For a long time, fusion research was regarded as basic research. In the meantime, however, the most powerful supercomputers, advances in the development of artificial intelligence, new laser diodes and high-temperature superconductors have brought fusion much closer to commercial application. In recent years, these technological advancements, coupled with continuously growing demands for energy, have also motivated private investors to invest in the fusion industry for the first time. Worldwide, 43 fusion start-ups, including four in Germany, raised over six billion dollars in private investment (Fusion Industry Association 2023).
The start-ups pursue a very broad range of technological approaches, each one unique. The various technologies that are being researched across all start-ups increase the chances of a commercial approach being found quickly. At this stage of development, however, it is not yet possible to predict which technologies will ultimately reach the market. Therefore, only focusing on one or a few technologies is not scientifically justifiable or recommended today (Metzler and Messinger 2023).
In order to ensure that Germany can remain in the race for the best technology and maintain its sovereignty in key technologies, the state must create the appropriate framework conditions. Such framework conditions are a minimum political requirement and primarily concern regulations and the approach to learning and training in universities and companies. In addition, the state needs to provide targeted incentives for the economy and reduce risks by structurally supporting both training organizations and the industry through the formation of concentrated fusion hubs with local ecosystems.
Reliable and risk-adjusted regulatory framework conditions must be created. Fusion power plants pose very few hazards, which also represent a significantly lower risk than fission power plants. If a legal framework is created now that is tailored to the hazard and risk profile of fusion power plants, a predictable, trustworthy environment can be created for start-ups and their investors. Adopting overly strict rules from the regulation of nuclear fission power plants would drive up the costs of fusion power plants. Last but not least, strict regulations also increase the likelihood that German start- ups will see initial success abroad, as the United States and the United Kingdom are already working on adapting their regulatory frameworks for fusion plants. The two countries also recently announced that they have entered into their own joint fusion development partnership (Leake 2023).
Germany’s expertise, which is already world-class in certain areas of basic research, must be strengthened and expanded further. In addition to physicists who deal with the physical processes behind fusion energy, engineers, plant engineers and materials scientists with specialist knowledge will also be needed in the future for large-scale process implementation and power plant development. With broad-based education and training in Germany, a strong international position can be achieved through the ability to better evaluate other and future fusion technologies too.
The time and cost plan for the ITER experimental fusion reactor has been revised several times over recent years. This shows how a potentially excellent project can be slowed down by complex framework conditions, tendering obligations, ineffective cooperation, political diplomacy and a lack of market ori- entation, which go hand in hand with purely state funding and long-term research plans.
Driven by their private investors, the fusion start-ups follow a strict, milestone-based roadmap and focus on the profitability of their fusion power plants. Unlike state-funded projects, they can adapt their strategy quickly and flexibly to new findings, technologies and market developments. If a milestone is not reached, measures are taken immediately, which can lead to drastic consequences and even the end of a project.
Germany and Europe is also home to a very adaptable and experienced SME sector as well as industrial groups, for example in automation technology, sensor technology, diagnostics, materials development, magnetic technology or the photonics/optics industry. These companies can supply components for fusion power plants as well as platform and cross-sectional technologies that can be used for various fusion approaches. With the right incentives, they could drive development and industrialization beyond pure fusion research together with fusion start-ups. In this constellation, they would be significantly faster than individual research institutions. Their technologies can also trigger innovations in other application areas and industries, and are not limited to fusion.
Start-ups should be supported by milestone-based public-private partnership models. A milestone-based approach similar to a SPRIND challenge ensures that high-risk projects with high profit potential are also supported, while approaches that prove to be unsuitable can be eliminated in order to limit financial damage. The possibility of failure must be expected and accepted.
The contribution of the public sector should also include access to research facilities and equipment as well as data centers. Exemplary programs can already be found in the United States and the United Kingdom (Hsu 2023).
SMEs should be supported in collaborative projects with industrial groups, fusion start-ups and research institutions. It is important for financial partners to take the lead as soon as possible and not the research institutions. The new BMBF funding program for the support of collaborative projects represents a first step for such initiatives that focus on a path towards market maturity.
An Important Project of Common European Interest (IPCEI) would also be a further step towards the market. An IPCEI on the topic of fusion could channel interim results from basic fusion research projects such as ITER, JET and WendelsteinX and use them to strengthen production capacities in the aforementioned industries or lead to the construction of a demo power plant. An IPCEI on photonics could combine both fusion technology with ancillary applications and the production of photonic circuits and sensors in one strategy.
Other models for supporting the supplier industry are also feasible. With a total of EUR 90 million over the next five years, SPRIND is already funding the development of laser technology in a subsidiary company. Another example of cross-sectional technology is superconductors which, in addition to fusion, can also be used in medical technology, wind turbines, electric aircraft and high-performance cables for power lines.
To accelerate fusion power plant development, companies and research institutions must work together to build larger centers or clusters for an active ecosystem with substantial investment. These centers or clusters require appropriate infrastructure, such as data centers, measurement systems or larger demo systems. Within this framework, facilities such as laser systems and space for tests and exper- iments should be offered, which should also be made available to or even determined by fusion start-ups. Such access reduces the capital requirements of companies, supports the transfer from basic research and, above all, supports the development of young talent, such as at the Culham Centre for Fusion Energy in the United Kingdom.
