Conpower

On 5 November 2026, the Williamsdale Battery Energy Storage System (BESS) officially reached Commercial Operation Date (COD), marking the start of commercial service for the largest energy storage installation ever built in the Australian Capital Territory.

CPP worked alongside owner Eku Energy as principal delivery partner on the project. The 250 MW / 500 MWh battery can supply roughly one-third of the ACT’s power needs during peak periods.

The battery stores surplus renewable electricity and releases it when needed, helping balance supply and demand, strengthen grid reliability and support the ACT’s target of net-zero emissions by 2045.

James Bolton, CPP’s Project Manager Operations QLD, reflected on the achievement and the people behind it.

“Reaching commercial operations at Williamsdale is a milestone everyone involved can be proud of. There’s been a lot of hard work getting here and I am grateful to our team, subcontractors and Eku for their efforts, for working together to resolve the challenges along the way. I hope everyone who worked on Williamsdale gets the chance to drive past it one day and tell someone, ‘I helped build that.”

A milestone achieved through collaboration

Reaching COD reflects the close working relationship between CPP and Eku Energy. Early involvement enabled the teams to develop the design together and resolve key details before construction began, establishing trust that carried through delivery.

Regular onsite collaboration kept communication open and helped resolve challenges as they arose. This shared approach brought together engineering expertise, practical problem-solving and a strong commitment to safety.

“This project demonstrates that the transition to renewables can be orderly, safe and beneficial for everyone. We have shown that with the right partners, you can build big and still build responsibly,” said Tom Best, Chief Operating Officer at Eku Energy.

From the start of construction through to commercial operation, the project recorded no reportable safety incidents—a milestone both organisations attribute to their shared commitment to safety and disciplined communication.

Engineering through a Canberra winter

Delivering major energy infrastructure through sub-zero mornings and frozen ground required the team to adapt conventional construction methods. This included warming the water used in concrete pours to prevent freezing.

Technology also supported efficient and safe delivery. Drones followed automated flight paths to capture site imagery, track progress and share updates with stakeholders, reducing the need for some on-foot inspections. Meanwhile, 3D LiDAR surveying supported the precise positioning of heavy transformers and high-voltage equipment.

CPP’s experienced team brought the engineering expertise and practical skills needed to deliver the project. Drawing on years of regional construction experience, long-serving crew members worked alongside newer local workers, sharing knowledge and maintaining a strong focus on safety and quality through Canberra’s demanding winter conditions.

Built to be a good neighbour

Consideration for neighbouring residents shaped the project from its earliest planning stages.

One of the facility’s most distinctive features is a nine-metre-high acoustic wall, designed to minimise noise from battery-cooling fans, including during quiet overnight hours. Its deep-green colour was selected in consultation with local council planners to blend with the surrounding rural landscape.

Community engagement continued throughout construction, keeping residents informed about activities and progress.

The project’s contribution also extends beyond the site. Through its Powering Big Dreams grant program, Eku Energy supports Canberra not-for-profits, charities, environmental groups and other community initiatives, sharing the benefits of the energy transition locally.

Supporting Canberra’s energy future

With Williamsdale BESS now in commercial operation, the ACT gains significant storage capacity to support a more flexible, reliable electricity network and make greater use of renewable generation.

For CPP, the achievement demonstrates what experienced teams and committed partners can accomplish together: major energy infrastructure delivered with engineering expertise, a shared focus on safety and care for the surrounding community.

CPP thanks Eku Energy, the ACT Government, the local community and every member of the project team who helped bring Williamsdale BESS to life.