Queensland is supporting Australia’s energy transition through its nation-leading uptake of rooftop solar PV, which is both an impressive feat and one that has the potential to create challenges for Queensland’s energy system by exacerbating declining minimum demand conditions. Energy Queensland is proposing to introduce a mechanism that can curtail the output of inverters such as rooftop solar PV systems in emergency situations to help balance the supply and demand of electricity and keep the system operating safely.

The backstop mechanism is intended to disconnect some customers’ distributed (or consumer) energy resources (CER) to arrest a system blackout in emergency minimum system load events. This will involve installing a generation signalling device (GSD) that can activate the demand response capability DRM0 in inverters connected to the Queensland electricity grid. The requirement to install a GSD will not apply retrospectively to existing systems, however, it is proposed that from November 2022, a GSD will be required for all customer connections or alterations of existing inverter energy systems where:

• The new connection has an aggregate installed nameplate capacity of 10kVA or above;
• There is a non-warranty replacement of an inverter, and the aggregate installed capacity is 10kVA;
• Inverter energy system capacity is added to an existing system which results in the total capacity being 10KVa or above. The new inverter will be required to have a GSD fitted.

In the near future, AGL believes that dynamic operating envelopes for solar PV will be one of the leading solutions to declining minimum demand conditions caused by the rapid proliferation of CER assets in Queensland. Until Queensland’s backend infrastructure can enable dynamic operating envelopes, it is important that the interim backstop mechanism includes appropriate safeguards to maintain consumer confidence in the future role of CER in the NEM while minimising the impact on investment certainty, consumer uptake, and the value of CER assets. In our submission we discuss a number of opportunities to improve outcomes for customers affected by the introduction of the backstop mechanism, including by:

• Incorporating the policy intention that the emergency backstop mechanism be used only as a measure of last resort into the regulatory framework.
• Explicitly excluding battery storage assets from the backstop mechanism and requirement to install a GSD.
• Introducing a requirement for DNSPs to notify impacted customers of the curtailment of their solar.
• Waiving any demand charge reset accumulated by customers during the curtailment period.
• Revising the implementation timeframe from November 2022 to 1 January 2023.

You can read the full submission here.