EnergyAustralia pushes forward with 335 MW pumped hydro project

From pv magazine Australia

Electricity “gen-tailer” EnergyAustralia has unveiled design details for its proposed Lake Lyell Pumped Hydro Project, providing an overview of key project elements including the upper reservoir design, site access roads, underground powerhouse, the switchyard and water intake location.

It is expected the pumped hydro facility, located approximately 110 kilometers west of central Sydney, will be capable of producing 335 MW of renewable energy for up eight hours during periods of peak demand.

EnergyAustralia, which is also seeking to develop a battery energy storage system at the Mt Piper site which will be able to dispatch up to 500 MW of power for up to four hours, said the pumped hydro facility will provide firming and other ancillary grid services in the Central West region, and across the state.

The project proposes to use the 32-gigaliter Lake Lyell, which was specifically built to supply water to the 1.4 GW Mount Piper coal-fired power station that is scheduled to close in 2040, as a lower reservoir with a new upper reservoir to be built in a gully on the southwest flank of the adjacent Mt. Walker.

The concept design also outlines plans for a new underground powerhouse which will contain two pump-turbines and electrical transformers. This will be accessed via two tunnels from portals built on the north side of Farmers Creek.

The project will also incorporate existing transmission assets, with the facility connecting to the National Electricity Market (NEM) via a new switchyard that will link to the existing 330 kV transmission lines that pass through the project area to the south of Mt Walker.

EnergyAustralia Project Director Michael de Vink said the concept design emphasises the company’s commitment to mitigating environmental, cultural heritage and other important impacts through “site-sensitive” design.

“This includes changes made following consultation with the community and initial environmental studies,” he said. “The siting of key elements of the project takes advantage of the natural geography of the site to avoid visual impacts, mitigate environmental impacts and maintain lake recreational access for the community.”

De Vink said the concept design will allow EnergyAustralia to plan further studies to assess the project’s environmental impact and “progress with more detailed engineering design work.”

“The next step for the project is more detailed assessments and continuing community engagement,” he said, adding that environmental studies are currently underway with findings to be included in the project’s Environmental Impact Assessment which is expected to be on public exhibition towards the end of next year.

EnergyAustralia, which is owned by Hong Kong-based CLP Group, said the Lake Lyell project is currently in the feasibility stage with a decision on proceeding likely to be made in the second half of 2025. It is anticipated construction would take at least four years, meaning the earliest the facility could be operating is 2029.