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SSE has taken a Final Investment Decision (FID) to proceed with construction of a new 100MW Battery Energy Storage System (BESS) in County Tyrone, marking a significant boost for the North’s energy infrastructure.
The Derrymeen BESS facility will be located beside the Tamnamore 275/110kV substation near Dungannon and will provide 100MW of capacity with two hours of storage, equivalent to 200MWh.
Once operational, it will play a key role in supporting Northern Ireland’s transition to a renewables-led electricity system.
The facility will store electricity during periods of high generation and release it back to the grid when demand rises, helping to balance the system and enhance security of supply. It will connect directly to the Tamnamore substation and participate in the all-island Integrated Single Electricity Market (SEM).
Construction is expected to begin later in 2026, following early-stage works such as detailed design and procurement of key equipment, including the main grid transformer, which are already underway. Grid connection works will be delivered in coordination with the System Operator for Northern Ireland (SONI) and Northern Ireland Electricity Networks (NIE).
The project is also expected to deliver economic benefits locally, supporting regional contractors and suppliers and creating employment during construction. At peak delivery, up to 30 full-time jobs are anticipated.
Heather Donald, Director of Projects Onshore Ireland at SSE Renewables, said the decision marked “another important milestone” in building a flexible and resilient energy system across the island of Ireland.
“Battery storage is essential to enabling a renewables-led electricity system, helping to store clean power when it is available and deliver it back to the grid when it is needed most,” she said.
“We are proud to be investing in Northern Ireland’s energy future.”
Following design refinements and engagement with the local council, the project has now progressed to FID and has secured a 10-year Capacity Remuneration Market (CRM) contract, beginning in October 2028.
