What Is Up with Nuclear Fusion?

Rembrandt: A Scholar in His Study // Public domain

In the midst of a global energy crisis, the USA researchers have achieved a breakthrough in the area of nuclear fusion. But what does it mean? Our energy expert Maximilian Reinhardt explains why this technology could make an important contribution to solving a host of serious issues.

The German energy debate is as heated as it is ever been, with the most contentious point being nuclear power. While some commentators consider the continued operation of German nuclear power plants unconscionable because of the operational risks and the resulting costs in perpetuity, advocates for nuclear energy highlight its carbon neutrality and the stringent safety standards of German reactors.

There is a heated debate around the question of whether the existing plants should be allowed to run a little longer – but that is not all. To compensate for the loss of power resulting from the shutdown of nuclear plants, more coal is being burnt to generate electricity. From a climate perspective, this is an undesirable development, made even less palatable by the voracious land hunger of the lignite open-cast mines and the resulting cultural destruction. Vocal and sometimes violent resistance against these developments has emerged from several political camps.

The same groups demand a massive roll-out of renewable energy capacity. But this is being slowed down by resistance from affected citizens, by regulatory hurdles, lacking infrastructure, and the chronic lack of technical experts. And that’s without even getting started on the significant technical challenges and the lacking base load capability of renewables. All of this has led to a stalemate: various political camps are blocking each other, preventing any progress – a situation which represents an increasing risk for Germany as an economic and investment destination.

Fact: Around 83% of German emissions in 2020 were energy-related. In other words, they resulted from the use of energy sources in the heating, transport or energy sectors.

Chart 1: Fossil fuels accounted for around three-quarters of Germany’s energy consumption last year

Source: Own diagram, based on data from AGEB
Source: Own diagram, based on data from AGEB

Nuclear Fusion

Against this backdrop, the most recent technological advances from the United States are a cause for optimism. For the first time ever, researchers in the USA managed to generate a positive energy balance during nuclear fusion experiments. In other words, for a fraction of an instant, the sun’s method of generating energy was imitated on earth, bringing a new and potentially revolutionary energy source one step closer to realization.

Admittedly, we should curb our enthusiasm. Nuclear fusion has been considered the energy of the future since the 1980s. It has been researched since the 1950s, in various experimental configurations. But now, for the first time ever, more energy was released in the process than was initially employed. In this sense, the successes of the US researchers can justly be described as a breakthrough.

However, the result was achieved under extremely complex laboratory conditions. Among other things, the experimental setup involved using the world’s most powerful laser to achieve the required operating temperature of about 60 million degrees centigrade – so the technology is clearly far from market readiness. So what makes this technology so special?


In nuclear fusion, atomic nuclei are melded together. More specifically, two light nuclei are fused into a single, heavier one. This requires immense amounts of energy, as matter has to be heated until it enters its “plasma” state. The heat provides the atomic nuclei with sufficient energy to overcome the physical force that normally causes nuclei to repel each other. It allows the components of the atomic nuclei to find a new arrangement, joining together to form a single nucleus.

In the process, the forces initially holding the nuclei together are released – and it is this energy release which, for the first time, exceeded the input energy used to power the lasers in the US experiment. The prospect is that this excess energy could be used by humanity.

The new atom created during fusion is lighter than the sum of the two original atoms. This so-called mass defect can be explained by Einstein’s theory of relativity. The theory states that mass and energy are equivalent – in other words, mass can be converted into energy. That is precisely what happens in nuclear fusion. In the case of small atoms – like hydrogen, for example – the forces released during nuclear fusion are enormous. The larger the atoms, the smaller the forces holding the nuclei together. Logically, less energy is released when larger nuclei are fused. Nuclear fusion is also the energy source powering stars, including our sun.

Fact: The components of all known elements since the beginning of the universe were created in suns over the course of millions of years. As a general rule, the heavier an element is, the younger it is.

