A detailed description of the capability of STORES to provide ancillary services. Provision of ancillary services is likely to be an important part of the economics of future storage plants.
Report extract
Provision of ancillary services is likely to be an important part of the economics of future storage plants. As noted by Kirby (2012), “The fast and accurate control capability available from most pumped storage plants and many hydro plants make them ideal providers of ancillary services” AEMO has a guide for ancillary services in the NEM that provides an overview of these services in Australia.
The existing pumped hydro facilities in Australia are typically not providing ancillary services as a major part of their operation. In the current market, pumped hydro sites are primarily used as peaking plant, generating in the early evening demand peak and pumping in the early morning demand trough. They are located in regions dominated by conventional thermal and hydro generation assets. Consequently, systems are not operating most of the time and are not providing significant ancillary services.
The histogram in Figure I shows the pumping and generating operation at five minute intervals of the Wivenhoe pumped hydro scheme in Queensland over the summer of 2017/18. In this 3 month period, a frequency of 90 would represent 100% operation at that time period. The highest usage is less than 10% for generation around 4pm and pumping at 4am with an average operation frequency of about 3.3%. In Queensland, the existing fossil fuel generation suite are dispatchable and provide most of the ancillary services.