Integrating Utility scale Renewables and Distributed Energy Resources in the SWIS

AEMO originally released a report in March 2019 entitled Integrating Utility scale Renewables and Distributed Energy Resources in the SWIS. This original report  highlighted the challenges to system security due to the expected continued growth of utility scale renewables and distributed energy resources (DER) under a no change to regulation or market constructs scenario. AEMO has now updated this original report with further analysis and recommendations that has captured the changing trajectory of drivers impacting system security since the original report and also to take account of the mitigatory initiatives, investment and reforms implemented since the original report. The new Report is entitled Renewable Energy Integration - SWIS Update.

The primary case made by the original report was:

1. Without changes to accommodate new technologies, voltage in the SWIS cannot be controlled within technical limits as the level of minimum power system operational demand approaches the present critical level of 700 MW. AEMO’s current forecasts of rooftop PV DER growth indicate that minimum operational demand will reach 700 MW between 2022 and 2024, depending on the PV DER installation rate and load growth and taking into account day-to-day variability in weather and load conditions.
2. System security risks are emerging now as the increase in large-scale renewable generation and DER displaces the dispatchable thermal generators that presently provide all system security services such as inertia, frequency control, system strength, and voltage control.
3. Technical standards and regulatory and market constructs require carefully designed but urgent change, to implement or incentivise new technologies in the SWIS such as synchronous compensation, energy storage, and increased inverter capabilities. These changes will support the management of power system security and effectively integrate renewable generation and DER in a way that facilitates efficient utilisation of existing and future electricity sources.

The key findings of the Renewable Energy Integration -SWIS Update released in September 2021 are

1. Since the March 2019 report, the early implementation of some of the WA Government’s Energy Transformation Strategy (ETS) program actions are providing AEMO with better operational capability. AEMO has also developed better tools and insights to manage system security and both Western Power and generators have made improvements to their assets. 
2. Some of the emerging system conditions identified as potential challenges for managing system security in the March 2019 Report have become more common, particularly as the change in energy supply mix to more renewable generation continues at record pace.  Low load conditions are now a permanent feature of the SWIS; AEMO, Western Power and Energy Policy WA (EPWA) have commenced a program of work for immediate and longer-term remedial action.
3. A paradigm shift to the effective management of the power system in prolonged periods of 100% renewable generation and zero net supply required from utility scale generation.
4. The implementation of various initiatives, investments, and WA Government-led reforms has enhanced the capability to manage the system to reasonably accommodate the persistence of lower operational demand. This has deferred to 2024 the point where power system operational conditions are likely to become insecure in the absence of additional measures, noting the system will for periods of time enter into a ‘zone of heightened threat’ due to diminished secure dispatch options prior to 2024.
5. Whilst these positive changes have improved the outlook, AEMO has identified priority actions to improve resiliency in the short term noting further work and reform is required to manage the power system in the new paradigm. Ongoing reform is a necessity – the WA Government has already announced ETS Stage 2 reforms which will be critical for ensuring that essential system services (ESS) continue to support the requirements of the power system and that existing providers and new entrants are appropriately incentivised.
6. The Whole of System Plan (WoSP) will be integral to steering the transition to the future power system, by determining a future system design that puts consumers at its centre, identifies the roles responsibilities of parties, and informs the investments to be made and how they interact with the market.