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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 - Preparing Response to Submissions
Environmental Impact Statement (EIS) Exhibition Complete
The McCullys Gap BESS Environmental Impact Statement (EIS) was publicly exhibited from 15 September to 12 October 2026.
The EIS provided detailed information about the project, existing site conditions, and the potential environmental, social and economic impacts of the development, along with proposed measures to avoid, minimise and manage those impacts.
The exhibition period has now closed, and submissions received during exhibition are available to view on the NSW Planning Portal, along with the EIS and supporting documentation:
Community Engagement
Engagement with the community and key stakeholders commenced in 2024 and remains 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 EIS and share feedback with the team.
We thank all community members, landholders, stakeholders and agencies who took the time to review the project and provide feedback during the exhibition period.
Response to Submissions and Next Steps
The project team is currently reviewing the submissions received during public exhibition and preparing a Response to Submissions Report, which will address issues raised by community members, stakeholders and government agencies as part of the planning assessment process.
The Response to Submissions Report will be submitted to the Department of Planning, Housing and Infrastructure in the coming months and will form part of the Department's assessment of the project.
The project team will continue to keep the community informed as the planning process progresses and will provide updates on key milestones and opportunities for engagement.
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 community team: 1800 329 172
• Email us: mccullysgap@bw-ess.com