Thea Energy previews Helios, a pixel-inspired fusion power plant

Fusion energy has the potential to rewrite trillion-dollar energy markets, but first, startups have to prove that their designs will work and won’t be too expensive. It’s not easy, especially when you consider that the massive magnets and lasers used in many designs must be installed with millimeter precision or better.

Fusion startup Thea Energy says its pixel-inspired reactor and specialized control software should be able to generate power without requiring the same level of perfection.

“It doesn’t have to be good at first,” Brian Berzin, co-founder and CEO of Thea Energy, told TechCrunch. “We have a way to adjust for defects on the back end.” This margin of error could give Thea an advantage over the competition.

Fusion power plants promise to deliver gigawatts of clean energy to the grid, but material and construction costs threaten to make them uncompetitive with cheap solar and wind. By building a power plant first and ironing out the software kinks, Theia could help significantly lower the cost of fusion energy.

But first the company must build a working prototype. Today, Thea is publishing details of its design, including details of the physics behind it. The startup shared the paper exclusively with TechCrunch.

Theia is working on a unique design for a star reactor, a specific type of reactor that uses magnets to stimulate plasma fuel to form. Magnets are one of the two main methods fusion scientists use to maintain and confine the heat of the plasma until fusion reactions occur. The other, known as inertial confinement, uses a laser or other force to squeeze tiny fuel pellets.

Most of the stars are built using magnets that look like a house in a Salvador Dali painting. But Theia’s design uses dozens of larger magnets and hundreds of smaller ones to create what we might call a “virtual” star.

In typical stars, magnets are designed to follow the contours of a shape meant to work with the quirks of the plasma, helping to confine it for longer using less energy than a tokamak, which uses a series of magnets of identical size and shape. However, stars have one major drawback: their irregular shape makes it difficult to manufacture magnets in large quantities.

So instead, Theia designed his reactor around small, identical superconducting magnets arranged in arrays. The startup will use software to control each individual magnet to generate magnetic fields that can replicate the oscillating shape of a star.

This approach has many pluses. For one thing, it allowed Thea to quickly replicate his magnetic design. In the past two years, the company has modified the design more than 60 times, Berzin said. “In most fusion companies, you’re dealing with car-sized magnets or car-sized lasers or car-sized wedges. Unfortunately that means it costs $20 million each and takes two years.” [to make]He said.

It also means the company can use software controls to fix any irregularities in the way the magnets are manufactured or installed. To test the original control system, Thea built an array of three-by-three magnets equipped with sensors. The controls, derived from the physics of electromagnetics, worked well. But the company also wanted to see how the AI ​​could handle the task, so it also trained a new person using reinforcement learning.

The team came away surprised at how well everything worked.

“We intentionally threw curve balls at the matrix,” Berzin said. “We intentionally disassembled a magnet by more than a centimeter. You could see it was completely out of line. It would have been very difficult for us to make it so poorly.” The team also tested superconducting materials from five different manufacturers as well as intentionally defective materials. “Every time we did that, the control system, without us turning knobs or intervening, was able to catch those faults,” he said.

Theia’s reactor design, the Helios, will use two types of magnets. On the outside, 12 large magnets of four different shapes will do the heavy lifting to keep the plasma contained. They resemble those in a tokamak, a type of donut-shaped reactor that Commonwealth Fusion Systems is building. Inside the large coils, 324 smaller circular magnets will adjust the shape of the plasma.

The startup expects Helios to generate 1.1 gigawatts of heat, which the steam turbine will convert into 390 megawatts of electricity at a cost of less than $150 per megawatt hour. The reactor will have to be shut down for a maintenance period of 84 days once every two years. If all goes well, that means its power factor — a measure of how much power it generates over a given period of time — will be 88%. This is much better than today’s gas-fired power plants, and almost as good as today’s nuclear power plants.

Helios is still in the conceptual stage. Theia must first build Eos, a proto-fusion device intended to prove the science behind the concept. The company will announce a location for Eos in 2026 with plans to have it up and running “around 2030,” Berzin said.

While she is building Eos, Thea plans to start working in parallel on Helios. It’s a similar approach to how Commonwealth Fusion Systems is progressing with work on Arc, its first commercial power plant, while building Sparc, its pilot plant.

For now, Berzin is looking forward to hearing from the fusion community. “This is the overview paper version. This will be followed by a very significant amount of work that will be released through peer review and publication,” he said. “Now is the time for us to go and establish partnerships, collaborate and engage end users to start building the first one.”