As Great Britain connects its largest battery to the grid, the spotlight isn’t just on the technology - it’s also on the execution. Delivering storage at this scale requires coordination across engineering, operations, and markets. From grid connection challenges to day-to-day performance, success depends on much more than megawatts and megawatt-hours — it’s about precision, planning, and people.

In this episode of Transmission, Lisa MacKay, Chief Operations Officer at Fidra Energy, shares what it takes to bring the UK’s biggest battery project from construction to operation. We explore the real challenges behind delivering large-scale storage - from managing contractors and timelines to optimising assets once they’re online, and what lessons this project offers for the future of flexibility and reliability in the power system.

What it takes to build and operate Great Britain’s largest battery.

The biggest challenges of scaling storage - from grid connection to commissioning.
How operational decisions impact commercial performance.
Lessons learned from running large-scale flexibility assets.
What GB’s biggest battery means for the wider energy transition.

About our guest

Lisa MacKay is the Chief Operations Officer at Fidra Energy, where she leads operations and organisational strategy across a growing renewable portfolio. With experience spanning development, trading, and leadership, she focuses on building resilient teams and scalable processes that support growth in a dynamic energy market. For more information on Fidra Energy, head to their website. https://fidraenergy.com/

About Modo Energy:

Modo Energy helps the owners, operators, builders, and financiers of battery energy storage solutions understand the market - and make the most out of their assets.

All of our interviews are available to watch or listen to on the Modo Energy site. To keep up with all of our latest updates, research, analysis, videos, conversations, data visualizations, live events, and more, follow us on LinkedIn. Check out The Energy Academy, our bite-sized video series breaking down how power markets work.

Building Britain’s biggest battery energy storage system with Lisa Mackay (Fidra Energy)

Transmission