South Australia is widely known as being the State with the largest proportion of variable renewable electricity (wind and solar PV) within Australia. This is expected to increase into the 50-100% range in the coming years. Interconnection with other regions, demand management and local storage are needed in order to ensure stable and affordable supply into the future. Pumped hydro energy storage (PHES) is the most mature and widely deployed electricity storage technology worldwide – 97% of globally installed grid storage is pumped hydro.

Although Australia is known to be arid, there is ample water to allow the use of closed-cycle PHES systems to balance the electricity grid. We calculate the annual requirement to be less than 1% of South Australia's annual extraction from the Murray River.

These sites were found using algorithms with defined search criteria within a geographic information system (GIS) platform. This platform was used to find detailed information, such as head, reservoir areas, and storage capacity. This list is not yet exhaustive – for example, mining pits have not yet been analysed. We are also in the process of developing a cost model that will determine the least cost option for the tunnelling between two reservoirs, and therefore the location of the lower reservoir. This information will be available in future releases of the SA atlas.

A simplified cost model can also be downloaded below.