Fusion energy: the future that is finally beginning to become a reality, with Sehila González

Fusion energy has for decades been a scientific and technological promise with the potential to transform the global energy system. Its appeal is undeniable: generating electricity without CO₂ emissions, without long-lasting radioactive waste and with abundant fuels. But the road from theory to actual commercial application has been long and full of challenges.

Within the framework of the Future Trends Forum (FTF), the think tank of the Bankinter Innovation Foundation, a new webinar has been held, this time with Sehila González, Global Director of Fusion Energy at Clean Air Task Force (CATF) and one of the most authoritative voices on the global drive for fusion energy. The session was led by Juan Moreno, Director of the Foundation.

This article brings together the key ideas of the meeting: from the fundamentals of fusion to the rise of private investments in fusion and the role of governments, including regulatory advances, technological challenges and the need to better communicate this emerging energy revolution.

If you want to watch the full webinar, you can do so in this video:

The Global Push for Fusion Energy with Sehila González de Vicente

From CIEMAT to Clean Air Task Force: Sehila González’s international career

Physics, advanced materials and energy marked the beginning of the career of Sehila González, one of the most influential voices in the global promotion of fusion energy. His journey began at CIEMAT, where he completed his PhD in fusion materials after obtaining a scholarship linked to the ITER project, to which Spain opted as the host country.

Since then, its trajectory has been as international as the fusion ecosystem itself. Sehila has worked in Belgium, Germany (leading the European materials program from what is now EuroFusion) and Vienna, where she was in charge of fusion activities at the International Atomic Energy Agency for more than eight years.

Currently, he leads the global fusion program at Clean Air Task Force (CATF), an independent U.S. think tank that promotes clean technologies from a technical, regulatory, and financial point of view. A few years ago, CATF detected that the merger was going from a promise to a real option, and created a specific program with Sehila at the helm.

In addition to her technical and strategic work, González also leads the Women in Fusion initiative, a global network to make visible and support women in this sector, historically dominated by men.

Before going into the advances, challenges and opportunities of this technology, Juan Moreno posed an essential question for those who are not yet familiar with the subject: what exactly is fusion energy?

What is fusion and why is it so promising?

Fusion energy is, in essence, the opposite of fission. While fission splits a heavy atom like uranium to release energy, fusion joins two light nuclei — usually isotopes of hydrogen — and generates an enormous amount of energy in the process. In both cases, the key lies in Einstein’s equation (E=mc²), which converts a small loss of mass into a large amount of energy.

The interesting thing about fusion is its very high energy density: with a relatively small plant, an enormous amount of energy can be produced. In fact, this is the same reaction that powers the Sun and the stars. Fusion is literally the energy that makes the Sun shine.

But replicating that process on Earth is no easy task. A machine is needed that can bind these nuclei together under extreme conditions, keep them stable enough and for the time necessary for the reaction to take place. That is why there are multiple designs and technologies in development: there is no single way to achieve it.

Unlike nuclear fission, which has been in commercial use for decades, fusion requires much more advanced and sophisticated technology. Even so, the potential of this clean, safe and practically inexhaustible source of energy justifies the effort.

Fusion: the energy of the Sun, without emissions or space limits

Fusion energy is not only clean; it is also the most fundamental source of energy we know. As Juan explained, all the energy we use on Earth – from solar to wind to hydro – comes, directly or indirectly, from the Sun. And the Sun shines thanks to fusion.

Compared to other clean energies, fusion has key advantages:

• Zero CO₂ emissions and no other polluting gases. The process consists only of joining two atomic nuclei, without combustion, without atmospheric residues.
• An unmatched energy density. A single kilogram of fusion fuel (deuterium and tritium) is equivalent to the energy of 100 kilograms of uranium or 10,000 tons of coal.
• Less land use. A fusion plant can generate enormous amounts of energy while taking up very little space. This may not be critical in countries with a lot of available land, but it is essential for densely populated regions such as Japan, Singapore, or certain areas of Europe.

These characteristics position fusion as a global energy solution that, in addition to being sustainable, is scalable and viable even in urban or geographically limited contexts.

Water and lithium: the clean and abundant fuel of fusion

In addition to being clean and energetically dense, fusion is also a virtually inexhaustible source. Why? Because its main fuel, deuterium and tritium, is accessible and abundant.

Deuterium is an isotope of hydrogen found in seawater. Tritium, also an isotope of hydrogen, is not found naturally in large quantities, but it can be generated within the fusion reactor itself, from a reaction with lithium. This is what is known as a self-sufficient system: the machine produces its own fuel while generating energy.

