Data centers turn out to be the killer app for solid-state power transformers

The transformer sitting in a shipping container in Lenox, Massachusetts is about 1 meter by 1.5 meters by 2 meters. It handled up to 1 megawatt of power off a live grid line while charging an electric vehicle battery, stepping voltage down and converting AC to DC in the same box. It’s been there since May 2026, and it goes home to North Carolina in September.

That demonstration is the most concrete evidence yet that the thing utilities have been waiting years for might get built by companies that don’t currently make transformers at all.

The 1880s design still running your grid

Conventional transformers are assembled by hand, and the fundamental design dates to the 1880s. Two copper wire coils, manually wound around a steel core, generate electromagnetic fields that step voltage up for long-distance transmission or down for homes and businesses.

The largest ones can’t be mass-manufactured. Each is custom-built for a specific utility’s substations.

That’s why customers now wait up to several years for delivery. The backlog isn’t just blocking new grid capacity for rising demand. It’s also stalling the replacement of transformers that are already old.

Semiconductor switching instead of hand-wound copper

Solid-state transformers do the voltage conversion with high-frequency semiconductor switching, and they can be mass-manufactured from materials like silicon carbide. They’re smaller and lighter. The designs are modular, so parts can be upgraded or swapped. And a single unit can handle several jobs at once.

That last part is what caught the attention of the companies building the biggest AI data centers. Those facilities are moving to direct current power architectures to feed server racks full of power-hungry AI chips, and a solid-state transformer can take AC straight off the local distribution network and hand back the DC those racks need. No separate device required for the conversion step.

“It’s kind of this one magic box that eliminates a lot of the infrastructure and also provides one control location that eliminates a lot of the interoperability challenges that you may see in a traditional data center, where various components within the data center are trying to regulate the same thing,” said Srdjan Lukic, a professor of electrical and computer engineering at North Carolina State University. “Now you have one conversion stage outside the data hall and then you just go straight to the rack.”

Where the money went

Data centers are the “killer application for solid-state transformers right now,” Lukic said. Amperesand, Heron Power and DG Matrix, all US companies, have together raised more than $280 million over the past year to get the technology to market.

The pitch to data center developers isn’t only about the box being clever. It cuts the copper and other materials a project needs, Lukic explained, and the smaller footprint frees up floor space for something else.

Whether that spills over to the rest of us depends on manufacturing. If commercialization works, it could ease the transformer supply crunch generally, which would mean more units available for grid upgrades that have nothing to do with AI.

“There are relatively few specialized companies that manufacture [conventional] transformers, while solid-state transformers are like an electronics device,” Lukic said. “It completely opens up the space for who can play in the transformer space, and also opens up where transformers can be manufactured.”

What’s actually inside the Massachusetts box

The unit under test has an active front end that talks to the grid, an AC/DC converter, and a high-frequency isolation transformer that steps voltage either direction. The hard part was that isolation component, custom-made to take the “full stress of the grid, the full distribution voltage” in a package that compact, Lukic explained.

It doesn’t look futuristic. “It looks like a big transformer box with a slightly different form factor, a big blob of what looks like steel,” Lukic said. “It replaces three blobs of steel with one blob of steel and removes a lot of the wiring and trenching that you would typically have to do for an electric vehicle application.”

The test site is a power delivery laboratory run by the nonprofit Electric Power Research Institute, and the work caps a collaboration with the New York Power Authority that started in 2018. Eight years to get one megawatt-class box through a summer of live testing is a reasonable measure of how slowly this moves.

The part that could reach your house

Engineering and commercialization problems are still ahead. Lukic’s hope is that data centers buying these things first will “derisk” the technology for everyone else, which is a polite way of saying the AI buildout is paying for the shakedown cruise.

“Beyond data centers, we can think about electric vehicle charging in densely populated areas,” Lukic said. “A lot of loads within our homes are now DC, so having that ability to distribute DC in modern homes will have some significant benefits.”

If you want to track whether this is real, watch what happens when the NC State unit ships back in September and what the test data says about how it held up through a Massachusetts summer. Everything else is a funding announcement.