expected to rebound during Q4 as installations increase. If the creation rate
over the first three quarters of 2021 (922,000 STCs/week) continues, a surplus of 11.3 million STCs would emerge
following Q4 surrender in February 2022.
The Clean Energy Regulator expects supply will exceed the 50.6 million certificates required to be cancelled under
the Small-scale Technology Percentage. Given the surplus, the clearing house is unlikely to see material use.