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 was a hydroelectric energy storage plant developed 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 would have stored 3.5 gigalitres of water to flow through turbines generating 225MW of electricity for up to 8 hours.

And, to ensure the scheme was not a drain on vital fresh water resources, it utilised readily available seawater as the working fluid.

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 three 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  Cultana pumped hydro energy storage concept. 

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

This funding was used to complete the project design, including detailed engineering work, geotechnical investigations, equipment specifications, environmental impact studies and design of grid connection works.

Meanwhile, there was extensive  consultation with all stakeholder groups. For further development, the project was contingent on securing a land lease from the Department of Defence which was unsuccessful. 

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 used seawater to drive the turbines. Unlike 97% of the world’s existing hydro systems this scheme would not consume precious fresh water resources, a key sustainability factor in Australia’s dry environment.

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

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

You may be interested in...