Stellarator Fusion Energy: Proxima Fusion’s Path to Steady-State Power
Speaker: Dr. Lucio Milanese (Co-Founder & COO, Proxima Fusion)
In 2023, Proxima Fusion emerged as the first-ever spin-off from the Max Planck Institute for Plasma Physics (IPP) in Germany. Their vision? A new class of power plants based on the world’s most advanced magnetic confinement fusion device: the stellarator.
At binding.energy 2025, Dr. Lucio Milanese, COO and co-founder, took the audience through an ambitious and technical journey—from Wendelstein 7-X (W7-X) to the first grid-scale commercial stellarator fusion reactor.
“Design, not control, is our strategy. Stellarators are harder to design—but easier to run.”
What is a Stellarator and Why Now?
Stellarators offer a unique edge over tokamaks: they are intrinsically stable, steady-state machines with no reliance on plasma current.
Key Differentiators:
| Feature | Tokamak | Stellarator |
|---|---|---|
| Current-driven plasma | Yes (needs pulsing) | No (fully external fields) |
| Operational mode | Pulsed | Continuous |
| Stability risks | High (disruptions common) | Low (disruption-free) |
| Design complexity | Medium | High |
| Operational ease | Complex | Easier, once built |
Proxima Fusion’s Scientific Roots
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Founded: 2023 in Munich
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Spin-off from: Max Planck Institute for Plasma Physics
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Employees: 70+ scientists and engineers
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Funding: €62 million from Breakthrough Energy, UVC Partners, Plural, High-Tech Gründerfonds
“We are building on W7-X. We want to turn the best stellarator in the world into a commercial reactor.”
Technology Stack: The Stellaris Architecture
Dr. Milanese presented Stellaris – Proxima’s flagship concept for a grid-ready, modular stellarator system.
Major Innovations:
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Modular high-field magnets (up to 20 T, developed with PSI & BNET)
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Breeding Blanket: WCLL with tritium breeding ratio of 1.07
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Divertor Design: Island divertor geometry
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Cooling & Materials: EUROFER97, <500 °C operation
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Reactor Size: Compact, scalable architecture
Milestone Timeline to Grid-Scale Fusion
| Year | Milestone | Notes |
|---|---|---|
| 2022 | Pre-spin-off work at IPP | Magnetic design studies begin |
| 2023 | Company founded | €7M seed + €55M Series A raised |
| 2025 | System Architecture Freeze | Stellaris reactor concept defined |
| 2026–2028 | Prototype Component R&D | Magnets, cooling, materials |
| 2029–2031 | FOAK plant construction | Net-energy stellarator |
Europe’s Strategic Advantage in Stellarators
Dr. Milanese emphasized how Europe leads globally in stellarator development:
• Wendelstein 7-X is the world’s most advanced stellarator
• Magnet technology leadership (PSI, BNET, KIT, IPP)
• Fusion workforce concentrated in Germany, France, Switzerland
• Regulatory alignment via EURATOM and national frameworks
“No other region has the talent, know-how and institutional support for stellarators like Europe.”
Infobox: What Makes Stellaris Unique?
Stellaris Highlights
- ✅ No plasma current → disruption-free
- ✅ 20 T modular superconducting magnets
- ✅ 24/7 operation – no pulsing
- ✅ Breeding blanket with TBR > 1.0
- ✅ Built on W7-X heritage with AI-assisted design
From Scientific Curiosity to Scalable Energy
Whereas many fusion ventures focus on burn physics or laser systems, Proxima Fusion prioritizes:
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Magnetic system architecture
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Component modularization
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Industrial integration
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Regulatory readiness
→ It’s about building a full power plant, not just a plasma experiment.
Why Stellarator Fusion Energy Matters Today
Unlike tokamaks, which rely on current-driven plasmas and must operate in pulses, stellarators are built for continuous operation. Their unique magnetic geometry makes them disruption-free, solving one of the most pressing issues in fusion stability. For policymakers and investors, this distinction matters: a stellarator promises reliability and predictability from the outset, qualities essential for grid-scale integration.
The Stellaris Advantage
Proxima Fusion’s Stellaris design represents a leap forward. By combining 20 T superconducting magnets with modular component architecture, Stellaris aims to bring steady-state power generation into a compact footprint. The inclusion of a breeding blanket with a tritium breeding ratio above unity ensures fuel self-sufficiency, a crucial requirement for commercial deployment. Unlike experimental devices, Stellaris is envisioned from day one as a power plant platform.
Europe’s Unique Position
Europe holds a strategic lead in stellarator technology. Wendelstein 7-X has already demonstrated the feasibility of advanced stellarator operation, while institutions such as PSI, BNET and KIT push magnet and material technologies forward. With Proxima Fusion, Europe’s decades of research are translated into a commercial pathway. This concentration of talent, infrastructure and regulatory frameworks makes Europe the natural birthplace of the first grid-scale stellarator.
Industrialization and Scaling
Proxima Fusion’s approach mirrors the mindset of modern technology companies: iterate quickly, modularize components, and integrate supply chains early. The comparison to SpaceX reflects this philosophy. Success depends not only on physics but on manufacturability and speed of iteration. For fusion to play a significant role in the energy transition, it must scale rapidly. Stellaris is designed with this principle in mind, prioritizing reproducibility over perfection.
Challenges Ahead
Designing stellarators is notoriously complex. The magnetic field geometry requires advanced computational models and precision manufacturing. Cooling, divertor design and long-term material resilience remain open challenges. Yet Proxima Fusion’s strong funding base, academic roots and partnerships position it to address these hurdles systematically. If milestones are met on schedule, the first-of-a-kind plant by 2031 could redefine fusion expectations worldwide.
The Future Outlook for Stellarator Fusion Energy
The next decade will be decisive for Stellarator Fusion Energy. With milestones such as high-field superconducting magnets, advanced divertor concepts and tritium breeding validation, the pathway from experimental devices to grid-scale plants is becoming clearer. Proxima Fusion’s Stellaris concept shows that disruption-free operation and 24/7 steady-state performance are no longer distant ambitions but engineering targets.
As global demand for carbon-free baseload power increases, governments and investors are looking for technologies that combine reliability with scalability. Stellarator Fusion Energy offers both: continuous operation without disruptions and a design that can be industrialized through modular components. If Europe maintains its leadership in this field, the continent could not only host the first commercial stellarator but also export the technology worldwide.
Ultimately, the future of Stellarator Fusion Energy will depend on how fast research can merge with industrialization. Success would mean a new class of fusion plants that run reliably, day and night, forming the backbone of a stable, clean energy system.
Final Message: Fusion Must Scale Like SpaceX, Not ITER
“It’s not about the perfect reactor. It’s about the scalable one.”
Dr. Milanese called for the commercial mindset to enter the fusion community: iterate fast, focus on manufacturability, build for integration.
