Thea Energy Publishes the Most Practical Fusion Power Plant Design and A Clear Path Toward Energy on the Grid

KEARNY, N.J., Sept. 09, 2026 (GLOBE NEWSWIRE) -- Thea Energy, Inc., a fusion power company advancing the stellarator for the commercialization of an abundant source of baseload energy, today announced a series of 16 peer-reviewed papers on its “Helios” power plant published in a special issue of Fusion Engineering and Design (FED). The Helios architecture is the most advanced iteration of a stellarator power plant to date that incorporates important breakthroughs essential for commercial deployment. Comprehensive details presented in this special issue validate Helios and its potential to provide cost-competitive, high-availability fusion power to end users. The special issue titled “The Helios Stellarator Power Plant Design by Thea Energy” is accessible on the Company’s website under “Presentations & Publications” and via FED.

Helios includes several breakthroughs for commercial fusion. The power plant architecture combines software-controlled magnet coils that are adaptable to real-world conditions; a continuous stellarator ‘divertor’ exhaust system capable of fusion power operations; and a stellarator sector-based maintenance scheme enabling long-term plant viability. Decades of research have established the stellarator as a mature fusion system. Building on this foundation and recent breakthroughs, Helios is designed to operate continuously and reliably, delivering approximately 400 megawatts (MW) of electrical power to the grid with zero risk of plasma disruption.

“The Helios power plant is technically viable, robust, and requires no scientific miracles to commercialize,” said David Gates, Ph.D., co-founder and chief technology officer of Thea Energy. “We have combined a sound physics basis with realistic engineering into a power plant that eliminates the complex, modular 3-dimensional coils that have historically been the stellarator’s ‘Achilles’ Heel’. Our system’s unique ability to operate continuously in the event of manufacturing deviations and operational wear is the key to making fusion power plants cost-competitive and commercial-grade. All things truly novel require thoughtful review and verification from external experts. We have the underlying science and engineering vetted by the global fusion community for the planar coil stellarator and are moving into industrial implementation. We look forward to working with our strategic partners to deliver abundant fusion power using this winning architecture.”

The Helios preconceptual design milestone was previously certified by the DOE in the inaugural phase of the Milestone-Based Fusion Development Program. Thea Energy was the first awardee company to receive certification of its plant design milestone as part of the program following a detailed review by a panel of independent fusion experts. The Company is on track to operate Helios in the 2030s following “Eos” its first large-scale integrated stellarator. Eos leverages the same planar coil stellarator architecture as Helios and will create power-plant relevant, world-leading fusion performance. Eos will directly benefit from the breakthroughs highlighted across this special issue.

Benedikt Geiger, Ph.D., associate professor at UW-Madison and co-guest editor of the special issue, added, “The Thea Energy team presents a comprehensive vision for a future fusion power plant, addressing critical subsystems including remote handling, heat transfer, cryogenics, power supplies, diagnostics and instrumentation, and planar-coil magnet engineering. The papers introduce several innovative concepts aimed at reducing risks that have traditionally been associated with stellarator-based fusion power plant designs. In particular, the exclusive use of planar coils and the incorporation of an ‘X-point’ divertor represent potentially transformative approaches that could significantly simplify engineering complexity and improve system viability. Moreover, the authors identify plausible pathways for addressing several longstanding challenges in fusion energy development, providing valuable insights and alternative perspectives for the broader fusion community. As such, the work has the potential to influence and expand future research directions in stellarator and fusion power plant design.”

Sophia Henneberg, Ph.D., Norman Rasmussen Career Development and assistant professor of Nuclear Science and Engineering at Massachusetts Institute of Technology and co-guest editor of the special issue, added, “Stellarators are a mature magnetic confinement fusion technology, but historically, complex coil geometries have constrained engineering choices. This special issue of FED presents Thea Energy’s preconceptual Helios design as a systematic, multidisciplinary body of work. It is a substantive contribution to the stellarator power plant design literature, and an important example of the private fusion sector submitting its work to rigorous peer review.”

Power plant highlights:

• Helios will continuously and reliably provide approximately 400 MW electric power to the grid with no risk of plasma disruptions.
• Helios is the most compact proposed optimized stellarator power plant with an 8 m major radius, largely enabled by its quasi-axisymmetric (QA) design and simpler hardware, resulting in a smaller footprint and cost.
• As a result of its practical, sector-based maintenance scheme, Helios has a high-capacity factor of over 85%, as well as a 40+ year system lifetime. Entire toroidal sectors are removed radially from the system more easily with a low number of unique parts.
• The QA configuration also allows for ample blankets and shielding, 1.2 m between the fusion plasma and magnetic coils, meaning components have a lifetime of that of the power plant.
• Helios leverages the world’s first tokamak-like X-point divertor in a stellarator power plant architecture. The X-point divertor has a simpler geometry that can exhaust gas 10x more effectively than prior stellarator divertors. With this approach, Thea Energy leverages extensive tokamak divertor experience to resolve a fundamental stellarator challenge that, until now, lacked a viable technical solution.
• Helios does not rely on future scientific breakthroughs, with a maximum magnetic field on the superconducting coils of 20 T, within realistic engineering parameters and performance levels previously achieved by large-bore HTS magnets.
• Power plants using the Helios architecture can leverage thinner and cheaper first walls, the barrier facing the fusion plasma fuel.
• Helios also uses known materials for plasma facing components, and neutronics analysis concludes a minimum 11-year and average 18-year lifetime for first wall systems, which also contributes to its overall high-capacity factor.
• High-fidelity simulations with state-of-the-art codes indicate low turbulent energy leakage (transport), meaning less heat leaks from the plasma. This creates a system with less heating power required compared to other proposed stellarators in development.
• Helios will use deuterium-tritium (D-T) fusion. D-T fusion has the lowest required triple product, highest cross-section, and allows Thea Energy to leverage a more traditional balance of plant using known technology for energy capture. This means Helios integrates well with how construction crews, supply chains, and people already work.

About Thea Energy, Inc.
Thea Energy, Inc. is commercializing scalable and economical fusion energy systems via its planar coil stellarator architecture. Thea Energy’s stellarator power plants will uniquely provide an abundant and safe source of zero-emission energy for the future of humanity. The Company has utilized arrays of mass-manufacturable magnets and dynamic software controls to reinvent the stellarator.

Thea Energy spun out of Princeton University and Princeton Plasma Physics Laboratory in 2022 to commercialize the stellarator, a mature magnetic confinement fusion architecture. The Company was selected as an inaugural awardee of the U.S. Department of Energy’s Milestone-Based Fusion Development Program following a detailed merit review process, and is also supported via six Department of Energy INFUSE awards and an ARPA-E SCALEUP award. Thea Energy is currently collaborating with leading national labs, academic institutions, and industrial partners to commercialize fusion energy on the fastest and most efficient path.

To learn more about Thea Energy’s mission, visit thea.energy and follow us on LinkedIn and X .

Contact
Madeline Joanis
maddy@thea.energy