AGL says pumped hydro “critical” to energy transition, as it updates its own plans

AGL Energy says feasibility studies are underway on its Muswellbrook pumped hydro joint venture, which proposes to build eight hours of energy storage capacity in the New South Wales Upper Hunter region, with a preferred technology solution on track for early 2024.

In an update on the 250MW/2000MWh project on Friday, AGL’s head of hydro Simon Kelley told a conference in Sydney that the gen-tailer was keen to play a leading role the build-out of new pumped hydro energy storage capacity in the transition to renewables.

“Pumped hydro energy storage will have a critical role to play in helping Australia to reach its net zero target by 2050,” Kelley told the 2023 NSW Heads of Water Forum.

“According to AEMO’s Integrated System Plan, deep storage, primarily pumped hydro energy storage, will have to increase by approximately 200GWh in addition to Snowy 2.0 by 2050 – that’s a significant increase from the 14.6 GWh available in the NEM today,” he said.

“This is a significant undertaking for everyone in the industry. And AGL, as the largest private owner and operator of hydro, can play a leading role in this.”

AGL is developing the Muswellbrook pumped hydro project as a joint venture with Idemitsu Australia Resources (IAR).

The project proposes to use an existing mine void from Idemitsu’s Muswellbrook Coal mine as the lower reservoir.

Upon demand, water would be released from the upper storage reservoir, with a 470m head height, and use gravity to turn the turbines and generate electricity.

Kelley says the project currently proposes to develop a 1.93 gigalitre upper storage reservoir, two 125MW fixed speed turbines, a roughly 470 metre head height (altitude difference between the two reservoirs).

For the roughly 2km run length between reservoirs the project proposes to use a combination of tunnel and surface waterway, and Kelley says it is estimated the project would take around four years to build. The capital cost has not yet been determined.

“AGL’s proposed Muswellbrook pumped hydro facility JV with Idemitsu will be a great example of the contribution that hydro long-duration storage can play in the NEM,” he told the conference.

“The feasibility study is already underway and a preferred technology solution is on track for early 2024.”