In practice, this means that the key elements of fusion are seawater and lithium, two resources available in much of the planet and already used, for example, in batteries.

Another key advantage: the intrinsic safety of the process. Unlike fission, which involves chain reactions that must be constantly monitored, fusion cannot get out of control. If the extreme conditions (temperature, pressure, and density) are not maintained, the reaction simply shuts down. There is no possibility of a traditional-style “nuclear accident.” And while this makes achieving a stable reaction a huge technical challenge, it’s also what makes fusion one of the safest energy sources we can imagine.

From the laboratory to burning plasma: how we know fusion is close

The combination of deuterium, tritium and lithium makes fusion a clean, abundant and safe source of energy. But getting the reaction to stick is not trivial. For fusion to occur in a terrestrial machine, three conditions must be met simultaneously: temperature, density , and confinement time. This is what is known as the Lawson criterion or triple product.

This parameter is key to measuring whether or not a machine is approaching the point at which fusion actually occurs. If the triple product is below the necessary threshold, there is no reaction. If you pass it, you enter what experts call burning plasma: a stage where the plasma begins to sustain itself and generate more energy than it consumes.

As Sehila explained, there is a well-known graph in the scientific community that shows how the different designs of reactors have evolved – from the first tokamak in the 50s to current machines such as stellarators, or inertial devices. On this upward curve are already large projects such as ITER (the international reactor under construction in France), SPARC (from Commonwealth Fusion Systems, in Boston) or EAST, in Hefei, China.

The trend is clear. It is no longer a question of asking if we will reach commercial fusion, but when. Technical progress, investment interest and international collaboration have accelerated the race.

One hundred million degrees: the magnitude of the challenge

If the triple product is the key formula to achieve fusion, temperature is one of its most demanding factors. For ignition to occur, the plasma has to reach around 100 million degrees Celsius. It’s a temperature that no other device on Earth needs to reach or can directly support.

Why so much? On the Sun, fusion occurs at lower temperatures because solar gravity creates an enormous density. But on Earth we don’t have that natural pressure, so we have to compensate with more temperature. And if we were to use other fuels, such as deuterium-deuterium (cleaner but less reactive), the temperature would have to double, further increasing the technological challenge.

This is one of the great challenges: there is no material that can withstand these temperatures. Therefore, instead of containing the plasma with physical walls, a fundamental trick of physics is used: magnetic confinement.

Plasma is made up of charged particles, and that allows its movement to be controlled using magnetic fields generated by superconducting coils. Thus, the plasma is “suspended” without touching the walls of the reactor. If I did, I would melt them instantly.

This is where magnets come into play. They are the tool that allows the plasma to be kept stable and in the right place long enough for fusion to occur. Its development has been key to recent advances in many of today’s designs.

Tokamaks, Lasers, and More: The Paths to Fusion

Confinement plasma to 100 million degrees without touching anything is not science fiction: it is the day-to-day design of fusion reactors. And in this challenge, different technological strategies have emerged, each with its own approach. They all seek the same thing – to overcome triple the product and achieve ignition – but they do so by different paths.

The most well-known are tokamaks and stellarators, both with toroidal designs (yes, like a donut). In them, the plasma circulates in the form of a ring and is kept suspended by magnetic fields generated by powerful superconducting magnets. While tokamaks – such as ITER or SPARC – are the most developed, stellarators – such as the Wendelstein 7-X in Germany – offer a more stable, albeit more complex alternative to build.

But not everything is based on magnets. There is also the inertial approach, where confinement is not magnetic, but by compression. Here, a small “pellet” – a microsphere with deuterium and tritium – is bombarded with lasers of the highest precision, heating and compressing it until fusion occurs. In December 2022, the NIF (National Ignition Facility) laboratory in California achieved for the first time a Q greater than 1, that is, it released more energy than was used to initiate the reaction. It was a historic milestone.

Between the two extremes lies a third approach: magneto-inertial fusion, which combines physical compression with magnetic confinement. It uses magnetic fields to heat and control the plasma, but it also compresses it with mechanical systems, such as pistons, increasing its density without relying so much on extreme temperatures.

Each of these technologies plays with the three key parameters of Lawson’s criterion – temperature, density and time – and represents a complementary path towards the same goal: to make fusion a clean, safe and commercially viable source of energy.

Why now? Technology, urgency and private capital

For decades, fusion energy was a promise that seemed always 30 years ahead. But that has changed. Today, not only are we talking more than ever about fusion, but we are seeing a real path to its commercialization. What happened?