A notable aspect of nuclear fusion is that it produces no long-lived radioactive waste or greenhouse gases that harm the environment. Furthermore, in the case of nuclear fusion, a loss of control causes the fuel to cool down rapidly. In case of an accident, it would not be possible to maintain the plasma state, meaning that the reaction would stop. The risk of a serious accident is therefore negligible. The implication is that in future, humanity’s energy needs could be covered at a low cost and without negative side effects – a more than attractive notion.

Fact: The ITER experimental reactor, operated by an international research consortium in the south of France, is the largest and most complex nuclear fusion project to date. Private-sector institutions are also intensifying their fusion research.

Research Projects

Developing a reactor concept that allows reliable nuclear fusion while keeping complexity in reasonable financial and personnel-related bounds could fundamentally change international energy policy. A range of national and international research groups, laboratories and companies are working on reactor prototypes.

As part of their work, they are exploring various physical effects and fundamental concepts. But all of the approaches are in pursuit of the same goal: to identify an affordable, climate-friendly and safe source of energy for the future – and to be the first to do so. As a result, private-sector involvement and risk capital investments in a range of start-ups have risen significantly, with the US clearly in the lead.

But nuclear fusion research is also attracting public sector funding. One of the most prominent projects is the ITER experimental reactor in the south of France. This joint project between the EU, the US, Russia, India, China, Japan, Switzerland, the UK, and South Korea is based on the promising, high-performance Tokamak design, in which atoms are pressed together using magnetic force, causing them to heat up. Immense temperatures can be achieved using this approach, while the magnetic field allows for the required density needed for the nuclei to fuse.

The ITER project is the world’s largest and most complex of its type. But it has been beset by complications, disputes, inefficiency and cost overruns. The project’s probability of success ultimately depends on much improved project management, the ongoing willingness to pay of the funding countries, and international science diplomacy. The project’s future is currently in question as a result of Russia’s invasion of Ukraine and rising tensions in the international discourse, as well as the system conflict between authoritarian regimes and liberal democracies. Completion and start of operations were initially scheduled for 2035, but that date is no longer achievable, according to the project leaders.


The US institute’s success has undoubtedly brought humanity significantly closer to the commercial use of nuclear fusion. But most experts expect it to take another 20 to 30 years before the technology becomes broadly available. Some critics are now describing investments in the technology as redundant, saying that it will be ready too late to be deployed in the fight against climate change. Instead, they say, the financial resources should rather be invested in rolling out renewables. But that view misses the bigger picture.

Liberal Arguments

There are several reasons why nuclear fusion research should be intensified.

  • Availability of energy: Fusion technology would make virtually unlimited amounts of energy available without unduly impacting the climate or the environment. Energy prices would drop drastically. Economic and social progress could effectively be uncoupled from energy. This would open the way to entirely new levels of prosperity and social participation.

Chart 2: The world’s hunger for energy is growing – bearing increased potential for conflict.

Source: Own diagram, based on data from the EIA
Source: Own diagram, based on data from the EIA
  • Peace: The ready availability of energy would lower tensions and conflicts of interest around scarce energy resources. Energy sources would lose their role as tools of diplomatic pressure and causes of war. This is because competition around energy would become irrelevant. Nuclear fusion could usher in a new age in global interstate politics. At the same time, international joint projects like the ITER experimental reactor in France counter the use of technology as an national trump card that causes tensions in the international balance of power.
  • Climate protection: Even if prosperous nations like Germany manage to keep within the narrow bounds of climate agreements without nuclear fusion, the hurdles are far higher for less developed economies. The growing populations of such countries want levels of prosperity comparable to those of the Western industrialized nations. This important and just demand is intrinsically linked to an exponentially growing thirst for affordable energy. Against this backdrop, nuclear fusion could be a financially attractive and greenhouse-gas-neutral alternative to fossil fuels that harm the environment.
  • Key technology: Nuclear fusion would undoubtedly become a key technology in many other areas. The related know-how is expected to become a strategically important and economically valuable resource. That is why the scientific and financial involvement of the European Union and of Germany is advisable from an economic perspective.

Written by: Maximilian Reinhardt

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