Many startups specialize in nuclear fusion, considered the Holy Grail of energy. And if the technology still seems far from coming to fruition, some of them are reporting encouraging progress, attracting ever more investors.
Because nuclear fusion has the potential to revolutionize many areas. Above all, it would mark a huge step forward in the fight against global warming. It is a question of reproducing the reaction which powers the stars and transforms them into an almost infinite source of energy, that is, the fusion of two atoms so that they form only one; Unlike nuclear fission today used in power plants, fusion does not produce radioactive waste.
Unfortunately, significant obstacles remain today to exploit nuclear fusion on a large scale, because its development requires astronomical resources. But the game is worth the candle, and recent breakthroughs, particularly in the areas of AI and processors, could change the situation.
Helion
This is the startup that offers the tightest schedule. And for good reason, it has concluded lucrative partnerships with Microsoft and OpenAI, whose CEO Sam Altman even sits on the board of directors. According to him, nuclear fusion is the key to allowing AI to continue its rapid development.
Founded in 2008, Helion uses deuterium and helium-3 as fuel. This technique sets it apart from other fusion companies, which often use tritium. The startup operates a type of reactor called “ reverse-field configuration » to confine plasma, a state of matter where the particles are very energetic and ionized.
Its accelerator uses pulsed magnetic fields to compress plasma until fusion occurs. Helion has already developed a series of prototypes, the sixth of which has reached the temperatures necessary for commercial fusion reactions, i.e. more than 100 million degrees Celsius. On the other hand, it has not yet achieved net positive energy production.
The startup, however, plans to manufacture the first operational commercial power plant by 2028, with the aim of providing up to 50 megawatts of clean energy initially. Helion has raised $608 million to date.
Tokamak Energy
This startup, founded in 2009, has raised more than 260 million dollars, and it is European! Based in Oxford in the United Kingdom, it is a leader in high-temperature superconductors, powerful magnets capable of generating intense magnetic fields, necessary to confine and control the extremely hot plasma required for the reactions of merger.
Its prototype, dubbed ST40, generated ultra-hot plasma of 100 million degrees Celsius in 2022. Its next generation, Demo 4, is currently under construction and aims to test the company’s magnets in “ relevant scenarios for fusion power plants “.
It aims not only to commercialize fusion energy by the 2030s, but also to become the first company to create a fusion device that produces a net energy gain. Ultimately, it sees itself designing compact fusion reactors, with a view to deployment on a global scale.
Marvel Fusion
Another European startup, Marvel Fusion was founded in 2019 and hails from Munich, Germany. It uses an approach called inertial confinement, that is, relying on very powerful lasers to heat and compress a small quantity of fuel. The principle, as with each nuclear fusion technology, is to create conditions of extreme temperature and pressure, similar to those which reign in the hearts of stars. This is when the nuclei fuse.
In this case, the inertia of the compressed material prevents it from escaping before the fusion reaction occurs. To achieve this, the startup fires powerful lasers at a target featuring silicon nanostructures, which cascade under the bombardment, compressing the fuel to the point of ignition. An innovative method that appeals: Marvel Fusion has raised $200 million.
First Light
Straight from Oxford, First Light also relies on inertial confinement. But rather than lasers, the young company founded in 2011 launches a projectile at extremely high speeds so that it hits its target. The latter is designed to amplify the force of the impact to compress the fuel to the point of ignition, triggering meltdown.
It seems rather simple, and it is the argument put forward by the company to promote its product which it considers commercially viable. To date, First Light has raised nearly $180 million.
Commonwealth Fusion Systems
This startup founded in 2018 is one of the most prolific in the sector, with no less than 2 billion dollars raised! Coming from the prestigious Massachusetts Institute of Technology (MIT), Commonwealth Fusion Systems specializes in high temperature superconductors. Like many other companies in the sector, it uses a tokamak, that is to say a donut-shaped chamber in which the gaseous fuel is freed of its electrons by an electric current, forming plasma.
This is heated to searing temperatures where the energy levels of the particles become higher than the electromagnetic force that prevents them from fusing. Its magnets make it possible to insulate the plasma: the more efficient they are, the less energy is required to maintain fusion temperatures.
The firm explains that it has developed magnets which make it possible to produce smaller and therefore less expensive fusion systems. She is developing SPARC, a demonstration project which will be the very first “ commercially relevant net energy fusion system “. Next, Commonwealth Fusion Systems aims to develop a fusion power plant of several hundred megawatts, planned for the early 2030s.
Zap Energy
Founded in 2017, Zap Energy uses an in-house method called Z-pinch. This involves passing an electric current through a thin plasma filament. This creates electromagnetic fields that heat and compress it.
Initially, this approach failed to contain the plasma for very long, but the startup solved this problem by making different sections of the plasma flow move at different speeds. Zap claims its system is smaller and more efficient than its competitors. An installation three meters wide, she assures, could supply “ a small town “. It raised $327 million.
General Fusion
She is one of the pioneers of this list, and supported by a certain Jeff Bezos. Founded in 2002, General Fusion focuses on magnetized target fusion, which involves compressing plasma more slowly than in inertial confinement techniques.
Its reactor consists of a wall of liquid metal surrounding a chamber into which plasma is injected. The liquid metal is rotated to create a vertical cavity in the center, then compressed. As a result, the cavity collapses and compresses the plasma, increasing its density and temperature to fusion conditions.
General Fusion, based in Canada, is currently building its first demonstration plant. Called LM26, it is expected to reach its scientific break-even point by 2026. The company has raised more than $440 million.
Xcimer
Xcimer is much more recent. Founded in 2022, the young company has raised $109 million. Its fusion process is based on the scaling and improvement of inertial confinement fusion technology demonstrated at the National Ignition Facility (NIF) research laboratory. This experiment produced more fusion energy than the laser energy used to power it, thereby achieving fusion ignition for the first time in the laboratory.
Thus, the startup is aiming for a laser system five times more powerful, equipped with walls of molten salts which surround the reaction chamber. They absorb heat, while protecting the first solid wall from damage.
Renaissance Fusion
Why not be chauvinistic to finish this ranking? It must be said that the young French start-up Renaissance Fusion, based in Grenoble and founded in 2019, is very promising. Having received 10 million euros from the government, in addition to 15 million euros from venture capital, it defines itself as the “ first magnetic confinement fusion startup in continental Europe “.
Its objective: to create more compact, more efficient and more economically viable stellarators. These devices, designed to confine hot plasma using twisted magnetic fields, are extremely arduous to design and construct due to the need to use complexly shaped magnetic coils to generate the fields.
Renaissance Fusion’s approach could potentially accelerate the development of commercial fusion power plants, with the company targeting the 2030s for a 1-gigawatt reactor capable of powering a million homes.
