The Fiddler’s Ferry battery energy storage system (BESS) is redeveloping part of the former coal-fired power station site in Warrington, Cheshire. The project is being developed by SSE Renewables. With a capacity of 150MW/300MWh, it will store electricity and supply it to the UK National Grid during periods of high demand.
Construction began in January 2024, following a final investment decision in December 2023. SSE Renewables appointed OCU Energy as the principal contractor and Fluence as the battery storage technology supplier. The project is listed as under construction on the developer’s official project page, with completion previously scheduled for 2026.
Project Scope and Technical Specifications
The Fiddler’s Ferry BESS will have a power output capacity of 150 megawatts (MW) and an energy storage capacity of 300 megawatt-hours (MWh). Therefore, the installation is designed to discharge electricity at full rated output for up to two hours, subject to operating conditions.
The Fiddler’s Ferry Battery Energy Storage System (BESS) project will use Fluence’s Gridstack battery energy storage platform, while OCU Energy is responsible for principal construction works. The development will occupy approximately 3.5 hectares of the former power station site and reuse the existing grid connection, reducing the need to establish an entirely new connection to the electricity transmission network.
Once operational, the system is expected to provide the UK’s transmission system operator with access to stored electricity equivalent to the demand of up to 250,000 homes for as long as two hours. However, this is an illustrative equivalent rather than a guarantee that the facility will continuously supply that number of households.
Construction Progress and Project Timeline
SSE Renewables reached its final investment decision in December 2023 and confirmed OCU Energy and Fluence as its delivery partners in March 2024. Construction began in January 2024, with SSE announcing in March 2025 that the project was progressing and remained scheduled for completion in 2026.
As of November 2026, SSE Renewables lists the facility as under construction. However, no revised commissioning date has been confirmed. The battery system has also not been confirmed as commercially operational.
Reuse of the Former Fiddler’s Ferry Power Station
The Fiddler’s Ferry BESS project forms part of the wider redevelopment of the former power station site. Previously, the facility ceased coal-fired generation in March 2020. Since then, Peel NRE has been redeveloping the site. Its plans include employment space, housing, infrastructure and other uses.
Meanwhile, the battery installation provides a new energy infrastructure use for part of the former industrial site. By storing electricity when it is available and releasing it when demand rises, the BESS can help balance fluctuations in electricity supply and demand. It can also support the integration of variable renewable generation, including wind and solar power, into the electricity network. This is a function that is being emulated by other projects across the region, including the 442MWh Smareg 13 BESS project in Bavaria aimed at stabilizing Germany’s grid.
The project’s reuse of an existing grid connection is particularly relevant because connecting new energy assets to the transmission network can be a significant development constraint. However, the facility is a storage asset rather than a power generator: it shifts electricity across time and does not independently produce renewable electricity.
Fiddler’s Ferry Battery Energy Storage System (BESS): Project Factsheet
Location: Former Fiddler’s Ferry coal-fired power station, Warrington, Cheshire, England, UK
Developer: SSE Renewables
Power capacity: 150MW
Storage capacity: 300MWh
Maximum rated discharge duration: Approximately two hours
Technology supplier: Fluence
Battery platform: Gridstack
Principal contractor: OCU Energy
Construction start: January 2024
Final investment decision: December 2023
Original target completion: 2026
Latest publicly stated status: Under construction
Grid connection: Existing connection at the former power station site
Primary purpose: Grid flexibility, electricity storage and support for renewable energy integration
Fiddler’s Ferry BESS Project Team
SSE Renewables : Project developer and investor.
OCU Energy : Principal contractor responsible for construction and project delivery.
Fluence Energy : Battery energy storage technology supplier, providing the Gridstack battery storage platform.
Peel NRE : Owner and redevelopment partner for the wider former Fiddler’s Ferry power station site.
Leave a Reply