The Australian Renewable Energy Agency (ARENA) (www.arena.gov.au) has announced $6 million of funding for Australia’s first energy storage project using compressed air. Canada-based Hydrostor will construct the Advanced Compressed Air Energy Storage (A-CAES) facility which will re-purpose the Angas Zinc Mine in Strathalbyn (60km south-east of Adelaide) and should become operational in 2020.

The $30 million commercial demonstration project will use the mine to develop a below-ground air-storage cavern that uses an innovative design to achieve emissions-free energy storage. The facility will provide synchronous inertia, load shifting, frequency regulation and support for grid security and reliability.

Using the existing mine will help to increase the renewable-energy supply to the South Australian and national energy grid, while also converting a brown-field site into a clean-energy hub.

Hydrostor also received $3 million of funding from the South Australian Government (through its Renewable Technology Fund).

The technology uses electricity from the grid to produce compressed air, which is stored in a purpose-built underground cavern kept at constant pressure using hydrostatic head from a water column.

During charging, heat from the compressed air is collected and stored, before the cooled air pushes water out of the cavern up to a reservoir on the surface.

To discharge, water flows back into the cavern, forcing air to the surface under pressure, where it is heated with the stored thermal energy and used to drive a turbine and generate electricity.

A-CAES has similar applications to pumped hydro systems. Most notably, it can provide the fast response required to ensure reliability of the power system, as more solar and wind power systems are installed.