Why DC-powered lighting matters for modern data centres
Author: Joe Peck
In this exclusive article for DCNN, Ton van de Wiel, Global Segment Manager, Intelligent Buildings at Signify, outlines why DC-powered LED lighting is emerging as a key consideration in making data centre infrastructure more efficient and resilient:
Building resilience from the ground up
The digital services that underpin modern economies – from media streaming to cloud computing – depend on a rapidly expanding global network of data centres. These facilities are not only critical to digital connectivity; they represent significant sources of employment, infrastructure investment, and tax revenue through construction and long-term operation.
Today, data centre operators face a convergence of challenges. Capacity requirements are accelerating due to AI-driven workloads, energy prices are rising, and expectations around sustainability and carbon reduction are becoming more stringent. In response, the industry is re-examining its electrical infrastructure. Direct current (DC) power architectures, once limited to niche applications, are gaining traction as a foundation for higher efficiency and greater operational resilience.
Within this shift, lighting – often treated as a peripheral system – can play a strategic role. DC-powered LED lighting combines high energy efficiency with relatively low implementation risk, making it an effective starting point for broader DC adoption. Beyond energy savings, lighting can also function as an intelligent layer within next-generation data centre infrastructure.
How power architectures are changing
Operating a data centre requires tight coordination between IT equipment, networking, cooling, security, and electrical distribution. Historically, alternating current (AC) has been the default for power distribution. However, as facilities’ scale and power densities increase, electrical efficiency has become a primary design concern.
Early facilities relied on 48V DC for backup systems – safe but capacity-constrained. This gave way to 230/277V AC distribution, followed by 380V DC for internal systems. Today, the extreme power demands of AI servers are driving another transition towards 650V DC and even 800V DC architectures.
According to the Open Direct Current Alliance (ODCA), 650V DC represents the optimal level for building-wide distribution, balancing efficiency with safety, while organisations such as NVIDIA and the Open Compute Project are investigating 800V DC. Despite promising high-power IT loads, these higher voltages do not yet deliver the same system-wide efficiency benefits as a facility-level 650V DC approach.
Outside the data centre sector, industrial sites are already deploying 650V DC systems to improve energy efficiency and resilience. One key advantage is the ability to capture regenerative energy from motor drives and robotics – energy that would otherwise be dissipated as heat. Because lighting is a continuous base load, it can readily absorb this recovered energy, reducing grid dependency and operating costs.
Integrating lighting, motors, renewables, and storage on a shared DC grid reduces conversion losses, cuts copper usage through fewer conductors, and lowers transmission losses compared with 400V AC systems. When paired with solar PV and batteries, DC grids also improve self-consumption, backup capability, and flexible energy management.
What’s driving the move?
The momentum behind DC power in data centres is rooted in both engineering logic and economics:
• Lower conversion losses — Conventional AC systems require multiple conversion steps, resulting in energy losses of up to 18%.
• Alignment with IT equipment — Servers and GPUs operate natively on DC power.
• Simpler renewable integration — Solar panels and battery systems produce DC, enabling more efficient connections.
• Reduced system complexity — Fewer transformers and rectifiers mean simpler installation and improved reliability.
• Preparedness for AI growth — Rising AI workloads are accelerating the shift towards DC-based power systems.
DC power is therefore not just an alternative distribution method, but a pathway to smarter, more resilient infrastructure.
Lighting as the first step
Among all building systems, lighting is often the most practical candidate for early DC adoption. Connected LED lighting allows operators to pilot DC distribution with limited risk before extending it to mission-critical IT loads.
The benefits are tangible:
• Capital expenditure savings — DC lighting cables reduce copper use by 40%. Three-conductor DC cables (L+, L-, PE) can transmit the same power as five-conductor 400V three-phase AC cables.
• Operational cost reductions — With only two current-carrying conductors, DC lighting avoids approximately 33% of cable losses compared with three-phase AC at the same current.
• Improved resilience — DC lighting can operate directly from on-site solar generation or battery storage, strengthening microgrid performance during outages.
DC-compatible luminaires and components are already commercially available. For example, Signify offers a 100W Xitanium LED driver designed for 620–750V DC operation, integrated into the Pacific LED Gen5 and Maxos Fusion luminaire families. These solutions achieve up to 165lm/W efficacy and can be paired with systems such as Signify Interact and Philips Dynalite. Driver-level efficiency can exceed 95%, with future potential to reach 200lm/W through ultra-high-efficiency LED modules.
Sustainability and ESG outcomes
DC-powered lighting supports measurable sustainability objectives:
• Lower carbon emissions through reduced conversion losses and material usage
• Support for certifications such as LEED Zero and BREEAM
• Energy optimisation with connected lighting systems, cutting lighting energy use by up to 75%
For hyperscalers like Amazon Web Services and Microsoft Azure, as well as colocation providers, these outcomes translate directly into stronger ESG reporting and progress towards carbon neutrality.
DC lighting can also be implemented incrementally. Some facilities deploy rack-level DC lighting while retaining an AC backbone. Others adopt facility-wide DC grids that integrate lighting, renewables, storage, and IT infrastructure.
In larger deployments, centralised emergency lighting connected to the DC backbone ensures continuous illumination during outages, reinforcing safety in mission-critical spaces.
A strategic role for lighting
As operators prepare for the next phase of digital expansion, DC-powered lighting offers a practical, high-impact entry point into efficient, renewable-ready DC infrastructure.
Modern connected lighting systems extend far beyond illumination. With embedded sensors measuring occupancy, daylight, temperature, humidity, and air quality, luminaires form a dense, facility-wide sensing network without the need for additional hardware. Using open protocols such as DALI, BACnet, and MQTT, DC lighting networks integrate with building management systems and DCIM platforms, enabling predictive maintenance, enhanced operational intelligence, and optimised cooling and space utilisation.
By simplifying cabling, reducing losses, and enabling intelligent energy management, DC lighting transforms illumination from a passive load into an active contributor to resilient, sustainable data centre operations.