According to Sehila González, there are two main reasons:

1. Key technological advancements
   Breakthroughs have occurred in recent years, especially in one critical component: high-field, high-temperature (HTS) superconducting magnets. These magnets allow for the creation of much more powerful magnetic fields, which drastically reduces the size and cost of fusion reactors.

The contrast is clear: ITER, the major international project in France, has a radius of 6.2 meters and uses 5-tesla magnets. SPARC, the reactor being built in Boston by Commonwealth Fusion Systems, has a radius of just 1.85 meters and uses 12-tesla magnets. In other words, a machine three times smaller, but with the same energy potential. The consequence? Smaller size, lower cost and much shorter development times.

2. Urgent energy need
   It is no longer just about being able to merge, but that society needs it. We need new sources of energy that are clean, firm and safe. And the merger meets all three of these requirements. This new context has attracted a wave of private investment, something unthinkable just a decade ago.

Moreover, this revolution does not come only from the world of fusion. Technologies developed in other sectors – such as HTS applied in magnetic resonance imaging – are now being harnessed in reactors. What was once expensive, bulky and experimental, is now beginning to be compact, viable and more accessible.

That is why, for the first time in 50 years, the question is no longer whether the merger will ever arrive, but when it will be a commercial reality.

Artificial intelligence: the new accelerator of fusion

In addition to advances in superconducting magnets and the push from private capital, there is a third transformative force: artificial intelligence. According to Sehila González, AI is already accelerating fusion.

Why? Because building a fusion reactor involves optimizing thousands of parameters with scarce, incomplete or unreliable data. A perfect scenario to apply AI models, which can analyze complex patterns, predict behaviors, and find more efficient designs in less time.

AI is helping to:

• Optimize reactor design, adjusting variables that previously required years of simulations and physical tests.
• Monitor plasma behavior in real time, anticipating instabilities and correcting deviations instantly.
• Reduce development costs and times, accelerating technology iteration cycles.

But in addition, AI also multiplies the energy emergency. Why? Because the development of artificial intelligence itself – with its huge models and data centres – triggers electricity demand. There are already data centers that consume more than 1 gigawatt – the equivalent of an entire nuclear power plant. To put it in context, all active nuclear power plants in Spain total 7 GW.

So artificial intelligence isn’t just helping to build fusion. It’s also making us need it more than ever.

And what do we do with so much energy? Technical and regulatory challenges

One of the most frequently asked questions is also the simplest: “How is fusion energy converted into electricity?” The answer, as Sehila González explained, is straightforward: just like in a traditional thermal power plant.

There is no innovation at that end point in the process. What changes is how heat is generated. In a fusion plant, heat is obtained from the ignited plasma, used to heat water, and the steam drives a turbine that generates electricity. The rest – the transport of that energy to the grid – is mature technology.

The really innovative thing comes first: how to achieve that extreme heat in a clean, safe and controlled way. And there, although progress is real, the technical challenges are still enormous.

Extreme materials for extreme conditions

In a fusion reaction with deuterium and tritium, a 14 MeV neutron is released. These neutrons, because they have no charge, cannot be controlled with magnetic fields. They travel freely and hit reactor materials, causing wear, degradation and, in some cases, activated waste.

These neutrons are much more energetic than those of traditional fission (2.5 MeV), so the materials must be much stronger. Europe has been leading the field for years with developments such as Eurofer 97, an alloy designed to withstand the onslaught of the fusion environment.

In addition, the materials of the “first wall”, i.e. those that are in direct contact with the plasma, must withstand extreme conditions of temperature and radiation. This makes materials design one of the most critical fields (and with the most industrial opportunities) of fusion.

Remote Maintenance and Opportunities for Industry

Another big challenge is maintenance. Since the conditions inside a fusion reactor do not allow for direct human intervention, everything must be done using robotics and remote access. This not only implies technical complexity, but also opens up new opportunities for engineering, automation and advanced robotics companies.

What about waste?

Although fusion does not generate long-lived radioactive waste, there are materials that are activated by exposure to neutrons. It’s a fundamental difference with fission: there’s no chain reaction, there’s no risk of collapse, and the waste is more manageable and on a smaller scale. Even so, a clear regulatory framework is required, differentiated from traditional nuclear power.

Here, as in other aspects, the merger requires not only technical advances, but also regulatory adaptation. The current regulation – designed for fission – does not always fit with the reality of fusion, and many experts are calling for legal frameworks to be updated to accelerate the commercial deployment of this technology.

