“While AC distribution is deeply entrenched, advances in power electronics and growing demand for AI infrastructure are driving interest in DC architectures,” says Chris Thompson, vice president of advanced technology and global microgrids at Vertiv.
AC to DC Conversion Challenges
Today, almost all data centers are designed around AC utility power. The electrical path involves several transformations before the electricity reaches the compute load. Power typically enters the data center as medium-voltage AC (1 kV to 35 kV), stepped down to low-voltage AC (480 V or 415 V) using a transformer, converted to DC inside an uninterruptible power supply (UPS) for battery storage, converted back to AC, and converted again to low-voltage DC (typically 54 V DC) at the server, giving DC power computing chips are supplied.
“The dual conversion process ensures that the output AC is clean, stable and suitable for data center servers,” says Luiz Fernando Huet de Besselaar, vice president of engineering and technology at Eaton.
That setup worked well enough for the amount of power required for traditional data centers. Traditional data center computational racks come in on the order of 10 kilowatts each. For AI, it is starting to approach 1 MW. At that scale, the energy losses of AC to DC conversion, current levels, and copper requirements become difficult to justify. Every conversion causes some power loss. On top of this, as the amount of power delivered increases, the sheer size of the converters, as well as the connector requirements of the copper busbars, becomes unsustainable. According to the Nvidia blog, a 1 MW rack This may require up to 200 kg of copper busbar. For a 1 gigawatt data center, this can amount to 200,000 kg of copper.
Benefits of High-Voltage DC Power
By directly converting 13.8 kV AC grid power to 800 VDC at the data center perimeter, most of the intermediate conversion steps are eliminated. This reduces the number of fans and power supply units, and leads to higher system reliability, lower heat dissipation, better energy efficiency and smaller equipment footprint.
“Each power conversion between the electric grid or power source and the silicon chips inside the server results in some energy loss,” says Fernando.
Switching from 415 V AC to 800 V DC in power distribution allows 85 percent more power to be transmitted through the same conductor size. This happens because the higher voltage reduces current demand, reduces resistive losses and makes power transfer more efficient. Thinner conductors can handle the same load, reducing copper requirements by 45 percent, improving efficiency by 5 percent, and reducing total cost of ownership by 30 percent for GW-scale facilities.
“In high-voltage DC architectures, power from the grid is converted from medium-voltage AC to approximately 800 V DC and then distributed throughout the facility on a DC bus,” Vertiv’s Thompson said. “On the rack, compact DC-DC converters reduce that voltage to the GPU and CPU.”
A report by technology consultancy group Omdia claims that high voltage DC data centers have already emerged in China. In the US, the Mount Diablo Initiative (a collaboration between META, Microsoft, and the Open Compute Project) is a 400 V DC rack power distribution experiment.
A handful of vendors are trying to get ahead of the game. Vertiv’s 800 V DC ecosystem integrated with the NVIDIA Vera Rubin Ultra Kyber platform will be commercially available in the second half of 2026. Eaton, too, is well advanced in its 800 V DC system innovation, courtesy of a medium-voltage solid-state transformer (SST), which will sit at the heart of the DC power distribution system. Meanwhile Delta has released 800 V DC in-row 660 kW power racks with a total of 480 kW embedded battery backup units. And, SolarEdge is hard at work on a 99%-efficient SST that will be combined with a native DC UPS and a DC power distribution layer.
But most of the industry is far behind. Patrick Hughes, senior vice president of strategy, technology and industry affairs for the National Electrical Manufacturers Association, says most of the innovation is happening at the 400 V DC level, although some are preparing 800 V DC. He believes the industry needs a complete, coordinated ecosystem, including power electronics, safety, connectors, sensing and service-safe components that scale together rather than in isolation. In turn, DC-specific devices require repurposing manufacturing capacity, expanding semiconductor and material supply, and clear, long-term demand commitments that justify major capital investments across the value chain.
“Many are taking a cautious approach, offering limited or customized solutions while waiting for clear standards, security frameworks and customer commitments,” Hughes said. “Building the supply chain will depend on stabilizing standards and safety frameworks so suppliers can design, certify, manufacture and install equipment with confidence.”
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