Copenhagen Infrastructure Partners (CIP) has taken final investment decision (FID) on a 350 MW/1,400 MWh battery energy storage system in south Ayrshire, Scotland, with construction now under way and commercial operation expected in the first quarter of 2028.
Kilmarnock South will use lithium-ion batteries connected directly to the transmission network. With a four-hour duration, it will be the longest-duration battery project in CIP’s UK portfolio when operational.
The project is expected to represent an investment of more than €270 million. CIP said the battery will be used to store surplus electricity from Scottish wind generation and discharge it when network capacity is available, providing flexibility as renewable generation increases.
Kilmarnock South is CIP’s fourth transmission-connected battery investment in Scotland, alongside Coalburn 1, Coalburn 2 and Devilla. Coalburn 1 entered commercial operation in August 2026.
Together, the four projects are planned to provide 1.85 GW of power capacity and 4.4 GWh of storage capacity once fully operational. CIP said this would be equivalent to almost one-third of Great Britain’s currently operational battery storage capacity.
“Kilmarnock South” will form part of CIP’s Copenhagen Infrastructure IV fund portfolio.
Nischal Agarwal, partner at CIP, said: “Well-sited battery energy storage projects provide valuable power system flexibility which enables the full benefits of low-cost renewables to be captured.”
UK energy minister Michael Shanks said Kilmarnock South would provide additional capacity for storing Scottish wind generation. “Together, these projects mean less homegrown power going to waste, greater energy security, and lower bills over the long term,” he said.
The project is being developed as Scotland continues to expand wind generation, creating periods when renewable output can exceed local network demand or available transmission capacity. Longer-duration storage can shift some of that electricity to later periods, although its effectiveness will depend on network conditions, market signals and the wider development of transmission infrastructure.
CIP said construction of Kilmarnock South is now under way, with the battery scheduled to begin commercial operations in early 2028.
