US fusion start-up Type One Energy has completed the first formal design review of Infinity Two, a 350 MWe power plant using stellarator fusion power technology. Type One says it is based on the world’s only implementable, peer-reviewed physics basis for a fusion power plant recently published by the Journal of Plasma Physics. The Infinity Two design is intended for a potential fusion power plant project with the Tennessee Valley Authority (TVA). Type One Energy signed a Cooperative Agreement with TVA in February to jointly develop plans the project.
Successful completion of the initial design review confirms that the Infinity Two technology approach, architecture, performance, and reliability requirements remain aligned with the expectations of TVA and the broader global energy market for a commercially viable First of a Kind (FOAK) fusion power plant.
The Infinity Two design review board, chaired by Type One Energy Chief Technology Officer Dr Thomas Sunn Pedersen, included several outside experts, including Dr George H “Hutch” Neilson from the Princeton Plasma Physics Laboratory and Dr Paolo Ferroni from Westinghouse Electric Company, to provide independent assessments of the engineering work.
“It is the first serious fusion power plant design that I’ve seen,” said Dr Neilson. “The work they’ve done to date provides a sound foundation for continued design development of what could be the first system to produce net electricity from fusion.”
Dr Ferroni, Chief Engineer for Advanced Reactors – GenIV/Fusion at Westinghouse noted: “I think it is important that the Type One Energy team is taking a comprehensive plant-level approach to develop their technology which includes a description of all necessary systems, not just the plasma core.”
The Type One Energy Infinity Two design is based on the company’s stellarator fusion physics basis, which for the first time realistically considered, in a comprehensive and unified manner, the complex relationship between competing requirements for plasma performance, power plant startup, construction logistics, reliability, and economics utilizing actual power plant operating experience. The Journal of Plasma Physics considered this approach to be “setting the gold standard for how this is done”.
Stellarators use powerful magnetic fields to contain the extremely hot plasma required for fusion. Unlike tokamaks, which rely on electric currents within the plasma to generate part of the magnetic field, stellarators use external coils to create the magnetic field that confines the plasma. The ability to maintain a stable plasma without relying on internal currents is a key advantage of stellarators, potentially leading to more efficient and continuous fusion power generation.
Type One earlier conducted an accelerated 18-month development programme for advanced modular high temperature superconducting (HTS) stellarator magnets. This programme was based on the company’s access to the proven Massachusetts Institute of Technology’s (MIT) VIPER technology for HTS cables in stellarator fusion magnets.
By taking advantage of a decade’s worth of basic R&D performed by MIT, together with access to certain additional VIPER technology utilisation capabilities, Type One Energy was able to significantly derisk and compress the development timeline for its advanced HTS magnets. In April, Type One announced tests to validate the performance of its own derivative VIPER technology when used in the complex geometric shapes of a modular stellarator magnet. The tests marked the beginning of an extensive magnet performance evaluation campaign, which will move to the MIT Plasma Science & Fusion Centre (PSFC).
The Infinity Two architecture is grounded in stellarator fusion technology, which has demonstrated stable, continuous steady-state operation at large scale by the Wendelstein 7-X (W7-X) machine at the Max Planck Institute for Plasma Physics in Germany.
By properly architecting Infinity Two, Type One says it is creating a proprietary fusion power plant design that supports a two-year power plant operating cycle separated by 30-day planned maintenance outages using existing materials and enabling technologies. The company also made use of its commercialisation programme to access the power generation industry’s deep expertise in power plant engineering design. Among other firms, AtkinsRéalis assisted in developing the design of those Infinity Two systems and structures not part of Type One Energy’s core focus on the stellarator fusion technology.
“Our ability to efficiently architect the initial Infinity Two design in an efficient, partner rich manner reaffirms our commitment to pursuing the lowest risk, shortest schedule, path to a commercially viable fusion power plant,” said Type One CEO Christofer Mowry. “The energy industry needs more reliable, clean, power generation technology that can meet the rapidly increasing demand for electricity and we are delivering a commercially compelling solution.”
