French utility company Engie has started commercial operations at two battery energy storage projects in Scotland, adding 100 MW of new grid-connected storage capacity. As reported by Solar Power Portal on 23 July 2026, the sites — at Cathkin, near East Kilbride, and Broxburn, west of Edinburgh — are each rated at 50 MW / 100 MWh, giving a 2-hour storage duration and providing rapid-response grid services to support round-the-clock integration of renewables.
The projects are ENGIE’s first two UK batteries. According to Engie, Broxburn is a 50 MW BESS in West Lothian and Cathkin is a 50 MW, 2-hour duration battery storage site in East Kilbride. Both were built by Canadian Solar’s e-STORAGE under EPC contracts announced by ENGIE UK in January 2025, and both connect into SP Energy Networks’ (SPEN) 33 kV distribution network.
At the time of the EPC signing, Aidan Connolly, Head of Battery Storage UK at ENGIE, said: “At ENGIE, we’re excited to work with Canadian Solar’s e-STORAGE and are pleased to have signed EPC contracts for our two 50 MW / 100 MWh BESS projects at Cathkin and Broxburn in Scotland. We are looking forward to the construction stage of this project, and are happy to be working with a company with the technical solution and delivery capabilities of Canadian Solar, who are also aligned with our commitment to a high standard of Health and Safety.”
According to Solar Power Portal’s coverage of the commercial-operation start, the two BESS projects will be operated using Engie’s AI-driven optimisation platform, Orus, which powers the projects’ dynamic response to the grid and manages the discharge of stored surplus energy when required. Solar Power Portal further reports that, with Cathkin and Broxburn now operational, Engie’s onshore renewable energy portfolio in the UK stands at 242 MW, alongside 2.1 GW of pumped storage hydro capacity already operational in the country.
Suresh Bhaskar, managing director for renewables and batteries UK and Ireland at ENGIE, told Solar Power Portal: “The commercial operation of Cathkin and Broxburn represents a major milestone for ENGIE’s battery storage ambitions in the UK. As renewable energy becomes an increasingly important part of the electricity mix, flexible storage infrastructure is essential to ensuring the grid remains stable, resilient and capable of supporting the transition to net zero.”
For Scotland, Cathkin and Broxburn add tangible, in-country flexible capacity into the central belt at a time when onshore wind repowering and offshore-wind consents are pushing more variable generation onto the grid — with the operational intelligence layered on top provided by an AI optimisation platform rather than a purely manual dispatch model.
