Energy Australia undertook a feasibility study to determine the technical and economic feasibility of a seawater pumped hydro energy storage (PHES) plant located at Cultana, to the south-west of Port Augusta in South Australia.
Report extract
One of the main challenges faced by the Australian energy sector is integrating a growing share of renewable energy sources in the electricity generation mix, while preserving the security and affordability of energy supply. Grid-scale energy storage is expected to play a key role in the gradual transition from dispatchable fossil-fuel fired generation to intermittent renewables by supporting the reliability of electricity supply and stability of the grid.
Many renewable energy developers are considering options for coupling battery storage with solar and wind power plants to effectively provide dispatchable energy. In addition, solar and battery hybrids are already becoming a viable alternative to reduce the dependence on diesel-fired generation in off grid locations. However, at current prices, battery storage does not appear to be financially viable to firm up large scale renewable energy supply into the electricity grid.
Pumped hydro energy storage (PHES) is expected to provide a viable solution for firming up intermittent renewables – it offers large capacity storage with longer hours of energy supply, and a long asset life. PHES utilises electricity at times of low demand or excess supply to pump water to the upper reservoir and returns the power to the grid through the turbine at times of high demand. In addition, PHES can provide a range of ancillary services critical to grid stability, such as inertia, voltage, frequency support, and system restart capabilities.