Infinity One (Type One Energy)

Overview

Infinity One is a prototype stellarator fusion device being constructed by the Type One Energy Group at the Tennessee Valley Authority (TVA) Bull Run Fossil Plant site in Clinton, Tennessee. The primary purpose of Infinity One is not to achieve net energy gain, but to serve as an integrated technology demonstrator. Its mission is to validate the critical systems and manufacturing processes required for Type One Energy's subsequent fusion pilot plant (FPP), named Infinity Two, which aims for commercially viable electricity generation.

The project represents a significant step in the commercialization of stellarator-based fusion energy. It focuses on de-risking two core enabling technologies: the use of high-temperature superconducting (HTS) magnets to create the complex, three-dimensional magnetic fields required for plasma confinement, and the application of advanced and additive manufacturing for fabricating the intricate stellarator components. The strategic partnership with TVA, a major U.S. utility, and its location at a decommissioned coal plant site, underscore a practical, grid-focused approach to fusion energy development. Infinity One is intended to provide crucial operational data on plasma performance, magnet system reliability, and overall plant integration, directly informing the design and engineering of its successor.

Physics / Mechanism

Infinity One is based on the stellarator concept, a magnetic confinement fusion device that uses external coils to generate a twisted, or helical, magnetic field to confine a hot plasma. Unlike the more common tokamak design, a stellarator does not require a large, inductively driven current within the plasma to create the confining field. This inherent property eliminates a major source of plasma instabilities known as disruptions, which can damage machine components and complicate steady-state operation. The ability to operate in a steady state is a key theoretical advantage for a future power plant.

The specific magnetic configuration of Infinity One is the result of advanced computational optimization. Modern stellarator designs are developed using sophisticated codes that solve the magnetohydrodynamic (MHD) equilibrium equations to find coil shapes that produce a magnetic field with desirable confinement properties. These designs, often termed 'quasi-symmetric' or 'quasi-isodynamic', aim to minimize the neoclassical transport of particles and energy out of the plasma, a historical challenge for stellarators. The goal is to create a magnetic geometry where particles behave as if they were in a simpler, more symmetric field, thus improving confinement.

A central technology for Infinity One is its reliance on high-temperature superconducting (HTS) magnets. HTS materials, such as rare-earth barium copper oxide (REBCO), can operate at higher temperatures (20–50 K) and generate stronger magnetic fields compared to low-temperature superconductors. This provides significant engineering advantages, including a larger thermal margin against quenches and potentially simpler cryogenic systems. For the complex, non-planar coils of a stellarator, HTS tapes offer manufacturing flexibility. The successful operation of Infinity One's HTS magnet system is a critical validation step for the economic and technical feasibility of a stellarator power plant, which requires strong, steady-state magnetic fields.

Historical development

Type One Energy Group was established as a spin-off company, building on decades of public-funded research in stellarator physics and engineering, primarily from the University of Wisconsin-Madison's Helically Symmetric eXperiment (HSX) and Germany's Max Planck Institute for Plasma Physics, home of the Wendelstein 7-X (W7-X) stellarator. The company was co-founded by a team of leading plasma physicists and engineers, including Dr. David Anderson, a prominent figure in stellarator research from UW-Madison.

The company's formation was driven by the convergence of three key advancements: the maturation of stellarator optimization codes, the commercial availability of high-performance HTS wire, and progress in advanced manufacturing techniques capable of producing the required complex geometries. These factors created a credible pathway toward a commercially viable stellarator design.

After its initial formation and securing private funding, Type One Energy began a site selection process for its first major device. A pivotal milestone occurred in June 2023, when the company announced a partnership with the Tennessee Valley Authority and the selection of the decommissioned Bull Run Fossil Plant site. This agreement provided a location with existing infrastructure, including substantial grid connections and cooling water access. The project received significant local and state support, including a $45.5 million grant from the state of Tennessee. The collaboration with nearby Oak Ridge National Laboratory (ORNL), a major U.S. Department of Energy research center with deep expertise in fusion science and materials, further solidified the project's technical foundation. Construction and site preparation began in 2024, marking the official start of the Infinity One project.

Current status

As of early 2026, the Infinity One project is in the construction and component procurement phase. The facility, designated the 'Fusion Demonstration Plant,' is being built on the Bull Run site in Clinton, Tennessee. Major site preparation and civil engineering work, which began in 2024, are well underway. This includes the construction of the main device hall, control rooms, and supporting infrastructure for power, cryogenics, and cooling systems.

