The concept design of the Lake Lyell Pumped Hydro Energy Storage Project. (Credit: Arup)
Lake Lyell Dam. (Credit: Arup)
Mount Walker, Queensland. (Credit: Shiftchange/Wikipedia)

Lake Lyell Pumped Hydro Project is a utility-scale pumped hydro energy storage scheme proposed to be developed by EnergyAustralia NSW in New South Wales (NSW), Australia.

Currently in the feasibility stage, the project is proposed to have a capacity of 335MW for up to eight hours.

The estimated cost of the project is approximately A$1bn ($661m), subject to adjustments during the design phase.

In September 2022, the NSW Government awarded A$11m ($7.2m) to EnergyAustralia to support the feasibility studies of the project.

To support the feasibility study, EnergyAustralia submitted the development application of the project to the Lithgow Council in May 2023. The company released the concept design of the pumped hydro project in December 2023.

The decision to proceed with the development of the project is likely to be taken in the second half of 2025.

It will be followed by three to four years of construction. During the construction period, the project is expected to generate around 600 jobs.

Lake Lyell Pumped Hydro Project is expected to commence operations in 2029.

Once operational, the project will be capable of supplying renewable power to more than 150,000 homes in New South Wales for up to eight hours.

Lake Lyell Pumped Hydro Energy Storage Location

The Lake Lyell Pumped Hydro Energy Storage Project will be located in on the traditional lands of the Wiradjuri Peoples, approximately 110km west of the Sydney Central Business District and 5km west of Lithgow.

The site was selected due to the favourable attributes necessary for a feasible pumped hydro project. It would also be able to utilise existing infrastructure associated with Mt Piper power station.

The project site will be accessible from the south from the Great Western Highway via Magpie Hollow Road and Sir Thomas Mitchell Drive.

A new bridge across the Farmers Creek, an arm of Lake Lyell, will be constructed to reach the lower intake/outtake site.

EnergyAustralia owns the land and water at Lake Lyell, including some surrounding areas. Overall, the project area is approximately 760ha.

Lake Lyell Pumped Hydro Energy Storage Project Infrastructure

The Lake Lyell Pumped Hydro Energy Storage Project infrastructure will consist of a lower reservoir, an upper reservoir, a powerhouse, power waterway tunnels and shafts, permanent access tunnels, a high-voltage switchyard, and other ancillary infrastructure such as administrative building, workshops etc.

The upper reservoir will be constructed adjacent to the southern shoulder of Mt Walker and will be connected to the Farmers Creek arm of Lake Lyell, which would serve as the lower reservoir for the project.

The upper reservoir would have a storage capacity of approximately 4.4 gigalitres (GL) of water with a gross head of approximately 255m. Permanent intake structures will also be constructed to direct water to and from the powerhouse.

Lake Lyell water body, the lower reservoir, will be capable of holding 34.1GL of water. The permanently submerged intake/outtake structures will be located at the northeastern edge of the lake.

A dredged channel will be created as per the current design of the project to reduce the scouring of the lakebed and potential debris/sediment carryover during operations.

Both the reservoirs will be connected through power waterway tunnels and shafts allowing water flow between both reservoirs via pump turbines in the powerhouse. The waterways include a vertical penstock shaft, a horizontal penstock, and a tailrace tunnel.

For easy and safe access to the underground infrastructure, permanent access tunnels will be built.

The pump turbine equipment will be located in the underground cavern type powerhouse to be built between the penstock and the tailrace tunnels. It will comprise two pump-turbine units, auxiliaries and transformers to distribute the generated electricity to the high-voltage switchyard.

Power Transmission

The high-voltage switchyard will be located on the low hill at the south arm of Farmers Creek opposite the water intake/outtake structure’s location.

The switchyard will support distributing power to the National Electricity Market (NEM) of Australia.

The powerhouse will be connected to the existing TransGrid transmission lines 76/77 Sydney South- Wallerawang- Ingleburn 330kV.

A short transmission line will be used to connect the existing transmission lines via the switchyard to the powerhouse.

Lake Lyell Pumped Hydro Energy Storage Project is expected to operate for up to 80 years.

Key Contractors

EMM Consulting was associated with the preparation of the scoping report for the Lake Lyell Pumped Hydro Energy Storage Project.

Engineering firm Arup conducted preliminary studies and found the project to be technically feasible.

Infrastructure construction company McConnel Dowell refined the Lake Lyell project’s scope and design.