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The project
Location
Muswellbrook (Upper Hunter), Muswellbrook Shire Council, New South Wales
Capacity
400 MW / 1600 MWh
Land size
9.4 hectares
Jobs
Creating up to 150 construction jobs, with ongoing operational roles and additional workers for routine on-site maintenance
Operations
The project will operate remotely 24/7 for at least 30 years, with routine on-site maintenance. After construction, all temporary work areas will be rehabilitated
Project status
Community Engagement
Engagement with the community and key stakeholders began in 2024 and is ongoing.
In April and July 2026, the project team hosted community drop-in sessions in McCullys Gap and Muswellbrook, providing an opportunity for community members to learn more about the project, discuss the upcoming Environmental Impact Statement (EIS) submission, and share their feedback with the team.
Preparing the Environmental Impact Statement (EIS)
The project team is currently finalising the EIS, which will carefully assess the potential environmental, social and economic impacts of the project.
Public Exhibition
Once complete, the EIS will be submitted and placed on public exhibition, where it will be made available for review and feedback as part of the planning assessment process.
Response to Submissions and Next Steps
Following exhibition, the project team will prepare a Response to Submissions Report, which will address feedback received during the exhibition period.
Additional community drop-in sessions will be held later in 2026 to share what we heard during exhibition and how community and stakeholder feedback has helped inform the project.
Site selection
Proximity to infrastructure
The location of the project was selected for its proximity to the existing Muswellbrook substation (330KV/132KV). Direct access to the transmission network reduces the amount of infrastructure needed to connect.
Regional profile
This project is positioned in the Hunter-Central Coast Renewable Energy Zone (HCC REZ). It strategically connects the NE REZ generation centre, the QNI (Queensland & NSW Interconnector), and the Sydney load centre.
Site characteristics
The project site has been carefully chosen because the existing land conditions make construction more straightforward, helping to minimise disruption and improve efficiency.
Why BESS
Large-scale battery systems contribute to the stability and reliability of our changing energy system. The energy stored in batteries is able to be used quickly and respond to changing conditions.
Typically, battery systems charge during the day when solar energy is plentiful and release the stored energy back into the grid at night.
Balancing supply and demand
Battery systems help bridge the distance between where the electricity is generated and where it is needed most. By storing excess generation and delivering power during peak periods, batterieshelp optimise the flow of electricity across the national energy network.
Enhancing Energy Security
Battery systems can adapt to changing energy network conditions within milliseconds which assists to provide a more stable and reliable system.
Supporting a diverse system
The way in which our electricity is generated and consumed is changing. Batteries are an essential part of a more diverse and resilient system that is able to respond to change.
Battery storage supports the reliability and stability of the New South Wales power system, helping ensure a consistent supply of electricity for homes, businesses, and communities.
The McCullys Gap BESS is being delivered by
BW ESS, a global energy storage developer, owner and operator.
BW ESS is a long-term developer, owner and operator of utility-scale battery energy storage projects. The company is headquartered in Zurich and operates across Europe and Australia.
Contact us
BW ESS is a long-term owner and operator, focused on building strong relationships with our communities.
We’re committed to open communication and genuine engagement, and welcome your questions or feedback about the McCullys Gap BESS.
Please feel free to get in touch:
• Complete the form below with your comments
• Call the consultation team: 1800 329 172
• Email us: mccullysgap@bw-ess.com