As the energy sector continues its transition towards a low-emissions and decentralised system, particularly with Australia’s world-leading uptake of rooftop solar, AEMO continues to observe new records across the National Electricity Market (NEM).
On 28 August 2022, mild temperatures and high levels of rooftop solar penetration helped set a new NEM winter minimum operational demand record of 14,159 megawatts (MW) at 12:30pm, down 34 MW from the previous winter record (22 August 2022). The all-time NEM minimum operational demand record remains at 12,936 MW (17 October 2021).
On the same day, new winter records were set in South Australia at 359 MW (previous winter record of 453 MW on 14 August 2021 and the all-time low of 104 MW on 21 November 2021) and Victoria at 2,951 MW (previous winter record of 3,003 MW on 22 August 2022 and the all-time low of 2,333 MW on 28 November 2021).
Operational demand refers to consumer demand that can be met by generation from the grid. Minimum operational demand is the lowest level of demand met by generation from the grid, which is usually driven by consumer-owned generation substituting grid-scale generation.
At the time of the NEM record, grid-scale and rooftop solar provided an estimated 50% of generation, coal 42% and wind 8%. This isn’t the first time total solar generation has exceeded total coal generation in the NEM. It first occurred in September last year and for the first time in winter on 19 August this year, underscoring the rapid transition underway in Australia’s energy sector.
The chart shows how day-time minimum coal demand has been falling in recent years, whilst total roof-top solar and grid-scale solar generation has been increasing.
“Clearly there is a fundamental shift in fuel mix occurring in the NEM. Identifying, quantifying and projecting trends in the NEM enables AEMO to accurately forecast minimum demands as they occur, but also to plan for and manage security and reliability for the future energy system,” said Mike Davidson, Manager – Operational Forecasting.
AEMO’s Quarterly Energy Dynamics report for the June 2022 quarter observed black coal-fired generation at its lowest second-quarter output since the NEM commenced in 1998, driven by outages, bidding changes and fuel supply constraints. While its share of the NEM supply fell to 43% in Q2 2022, grid-scale renewable generation supply reached 31.8%.
“Almost 3,000MW of rooftop solar was installed across the NEM in 2021, which outshone the previous high of 2,532 in 2020,” said Mr Davidson.
AEMO is working with governments and industry on a range of measures to maintain energy security, including developing new tools, standards and system services to help keep the power system safe and reliable so that the grid can run at times of up to 100% peaks of instantaneous renewable generation by 2025.
This will enable the transition to low-emissions energy whilst creating more opportunities for consumers to benefit from new, decentralised technologies like solar, batteries, and electric vehicles.