Germany already offers research locations that would be ideally suited as hubs for such activities, such as Darmstadt with the GSI Helmholtz Centre for Heavy Ion Research and the Technical University, Munich with the Max Planck Institute for Plasma Physics, the Centre for Advanced Laser Applications and two universities, Dresden with the Helmholtz-Zentrum Dresden-Rossendorf and Dresden University of Technology, the KIT in Karlsruhe, the Forschungszentrum Jülich or Hamburg with the Deutsches Elektronen-Synchrotron (DESY). All of these locations also offer the possibility to address users beyond fusion, especially at the laser research facilities.
Over the last few decades, research has created an excellent basis for the commercial application of fusion. However, the development of cost-effective power plants will not be the result of research, but must instead be driven by industry and start-ups. This development process towards a fusion energy economy must be structurally strengthened through public-private partnership measures and flanked by research. As it is not yet clear which concepts will ultimately make it to the market and prove to be sustainable in the long term, flexible, milestone-based programs are essential. Increased support for platform and cross-sectional technologies must also be available early on in the value chain. The necessary regulatory framework and improved training can only be driven by the state and should therefore be one of its main concerns.
Unlike the fuel used in today’s nuclear power plants, the safety risk associated with fusion power plants is extremely low, as a fusion process does not trigger a chain reaction, regardless of the fuel. Most technological approaches to generating fusion energy use tritium and deuterium as fuel. Tritium and deuterium are so-called isotopes of hydrogen, which have additional neutrons compared to light
hydrogen. So far, only a few start-ups aim to combine helium-3 nuclei or boron with hydrogen as fuel. On Earth, tritium only exists naturally in small quantities. However, it can be produced directly in a fusion power plant from lithium, which is available in large quantities. Tritium has a half-life of just 12.3 years. It is only slightly radioactive and is also only present in small quantities in the combustion chamber at any one time, which means that it would also be highly diluted if dispersed in the air. The radioactivity of tritium is so low in energy that it cannot penetrate human skin from the outside (Max Planck Institute for Plasma Physics 2023). Although the tritium cycle and the fast neutrons produced in the process, which can radioactively activate the walls of reactors, complicate the design of fusion power plants, the other, non-radioactive fuels, which hardly produce any fast neutrons, are significantly more difficult to fuse.
Two main methods are followed to fuse the fuel: long-term confinement of the plasma to be fused by external magnetic fields, so-called magnetic confinement, or short-term confinement by the inertia of the involved mass itself, which is known as inertial confinement. There are also various ignition mechanisms.
With magnetic confinement, the generated plasma is heated in large ring-shaped systems using various techniques and held together by a large number of superconducting magnets. The two most prominent approaches involve apparatus known as a tokamak (simple geometry plus external current) and a stellarator (complex geometry). The tokamak is the most thoroughly researched concept, but it struggles with plasma instabilities. These instabilities are caused by the dynamics of the alternating magnetic fields, as the externally applied magnetic fields are supplemented by an internal magnetic field generated by an electric current that is permanently conducted directly through the plasma. Although the stellarator is more stable, it requires unevenly bent magnetic coils in order to dispense with the internal magnetic field, the shape of which is difficult to calculate and manufacture.
For inertial confinement fusion, a fuel pellet is usually compressed and heated by high-intensity laser beams. Depending on the concept, the pellet is ignited by other external drivers such as particle or laser beams, for example. It is operated in pulsed mode.
Now, the initial ignition of the fusion process with just a few cores is no longer a challenge. Instead, the challenge in all approaches is how to trigger the fusion process in a stable manner and keep it running for as long as possible without repeated ignitions. If the fusion process is self-sustaining after initial ignition, like the sun, for example, its maintenance consumes less energy than it generates and the power plant begins to become cost-effective. Critical components include laser systems and conventional magnets, which are currently energy inefficient.
Several fusion start-ups already exist in Germany: Proxima Fusion and Gauss Fusion, bothwith the aim of developing a stellarator (magnetic confinement), and Focused Energy and Marvel Fusion, each pursuing a different approach with laser (inertial) fusion. They are joined by the SPRIND subsidiary Pulsed Light Technologies.
Pulsed Light Technologies GmbH (PLT) is a fully owned subsidiary of SPRIND and will receive a loan of approximately EUR 90 million from the SPRIND budget over the next five years. Rather than developing products, PLT works on demonstrators/IP of core technologies that reduce the high technical risk and indirectly also the economic risk for future laser manufacturers or other suppliers in today’s precarious market.
The aim of PLT is to develop the infrastructure required for laser-driven fusion. It will focus on issues that are crucial for fusion, but which are not part of the core development or IP of start-ups working on the development of a fusion power plant.
Laser systems are currently being developed in collaboration with laser fusion start-ups based in Germany to demonstrate the key elements of such systems that are required for subsequent power plant operation. The two collaborative partners Marvel Fusion (Munich) and Focused Energy (Darmstadt) are focusing on different approaches with different laser system requirements.