The Angas A-CAES Project will be sited at a mine 50 km southeast of Adelaide—the Angas Zinc Mine near Strathalbyn, currently in care and maintenance. By selecting this site, the project will repurpose existing underground mining infrastructure as the A-CAES system’s sub-surface air storage cavern, benefiting both the electricity grid in South Australia and the local community by converting an unused brownfield site into a clean energy project that drives economic development.


The project's proximity to Adelaide will enable the system to deliver substantial value to the South Australian electricity network. 


Hydrostor’s Angas Project is Australia’s first Advanced Compressed Air Energy Storage (A-CAES) facility. A-CAES is an emissions-free, long duration energy storage technology, uniquely suited to enable the transition to a cleaner, more reliable electricity grid. It combines mining techniques with state-of-the-art mechanical systems to produce a fuel-free, grid-scale energy storage system using compressed air that can be flexibly sited.


The 5 MW facility will be dispatched into the National Electricity Market (NEM) to provide synchronous inertia, load shifting, frequency regulation, and support grid security and reliability. It will also enable the integration of variable renewable energy resources, such as solar and wind. The project demonstrates A-CAES as new flexible capacity and grid stability technology.


The project has been awarded a combined total of $9 million of grant funding from the Australian Renewable Energy Agency (ARENA) and the Government of South Australia Renewable Technology Fund and is expected to be in service in 2020.


Hydrostor acknowledges Terramin Australia Limited support in developing this project and its beneficial application to South Australia. 


Angas Zinc Mine - Future Site of Hydrostor's Angas

A-CAES Project

A-CAES 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 a purpose-built 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. For an animation on how the technology works, see



The proposed facility will consist of the three surface components:


  1. Energy-conversion plant

  2. Electrical and controls module

  3. Water reservoir


The project will repurpose portions of the existing underground mine as the A-CAES system’s storage cavern as indicated in the underground schematic.

3D Model of Aboveground Angas A-CAES Project Infrastructure

Underground Schematic of Angas A-CAES Project


Renewable Energy

Firms renewable energy and provides emissions-free capacity, increasing grid reliability and stability.


Economic Growth

Provides diversified job opportunities and develops a new industry sector for the region.


Skills Development

Acts as an innovation hub to inform investors, industry practices, and provide training.


The views expressed herein are not necessarily the views of the Australian Government, and the Australian Government does not accept responsibility for any information or advice contained herein.


+ 1 (416) 548-7880

Canada Office

365 Bay Street, Suite 300
Toronto, Ontario,
Canada, M5H 2V1

Australia Office

431 King William Street, Level 13,
Adelaide, South Australia,
Australia, 5000


The Unreasonable Group logo
  • White LinkedIn Icon
  • White YouTube Icon

© 2018 by Hydrostor Inc.

Hydrostor logo, an Advaced Compressed Ai Energy Storage (A-CAES) tecnology company