A 120 kW rack was a design ceiling five years ago. A 1.2 MW rack is a 2026 reality, and the serious operators are already planning past it. When the rack is that dense, 415V AC distribution runs out of copper before it runs out of physics. The industry answer is 800V DC from the power room to the rack, with the final 48V step happening at the server.
That answer is correct. It is also the easy part of the problem.
What we see in practice is that the rectifier, the busbar, and the sidecar power shelf are well-understood pieces. The vendors (Delta, Vertiv, Eaton, ABB, Siemens, Lite-On, Bel Power) have credible roadmaps. The harder questions are adjacent.
Grounding and bonding on a DC bus behave differently than on AC. Fault-clearing strategy is not a port of the AC playbook. Arc-flash modeling under DC is its own discipline, and the NFPA 70E guidance is still catching up to the buildouts. Commissioning a DC-first hall with a crew that has spent twenty years on AC is a training cost, not a design cost, and it shows up in schedule risk if it is not budgeted.
Then there is the interconnect. Behind-the-meter gas turbines are moving from exotic to default for gigawatt campuses because utility queues are long and because hyperscalers have money to spend waiting out permitting. The BTM generation deck has to land into a DC-friendly bus without a chain of conversion losses that defeat the whole point.
Our operator lens on this: the pure-play power vendors will deliver the equipment on time. The integration risk lives in the seams. Between the power shelf and the liquid-cooling CDU. Between the BTM turbine controls and the data-hall EPMS. Between the electrical contractor who has bid AC-first for three decades and the MEP design that assumed a clean DC commissioning. Between the Nvidia reference architecture and the specific site's reality.
The operators that get 2027 rack deliveries on schedule will be the ones who treated the 800V DC conversion as a commissioning problem and a supply-chain problem, not a silicon problem. The ones who wait for a vendor to hand them a turnkey answer will be commissioning in 2029.