This green-tech startup is taking the nuclear option to power data centers

On a recent afternoon in DC, I shielded my eyes in front of the Walter E. Washington Convention Center, gazing up alongside attendees wearing badges for the Data Center World conference that was happening just inside. During the lunch hour, however, the main attraction was being hoisted into place by a crane: a micro-scale nuclear reactor.

Weighing in at 22 tons and standing 48 feet tall, there’s nothing micro about the unit, billed by its creator, Last Energy, as a prototype for a system that could eventually help meet the world’s growing need for clean energy to power data centers.

“With the advent of AI and what we’re seeing in the power-demand increases, data centers are going to become a huge, power-hungry customer for the grid,” John Chaplin, VP of commercial at Last Energy, told me as we looked on. “Nuclear is a unique solution.”

Last Energy’s plants are typically constructed next to data centers, Chaplin said, and the plant’s power supply—the reactor—is buried deep in the ground and encased in steel for safety.

According to BBC News, each reactor can power the equivalent of 20,000 homes. For data centers, this means an around-the-clock, guaranteed energy supply that has the added benefit of being carbon-free, Chaplin said.

So far, VC-funded Last Energy has only deployed its systems in Europe, but it’s seen a measure of success there.

“We’re in four key markets there: Poland, Romania, the Netherlands, and the UK. And across those four markets, we have an order book of 55+ units,” Chaplin said. “We are targeting turning the first unit on in 2025.”

These markets made the most sense for Last Energy’s first deployments because of the countries’ relatively high energy costs and government support for nuclear energy development, according to Chaplin.

As it looks ahead to going live with its European plants, Last Energy has also set its sights on finding its first commercial partner in the US, Chaplin said, which will mean overcoming preconceived notions about the feasibility of nuclear energy.

“Nuclear has struggled with this perception of being over-budget and over-time and constantly overpromising and under-delivering,” he said. “What we need to focus on is delivering a project where we deliver it on cost, and on time, and be able to show that this is a viable technology that capital can come into.”

In the meantime, Chaplin said, Last Energy is looking to demonstrate that nuclear energy “isn’t a scary technology.” Part of that mission is making the reactor prototype more visible.

After completing an exhibition circuit that included Houston and the Washington Convention Center, Last Energy plans to permanently display the unit on a vacant lot it acquired just off of DC’s busy U Street corridor.

“As people decarbonize, become more electrified, the need for stable, carbon-free baseload power on our grids is extremely important. And nuclear is going to play a large part,” Chaplin said.

Correction 04/22/24: This piece has been edited to reflect Last Energy's future plans about US expansion.