For Proxima Fusion, the transition from research to an industrial fusion project also runs through a material tens of thousands of kilometers long. The German startup has announced plans to build a 140 million euro factory to produce high-temperature superconducting tapes, the HTS tape that will power the magnets of its future power plant.
The move signals a major shift in scale. Until now, the fusion debate has focused primarily on the ability to achieve and control plasma—the ionized gas in which the reactions must take place. But a reactor cannot exist without a supply chain capable of delivering highly specialized materials, with industrial requirements and quantities that are out of the ordinary. For Proxima, securing superconducting tape means taking direct action on one of the most delicate parts of its technical design.
The investment will be covered by public and private funds. Bassa Sassonia will contribute 21 million euros. The announcement also comes a few months after a 411 million euro round that positioned the company among the best-funded fusion ventures. The factory is expected to serve both the demonstration phase and the eventual commercial power plant: it is therefore not a side project, but a piece of the roadmap with which Proxima aims to transform its design into a power plant.
Why HTS tape is central to a fusion reactor
Fusion reactors must confine plasma brought to extreme conditions. To achieve this, many designs use intense magnetic fields: the field does not directly produce energy, but keeps the plasma away from the machine’s walls and gives it a controllable configuration. The quality and power of the magnets therefore impact the size, architecture, and expected performance of the entire system.
HTS tapes are made from superconducting materials that, under expected operating conditions, can carry current without the resistive losses typical of conventional conductors. The term “high temperature” must be understood within the context of superconductivity: it does not mean the material can operate at room temperature, but rather that it can function at higher temperatures than more traditional superconductors. This characteristic enables the generation of very strong magnetic fields and has helped make more compact, efficient reactors more viable compared to certain earlier configurations.
The scale of consumption outlined by Proxima brings the supply challenge into sharp focus. Its demonstration plant will require 20,000 kilometers of HTS tape; a commercial power plant will need twice that, around 40,000 kilometers. This is not simply a matter of procuring an off-the-shelf component on the eve of construction. It requires manufacturing capacity, supply continuity, and a product engineered specifically for fusion magnets.
Potential demand does not come solely from Proxima. If multiple fusion projects reach the construction phase, the sector could absorb a significant share of global HTS tape production. The same material is also drawing interest from other markets: Veir, for instance, uses it to increase efficiency and power density in data center infrastructure. The factory announced by the startup should be viewed in this context, where an enabling technology for fusion could become a bottleneck across several power sectors.
An industrial dependency weighing on the timeline
Today, the vast majority of HTS tape manufacturing is concentrated in China and Japan. For a European company working on a fusion plant, relying on Asian suppliers can present an industrial risk: limited availability, competition with other buyers, long lead times, and the need to tailor materials to highly specific requirements. Building in-house capacity does not automatically eliminate those risks, but it gives Proxima greater control over a component directly tied to the development of its magnets.
It is an argument that goes beyond the simple issue of manufacturing localization. A fusion reactor brings together physics, cryogenics, power electronics, vacuum systems, advanced materials, and complex industrial plants. In such a project, delays or constraints on a single component can impact the program as a whole. Superconducting tape, in particular, is a technical raw material whose demand is driven by the geometry of the magnets, their power output, and the number of machines planned for construction.
Proxima's move can therefore be seen as an effort to bring a critical part of the supply chain in-house before demand surges. The company is not announcing a new scientific breakthrough in fusion, nor an operational date for a power plant. It is establishing manufacturing capacity dedicated to a necessary ingredient to get there. It is a meaningful distinction: producing HTS tape alone does not resolve the physics and engineering challenges separating a demonstrator from a commercial facility, but it reduces uncertainty around a critical supply.
From funding to industrial testing
The 411 million in funding previously raised gave Proxima significant resources to advance along its path. The 140 million commitment for the factory shows that part of the challenge lies not only in the lab or in design software, but in the availability of production infrastructure. The participation of Bassa Sassonia, with 21 million, adds a public component to an investment whose impact is also industrial: creating European capacity in a technology currently dominated mainly by Chinese and Japanese manufacturers.
However, several steps remain to be verified. The announcement concerns the factory construction plan and does not disclose, in the available details, completion timelines, annual production capacity, exact location, or final facility specifications. Nor does it clarify what share of future demand will be met internally versus through external procurement. These are factors that will matter in understanding whether the facility can fully meet the needs of the demonstrator and, later, of a commercial power plant.
Then there is the quality issue. In the superconductor sector, producing large volumes of material is not all that matters: the tape must meet the specifications required by magnets subjected to demanding operating conditions. The transition from planned production capacity to qualified supply for a reactor is therefore part of the bet. Proxima will have to demonstrate that its chosen vertical integration is compatible with the performance and reliability required by its project.
For Europe, the deal provides an indicator of how the fusion race could evolve. The competition will not just be about who manages to control the plasma or raise the most capital, but also about who can secure magnets, materials, and factories capable of reproducing them. In the case of Proxima Fusion, the 140 million euros allocated to HTS tape represents precisely that: an investment in a seemingly hidden technology, yet one destined to impact the ability to build the promised machines.
