Welcome to the eleventh edition of Energy Spectrum Australia.
The below extract has been taken from our eleventh edition, and if you have enjoyed reading this article and want to read more about the latest developments in the Australian energy market, please contact Ben Cerini, email@example.com for more information.
AEMO completes Power System Frequency Review
The Australian Energy Market Operator (AEMO) published it 2020 Power System Frequency Risk Review – Stage 1 Final Report on 31 July.
AEMO is developing the 2020 Power System Frequency Risk Review (PSFRR) in a staged approach, with the stage 1 report being developed after initial consultation with transmission network service providers (TNSPs). It considers forecast power system conditions over a five-year outlook period, to 2025, and reviews the relevant non-credible incidents since the 2018 PSFRR that have caused significant frequency deviations, including the adequacy of actions taken to manage their impact. It also contains observations about emerging risks and the impact of the changing generation mix and climate.
AEMO outlines a range of recommended options to increase the capability and effectiveness of South Australian under-frequency load shedding (UFLS) schemes from late 2020. These include adding more load to the UFLS scheme and introducing dynamic arming for UFLS circuits in reverse flows. It also recommends a new protected event for the non-credible separation of South Australia, that will initially allow Heywood interconnector flows to be limited in periods when the UFLS schemes are not effective enough to prevent cascading failures and a potential black out.
In Queensland, there is potential need for new protected event declaration. Modifications to the existing Special Protection Schemes are required to be effective during periods of higher southerly flows. These are becoming increasingly frequent as new generation projects come online in north Queensland.
In stage 2 of the PSFRR, AEMO will consult more extensively with TNSPs and other stakeholders about the identified priority events. The stage 2 report is expected to be published in December 2020 (see Figure 1).
The review reveals issues with managing the grid as it transitions to include more renewable as well as distributed energy. Accordingly, the historic mechanisms designed to manage frequency are increasingly less effective.
The issue regarding disconnections as part of underfrequency load shedding is getting more complicated. This is due to the large volume of rooftop solar that may be causing feeders to reverse flow. Disconnecting these feeders would also remove the generation which would result in a net loss of generation further exacerbating the underfrequency issue. While this is currently being assessed for SA it should really be evaluated for the other states and developing action plans as rooftop solar penetration grows. Rooftop solar is set to double if not triple over the next decade across the NEM.
Interconnection is also identified as one of the major vulnerabilities in the NEM. NEM regions are, in reality, only lightly interconnected. While this is ok from a generation perspective with most generation originating in the same state, FCAS is procured globally. It seems AEMO can see the benefits of instigating local FCAS requirements, which could also assist to incentivise more providers to participate in emergency frequency control schemes (EFCSs).
In February and January of 2020, we saw 10 reviewable operating incidents, compared to 2, 6, 8 and 4 between 2016 – 2019. Stage 2 assessment is likely to find new alternatives that may provide contracting opportunities to stack revenues for flexible resources.