London, UK – 18 June 2026 

Zenobē, the UK’s leading owner and operator of transmission connected batteries, today announces the financial close of its 200MW/800MWh battery energy storage system (BESS) at Coalburn, South Lanarkshire, Scotland.

The project represents a significant milestone for the UK’s energy transition, becoming the first four-hour duration battery storage project connected to the transmission network to reach financial close.

Today’s announcement comes just four years after Zenobē’s one-hour 100MW battery in Capenhurst, the largest project in Europe and the first to directly connect to a GB transmission network at the time, commenced commercial operations. Delivered without subsidy, the Coalburn project demonstrates the maturity of the battery storage market in the UK and the rapid evolution of battery technology.

Preparatory works on the site have begun and construction will start in earnest in July, with commercial operations expected in 2028.

The longer duration of the battery reflects increasing demand for flexible storage on the transmission network to support a net zero grid. Coalburn will operate at a maximum import/export of 200MW for four hours of storage (800MWh). It can also operate at a number of different power and duration outputs, providing 100MW for up to eight hours (800MWh) or 50MW for up to sixteen hours (800MWh) for example, highlighting the flexibility of the asset.

Zenobē is developing the project alongside experienced global partners with Canadian Solar’s e-STORAGE supplying the battery systems and Omexom delivering the balance of plant works. Drax Group plc will manage the commercial trading of the asset via a toll contract, supporting its integration into the wider energy market.

The project has secured financing from a group of leading international lenders, including Landesbank Baden-Württemberg (LBBW), ABN AMRO, Mizuho and Siemens Financial Services.

All lenders also participated in Zenobē’s 400MW battery project in Eccles reflecting the confidence in large scale battery storage assets and the strength of the UK’s evolving flexibility market. 

Coalburn is a continuation of Zenobē’s broader strategy to deploy large scale storage assets that support the decarbonisation of the grid by enabling greater integration of renewable energy, for a more secure and affordable grid. Zenobē currently has 3.3GWh of battery assets in operation or construction in the UK.

James Basden, Founder Director of Zenobē said: “Coalburn is our fourth large scale project in Scotland to achieve financial close in the last eighteen months. Together with our investment in Scotland’s EV bus fleet, this means Zenobē has invested over £1bn in the last three years to make clean transport and clean power more accessible for millions of people.

Despite considerable regulatory upheaval, the Coalburn project demonstrates Zenobē’s continuing commitment to enabling the delivery of the government’s Clean Power 2030 ambition. Working in partnership with our supply chain, local authorities and communities, the project will strengthen system flexibility, support the integration of low-cost domestic renewable generation and enhance energy security.

By enabling a more efficient and resilient electricity system, projects like Coalburn can help reduce costs for consumers while accelerating decarbonisation. Importantly, this investment is being delivered through competitive markets and ongoing innovation, demonstrating how private capital can support the energy transition without relying on direct subsidies.”

Jeff Roy, President of e-STORAGE, said: “We are proud to partner with Zenobē at Coalburn. By engineering our own batteries, power conversion and EQ-S energy management into one optimized system, and standing behind it for twenty years, we give Coalburn the long-term, reliable technology it can depend on for stable returns. Across the UK, we have 5.7 GWh of storage in operation or under construction — a testament to the depth we bring to Zenobē, and a capability we will maintain as the country’s clean power transition calls for storage it can rely on.”

Jose Garcia, Business Unit General Manager – Renewables Scotland, Omexom said: “The award of this project reflects the strength of our partnership and the results we have achieved together. Over the past two years, we have demonstrated our ability to deliver complex grid-scale storage solutions successfully with Zenobe, and we are committed to exceeding expectations once again as we continue to grow and strengthen this relationship.”

Ash Hein, Flexgen Business Development Director at Drax Group, said: “We are really excited by the progress Zenobē and partners are making with Coalburn. Under our tolling arrangement, once the battery storage asset is commissioned, we will optimise its use to support power markets and provide grid stability services. Coalburn and our recent agreements and acquisitions, including the AI-enabled optimisation platform, Flexitricity, demonstrate the good progress we are making on growing our Flexgen business in line with the UK’s Clean Power ambitions.” 

A community benefit fund is currently being developed in collaboration with the local community, with a focus on reflecting local priorities.