View of the sun from under the water; View of the sun from under the water;

Cultana pumped hydro energy storage project, South Australia

World’s largest saltwater pumped hydro for South Australia

The Cultana pumped hydro energy storage project is a hydroelectric energy storage plant being planned for the Australian Defence Force’s Cultana Training Area, near the north-western tip of the Spencer Gulf in South Australia. 

When complete, the scheme will be able to store 3.5 gigalitres of water to flow through turbines allowing the generation of 225MW of electricity for up to 8 hours.

And, to ensure the scheme it is not a drain on vital fresh water resources, the plan is to utilise readily available seawater.

Project Summary


225MW of electricity generated for up to 8 hours

3.5gigalitres of water flow

When a catastrophic power grid failure plunged South Australia into darkness in September 2016, it caught many by surprise, creating debate about how we best provide for Australia’s future power needs.

While the causes of the failure were discussed, few knew that for the previous 3 years a talented team of Arup researchers, designers and engineers were already looking into South Australia’s future energy needs. Funded through Arup’s Global Research Challenge, the team analysed energy generation, need and capacity, identifying significant risks that could lead to uncertainty surrounding the ability to deliver power to the region’s homes and businesses.

From this research with Melbourne University’s Melbourne Energy Institute came the Cultana pumped hydro energy storage project. 

It is being developed by Arup and EnergyAustralia with funding assistance from both the Australian Renewable Energy Agency (ARENA) and South Australian Government.

The project received a second round of funding from ARENA and the South Australian Government Renewable Technology Fund in 2018 in order to continue feasibility studies and advance the project to a final investment decision. 

This funding is being used to complete the project design, including detailed engineering work, geotechnical investigations, equipment specifications, environmental impact studies and design of grid connection works. Ongoing consultation with all stakeholder groups will also continue to ensure any potential concerns or issues can be appropriately addressed. 

The estimated time to build and commission would be three years.


What is pumped hydro?

Pumped hydro works by linking two bodies of water, usually held within dams, one higher than the other, allowing water to flow through turbines between the two when energy is required. The higher dam acts like a battery, storing the potential energy of water that can be released on demand; meaning that, within minutes, electrical energy can be delivered to the grid.

During off-peak times, when energy is cheap to use, the system pumps water from the lower dam to the upper dam, recharging the battery.

How pumped hydro works How pumped hydro works

Why is this project different?

In an innovative, sustainable design, the Cultana Pumped Hydroelectric Energy Project will use seawater to drive the turbines. Unlike 97% of the world’s existing hydro systems this scheme will not consume precious fresh water resources, a key sustainability factor in Australia’s dry environment.

When complete the scheme will deliver the equivalent of 60,000 home battery storage systems, but at one-third of the cost. Power will be available on demand, so when South Australia swelters through summer, pressures on peak demand is mitigated.

And whilst freshwater schemes have been in operation globally for a number of years, this scheme will be the second example of a seawater pumped hydro storage plant anywhere is the world and it would also be the largest.

Arup’s research identified significant opportunities for large-scale storage solutions to enable further renewable utilisation, whilst maintaining grid stability and certainty of delivery. ”

Mike Straughton Mike Straughton Australasia Environment and Resources Leader