First stage BESS at Mortlake Energy Hub grows to 1,449 MWh as EPC deal signed

While Origin Energy in Australia has just completed a battery energy storage project at the Mortlake Power Station in western Victoria, the Mortlake Energy Hub is separately progressing with the first stage (MEH-1) toward construction with major contracts signed.

Yanara, formerly BrightNight Asia Pacific, has signed an A$790 million engineering, procurement and construction contract with Gamuda Engineering for MEH-1. The companies had already worked together during an early contractor involvement phase covering design, procurement and construction planning. It will be Gamuda’s first major project in Victoria, with its parent company based in Malaysia.

The first stage pairs 435 MWp of solar with a 1,449 MWh battery. That is an increase from the 1,200 MWh specification Gamuda previously gave for Stage 1. Gamuda’s announcement also describes the battery as 300 MW with a 4.5-hour duration, although those figures do not reconcile with the 1,449 MWh capacity in the contract disclosure. ESS News has contacted Gamuda for clarification.

The project will connect to Victoria’s 500 kV network through the Mortlake Terminal Station. Gamuda expects it to be energized in April 2028 and begin operations in the first quarter of 2029.

The wider energy hub has been described as a 450 MW solar farm with a 600 MW / 2,400 MWh battery across two stages, and that scope changed in December 2025, with the solar plant upgraded from 350 MW. The latest first-stage duration for the BESS therefore also leaves the eventual capacity split between the stages unclear.