Australia's huge and growing fleet of home batteries are delivering "enormous benefits" to grid, even without being connected to VPPs, AEMO chief says.

Batteries – big, small and in-between – are "fundamentally changing" the electricity system – while also changing the outlook for AEMO's grid blueprint.

Australia's huge and growing fleet of home batteries are delivering "enormous benefits" to grid, even without being connected to VPPs, AEMO chief says.