August 6, 2019: Australia’s government gave the go-ahead in July for the country’s first compressed air energy storage facility, to be provided by Canadian firm Hydrostor’s Australian subsidiary Hydrostor Australia.
The 5MW Angas A-CAES project, costing A$30 million ($20.7 million), to be sited at the Angas Zinc Mine near Adelaide, will provide synchronous inertia, load shifting and frequency regulation to support grid security and reliability for Australia’s National Electricity Market.
The project will repurpose existing underground mining infrastructure to install the sub-surface compressed air system, thus converting an unused brownfield site to a clean energy project.
A total of A$9 million ($6.2 million) in grant funding has been awarded to Hydrostor for the project, A$6 million from the Australian Renewable Energy Agency and A$3 million from the government of South Australia through its Renewable Technology Fund.
“Compressed air storage has the potential to provide similar benefits to pumped hydro energy storage, however it has the added benefits of being flexible with location and topography, such as utilizing a cavern already created at a disused mine site,” said ARENA CEO Darren Miller.
The technology works by using electricity from the grid to run a compressor, producing heated compressed air. Heat is extracted from the air stream and stored inside a proprietary thermal store, preserving the energy for use later in the cycle.
Compressed air is then stored in the underground cavern, which is kept at a constant pressure using hydrostatic head from a water column.
During charging, compressed air displaces water out of the cavern up a water column to a surface reservoir, and during discharge water flows back into the cavern forcing air to the surface under pressure, where it is re-heated using the stored heat and then expanded through a turbine to generate electricity on demand.