On 19 February 2016, the Australian Energy Market Operator (AEMO) published a joint report with ElectraNet on network reliability given the high penetration of renewable energy in South Australia.
The report finds that under normal operating conditions (i.e. with no equipment failure) the SA power system can continue to operate securely and reliably. However, the stability of SA’s electricity supply does however rely heavily on the transmission network (Heywood Interconnector) connecting SA to Victoria remaining in service and uninterrupted.
The report explains that typically, large conventional power stations have provided power system support services, such as frequency and voltage control. Some large generators are exiting the SA market and SA leads Australia with regards the penetration of renewable energy systems. With fewer large generators, advances in battery storage, increasingly active consumer behaviour, and demand patterns continuing to shift and challenge traditional profiles the report suggests that these power system support services need to be sourced by other means.
The report notes that ElectraNet is exploring potential network solutions to help address the emerging challenges of the changing generation mix, including a new high capacity interconnector between SA and the eastern states and the potential role of grid-scale electrical storage.
ElectraNet is the transmission network service provider for SA and works closely with AEMO to maintain power system security. The 2015 Report follows on from the initial report published in October 2014.
The ability to maintain system frequency at around 50Hz is critical to maintaining power system security. Frequency control support services provide a fast injection of, or fast reduction in energy to balance supply and demand and thereby maintain frequency within acceptable limits following a power system event or incident.