Western Sydney Pumped Hydro Project

Proposed Western Sydney Pumped Hydro Project

The Western Sydney Pumped Hydro (WSPH) is a project proposed by ZEN Energy to repurpose a disused coal washery site on the eastern side of Lake Burragorang, approximately 24km upstream from the Warragamba Dam wall.

The WSPH project will store energy during periods of surplus electricity generation and has the potential to deliver 1GW (1,000 megawatts) of on-demand electricity for up to eight continuous hours at peak times to 500,000 local homes.

WaterNSW has awarded ZEN Energy a development agreement following a competitive tender process. It is the fourth agreement under the WaterNSW Renewable Energy and Storage Program following the announcement of ACEN Australia’s proposed Burrendong pumped hydro project in December 2022 and the Upper Hunter Hydro projects at Glennies Creek and Glenbawn dams in February 2024. ZEN Energy is an Australian-owned and operated energy retailer.

Under the agreement, ZEN Energy will get access to WaterNSW land and reservoirs to support the development of a pumped hydro project through the feasibility and planning stage.

During this initial stage, ZEN Energy will seek to secure all necessary approvals and consent for their projects. If successful, the company will then enter into an agreement with WaterNSW to undertake construction and operation of the project.

Should the project proceed to construction, it is expected to create approximately 1500 construction jobs and 80 ongoing operations jobs.

As custodians of Sydney’s water supply, our most critical factor in considering this proposal was making sure that the project does not impact the quantity or quality of the water supply from Warragamba Dam at any stage.

The project site is a significant distance, so 24km away, upstream from the dam wall where water is extracted for delivery and is then treated by Sydney Water.

WaterNSW has conducted a water quality risk assessment on all aspects of the proposal and we will continue to do our own analysis regularly, during the planning and approval processes.

Graphic that explains the pumped hydro process.

Frequently asked questions

Who will own the project?

ZEN Energy, Australia’s first 1.5°C energy company, is behind the proposed project.

ZEN is Australian owned and operated, and is focused on delivering renewable energy across Australia with development projects in South Australia and New South Wales.

ZEN also supplies electricity to customers including Bunnings in Victoria and South Australia, CSIRO in New South Wales, Victoria, and the Australian Capital Territory and the Southern Sydney Regional Organisation of Councils (SSROC) which comprises 25 local councils in New South Wales, four of them in the top ten by size.

WSPH neighbouring councils, Campbelltown, and Liverpool, are ZEN customers and are both currently sourcing 70 per cent renewable electricity for their communities. Through SSROC, ZEN is providing energy to some of Sydney’s most iconic community assets like North Sydney’s Olympic pool and the Bryian Brown theatre in Bankstown.

For WSPH, ZEN is working with SADA Group which has been successfully rehabilitating the coal washery site at Nattai. WaterNSW has granted ZEN the right to access Lake Burragorang – via a competitive process - to undertake feasibility studies and start working with the community to shape the project.

What benefits will the project deliver?

  • 1500 construction jobs and 80 operations jobs (regional, total; construction, ongoing).
  • Capable of powering over 500,000 homes power for 8 hours. That is enough to power all nearby local communities (Wollondilly, Camden, Liverpool, and Campbelltown) nearly 3 times over, or close to 30% of all homes in Sydney.
  • The project will also invest in the local community through a community fund.

The WSPH aims to share significant economic and non-financial benefits of the project with local community stakeholders and Traditional Owners, subject to early and ongoing engagement and co-design. These include:

  • contribution of a $1 million per annum Community Benefit Sharing Scheme for the local community, nearby landowners, Traditional Owners and First Nations communities which will be co-designed according to local needs and plans
  • $5 million initial funding injection to the community for supporting identified value-add projects and initiatives, and an additional $5 million every 10 years into a community fund
  • during construction, there is the potential to upgrade associated WaterNSW infrastructure, local roads and surrounding community amenities
  • income opportunities for local businesses and service providers.

How is WaterNSW involved?

