Page - 203 - in Book of Full Papers - Symposium Hydro Engineering

energy cannot be dispatched unless it has been stored in some way. With increasing proportions of renewable generation in the energy mix, the dispatchability of generation to meet demand becomes more important, as shown in Fig 3. Once way of improving the dispatchability of renewables is to add storage in the power system Fig. 3 Comparison of a baseload dominated electricity system (left) and a variable and dispatchable model (right) [4] There are a number of different types of storage but the two being discussed most widely right now are batteries and pumped storage hydropower. These two technologies are very different and there are some limitations involved in comparing a well-known and established technology, like pumped storage, with one that is new and developing rapidly, like battery technology. Pumped storage hydropower is based on well-established synchronous generation, providing critical ancillary services to the grid, through the provision of inertia, frequency and voltage support and sufficient fault level support. Battery inverter technologies are still catching up on most of these fronts. The potential for batteries to provide ‘synthetic inertia’ or fast frequency response is high but they rely on system strength to be able to deliver this support. They offer minimal support with fault levels but can still provide some support to system frequency and voltage regulation. Recent electricity price spikes and a state-wide blackout in the state of South Australia have highlighted the need for reliable power to balance the potential volatility of some renewable power sources. 2.2. HYDRO STORAGE PROJECTS With an increased amount of renewable energy within the Australian grid, hydro storage has gained increased attention. Whether this be pumped storage hydropower, like the Kidston pumped storage project in Northern Queensland, or better use of existing hydropower storages, like Tasmania’s “Battery of the Nation” concept. Since connecting to Australia’s National Energy Market via the Basslink interconnector in 2006, the flexible hydropower system of the island 203