Spillovers, digital twins and a key centre in Spain: fusion as a driver of innovation

Fusion energy doesn’t just promise to transform the global energy system. As with the space race, it is generating a powerful spillover effect: technologies developed to withstand the extreme conditions of fusion are beginning to be applied in fields such as nuclear medicine, the aerospace industry, robotics, the manufacture of advanced materials or artificial intelligence applied to complex physical processes.

If something works inside a fusion reactor, where temperatures of 100 million degrees and magnetic fields of 12 teslas operate, it can work in almost any other environment.

And at the heart of this technological leap, Spain plays a key role. IFMIF-DONES is being built in Granada, a unique facility in the world that will allow materials to be bombarded with 14 MeV neutrons – such as those generated by fusion reactions – to verify their real resistance. Without such facilities, fusion cannot be scaled to an industrial level, because no regulator would approve a fleet of reactors without validated experimental data. IFMIF-DONES puts Spain at the centre of the global map of fusion energy.

Network integration and real cases: fusion is already finding its place

One of the great advantages of fusion is that, once generated, the energy can be managed like any other firm source. It is transferred to the electricity grid by turbines that convert heat into electricity, as is already the case in traditional thermal or nuclear power plants. In addition, waste heat can be used for industrial processes or stored with already available technologies, such as thermal batteries or molten salts.

A case in point: the US company Type One Energy has recently signed an agreement with the Tennessee Valley Authority (TVA), a large utility in the southern US. The goal: to repurpose a decommissioned former coal plant as a site for its prototype reactor, Infinity-2. These types of moves demonstrate how fusion is not only compatible with current infrastructures, but can accelerate an orderly energy transition, reusing what already exists and reducing implementation costs.

Beyond technical advances, this type of alliance is key to integrating fusion into the real energy system, with all the guarantees of connection, regulation and operational viability.

Will there be enough tritium and lithium? And what about regulation?

Before closing the technical block, there was still a doubt in the webinar chat: will the resources be enough to sustain fusion energy? The short answer: yes.

Tritium, one of the two key fuels along with deuterium, is scarce and has a half-life of about 12 years, so it disappears naturally. Today it is obtained as a by-product in some fission reactors, but the goal in fusion is for each reactor to be self-sufficient: the neutrons generated in the reaction impact lithium, thus producing new tritium within the system itself. This is what is known as a self-sustaining cycle.

Will lithium be a bottleneck? Not either. Sehila makes it clear: calculations indicate that the demand for lithium for fusion will be minimal compared to that demanded by the battery industry. There is no risk of real competition.

A regulation at the height of technology

Where there is pending – and urgent – work is in the regulatory framework. As of today, most countries do not have specific legislation for mergers. The automatic reflex is to try to fit it into the nuclear fission regulations, but that is a mistake.

As Sehila emphasizes, fusion has nothing to do with fission: there is no chain reaction, there is no risk of meltdown, and the residues are completely different. For this reason, countries such as the United Kingdom and the United States have already moved towards differentiated regulations, adapted to the real characteristics of the merger. Japan, Finland and Germany are also working on it. In Spain, the debate is on the table.

The important thing is not that regulation is more lax, but that it is proportionate, adequate and clear, and that it does its job: to protect the public, workers and the environment, without blocking technological development.

In the end, as with other emerging technologies, regulation can be a brake… or an accelerator.

The Global Race for Fusion: Private Investment, Innovation Hubs and Spain’s Role

One of the big catalysts for the current push for fusion energy has been the influx of private capital. In recent years, more than 10,000 million dollars have been invested in startups and companies in the sector. This has been a game-changer.

Before, the merger was a matter of laboratories and long-term public projects. Now, with private investment, times are shortening, the pressure to reach the market is growing and business models are being born that push towards real commercialization.

The United States and the United Kingdom: the private epicenter

The United States is leading strongly. Commonwealth Fusion Systems alone, a spin-off of MIT, has raised almost 3,000 million dollars. It is followed by dozens of startups such as Type One Energy, TAE Technologies or Helion, each with its own technology: tokamaks, stellarators, inertial fusion or hybrid approaches.

In the United Kingdom, Tokamak Energy stands out, but there are several more. Both countries have public policies that support private capital, create favorable regulatory environments, and activate highly effective public-private collaboration schemes.

