Solid-State Transformers Move to Center Stage as AI Load Tests the US Grid

The AI boom's gargantuan surge in energy demand is stress-testing America's aging grid — and, increasingly, opening the door for the modernization that a staple of the system has needed for decades. Solid-state transformers, a redesign of the conventional transformer, are emerging as a key part of that fix.

**A system under strain**

Critics warn the wave of new grid connections driven by the AI buildout could push up electrical bills in the near term and, over the longer run, risk outages and other technical problems, according to TechCrunch. At TechCrunch Disrupt earlier this month, however, executives and policy advocates pushed back on the gloom, arguing the flood of new energy connections is creating opportunities as well as stress.

"It's a very different electric grid, right?" said Apoorv Bhargava, founder and CEO of WeaveGrid, at the event, per TechCrunch. "We're dealing with a ton of new variables, including renewable energy. We're dealing with a ton of new load in the form of electric vehicles and data centers and heat pumps, and the ability to manage and orchestrate is fundamentally what utilities are now grappling with."

**A century-old backbone**

Transformers are the nearly invisible workhorses of the grid, stepping voltage up for efficient long-distance travel and back down for delivery to homes and businesses. They are also complicated, in short supply, and built on a basic design that has gone essentially unchanged for about a century, according to MIT Technology Review.

Conventional transformers do their work with specialized steel alloys and miles of copper wire. Incoming electricity flows through loops on one side of a magnetic core, inducing voltage in loops on the other — a process called magnetic induction. The ratio of loops sets the voltage change: more loops on the secondary side step voltage up, fewer step it down.

The voltage path for a typical US solar plant illustrates the stakes, MIT Technology Review reported: an inverter converts the plant's DC output to AC at around 480 volts; transformers step that up to as much as 115,000 volts for transmission lines; and further transformers step it back down to 120 and 240 volts for homes. Transformers also provide galvanic isolation — no direct electrical path through the device — which helps limit disturbances and improve safety. The problem, said Srdjan Lukic, a professor of electrical and computer engineering at North Carolina State University, is that today's units are big, bulky, and difficult and expensive to replace.

**The solid-state alternative**

Solid-state transformers graft power electronics onto that blueprint. Instead of operating at the grid's fixed frequency, they convert incoming AC power to DC, then to higher-frequency AC using switches made of semiconductors such as silicon carbide, before converting again to the required output form. Because the semiconductors control frequency and stability so tightly, the magnetic core can be much smaller — some units come in at roughly one-tenth the size of a conventional transformer with the same capacity, Lukic told MIT Technology Review.

The technology also does more than step voltage. Solid-state transformers can absorb the functions of separate rectifiers and inverters, shrinking the footprint of electrical equipment and potentially cutting the amount of power lost in the system, MIT Technology Review reported. They remain in development, however, and cannot yet replace all traditional units — notably the largest transformers used at high voltages for long-distance transmission.

**A real-world test**

Early results suggest the technology is nearing real-world deployment.