Shell Energy Australia, global oil and gas major Shell Plc's renewable energy business in the country, and AMPYR Australia (AMPYR) signed an agreement to develop a battery energy storage system, the companies said on Oct. 14.

The proposed 500-megawatt battery project will be built in the central west region of Australia's New South Wales (NSW) state, Singapore-based renewable energy firm AMPYR said.

The construction is expected to begin in the middle of next year, subject to all relevant approvals and financing.

Shell Energy will hold the rights to charge and dispatch energy once the project becomes operational, the companies said in a statement. They did not disclose the project's cost.

"[This] will be one of the largest battery storage projects in NSW, contributing to the reliability of the national electricity market and further advancing Australia's clean energy future," AMPYR director Ben Salmon said.

The environmental impact statement of the battery energy storage system project is expected to be released for public consultation later this month.

In June, NSW had said it would invest A$1.2 billion (US$760 million) in new transmission lines over 10 years to speed up connections to the grid for new renewable energy projects as the state looks to shift to greener power.

Battery energy storage is essential for preventing blackouts — amid coal-fired plants being retired in Australia — as it can absorb energy during the day when prices are cheap and release the energy when wind and solar power are not available, typically when prices are higher.