The small room with a big impact: inside E.ON's UK energy control hub in the heart of London

Tucked away in a 150-square-foot room—smaller than your average double bedroom—is the nerve centre of a vast and essential operation: E.ON’s UK City Energy control room, located within Citigen, London’s hidden green powerhouse.

From this compact control room, over 70 operational energy sites across the UK are remotely monitored and managed in real-time. These sites, connected through district heating schemes, are crucial in ensuring that thousands of homes and businesses across the country receive reliable and sustainable energy.

But what exactly happens inside this small yet mighty room? Our highly skilled team optimises energy use and drives efficiency for more than 6,000 buildings and over 52,000 customers across the UK. Essentially, this means that when the weather’s hot, we provide cooling—and when winter comes, we ensure warmth. We can also anticipate peaks and troughs in energy demand—like the start of the workday in the office or when people are more likely to pop on their kettle to watch Eastenders of an evening—to deliver the most efficient energy supply to homes and businesses alike.

The Citigen control room is staffed 24/7 by a team of seven specialist control room operators who manage day-to-day energy controls and ensure the smooth running of operations. Remarkably, they are able to resolve 60-70% of issues at any of the energy centres or business sites they monitor without the need for on-site intervention. However, in cases of unplanned incidents—such as equipment failures, fires, or flooding—an energy centre engineer is dispatched immediately. If necessary, the situation is escalated to on-call partners or third-party services like the fire brigade to address safety concerns.

On the commercial side, the team monitors 17 business sites and manages connections to an additional 50 commercial locations. Among these, Citigen directly manages 28 sites, including notable locations like the Barbican, the Guildhall and The Museum of London via its low carbon heating and cooling system. Citigen is just one of our energy centres—there are 71 others managing sites across the UK, with 60 located within the M25 boundary.

Our customers include major names like Queen’s Medical Centre (QMC) in Nottingham, Britvic in Rugby, Michelin Tyres, and D.S. Smith, a B2B paper manufacturing company. The heat networks control room also oversees operations for prominent locations such as Westfield shopping centre in White City, as well as TikTok and Snapchat head offices in Farringdon.

In this small room with a big impact, E.ON’s UK City Energy control room based in the heart of The City continues to drive forward the future of energy management, ensuring efficiency, sustainability, and reliability for thousands of customers across the UK and beyond.