China: Volume, Speed and Strategic Vision

China plays in another league: volume. It has invested since the 80s and has gone from receiving a tokamak donated by Germany to building some of the most ambitious reactors in the world, such as EAST, which has broken stability records, or BEST, its new tokamak in Hefei. It is also developing cutting-edge infrastructures such as CRAFT, dedicated to robotics and material testing. There, fusion is based on a clear vision: everything that can provide energy is strategic.

Europe: knowledge is there, but there is a lack of industrial policy

In Europe, the situation is paradoxical: we have some of the world’s leading experts and research centres, but we are not knowing how to take advantage of it to create industry.

European startups are concentrated in Germany, with some initiatives also in the United Kingdom and France. But most private capital is leaving for the US, including from European companies. For example, the oil company ENI (Italy) is one of the main investors in Commonwealth Fusion Systems, based in Boston.

According to Sehila González, Europe has a unique opportunity, but it needs to act quickly: coordinate investments, create specific regulation and encourage public knowledge to make the leap to business.

In fact, the Clean Air Task Force has promoted a proposal for a European fusion strategy, aligned with the Draghi report, and on November 4 they will present their ideas at the European Parliament in Brussels.

Spain: much more than an emerging player

Spain has more capabilities than are usually recognized. On the one hand, there is CIEMAT, the national fusion laboratory, which coordinates one of the most powerful groups on the continent. In addition to this, there are universities with leading groups in materials, neutronics or simulation, such as the UNED or the CIT of the Basque Country.

But the most remarkable thing is that in Seville there is an operational tokamak, built entirely in Spain by a group from the University of Seville. This team is already exploring its transformation into the first Spanish fusion startup, with mature and competitive technology.

In addition, there is IFMIF-DONES, the facility that is being built in Granada and that will be key to validating the materials of future reactors. Without that piece, fusion will never go from the lab to industry.

And it should not be forgotten that the Spanish industrial fabric has already provided components to ITER and is organizing to do so with IFMIF-DONES. This consolidates a national supply chain in fusion, which can be a strategic advantage in the energy transition.

“Spain can be a front-line player. We have the technology, the knowledge and the industry. All that remains is to align industrial and regulatory policy to take advantage of the moment,” Sehila summarises.

When will the Merge arrive? From the eternal promise to the real countdown

For decades, fusion energy has been “the energy of the future… which always will be.” The famous joke of “30 years from now” has accompanied this technology since its origins. But that has changed. And it’s not just the experts who say it, the industry says it too.

Today, companies such as Helion (which has already signed purchase agreements with Microsoft or Nucor) project to have their first machines in 2028-2029. Tokamak Energy is aiming for 2032 with its machine under construction in Virginia, backed by Google and Nvidia. Type One, which has just signed an agreement with the US utility Tennessee Valley Authority, plans its pilot plant for 2032-2033.

According to Sehila González, three stages must be distinguished:

1. Experimental machines such as SPARC (Commonwealth Fusion Systems) or PEST (China), planned before 2030.
2. Prototypes of commercial plants, which already resemble an operational plant, between 2032 and 2035.
3. Industrial fleets, starting in 2040, with multiple reactors connected to the grid.

And what will happen when the first technology works? An avalanche of investment. As in other tech sectors, the first technical milestone will unleash financing rounds, IPOs and a multiplier effect.

But there is one condition: regulation. “The country that does not have adequate regulation will be left out,” warns Sehila. Not only will it be unable to develop this technology, but it won’t even be able to adopt it. And regulation is not improvised: it requires time, vision and political will.

His prediction:

“By 2040, fusion energy has to be on the grid. To a greater or lesser extent, but it has to be generating electrons.”

At the Bankinter Innovation Foundation, we will continue to promote this conversation. Because the opportunity is historic. Europe and Spain have the knowledge, the scientific and industrial capacity, and the time is now. All that remains is to activate the right levers – regulation, financing, talent – so as not to be left out of the energy that can reconfigure the world energy map.

Next webinar: Leadership in fusion

We invite you to the next webinar of the Future Trends Forum’s fusion energy cycle, which will take place on October 30, in which we will have two international references:

• Susana Reyes, from the USA, Vice President of Chamber and Plant Design at Xcimer Energy, specialized in laser fusion.
• Itxaso Ariza, from the United Kingdom, Chief Technology Officer (CTO) at Tokamak Energy, one of the most advanced startups in magnetic fusion.

Two Spanish women leading the energy future from the international arena.

In the meantime, we invite you to read the report Fusion Energy: An Energy Revolution in the Making and the articles on the presentations of some of the experts who attended the forum.