US firm unveils compact stellarator design to supply 400 MW nuclear energy to grid

Fusion power company Thea Energy has detailed a fusion power plant designed to continuously supply approximately 400 megawatts of electricity to the grid. The New Jersey-based company unveiled the Helios architecture on September 9 through a collection of 16 peer-reviewed papers published in a special issue of Fusion Engineering and Design. The proposed US stellarator combines adaptable software-controlled magnets, a continuous exhaust system and a sector-based maintenance approach. Together, these technologies are intended to make fusion power reliable, cost-competitive and suitable for commercial operation. Planar coils simplify stellarator engineering Stellarators use magnetic fields to confine the extremely hot plasma required for fusion. Although decades of research have established the concept as a mature fusion system, the complicated three-dimensional coils traditionally used by stellarators have created major engineering challenges. Helios replaces those complex modular coils with an arrangement of planar magnets controlled through software. This configuration is designed to remain operational despite manufacturing deviations and wear that develops during extended operation. “The Helios power plant is technically viable, robust, and requires no scientific miracles to commercialize,” said David Gates, co-founder and chief technology officer of Thea Energy. According to the company, the quasi-axisymmetric design also allows Helios to be more compact than other proposed optimized stellarator power plants. The system has a major radius of eight meters, helping reduce both its physical footprint and projected cost. Continuous system targets reliable grid power Unlike fusion concepts that operate in pulses, Helios is designed to run continuously. The company says the plant could provide roughly 400 MW of electrical power without the risk of plasma disruptions, supporting its intended role as a source of baseload energy. Its architecture includes an X-point divertor, which continuously removes exhaust from the stellarator during fusion operations. The design also divides the plant into maintainable sectors, allowing equipment to be accessed and serviced over its operating life. “The papers introduce several innovative concepts aimed at reducing risks that have traditionally been associated with stellarator-based fusion power plant designs,” said Benedikt Geiger, associate professor at the University of Wisconsin–Madison and co-guest editor of the special issue. The published research covers several systems needed to turn the fusion concept into an operational power plant. These include remote handling, cryogenics, heat transfer, power supplies, diagnostics, instrumentation, and planar-coil magnet engineering. Helios follows DOE-certified milestone The US Department of Energy previously certified Helios’ preconceptual design during the first phase of its Milestone-Based Fusion Development Program. Thea Energy became the first participating company to receive certification for its plant-design milestone following an independent expert review. Before operating Helios, the company plans to develop Eos, its first large-scale integrated stellarator. Eos uses the same planar-coil architecture and is intended to demonstrate fusion performance relevant to a commercial power plant. Thea Energy says Helios remains on track to begin operating in the 2030s. The newly published papers now provide the wider fusion community with a detailed, multidisciplinary account of the physics and engineering behind that commercial objective.Get the latest in engineering, tech, space & science - delivered daily to your inbox.Atharva is a full-time content writer with a post-graduate degree in media & amp; entertainment and a graduate degree in electronics & telecommunications. He has written in the sports and technology domains respectively. In his leisure time, Atharva loves learning about digital marketing and watching soccer matches. His main goal behind joining Interesting Engineering is to learn more about how the recent technological advancements are helping human beings on both societal and individual levels in their daily lives.