Australian renewable energy company ZEN Energy has announced plans to convert Sydney’s biggest water storage facility into a pumped hydro station and provide stability to the local grid.  

The planned Western Sydney Pumped Hydro project will be located on the site of a former coal washery in Nattai, NSW. Once complete, it will be able to supply up to 1GW of clean energy on demand, enough to support the local electric grid for eight continuous hours and deliver the equivalent of 500,000 homes and businesses.  

While the project awaits approval, ZEN has begun consultation with locals, traditional owners and other stakeholders to “co-design” the project. If approved by all relevant authorities, construction is due to begin in 2027 and be completed by 2031. 

Water will be pumped through underground tunnels from Lake Burragorang to a holding reservoir 400m above the lake. During times of high electricity demand, this water can be released through underground turbines that supply power to the grid. Crucially, the system operates as an entirely closed loop, meaning no water will be lost from Lake Burragorang. 

“The vast water reserves of Lake Burragorang can supply Sydneysiders with clean drinking water and clean, renewable energy as well,” said ZEN CEO Anthony Garnaut in a press release. 

“Large-scale energy storage projects like Western Sydney Pumped Hydro are key to keeping the lights on and energy prices in check in NSW as our coal-fired power stations age and retire over the next decade.” 

Garnaut added that the project, marking the company’s entry into the renewables space in NSW, is a “key milestone” that will help achieve “a 1.5-degree world for all”. 

The state of NSW has recently seen a new influx of interest in pumped hydro development. In February 2024, WaterNSW selected Upper Hunter Hydro, a company founded by former Australian Prime Minister Malcom Turnbull, to conduct investigations into pumped hydro developments in the state.