WaterNSW is the owner and operator of the lake and relevant surrounding land.

ZEN has been granted the right from WaterNSW to access the site and undertake investigative studies for WSPH, following a competitive tender process in 2022. This key step has also triggered ZEN’s ability to engage early with key local stakeholders.

ZEN will work closely with WaterNSW as the project develops and comply with requirements and strict regulations that apply to the site.

The project will be developed solely by ZEN, not the NSW Government or WaterNSW.

Why is WaterNSW considering a renewable energy project like this on its land and assets?

One of our strategic priorities at WaterNSW is to help build a sustainable future and we have a terrific opportunity, being one of the largest landholders in the state, to use our land and assets in a more sustainable and responsible way.

WaterNSW has been seeking private sector investment in renewable energy generation and/ or storage projects, such as pumped hydro on WaterNSW land and assets in a bid to support NSW energy security and importantly support the achievement of the NSW Government renewable energy objectives that are outlined in the NSW Electricity Strategy.

How does pumped hydro work?

Pumped hydro is the most common and efficient method for long-term storage of energy in the world. It works like a large natural battery, using water to store and generate energy.

When there is extra electricity available from solar and wind, water is pumped uphill from a lower reservoir to an upper reservoir. This water is then released to generate electricity via a turbine during periods of high demand, like dinner or breakfast time.

By using the movement of water to produce renewable energy, power is available to be used when needed.

This proposed plant will be very efficient, and able to make energy available in just minutes for up to 8 hours. Most battery technologies available today last only 2 hours. With a lifespan of 70-100 years, pumped hydro assets also last five times longer than current battery systems.

There are many operating examples of pumped hydro projects in Australia and around the world used for water supply and electricity, including the Shoalhaven Scheme in southern NSW.

Why was this site chosen for pumped hydro?

The site meets various suitability factors needed for pumped hydro:

  • It is steep enough – the site has a large 400m elevation change over 3.1km supporting the requirements to efficiently generate electricity from hydro power.
  • Available water – the site has a secure and accessible water source, with existing lower reservoirs and upper reservoir in a former coal washery, avoiding the need to develop new water storages in natural undeveloped locations.
  • Close to transmission – the site is close to existing transmission lines and renewable energy zones, with good site access, suitable geology, land availability and appropriate land zoning.
  • Low impact – from preliminary investigations, there will be minimal adverse impact on the environment, culture, and community. Detailed studies and engagement with local Traditional Owners and interest groups will be commencing in the near future.

Will the project impact Sydney’s water security?

The project will not impact Sydney’s water security.

The WSPH scheme will not impact the Warragamba operations and drinking water can be extracted as usual, even during drought.

Water required by the project – should it proceed – is utilised in a continuous loop, rather than actually lost. The amount of water being cycled will be less than 0.5% of the volume of Lake Burragorang, much less than the amount lost from the lake each year through evaporation (around 2-3%).

Will the quality of Sydney’s drinking water will be affected? 

No. The operation of WSPH will not negatively impact the quality of Sydney’s drinking water and this consideration will be a key component of the planning impact assessment phase, should the project proceed.

A water quality monitoring plan will be developed in conjunction with WaterNSW to ensure there is no impact on water quality. The project will also be subject to rigorous and robust planning assessments, regulations and management plans for water quality and security.

Will you extract water in dry conditions / in times of drought? 

The WSPH project will not impact WaterNSW’s ability to provide water during drought events.

There are agreements in place between WaterNSW and ZEN to ensure the WSPH scheme does not impact drinking water availability during a drought.  

Since Warragamba Dam was first constructed in the 1960s, the lowest the water volume has dropped during drought is 37% of its full capacity. The pumped hydro scheme has been modelled at this low level and can continue to operate with no impact to water supply.


Renewable Energy and Storage Program enquiries should be directed to:

WaterNSW Renewable Energy and Storage Program Engagement team

Phone: 0427 403 620

Email:  engagement@waternsw.com.au

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