Portuguese 
English 
Spanish 
5 min of reading 
0 comments 
35 countries spent over 20 billion euros to build a reactor in southern France that promises to produce 500 MW of energy using only 50 MW of input — the main magnet is 18 meters tall, strong enough to lift an aircraft carrier, and the plasma will reach 150 million degrees
It is the largest energy experiment in human history.
The ITER — International Thermonuclear Experimental Reactor — is being built in Cadarache, in southern France, surrounded by the hills of Provence.
There are 35 countries working together on a single project: the European Union, United States, China, Russia, India, Japan, and South Korea.
-
In the United States, 99% of all new electric capacity in 2026 will be from solar, wind, and batteries — totaling 86 GW in a single year, the largest jump since 2002, while natural gas accounted for only 7%.
-
The ‘artificial sun’ of China did what physicists said was impossible — it maintained stable plasma at densities that exceed the theoretical limit and took a real step towards unlimited fusion energy.
-
With US$ 629 billion invested in 1,900 clean energy projects, Brazil consolidates itself as a renewable powerhouse — but still relies on fossil thermal power plants for 15% of its energy matrix.
-
In just 12 months, Brazil will install the equivalent of 9 nuclear power plants in solar and wind energy — a total of 9,142 MW new, a jump of 23.4% compared to the previous year.
The cost has already exceeded 20 billion euros (about US$ 22 billion) — and continues to rise.
The objective is simple to explain, but extraordinarily difficult to achieve: to reproduce on Earth the nuclear reaction that powers the Sun and prove that it is possible to generate clean and virtually unlimited energy from the fusion of hydrogen atoms.
If it works, it will forever change how humanity produces and consumes energy.
500 MW output with only 50 MW input — the Q≥10 factor
ITER was designed to achieve a factor called Q ≥ 10.
In fusion language, this means producing 500 thermal megawatts of fusion energy using only 50 MW of energy to heat the plasma.
In other words: 10 times more energy comes out than goes in.
If it works, it will be the first demonstration in history that nuclear fusion can generate significantly more energy than it consumes on an industrial scale.
The plasma temperature inside the reactor will reach 150 million degrees Celsius — ten times hotter than the Sun’s core, which is “only” 15 million degrees.
To give you an idea, no known material in the universe can directly withstand this temperature.
The plasma needs to be kept suspended by extremely powerful superconducting magnetic fields, without touching anything at all — a dance of physics and engineering that challenges the limits of what humans know how to build.
How a tokamak works — the donut that mimics the Sun
ITER is a tokamak — a giant “donut-shaped” device, technically called toroidal.
Inside it, heavy hydrogen (a mixture of deuterium and tritium) is heated until it transforms into plasma — a state of matter where electrons separate from atomic nuclei.
Extremely intense superconducting magnetic fields confine this plasma, keeping it circulating inside the “donut” without touching the inner walls.
When deuterium and tritium atoms fuse under these extreme conditions, they release enormous amounts of energy in the form of high-speed neutrons.
It is the same process that has made the Sun shine for 4.6 billion years and will continue to shine for another 5 billion.
The difference is that the Sun uses the colossal gravity of 330 thousand times the mass of the Earth to confine the plasma.
ITER needs to replicate this confinement using only magnets — in a chamber that fits inside a building.
10 times larger than any existing tokamak
ITER is 10 times larger than Japan’s JT-60SA, currently the largest operating fusion reactor in the world.
ITER’s main magnet is 18 meters tall and 4.25 meters in diameter.
Its magnetic force is so intense that, theoretically, it could lift an entire aircraft carrier from the sea.
In May 2025, all components of the central magnetic system were finally completed — a milestone that took years of manufacturing distributed across factories in multiple countries.
Furthermore, ITER will be the first tokamak to use deuterium-tritium as real fuel at scale — all previous tokamaks have only used hydrogen or deuterium in their experiments.
Who pays — and how much each contributes
The European Union, which hosts the project, bears 40% of the costs.
The other six members — China, India, Japan, South Korea, Russia, and the USA — divide the remaining 60%.
Each country manufactures specific components in its own industries — magnets in Korea, vacuum chamber in Japan, heating systems in the USA — and sends them to Cadarache for final assembly.
It is one of the largest exercises in international collaborative engineering ever attempted — more complex even than the International Space Station in terms of component integration.
8 years of delay — and the reasons
ITER’s first plasma was originally scheduled for 2025.
The new schedule, approved by the ITER council, pushed the dates significantly:
- 2033: first plasma — the first time the reactor will turn on
- 2036: full magnetic power — all systems operating together
- 2039: final phase with deuterium-tritium fusion — the project’s main objective
Director-General Pietro Barabaschi attributed the delays to a combination of factors: “the Covid-19 pandemic, quality problems in the reactor’s design, internal culture, and an overly optimistic assembly schedule.”
Costs have also exploded far beyond the original budget, drawing criticism from analysts and politicians in several contributing countries.
After ITER — the path to your home outlet
Even if ITER works perfectly and achieves Q≥10, it will not generate electricity for the grid.
ITER is an experiment — it proves that fusion can work at scale, but it is not a power plant.
The next step would be DEMO, a commercial demonstration reactor designed to generate fusion electricity for the first time and feed it into the grid.
DEMO is planned for the 2040s — meaning it will still be 15-20 years until fusion generates the electricity that reaches your home outlet.
It is a long-term prospect, but each step — EAST, KSTAR, ITER — brings humanity closer to an energy source that can definitively solve the climate crisis.
Caveats
ITER is not a power plant — it is an industrial-scale scientific experiment.
Costs have already exploded to over 20 billion euros, and some critics consider the project an example of “scientific over-optimism” that consumes resources that could go to already proven renewables like solar and wind.
The instability of plasma at temperatures of 150 million degrees without damaging the reactor remains a colossal technical challenge that no previous experiment has faced on this scale.
Furthermore, geopolitical tensions between project members — particularly between the USA, Russia, and China — create uncertainties about the continuity of long-term cooperation.
Still, if ITER works, it will prove that humanity can master the energy of the stars — and the race to commercialize it will accelerate exponentially, with private companies like Helion, Commonwealth Fusion, and TAE Technologies already in line to turn science into business.
Seja o primeiro a reagir!