The Clean Energy Council (CEC) wants to pay grid-scale batteries to absorb excess solar generation during low-demand periods.
The CEC has put forth a formal rule change request to the Australian Energy Market Commission (AEMC).
It proposes the creation of a new co-optimised ancillary service called the Minimum System Load (MSL) Reserve. This mechanism would allow the Australian Energy Market Operator (AEMO) to procure load response in specific volumes over fixed periods, providing a tool to mitigate emerging system security risks as daytime minimum demand plunges across the National Electricity Market (NEM).
The CEC argues the service is critical to maintaining grid stability amid rising minimum system load challenges, driven largely by the proliferation of consumer energy resources (CER).
“As the penetration of solar PV increases, the NEM is increasingly experiencing periods of very low, and even negative, operational demand during the day,” the rule change request notes.
The MSL Reserve would operate similarly to existing Frequency Control Ancillary Services (FCAS), with dispatch determined through the NEMDE co-optimisation process.
However, unlike FCAS – which addresses frequency events – the MSL Reserve targets forecast system minima, enabling pre-emptive charging actions from batteries or other flexible loads.
By being available to charge when needed, large-scale batteries could help manage minimum demand events and avoid emergency interventions like involuntary curtailment of rooftop solar.
The CEC also highlights that this market signal would enable more predictable investment in flexible, dispatchable load infrastructure.
The rule change complements ongoing work across market reform pathways, including CER integration, tariff modernisation and new roles for distribution-level market operators.
In its concurrent submission to the AEMC’s pricing review, the CEC warns that outdated static tariffs and rigid consumer frameworks are hindering the value and flexibility CER can bring.
“The NECF is poorly equipped to manage this complexity,” the submission says.
“It does not adequately address new business models or the rights and responsibilities of prosumers and non-traditional service providers.”
The AEMC is expected to assess the MSL Reserve proposal as part of broader efforts to address emerging system security risks and improve market efficiency under high-penetration renewables.