Ken Knight, Head of Data Centres, UK & Ireland at Zumtobel Group, explains why lighting should be considered part of a data centre’s resilience strategy.

Spend enough time working in modern data centres and one thing quickly becomes apparent. As facilities evolve to support artificial intelligence, the conversation is no longer simply about adding more computing capacity. It is about ensuring every element of the supporting infrastructure can keep pace. Power resilience, cooling capacity, connectivity and security naturally dominate those discussions.

Lighting rarely features in the same conversation.

Yet, having recently delivered lighting schemes for two very different data centre environments – one an AI-ready campus undergoing phased expansion, the other developed around long-term operational efficiency and sustainability – it has become clear to me that the industry has quietly outgrown the way it thinks about lighting.

When everything is operating normally, lighting is easy to overlook.

When something goes wrong, however, it becomes part of the operational infrastructure that helps engineers respond safely, identify faults quickly and restore normal operation with confidence.

That shift is changing the way lighting should be considered in the modern data centre. Not as a system that simply lights a space, but as one that actively supports resilience.

The reality is that resilience isn’t only about keeping servers online.

However sophisticated a facility becomes, there are still moments when people have to intervene. Equipment requires commissioning. Hardware needs replacing. Planned maintenance must be carried out while adjacent systems stay operational. Unexpected faults demand immediate investigation, often within tightly controlled maintenance windows where time is limited and accuracy is critical.

At these moments, engineers become part of the resilience strategy themselves. The environment they work in therefore deserves just as much consideration as the technology they maintain.

This is where lighting moves beyond its traditional role.

For many years, lighting design has been judged against familiar metrics such as lux levels, uniformity and energy efficiency. Those remain important, but they don’t always reflect the reality of working inside a live data centre.

Maintenance engineers rarely spend their time looking at the floor.

Their attention is focused on equipment racks, cable management, distribution boards and plant. They need to identify labels, distinguish connectors, inspect components and trace faults quickly and accurately. Poor visibility doesn’t simply slow the task down; it increases the likelihood of mistakes, repeat visits and unnecessary disruption.

Good lighting doesn’t just help engineers see. It helps them assess, diagnose and make decisions, allowing maintenance to be completed more efficiently and with greater confidence. In facilities where every maintenance window is carefully planned, those benefits quickly become operational ones.

Artificial intelligence is accelerating that shift. Higher rack densities and evolving equipment layouts are placing new demands on lighting in both new and existing facilities.

Existing data centres are increasingly being refurbished in phases, with new technologies introduced while operations continue. Lighting must adapt alongside those changes, supporting evolving layouts without becoming another system that requires wholesale replacement.

That calls for a different approach to lighting.

Rather than treating it as a fixed building service, it should be considered part of the operational infrastructure, designed to adapt as facilities change, minimise disruption during refurbishment and continue supporting engineers as operational requirements evolve.

This also supports a broader shift towards whole-life performance. Infrastructure that lasts longer, requires fewer maintenance interventions and adapts without wholesale replacement not only improves resilience but also contributes to long-term sustainability.

Perhaps nowhere is lighting’s contribution more apparent than when normal operation is interrupted.

Whether responding to equipment failures, electrical issues or emergency maintenance, engineers rely on clear visibility to assess situations quickly and move safely through technical environments. Lighting becomes another system helping people restore normal operation, rather than simply illuminating the route to get there.

When considering resilience in data centre lighting design, it is important to look beyond fixture reliability alone. Interleaved power circuits can help maintain lighting availability during faults or maintenance events. Equally important is the ability to provide resilient power distribution without significantly increasing cable volumes. This can simplify installation, reduce congestion in already crowded service routes and improve overall maintainability.

Emergency lighting must also be recognised as a critical component of the resilience strategy, particularly when considering what happens when things go wrong. In the event of a power failure, equipment fault or evacuation, emergency lighting provides the visibility needed to protect personnel and support safe access and egress.

This is especially relevant in data centres, where operating environments can be challenging for electronic equipment, with temperatures in some areas reaching 50°C or higher. Designing lighting and emergency systems that can continue to perform reliably under these conditions is essential to maintaining both safety and operational continuity.

Lighting can also play a role in physical security. Integrated sensor networks do more than just manage energy; they can provide real-time data on occupancy and movement within sensitive data halls and plant rooms.

During a power outage or critical system failure, lighting can also support surveillance continuity. Where CCTV equipment remains operational, emergency illumination can help maintain usable footage, while allowing security personnel to navigate safely to secure access points or manual overrides. By maintaining visibility during a crisis, lighting can support security procedures and reduce the risk of a technical failure escalating into a security breach.

This highlights a wider shift in thinking.

For years, conversations around lighting have focused on technical outputs: lux levels, watts and efficacy.

Those metrics still matter.

But operators and facilities teams are increasingly asking different questions.

• Can engineers identify faults more quickly?
• Can maintenance be completed safely within live environments?
• Can infrastructure adapt as the facility evolves?
• Can supporting systems reduce disruption rather than create it?

These are operational questions.

Lighting won’t answer them on its own, but it contributes to every one of them.

As modern data centres continue to evolve to support AI, higher-density computing and increasingly critical digital infrastructure, resilience will depend on more than power and cooling alone. It will depend on every supporting system enabling people to respond effectively when they are needed most.

Perhaps that’s the real lesson.

The best lighting installations are rarely the ones people notice during normal operation.

They are the ones that quietly help engineers work safely, make better decisions and restore normal operation more quickly when the unexpected happens.

Because when everything is running normally, lighting simply lights the space.

When things go wrong, it helps keep the operation moving.