Type One Energy is concurrently engaged in the detailed final design and fabrication of the core machine components. A significant focus is on the manufacturing of the HTS magnet coils. The company is working with industrial partners to scale up the production of the complex, non-planar coils, a process that involves precise winding of HTS tape and advanced structural support systems. This manufacturing effort is one of the project's most critical and longest-lead-time activities. According to a 2023 project timeline, the facility construction is targeted for completion around 2025, with the device assembly and commissioning to follow. The project is on a path to validate the integrated system performance before the end of the decade, providing essential data for the design of Infinity Two.

Notable implementations

Infinity One is the flagship project of /companies/type-one-energy. The entire program is structured around a two-step strategy, with Infinity One serving as the risk-reduction prototype for the subsequent Infinity Two fusion pilot plant.

• Type One Energy Group: The primary developer, responsible for the stellarator design, technology integration, and overall project management. The company's approach is heavily reliant on computational design and partnerships with established research institutions and industrial suppliers.
• Tennessee Valley Authority (TVA): As a major partner and host, TVA provides the site and critical infrastructure. This partnership is a model for public-private collaboration, directly connecting fusion development with an end-user utility and a clear path to grid integration. TVA's involvement ensures that practical considerations for a future power plant, such as licensing, maintenance, and grid stability, are incorporated early in the development process.
• Oak Ridge National Laboratory (ORNL): Located near the Infinity One site, ORNL provides world-class expertise in fusion materials, neutronics, HTS magnet technology, and high-performance computing. This collaboration allows Type One Energy to leverage decades of federally funded research and specialized diagnostic capabilities.

Open challenges

While Infinity One is designed to address many technical hurdles, several significant challenges remain. The primary challenge is the successful fabrication and operation of the large, complex HTS magnet system at the required scale and precision. Manufacturing dozens of unique, non-planar coils to tight tolerances and ensuring their structural integrity under immense electromagnetic forces is an unprecedented engineering task. Any significant delays or failures in magnet production would directly impact the project timeline.

Another key challenge is achieving the targeted plasma performance. While modern stellarator designs predict excellent confinement, Infinity One will be the first large-scale device to test some of these optimized configurations with HTS magnets. Validating that the 'as-built' magnetic field quality matches the 'as-designed' specifications is crucial. Minor field errors from manufacturing imperfections can degrade confinement, and developing techniques to measure and correct these errors will be a critical area of research.

Finally, the integration of all subsystems—including cryogenics, vacuum systems, plasma heating, and diagnostics—into a reliable, operational facility presents a complex systems engineering problem. Ensuring all components work together as designed during sustained operational campaigns will be the ultimate test of the integrated system and a necessary precursor to designing a reliable power plant.

Outlook

Over the next 5 to 15 years, the Infinity One project is poised to achieve several critical objectives that will shape the future of commercial stellarator development. In the near term (5 years), the primary goal is the completion of construction, assembly, and commissioning of the device. The project aims to achieve first plasma in the late 2020s. The initial operational campaigns will focus on system shakedown, magnet performance validation, and characterization of the magnetic field structure.

Following first plasma, the subsequent phase will involve detailed plasma physics experiments. The key objective will be to achieve and sustain high-performance plasma discharges, validating the confinement properties of the optimized stellarator design. This data will be benchmarked against theoretical models and will be the most important input for finalizing the physics basis of the Infinity Two pilot plant. A successful experimental campaign on Infinity One, demonstrating predictable and stable plasma confinement in an HTS-based system, would significantly de-risk the path to a commercial FPP.

Within a 10-15 year timeframe, the operational data and engineering experience from Infinity One are expected to directly enable the final design and construction of Infinity Two. The success of Infinity One would provide the technical confidence and operational proof points needed to attract the substantial capital investment required for a full-scale pilot plant. Therefore, the performance of Infinity One in the coming decade is a critical barometer for the viability of Type One Energy's commercialization strategy and a key milestone for the broader field of stellarator-based fusion energy.

References

1. Type One Energy to build fusion energy 'demonstration plant' in Tennessee — World Nuclear News (2023)
2. Type One Energy to Build Stellarator Fusion Prototype in Tennessee — POWER Magazine (2023)
3. Project Infinity: Type One Energy Group, TVA, and ORNL Partner to Build a Fusion Demonstration Plant in East Tennessee — U.S. Department of Energy (2023)
4. Type One Energy Announces Partnership with TVA to Locate its Fusion Demonstration Facility 'Infinity One' at the Bull Run Fossil Plant Site — Type One Energy (2023)
5. The promise of the stellarator — MIT News (2023)
6. Properties of quasi-isodynamic stellarator magnetic fields — Physics of Plasmas (2015)
7. Governor Lee, Commissioner McWhorter Announce Type One Energy to Invest $223.5 Million in Roane County — Tennessee Department of Economic and Community Development (2023)