TL;DR: AI racks have gone from about 8 kW to over 100 kW in just a few years, with 1 MW designs already on the roadmap, and the old 54V setup cannot carry that much power without an absurd amount of copper. The industry is moving to 800V DC anyway, but the codes and certifications have not caught up, so most buyers are still ordering traditional transformers with long backlogs. Solid-state transformers work with either version of 800V, which makes them one of the safer bets while that gets sorted out, especially from companies that get UL-certified early and build strong control software.
Data Centers Need Power Standards
Before server racks began optimizing for AI workloads (pre-training, inference, and post-training), the average rack drew about 5-8 kW (Uptime Institute, via Upsite). As AI has proliferated and compute has moved from a nice-to-have to a necessity, it is clear we need to prepare for far more power draw. For example, Nvidia’s Blackwell rack systems pull 120 to 140 kW. The power draw is a core driver for why data center build outs will have to move away from air cooling (which usually tops out at 50 kW per rack) to direct-to-chip liquid cooling.
In the future, we should expect racks approaching 1 MW (1,000 kW), which cannot be powered the old way. In today’s AI racks, power arrives from the grid as Alternating Current (AC) which is then stepped down to a lower voltage using a transformer until it is converted to a low-voltage Direct Current (DC), ~54 volts, inside the rack. The lower the voltage, the higher the current, which requires thicker and thicker copper. At 54 volts, the copper needed rises roughly in line with a rack’s power draw, because with the voltage fixed, every extra kilowatt has to come from more current.
The industry today has consensus that the power delivery needs to change, but we have not been able to determine a standardized solution. To be clear though, the problem is twofold: equipment and regulatory constraints.
Overview of the problem
The grid delivers AC and chips run on DC. Instead of power getting converted several times between the grid and the chip, a new design would convert it once, close to where power enters the building, and carry 800-volt DC to the rack.
A good analogy to understand why we need to deliver a higher voltage is a water hose. A pressure washer moves a lot of water through a thin hose because the pressure is high. To move the same amount of water at low pressure, you need a much wider hose. Voltage is the pressure: raise it, and the same power flows through far thinner copper.
The future of power for data centers is likely to lean heavily on the development of solid-state transformers installed on-site but we need standards. An SST does the same job as a traditional transformer (changing power from one voltage to another), but it is built from electronics instead of a big block of copper and steel, and it can deliver DC power directly. Should it be ±400 volts or 800 volts, which is really a question of how the system is grounded? And how do all the parts connect? This is where it also becomes a regulatory concern because data center build outs require tons of approvals and certifications.
Why Is There No Standard?
The market moved extremely fast: The industry had only just standardized on 48–54-volt racks when AI arrived and power draw jumped 10x+ in a few years.
Big Tech built around their own supply chains: Some hyperscalers first backed ±400 volts, partly to reuse cheap EV parts, while Nvidia pushed 800 volts. In August, Google and Microsoft joined Nvidia behind 800 volts as an open standard, but the details are unwritten and AWS has not committed.
Rulebooks: Standards firm up as hardware matures. The Open Compute Project (OCP) is only on Solid-State Transformer (SST) Specification v0.3 and realistically you would not establish a standard until at least v1.0.
We are still in the early innings.
The Promise of Solid-State Transformers
Traditionally (and we mean something that has barely changed in a century), a transformer is a big block of copper and steel. They are big and heavy and can only step AC voltage up or down instead of being able to actually make DC. A solid-state transformer does essentially the same thing but it is built from power electronics, which eases the current supply chain bottleneck for traditional transformers.
Inside a SST, silicon carbide switches chop the power into AC that flips tens to hundreds of thousands of times a second, versus 60 times a second on the grid, and because a transformer’s core shrinks as frequency goes up, the magnetics end up a fraction of the size. Most importantly, an SST can take AC straight from the grid and turn it into the 800-volt DC the racks need, all in one box, while holding the voltage steady through software. A traditional transformer can’t make DC at all.
With all of this in mind, SSTs can actually hedge against the lack of standards because many SSTs can be configured for ±400-volt racks today and 800-volt racks tomorrow. They are built in electronics factories, which reduces the need for copper-and-steel plants that have backlogs. And silicon carbide, the material inside the switches, keeps getting cheaper. Prices for 6-inch silicon carbide wafers fell more than 20% from mid-2024 to around $400 or less through 2025, as suppliers added capacity faster than demand grew (TrendForce).
This is the promise, at least. There are still downsides, such as higher upfront costs, a shorter lifespan with more failure points, and a supply chain that shifts from copper and steel to silicon carbide, where China controls a growing share.
Takeaway: AI racks have gone from about 8 kW to over 100 kW in just a few years, with 1 MW designs already on the roadmap, and the old 54V setup cannot carry that much power without an absurd amount of copper. The industry is moving to 800V DC anyway, but the codes and certifications have not caught up, so most buyers are still ordering traditional transformers with long backlogs. Solid-state transformers work with either version of 800V, which makes them one of the safer bets while that gets sorted out, especially from companies that get UL-certified early and build strong control software.
Have a great weekend,
Josh