Nuclear fusion: where mechanical engineering comes into play

Nuclear fusion sounds like the distant future. But for many mechanical engineers, it could become relevant sooner than the timeline for the first commercial power plant suggests. Because before a fusion reactor reliably delivers electricity, facilities must be built, components manufactured, materials tested, supply chains established, and maintenance concepts developed. That is exactly where the strengths of mechanical and plant engineering lie.

The principle of nuclear fusion is well known: light atomic nuclei merge into heavier nuclei, releasing energy in the process. In the sun, this happens under enormous pressure and at extreme temperatures. On Earth, these conditions must be created technically. This requires plasmas with temperatures of many millions of degrees, stable confinement methods, and materials that can withstand stresses that hardly occur in conventional industrial plants.

This makes nuclear fusion far more than a topic of plasma physics. It is high-precision mechanics, vacuum technology, cryogenics, laser technology, magnet construction, materials development, automation, sensor technology, robotics, and quality assurance all in one. The step from experiment to power plant will succeed only if these disciplines are mastered industrially.

Nuclear fusion: Wendelstein 7-X generates stable plasma

The nuclear fusion experiment in Greifswald has passed a milestone. The researchers reached 1.3 gigajoules - and a record for discharge time: the hot plasma could be maintained for eight minutes.

Why nuclear fusion is an issue for mechanical engineering

The central question is not only when the first fusion power plant will feed electricity into the grid. For industry, it is at least equally important who can supply the machines, components and processes needed for this. Fusion facilities require components that function under extreme conditions: large and tight vacuum chambers, superconducting magnet coils, cryogenic cooling systems, highly resilient wall materials, precise target feed systems, laser systems, valves, pumps, sensors and remote-controlled maintenance technology.

This creates tasks that sound familiar to mechanical engineering - only under significantly tightened requirements. It is about tight tolerances, reproducible processes, stable supply chains and high plant availability. A physical experiment may be unique. A power plant must be maintainable, licensable, safe and economically operable.

Mechanical Engineering Summit 2026: nuclear fusion as a topic for industry

The future topic of nuclear fusion will also be taken up by the Mechanical Engineering Summit 2026 in Berlin. There, when it comes to nuclear fusion, it is not only about energy policy or research, but about industrial opportunities: Which competencies are needed?  And how can it be prevented that Germany does strong research, but the later value creation takes place elsewhere? The topic is meant to move away from myth and toward real, actual, value-creating application. Participants should be able to classify the topic away from the buzzwording and recognize their opportunities. It has already been established in the summit program that nuclear fusion will be given space in the "Future Business" forum on the second day of the event, 11.11.26. Contributions have already been confirmed by Prof. Dr. Claudia Eckert, the president of acatech,  and Prof. Dr. Maximilian Fleischer, Chief Key Expert at Siemens Energy Global. 

Two technological paths dominate

In nuclear fusion, two technological approaches are currently above all at the center of attention. The first is magnetic fusion. In this process, a hot plasma is confined with strong magnetic fields. The best-known designs are tokamak and stellarator . In the tokamak, the ring-shaped plasma is stabilized by magnetic fields and a current generated in the plasma. The stellarator, by contrast, works with complexly shaped external magnet coils. This makes design and manufacturing demanding, but promises advantages for later continuous operation.

The second approach is laser or inertial fusion. In this process, extremely powerful laser pulses strike a tiny fuel pellet. This target is compressed and heated so strongly that fusion reactions begin. For a power plant, however, this process would not have to work just once in the laboratory. It would have to run at a high repetition rate, with high efficiency and industrial robustness. This places enormous demands on lasers , optics, target manufacturing, feed systems and process control.

The fuel is usually considered to be a mixture of deuterium and tritium. Deuterium occurs in water. Tritium is radioactive and exists in nature only in small quantities. A future fusion power plant would therefore have to produce tritium itself as much as possible, for example in so-called breeding blankets. There, lithium can be converted into tritium through neutron bombardment. These breeding blankets must at the same time remove heat, withstand radiation and be safely integrated into power plant operation. For materials engineering, manufacturing and plant engineering, this is one of fusion's most demanding tasks.

