# Origin Energy Commissions $400M 300 MW / 650 MWh Mortlake BESS with Grid-Forming Inverters in Victoria

> Delivered ahead of schedule by EPC partner Fluence Energy and co-funded by ARENA, the 300 MW / 650 MWh Mortlake battery system delivers critical virtual inertia, system strength, and peak-firming capability to Australia's National Electricity Market (NEM).

- **Publish Date:** 2026-09-18
- **Category:** energy-storage
- **Reading Time:** 4 min
- **Original Source Citation:** [Origin Energy & Australian Renewable Energy Agency (ARENA)](https://www.originenergy.com.au)
- **Tags:** BESS, Origin Energy, Grid Forming, Australia, Fluence, System Strength, Victoria
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## Accelerated Commercial Operation Ahead of 2026–2027 Summer Peak

Origin Energy has officially commenced commercial operation of the Mortlake Battery Energy Storage System (BESS), situated adjacent to the Mortlake Power Station in south-west Victoria. The approximately $400 million AUD installation was completed ahead of its initial late-2026 timeline.

With a nameplate output of 300 MW and 650 MWh of usable energy capacity, the facility absorbs daytime rooftop and utility-scale solar generation, discharging clean electricity during evening peak hours to supply approximately 140,000 households.

## Grid-Forming Inverters Emulating Synchronous Generator Stability

Supported by the Australian Renewable Energy Agency (ARENA) and engineered with Fluence Energy, Mortlake is equipped with advanced grid-forming inverter technology that allows the battery units to establish reference voltage and frequency waveforms independently.

As conventional coal-fired thermal generation retires across southeastern Australia, the facility delivers vital synthetic inertia, system strength, and fast frequency response (FFR), replacing the mechanical rotational momentum historically provided by spinning turbines.

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