Australia’s most powerful battery finally reaches full capacity as replacement transformer energised

The most powerful battery to be built in Australia has finally reached full capacity – more than a year behind schedule – with the arrival and energisation of a new transformer, replacing the equipment that was damaged last year in a “catastrophic” incident.

The Waratah Super Battery is contracted to play a key role in Australia’s energy transition as a kind of giant “shock absorber” to the grid, and at 850 megawatts (MW) its capacity makes it the biggest in the country and also the most powerful machines of any type to be connected to the grid.

It has only two hours of storage (1680 megawatt hours) but that is largely because its revenue plans are focused on short duration market opportunities and grid security contracts – including the Security Integrity Protection Scheme (SIPS) it has landed, also the largest of its type.

The rollout of those plans were stymied last October when one of the facility’s three transformers failed in what the company described as a “catastrophic incident”, just as the battery was working through the last of its extensive commissioning processes.

A second transformer was also damaged, and had to be repaired, but one had to be entirely rebuilt by Australian company Wilsons Transformers.

The 170 tonne machine has now arrived on site, has been energised, and is ready to complete the testing that will enable the battery to operate at full capacity and deliver its 700 MW SIPS contract in full.

On Wednesday, at 2.15 pm, the battery was charging at what appears to be a record rate of 774 MW, at least for a five minute period, according to Open Electricity. Then, at 3.05pm, it injected 850 MW into the grid, reaching full capacity for the first time.

The Waratah Super Battery is one of the most watched projects in Australia, largely because of its size, its unique role in the grid, and because it is also built at the site of one of Australia’s shuttered coal fired power stations, Munmorah on the Central Coast of NSW.

It is owned and developed by Akaysha Energy, which has also delivered the Orana big battery in the central west of NSW – sized at 410 MW and 1640 MWh – and two smaller batteries in Queensland, Brendale and Ulinda Park.

The SIPS contract written for the Akaysha battery allows transmission lines feeding into the state’s major demand centres to operate at greater capacity, with the battery acting as the “shock absorber” to respond to any disturbances that might occur.

It was originally designed to support the grid after the expected closure of the Eraring coal generator, the country’s biggest, in 2025, but that closure has been delayed twice, now scheduled for April, 2029. However, the SIPS contract is still considered important to bring in more capacity from wind and solar projects in the regions.

The Waratah battery has been delivering half of its SIPS contract, initially with a single transformer and then with the help of the second transformer after it was put back into service in June.

Its operating limit until now has been 700 MW, but once the third transformer completes its tests, it will be able to operate at full capacity – although it will rarely do so because of the nature or the SIPS contract (essentially puts in on standby), apart from any lack of reserve (LOR) events.

Note: Story updated with latest activity that took battery facility to its full output for first time. Graph also updated.

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