Chinese solar giant Trina Solar has unveiled plans to build Australia’s largest energy storage facility at Kemerton, an industrial estate south of Perth.

The proposal involves building a facility with a capacity of up to 660 megawatts (MW) and a storage capacity of 2,640 megawatt-hours (MWh), which would be larger than the 560 MW, 2,420 MWh Collie Battery currently being built by Neoen in the same state, and the 275 MW, 2,200 MWh Richmond Valley Battery proposed by Ark Energy in New South Wales.

The size of large battery projects is growing rapidly, with many new projects being about 20 times larger – in terms of storage – than Tesla’s original large battery at Hornsdale, which began in 2017 as a 100 MW, 129 MWh project and was later expanded to 150 MW and 197 MWh.

There are at least three major battery projects in Western Australia with capacities in excess of 2000MWh currently underway, with two already under construction – a Neoen battery in Collie and another of 500MW, 2000MWh being built by state-owned Synergy in the same town.

Collie is home to the last remaining coal-fired power generators in the state, all of which are due to be retired by 2030. Because the main WA grid is isolated and not connected to any other grid, it must rely on its own internal resources to provide system services and storage needs to meet demand requirements.

Modelling by the state government predicts demand is set to rise significantly in the coming decades, largely due to the development of new, energy-intensive green industries seeking cheap, carbon-free renewable energy sources.

The state is predicting that there could be a need for 50 gigawatts (GW) of new wind and solar power in the coming decades, all of which would need to be backed up by battery storage.

Trina’s proposed Kemerton Battery will be sited on approximately 19 hectares of land that was previously cleared for sand mining and is currently located on an industrial estate south of Kwinana, just 3km from the main connection point at Kemerton Terminus.

“The sand mining operation is nearing completion, providing an opportunity to rezone the site to meet the state’s renewable energy goals,” reads a planning application submitted to Harvey County Council.

Interestingly, the 2,000-hectare Kemerton industrial estate has been the site of several previous proposals, including one from Carnegie Clean Energy more than five years ago and a 200MWh project proposed by Neoen in 2022, which was rejected by planning authorities, according to ABC reports.

Interestingly, in February of this year, Sunrise Energy proposed building a 100 MW, 400 MWh battery in exactly the same location, on land also owned by Lyndon Edwards.

The Kemerton battery is one of three battery storage projects being developed by Trina Solar in Australia, with the company already developing the 500MW and 1000MWh Kiewa Valley BESS project in Victoria and the 270MW and 540MWh Augusta BESS project at Port Paterson in South Australia.

Trina says the Kemerton battery will charge during the day by absorbing excess solar energy generated by rooftop solar panels on homes and businesses across the state and a growing number of large-scale solar farms. It will feed electricity back into the grid during peak evening hours.

Trina says the battery will also increase the reliability of the proposed wind resource in the southern region by stabilising its production.

Construction is expected to begin in the third quarter of 2026 and last about two years. The company says it is still working on combined studies and detailed design. The project will require 800 battery units and 200 inverter units, but a contractor and suppliers have not yet been selected.

For more information on battery storage projects, see Renew Economy’s map of large-scale battery storage sites in Australia.