Plans to install a big battery with up to six hours storage in a sweet spot between a coal generation hub and major electricity demand centres have been waved through the federal green queue.

German energy giant RWE says it received official sign-off to operate Australia's first eight-hour battery energy storage system at full capacity.

RWE has received official sign-off from the AEMO and Transgrid to operate Australia's first 8-hour BESS at full capacity.