Neoen’s Collie battery to be Australia’s biggest after winning new contract to flatten solar duck

French renewable energy and storage developer Neoen is to nearly triple the size of its already giant Collie battery, making it the biggest in the country after winning another contract to help flatten the growing solar duck curve and fill in for coal in Western Australia.

The contract win means Neoen will add a 341 MW, 1363 MWh second stage battery to the Collie facility. Its first stage, already under construction, is sized at 219 MW and 877 MWh. Both are to be built with Tesla Megapack batteries, and by contractor UGL.

It will mean the Neoen Collie battery will be sized at a total 560 MW and 2,240 MWh, and will be the biggest in Australia, trumping Synergy’s 500 MW, 2000 MWh battery that is under construction just a few kilometres away in Collie, and the 275 MW/ 2,200 MWh eight hour battery that Ark Energy will build at Myrtle Creek in NSW.

Neoen says the combined battery will have the ability to “charge and discharge 20 per cent of the average demand” in W.A.’s main grid, known as the South West Interconnected System.

It will also signal a remarkable transition in the coal-town of Collie, where the state’s remaining coal fired power generators are expected to be shuttered within the next five years.

Coal is still providing around 40 per cent of WA’s annual electricity demand, but is being marginalised by the growing influence of rooftop solar and other cheaper renewables, and by its own surging costs, reliability issues and pollution.

Together, the two Collie batteries owned by Neoen and Synergy will be able to provide up to 40 per cent of the average demand in the SWIS, and will play a key role – along with other batteries at Kwinana and Wagerup, is soaking up excess solar in the middle of the day, and discharging into the evening peaks.

It’s similar to the transformation in California, where battery storage is accounting for nearly 30 per cent of supply in the evening peaks. The remarkable thing about WA’s SWIS is that it is an isolated grid, with no connections to other states or countries.

Neoen says that Collie Battery Stage 2 is contracted to provide 300 MW of storage capacity for 4 hours discharging across the evening peak. “This is intended to address the risks AEMO has identified related to the retirement of coal power plants, high penetration of rooftop solar and increasing energy demand in Western Australia,” it says.

Jai Thomas, the coordinator of energy in W.A., says the new Collie battery is another important step toward a greener and more resilient power system.

“Once complete, the battery will be a massive boost for energy storage and stability in the South West Interconnected System,” Thomas said in a statement.

Kate Ryan, the W.A. general manager at the Australian Energy Market Operator, also said the Collie Battery will play an important role as “we navigate through Western Australia’s energy transition,” and would support the state’s future energy needs as coal-fired generation retires.”

The contract awarded by AEMO is for so called Non-Co-optimised Essential System Services (NCESS) – and requires big batteries to soak up solar for a period of four hours and discharge that capacity for four hours across the evening peak.

The initial contracts – which have also been won by Synergy’s Kwinana battery, the Collie batteries and Alinta’s Wagerup facility, will run for two years from October, 2025, when more coal units are due to be retired.

It could also deliver another big windfall for Neoen, which upped its forecast earnings for the 2025 year by nearly $150 million after the first stage of its Collie battery won the initial contract last year.

Neoen built Australia’s first big battery at Hornsdale in 2017 – known then as the Tesla big battery – and has since added the Victoria Big Battery, which remains the biggest in the country for the moment, and the smaller Bulgana battery in Victoria.

It is also building the Capital battery in the ACT, the Blyth battery in South Australia, which will help supply “baseload renewables” to BHP’s giant Olympic Dam mine, and the Western Downs battery in Queensland. It has numerous others in the pipeline. The Collie batteries are its first four-hour battery projects.

Neoen chairman Xavier Barbaro said long duration storage is becoming a clear need for electricity networks in transition, particularly as new constraints emerge.

“Neoen is at the forefront of designing solutions to meet this need, as this wonderful new success of Collie Battery Stage 2 demonstrates,” he said.

“It is thanks to its speed, agility and competitiveness that Neoen will play a vitally important role in energy storage in Australia, and around the world.”

It is expected more contracts with battery projects for the NCESS service will be announced by AEMO, which was seeking up to 440 MW of battery (with fours of storage) in its latest NCESS tender.