Australian City Turns To Compressed Air Project For Storage Of 1.5 GWh

Broken Hill, a city in rural New South Wales, Australia, has opted for advanced compressed air energy storage for energy storage. The project can be completed and commissioned by 2025, if not earlier. The advanced compressed air energy storage (A-CAES) technology, Hydrostor, has been proposed by a Canadian company recently releasing a statement that its 200MW/1,500MWh Silver City Energy Storage Center project was identified as the best-placed.

Compressed Air technology works on the same principle as Solar CSP. In this case, surplus electricity is used to compress air.

Capture Heat in Thermal Store. Heat is extracted from the air stream and stored inside a proprietary thermal store preserving the energy for use later in the cycle. Store the compressed air in a purpose-built cavern where hydrostatic compensation is used to maintain the system at a constant pressure during operation. Finally, Hydrostatic pressure forces air to the surface where it is recombined with the stored heat and expanded through a turbine to generate electricity on demand.

Hydrostor CEO Van Walleghem said the company can simply provide technology for customers, or as in the case of Broken Hill and its two California projects, can also seek out opportunities for projects and enter the development process itself. The Hydrostor technology is called ‘advanced’ compressed air because it makes some notable improvements on compressed air energy storage which has been in operation at two sites totaling 400MW in the US and Germany for many years.

The company also claims that unlike pumped hydro energy storage (PHES), A-CAES is relatively easy to site and construct, requiring far less space and water, while geoengineering is largely limited to underground cavern tunneling.

The long-duration energy storage (LDES) system would connect the stored energy with the National Electricity Market (NEM) and help the region’s capacity-constrained network free up space for more renewables. Marie Jordan, executive general manager of Transgrid networks, said the Hydrostor project is the high-voltage transmission network operator’s “preferred long-term solution… in the long-term interests of electricity customers”. “As we continue the transition to renewable energy, we must prioritise clean energy solutions, which support the nation’s goal of decarbonisation and its leadership in the renewable technology sector,” Jordan said.

A mining region in the western outback of New South Wales (NSW), Broken Hill has become host to a number of utility-scale solar PV and wind energy facilities. Hydrostor’s Silver City project has already been awarded a transmission reliability contract by the system operator.