Low-Voltage DC Power Distribution for Data Center Infrastructure

About This Document

This Open Compute Project white paper examines low-voltage DC (LVDC) power-distribution architectures for data centers amid rapid growth in AI workloads and rack power density. It compares staged pathways from conventional AC power to DC distribution, covering power-conversion boundaries, grounding, protection, energy storage, reliability, and grid interaction. Rather than prescribing a single topology, the document establishes a technical framework for data center operators, designers, manufacturers, utilities, and regulators.

Key Takeaways

• Growing AI workloads, highly dynamic demand, and increasing rack densities are making efficiency, scalability, and grid interaction critical constraints for traditional AC architectures.
• LVDC can reduce the number of power-conversion stages, make more effective use of conductors, and simplify energy-storage integration, although the ultimate benefit depends on the specific topology, load profile, and maturity of the equipment ecosystem.
• DC-powered HPR v4 raises single-shelf capacity to 100 kW; further scaling is constrained by the existing 50 VDC vertical busbar, prompting consideration of raising in-rack distribution voltage to 800 VDC.
• The familiar UPS maintenance bypass cannot simply be carried over to LVDC: redundancy must be provided at the power-block and/or distribution level, potentially with a DC static transfer switch further upstream.
• The choice among AC, hybrid, and DC architectures should account for availability requirements, grounding, fault protection, voltage standards, local practices, and the availability of compatible equipment.

Key Figures

Initial release date

30 марта 2026

Version 1.0 and the document’s first release.

Document length

155 страниц

Document pagination.

Upper limit of LVDC

≤1 500 VDC

The document’s defined scope for low-voltage DC distribution.

HPR v1 capacity

33 kW

AC-powered power shelf in an ORv3 HPR rack.

HPR v2 capacity

72 kW

AC-powered power shelf in an ORv3 HPR rack.

HPR v4 capacity

100 kW

DC-powered power shelf using the Mt. Diablo Power Rack.

HPR v4 power-density increase

39 %

Stated increase in power per power shelf, partly enabled by eliminating AC/DC conversion.

IT rack space released

примерно 12–16 OU

Space made available by moving in-rack energy storage to the Power Rack.

Increase in available IT rack space

27–36 %

Additional compute capacity in a rack of the stated height after relocating energy storage.

Existing vertical busbar voltage

50 VDC

Identified as a constraint on further in-rack power scaling.

Example in-rack DC distribution voltage

800 VDC

Stage 1a reduces this voltage to a level below the existing vertical-busbar voltage.

Example AI load served by one MV-to-LV power block

3+ MW

Illustrative scale of the supplied AI load.

Target availability for AI training data centers

99,9 %

Stated target availability level for training environments.

Target availability for AI inference data centers

99,999 %

Stated target availability level for inference environments.

Assumed data center service life

около 10 лет

Used to assess failure rates and the need for spare equipment.

NExT Factory operating range

до 750 VDC

Symmetrical two-wire DC distribution.

EU Low Voltage Directive DC range

75–1 500 VDC

Applicability range of the EU Low Voltage Directive.

Energy-use reduction in the BMW example

8,8 %

DC-powered manufacturing cell after nearly two years of operation compared with AC.

Minimum voltage for potential corona discharge

300 V

May occur at sharp edges, defects, and low pressure.

Sustained overvoltage requirement for DER

110 %

Requirement for distributed energy resources; also applied to grid-forming operation in islanded mode under UL 3001.

Practical Value for Data Center Owners

For data center owners and project teams, this paper provides a baseline technical benchmark for evaluating LVDC at AI facilities: comparing conversion stages, BBU placement, busbar voltage, and redundancy requirements against a conventional AC design. It is particularly useful during conceptual design and engineering phases for determining whether a 50 VDC busbar becomes a constraint in high-density racks, and for choosing between 800 VDC in-rack distribution and broad-range distribution up to 1,500 VDC. The central design risks are protection, grounding, AC/DC conversion resilience, and the absence of a conventional UPS maintenance bypass in LVDC topologies.

Where It Applies

Topics