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The benefits of using direct current power for data centers
As AI workloads increase power demands, data center admins are looking at direct current systems to boost energy efficiency and simplify power distribution.
Data centers are facing a growing power problem with no simple fixes. The International Energy Agency projects that global data center electricity consumption will surge from 415 TWh in 2024 to 945 TWh by 2030. This increase is driven by GPU-dense racks, AI workloads and hyperscale expansions, which are pushing traditional power infrastructure to its limits.
To address this challenge, data center facility owners are compelled to seek new methods for delivering electricity to their hardware to achieve greater efficiency. One promising approach is to bypass power conversion by using direct current (DC) sources.
DC data centers convert alternating current (AC) power from their local grids to DC at the facility's edge, then distribute it internally. This approach is gaining traction among data center owners, hardware vendors and the broader data center industry.
This article will explore the benefits of DC power in data centers, highlighting its potential to enhance energy efficiency and reduce costs amid rising electricity demand from AI workloads and hyperscale expansions.
AC and DC power: Understanding the difference
To understand why DC data centers may be in your future, here's the difference between the two power types. AC changes direction in a repeating cycle, making it efficient for long-distance travel. DC flows in one direction and is what most technology hardware uses.
Electrical conversions are necessary because utilities deliver AC power while hardware requires DC power. However, every conversion costs energy and money. In traditional data centers, electricity arrives using the AC grid and is converted to DC at the UPS to charge the battery backup. It's then converted back to AC for distribution throughout the facility and converted back to DC inside each hardware unit's power supply.
Each conversion loses energy and produces additional heat. As a result, the device needs to draw more power, which generates more heat. This creates a self-heating cycle that also produces power waste, which costs time, energy and money.
The benefits of DC power in data center infrastructure
DC power offers data center operators a range of infrastructure advantages over traditional AC distribution, such as less wasted energy, lower infrastructure complexity and reduced cooling requirements.
Fewer conversions, less wasted energy
The efficiency case for DC power is straightforward: remove conversion stages from the process and save energy. DC data center architectures eliminate several conversion points, including at UPS units and PDU transformers, reducing energy loss by 7% to 20% compared to typical power flows.
Scale that across colocated or hyperscale facilities, and the incremental gains add up quickly. A 1% efficiency improvement across a 1 GW campus avoids approximately 10 megawatts of losses, Hartwig Stammberger, chair of the board of the Open Direct Current Alliance (ODCA), told Data Center Knowledge. Current data center DC deployments typically operate at 48 VDC or 400 VDC. The Open Compute Project's Mt. Diablo initiative is already demonstrating 400 VDC rack distribution capable of supporting 1 MW racks.
Lower infrastructure complexity
Fewer conversion stages mean fewer components, less wiring and a simpler power flow overall. DC distribution eliminates the intensive monitoring and balancing required by most traditional facilities, thereby reducing the software and human resources needed to manage the facility. That simplification has real value for facility owners and operators managing increasingly dense and power-hungry hardware.
Reduced cooling requirements
The integration of DC infrastructure helps remove heat sources at each conversion point. Fewer conversions mean less heat generation within the facility, allowing HVAC systems to operate more efficiently. The bonus is that the facility's power usage effectiveness improves since it's using less energy to cool itself.
Higher equipment densities
The Center of Expertise for Data Center Energy found that DC data centers can have higher equipment densities because the overall environment is cooler. This makes DC architecture particularly well-suited for hyperscale and GPU-heavy data centers.
Longer battery lifespan and backups
In a DC-native architecture, batteries can connect directly into the DC infrastructure without the additional conversions required in AC systems, enabling more efficient charging and discharging of backup power. This reduces battery costs by reducing replacements and ensures more reliable uptime, even on battery power.
Better fit for renewable energy
Solar panels and on-site battery storage both inherently generate and store DC power, making it easier to integrate into a DC-powered data center. Facility owners can increase their renewable energy usage while reducing their overall operating costs. Renewable energy isn't ready to consistently power a data center, but incorporating it more often into a DC data center's energy mix makes it more flexible.
Telecoms proved that direct current power works
Before DC data centers became a hot topic in technology circles, the telecommunications industry had already operated mission-critical infrastructure on DC power.
Telephone exchanges and central offices operated on DC power feeds and backups for decades, providing a stable environment that supported mission-critical workloads. Those facilities are standardized on a 48 VDC system, a voltage level low enough to meet electrical safety thresholds while still reliably powering their equipment and backup systems. Data center owners are now revisiting DC power as a viable alternative to traditional AC distribution, fueling growth in the telecom DC power sector, which is expected to reach $12.35 billion by 2033, according to Data Insights Market.
Challenges to the DC data center
While there are many compelling benefits to a DC data center, the path to going fully DC isn't frictionless. Standards across the globe are the biggest challenge, as the regulations and electrical codes that govern data center construction haven't kept pace with the evolution of technology. Retrofitting existing AC data centers also requires significant investment in infrastructure and money, and the DC-first hardware ecosystem is still maturing.
Most facility owners and operators will consider a phased or hybrid approach in the near future to capture the benefits without a complete overhaul. Full DC applications are most viable in new builds or major facility upgrades, as they can be incorporated into the design from the start.
Industry momentum is building
Building a DC-powered data center is no longer a fringe concept in the tech world. Google, ABB, Siemens and the Open Compute Project formed a working group to explore how DC power can supply data centers today and in the future. Another group is looking at ways to standardize low-voltage DC supply for data centers, while others are exploring how to align DC power distribution standards across international regulatory bodies.
On the higher end of the voltage spectrum, Eaton and Nvidia are jointly developing 800 VDC reference architectures designed to support 1 MW and beyond rack densities that next-generation AI workloads will require.
Julia Borgini is a freelance technical copywriter, content marketer, content strategist and geek. She writes about B2B tech, SaaS, DevOps, the cloud and other tech topics.
