AEMO’s latest Quarterly Energy Dynamics report shows that wholesale electricity prices averaged $63 per megawatt hour (MWh) in the September quarter, down 41% from the June quarter ($108/MWh) and 71% ($216/MWh) from Q3 2022.
By region, South Australia recorded the highest average quarterly price at $92/MWh, followed by New South Wales ($81/MWh), Queensland ($65/MWh), Victoria ($49/MWh) and Tasmania ($29/MWh).
Total electricity supply by fuel type saw renewables (wind, grid-scale and rooftop solar, hydro and other sources) contribute 38.9% of total supply, up 4.6%, while black coal’s share fell 3.4%, primarily due to the Liddell Power station closure, and gas fell 2.3%. Brown coal’s market share increased 1%, mainly due to fewer unplanned outages.
AEMO Executive General Manager Reform Delivery, Violette Mouchaileh, said that the growing influence of renewables in the NEM was apparent in the warmer September quarter as prices returned to historical levels.
“Record renewable generation output helped push down average wholesale electricity prices by more than two-thirds, double the occurrence of zero or negative wholesale prices (19%) and reduce total emissions by 11% compared to the previous September quarter,” Ms Mouchaileh said.
“Renewables also supplied a record 70% of total energy used over a half-hour period, with rooftop solar contributing 39%, again highlighting the likely benefit from coordinating rooftop solar and home batteries.
“Potential renewable output hit a record 98.6%, which combines dispatched generation and available wind and solar farms that were bidding above the spot price and therefore not dispatched into the wholesale market,” she said.
In the September quarter, maximum rooftop solar output reached a record 11.9 gigawatts (GW), a 3% increased on the previous record, while maximums for grid-scale solar (5,949 MW) and wind (8,040 MW) output increased 7% and 10%, respectively.
Regarding new connections, 1.7 GW of new projects were progressing through registration and 2.1 GW commissioning to full output, compared to 2.4 GW at the end of Q3 2022. A further 10 GW of new projects were finalising contracts and under construction (pre-registration), up from 6.8 GW at the end of Q3 2022.
“The pipeline of new renewables, if supported by firming generation – batteries, hydro and gas – and transmission, will help meet reliability gaps and share low-cost, low-emissions energy to homes and businesses,” Ms Mouchaileh said.
Total east coast gas demand decreased by 3% this quarter compared to Q3 2022, driven by warmer weather, lower gas-fired generation (-12 petajoules (PJ)), and reduced demand across AEMO gas markets (-19 PJ). Quarterly average wholesale prices were 60% lower than the same quarter last year, $10.41 per gigajoule (GJ) compared to $25.94/GJ.
In the Western Australian Wholesale Electricity Market (WEM), the quarterly weighted average Balancing Price was $99/MWh, the highest average for Q3 and a 27% increase from Q3 2022, but lower than the Q2 record. The weighted average Short-Term Electricity Market price for Q2 2023 was $91/MWh, a 33% increase compared to Q3 2022.
“Total demand in the WEM decreased slightly in the September quarter, despite above average temperatures, due to growth in rooftop solar generation, up 11% compared to Q3 2022,” Ms Mouchaileh said.
“Similar to the east coast, rooftop solar contributed to new records in Western Australia. This includes an all-time minimum demand record (595 MW), the highest Q3 instantaneous renewable penetration (81.9%), and a maximum rooftop solar output accounting for 76.3% of total energy supplied,” she said.
WA domestic gas production was 99 PJ, a decrease of 8.6 PJ (-8%) from Q3 2022. Consumption decreased compared to Q3 2022 as well, at 99.9 PJ, a decrease of 6.7 PJ (-6.3%). There was a net withdrawal from storage of 1.2 PJ, which is a 0.5 PJ increase in withdrawals compared to Q3 2022.