Trumpf: Hagen Zimer on the future of laser technology

Hagen Zimer, CEO laser technology at Trumpf, is enthusiastic about the many possibilities the technology brings. What lasers will be used for in the future, among other things.

Germany has strong research anchors

Germany has a dense research landscape for nuclear fusion. A key role is played by the Max Planck Institute for Plasma Physics with sites in Garching and Greifswald. In Garching, the ASDEX Upgrade tokamak is operated. In Greifswald stands Wendelstein 7-X, the world's largest fusion facility of the stellarator type.

Wendelstein 7-X shows particularly clearly how strongly fusion research already depends today on high-performance mechanical engineering. The facility operates with 50 non-planar superconducting magnet coils; a total of 70 superconducting coils are installed. Their manufacturing, assembly, cooling, and integration are not peripheral topics, but the core of the technology.

Wendelstein 7-X: how a stellarator is making history

Ten years, countless records - Wendelstein 7-X has developed from a research experiment into a beacon of hope for fusion energy. A look behind the magnetic coils reveals a century project with global appeal.

The Karlsruhe Institute of Technology is also an important actor. There, among other things, the focus is on safety issues, materials, breeding blankets, tritium cycles, plasma heating, and fuel supply. Forschungszentrum Jülich works on the interaction between plasma and wall materials as well as on materials that must withstand extreme heat fluxes and intense neutron radiation.

Fraunhofer, in turn, contributes the application-oriented perspective. Several institutes are working on laser technology, optics, additive manufacturing, materials, target production, non-destructive testing, tritium barriers, and repair technologies. This brings fusion closer to industrial issues. It remains research, but is increasingly also becoming an engineering task.

Start-ups drive commercialization

In addition to the research institutes, several companies are emerging in Germany that are pursuing different paths to fusion:

Proxima Fusion emerged from the environment of the Max Planck Institute for Plasma Physics and is relying on the stellarator. The company wants to further develop findings from Wendelstein 7-X toward a power-plant-capable design.

• Focused Energy, with roots at TU Darmstadt, is pursuing the path of laser fusion. The company wants to advance its technology at the Biblis site. RWE is involved as a strategic partner and contributes, among other things, site and permitting experience. This shows that energy suppliers, too, are dealing at an early stage with the question of what role they can assume in a possible fusion market.

Marvel Fusion from Munich is also working on laser-based fusion and is relying on ultrashort-pulse laser technology as well as nanostructured fuels. Gauss Fusion, in turn, is pursuing the path of magnetic fusion and sees itself as a European industrial player for future fusion power plants.

What ultrashort-pulse lasers make possible in industry

USP lasers process materials that other lasers struggle with. What they can do is shown, for example, by laser systems from Trumpf.

For traditional mechanical engineering, such start-ups are interesting for two reasons. First, they need partners who turn laboratory processes into robust systems and components. Second, early supply chains are emerging around them. 

In connection with the IFE Targetry HUB, Fraunhofer mentions, among others, Focused Energy, KIT, TU Darmstadt, as well as companies such as Kern Microtechnik, Diamond Materials, Plasmatreat, LightFab and ModuleWorks. In projects on laser-driven neutron sources, Trumpf, Photonis Germany, RWE, Fraunhofer ILT, HZDR and TU Darmstadt are also mentioned.

Where mechanical engineers are specifically needed in nuclear fusion

• A first field is precision manufacturing. Magnet components, target systems, optical components, combustion chamber structures and cooling channels require accuracy, process stability and robust quality assurance. Machine tools , measuring machines, automation and digital process chains thus become key technologies.
• A second field is materials and surface technology. In fusion systems, materials such as tungsten, specialty steels, composite materials or new alloy concepts are used. They must be processed, joined, tested and monitored during operation. Additive manufacturing can offer advantages where complex cooling structures, functional integration or difficult-to-machine materials are required.
• A third field is vacuum, cryogenic and fluid technology. Magnetic fusion requires high vacuum and cryogenic cooling for superconducting magnets. Laser fusion requires precise process environments, protected optics and target handling with a high repetition rate. Pumps, seals, valves, sensors, actuators and control technology thereby become critical components.
• A fourth field is robotics. Components inside a fusion reactor can be activated by neutrons. Manual maintenance there is only possible to a very limited extent. Future systems therefore need remote-controlled and partially automated maintenance systems. Gripping technology, image processing, condition monitoring, secure control architectures and remote handling thus become important building blocks.
• The fifth field is industrialization itself. A research reactor can be created over years as an individual project. A power plant needs different standards: ability to supply, standardization, cost control, maintenance concepts, proximity to series production and robust project structures. This is precisely where mechanical and plant engineering can contribute its experience from other high-technology industries.

