Edge have investigated seasonal trends from FCAS cumulative costs, specifically with regards to lower FCAS. Raise FCAS charges are paid by the causer (generator), and lower FCAS charges are paid for by the consumer.
Firstly, considering the raw data, we can observe that there does appear to have been some increase in total FCAS charges by year, however specifically, we can see that these mostly come in large spikes in one state’s FCAS charges in a specific month, as opposed to all states growing proportionally.
Excluding the monthly breakdown, the data shows FCAS charges growing from 2018 to 2022, with a reduction in 2023. Notably, the summer of 2024 and the December 2023 period were under the RRO in SA, and the summer was notably mild compared to forecasted conditions, which may have impacted FCAS pricing during that period.
An analysis of the monthly data reveals state-specific seasonal trends, occasionally disrupted by anomalies or significant events. Analysing the monthly patterns for each state reveals the following seasonal effects:
In New South Wales, FCAS charges are typically lower in the winter, increasing from August to January before declining.
In Queensland, FCAS charges primarily occur from August to November, though Queensland remains highly reactive, with spikes in March and May reflecting this behaviour.
South Australia reflects behaviours from both New South Wales and Queensland, where FCAS charges rise post-winter and through spring, with significant spikes in 2020 and 2019 elevating the averages for February and November, respectively.
Tasmania has no obvious seasonal effects observed with prices remaining relatively consistent throughout the year.
Victoria mimics behaviours similar to New South Wales, with low FCAS charges in winter, increasing from August to January before declining.
Depending on the state, strategies could be developed to proactively lower FCAS charges, particularly in response to sudden frequency deviations over short periods. Energy users can deploy onsite batteries or demand side response abilities, that discharge during periods of high FCAS pricing to provide spontaneous services.
The highest payout services are predominantly Lower slow 60sec and Lower fast 6sec, which require batteries capable of responding within the specified 60-second and 6-second windows. While there is a very fast FCAS market (1-second raise / lower), this market is currently used less compared to the standard 6/60-seconds markets.