The Stanwell Battery project is closing in on another important milestone with the energisation of its two high‑voltage transformers.

During Stanwell’s recent Energy Exchange roadshow, Stanwell’s CEO Michael O’Rourke, EGM Energy Markets Steve Quilter and EGM Business Services Sophie McNaughton took the opportunity to tour the Stanwell Battery site, receiving a firsthand update on the project’s progress.

Energising the 275kV to 33kv power transformers means they will be safely connected to live electricity for the first time and marks a significant step forward as the project transitions from construction into testing and commissioning.

The process will kick off on 16 May, with energy supplied to the Stanwell Battery substation. Then, over the next seven days, a series of power quality tests will be run before switching on the two large transformers.

On 23 May, transformers will be powered up and allowed to absorb energy for 24 hours. After that, the rest of the battery’s systems, excluding the individual Megapack units, will be gradually energised. These systems include the 33kV switch rooms, collector feeders and the medium voltage transformers that connect every individual BESS unit to the 33kV network.

This step-by-step process will take several months to finish.

The transformers play a critical role in how the large‑scale battery will operate.

They allow electricity to be safely converted to the correct voltage so energy can flow between the battery and the Stanwell switchyard, enabling the battery to both charge from the grid and discharge electricity back into the National Electricity Market when required.

This energisation process is carefully planned and carried out under strict safety procedures.

While energising the transformers is a major achievement, it does not mean the battery is supplying power yet. Additional testing and commissioning will continue to ensure the system is safe, reliable and fully ready to commence operations in early 2027.