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From large-scale experiment to industrial topic

For a long time, nuclear fusion was above all large-scale research financed by the state. ITER in France, ASDEX Upgrade in Garching and Wendelstein 7-X in Greifswald stand for this approach. Large systems, long runtimes, international programs.

Meanwhile, the picture is changing. Start-ups, investors, energy companies, photonics companies, and mechanical engineering firms are joining in. The German federal government has included nuclear fusion as a key technology in its high-tech strategy and adopted a Fusion Action Plan. Additional funds are to flow into research, infrastructure, and technology demonstrators.

Nevertheless, classification remains important: nuclear fusion is not a short-term answer to high electricity prices, security of supply, or the transformation of the energy system. Today, no commercial fusion power plant supplies electricity. The timing of a first economically operated power plant cannot be reliably predicted.

Acatech also describes the path as demanding. According to this, a fusion power plant in Germany by 2045 would only be achievable if research, industry, infrastructure, and the development of skilled workers are significantly accelerated. Particularly important are neutron test infrastructures, breeding blankets, material development, and the industrialization of component manufacturing.

This makes it clear: fusion requires not only scientific progress. It requires industrial implementation capacity.

Why early involvement can pay off

For mechanical engineering companies, opportunities do not arise only when building a commercial power plant. They already arise in research facilities, demonstrators and test infrastructures. Machines are needed for target production, laser optics manufacturing, magnet components, vacuum chambers, heat exchangers, specialty pumps, coating technology, non-destructive testing, digital twins and plant automation.

In addition, there are spin-offs. Technologies from fusion can become usable earlier in other markets: high-performance lasers, neutron sources for material testing, new measurement methods, radiation-resistant sensors, additive repair processes or material data platforms. The economic benefit therefore does not depend solely on when a fusion power plant first sells electricity.

Strategically, it is about positioning. If fusion were to become a global power plant market, standards, supplier structures and system architectures would emerge early. Those who have already gained experience with components, processes and plants would then likely have better prospects than companies that only enter at the time of the first major order.

No energy policy for tomorrow

Despite all the momentum, caution remains advisable. Nuclear fusion is not a technology for the next legislative period. Many questions remain open: tritium supply, material service life, maintenance, economic viability, permitting, plant availability and costs. Particularly difficult is the transition from successful individual experiments to continuous operation that meets the requirements of a power plant.

The economic role in the energy system is also not clarified. A fusion power plant would be a highly complex and capital-intensive system. Whether it can hold its own against renewable energies, storage, grid expansion, hydrogen power plants or other flexibility options remains to be seen.

Precisely for this reason, the industrial debate should be conducted soberly. It is not about the image of “sun fire from the socket.” It is about components, manufacturing processes, standards, supply chains, risks and business models. For mechanical engineering, that is the actually exciting question.

Fusion needs industrializers

Nuclear fusion remains a long-term technology. But it is no longer only a matter of physics. An industrial environment is emerging from research in which mechanical engineers, plant engineers, automation specialists, materials specialists and precision manufacturers can play an important role.

Research institutions such as IPP, KIT, Forschungszentrum Jülich, Fraunhofer and TU Darmstadt provide foundations and technology building blocks. Start-ups such as Proxima Fusion, Focused Energy, Marvel Fusion and Gauss Fusion are driving different approaches forward. Industry must turn this into robust plants, components and processes.

For mechanical engineering, the opportunity lies at the interface between research and power plant. Those who master extreme temperatures, high vacuum, specialized materials, automated manufacturing, robotics, quality assurance and process stability will find in fusion a demanding field of the future. It is still open when this will become a broad power plant market. But one thing is clear: If nuclear fusion succeeds, it will not only be a success of physics. It will also be a success of mechanical and plant engineering.