On the Sun, this happens all the time: atoms combine, that is, a thermonuclear fusion reaction occurs, as a result an unimaginable amount of energy is released. Scientists have long dreamed of such energy, and here on Earth it can be obtained by creating controlled thermonuclear fusion reactions.
But so far it has not been possible to get it.
After the end of World War II, scientists around the world are trying to achieve this.
With the help of experimental reactors in Russia, the USA, England, Japan and many other countries, short-term thermonuclear fusion processes were obtained, but everywhere more energy was used to maintain this process than to obtain energy itself, explains Søren Bang Korsholm, a senior researcher at the Technical University of Denmark (Søren Bang Korsholm).
In the distant future
The Danish scientist and his colleagues at the Department of Physics of the Technical University are participating in a global scientific project, which in 2025 will allow the implementation of an effective thermonuclear fusion process - i.e. more energy will be allocated than spent to obtain it. Nevertheless, it is believed that we will not be able to see power plants operating on the principles of thermonuclear fusion for many years.
“Only in the fifties of this century, the energy of thermonuclear fusion power plants can be used in power grids. In any case, these are the guidelines for the European thermonuclear fusion program,”he says.
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Despite the remoteness of the prospects, many scientists, like Søren, are seriously working on the issues of thermonuclear fusion energy. And there are good reasons for this. For a power plant operating on the principles of thermonuclear fusion, an infinitely small amount of nuclear fuel is required, in addition, they do not have emissions of CO2 and other harmful substances.
Cheap green energy
When you charge your smartphone today, 24% of the electricity in this case comes from coal-fired thermal stations. It is heavy and not particularly environmentally friendly energy production.
“To produce one gigawatt of electricity, a coal-fired power plant must burn 2.7 million tons of coal annually. And fusion stations require only 250 kilograms of nuclear fuel to achieve the same effect. 25 grams of nuclear fuel is enough for such a power plant to supply energy to one Dane for his entire life,”says Søren Bang Korsholm.
Unlike coal, fusion does not emit CO2 and thus does not affect the climate.
"The only 'direct' production waste of nuclear fusion energy is helium, and it can be used in a wide variety of applications. This is about 200 kilograms of helium for the entire year," he explains.
However, fusion energy has a small problem. Here you cannot do without radioactivity completely. "The inner surface of the reactor becomes radioactive, but this is a form of radioactivity that becomes safe after 100 years," says the scientist. Then this material can be used again.
Nearly Endless Nuclear Fuel
Unlike coal, the fuel for a fusion power plant does not need to be dug out of the earth. It can be obtained by pumps from the sea, because the energy of thermonuclear fusion is obtained using heavy hydrogen (deuterium), which is extracted from sea water.
“The sea provides nuclear fuel that will be enough for energy consumption around the world for billions of years. Therefore, we will not be left without energy if we learn to use the energy of thermonuclear fusion,”explains Søren Bang Korsholm.
In addition to heavy hydrogen deuterium, scientists use superheavy hydrogen tritium in the fusion reactor. It doesn't exist in nature, but it is made from lithium, which is the same substance used in batteries.
In the reactor, heavy and superheavy hydrogen merges after the temperature in the reactor reaches 200 million degrees.
“The temperature in the reactor is unimaginably high. For comparison, the core temperature of the Sun is only 15 million degrees. In this way, we create a much higher temperature,”he says.
France's giant nuclear reactor
Søren Bang Korsholm and many of his colleagues at the Technical University are participants in a large international project ITER, where the EU, the USA, China and many other countries are collaborating to build the world's largest fusion reactor in the south of France. It will be the first reactor of its kind to provide more energy than it consumes.
“ITER, according to the project, will produce 500 megawatts, while 50 megawatts will be required to warm it up. It consumes a little more than 50 megawatts of energy because we use some of the energy for cooling and magnets, which is not taken into account in this case, but it gives a nice surplus of energy in the reactor itself,”he explains.
According to the scientist, the reactor will soon be ready for operation.
“In 2025 the reactor will be ready for the first test, after that we will upgrade it until it is fully ready in 2033,” says Søren Bang Korsholm.
Showcasing the energy of the future
But one should not think that after the completion of the ITER project, the electricity, thanks to which our refrigerator works, will be the energy of thermonuclear fusion. The reactor will not produce electricity.
“ITER is not a power plant. The reactor is not being built to generate electricity, but to demonstrate the possibility of using thermonuclear fusion as an energy source,”he says.
The scientist hopes that the project will have commercial partners who will pay attention to the possibilities of thermonuclear fusion energy.
“Maybe large energy companies and oil companies will start investing in fusion energy when they see its potential. And who knows, maybe such power plants will appear in the near future,”says Søren Bang Korsholm.
Next stop is the moon
If scientists manage to create efficient power plants based on thermonuclear fusion, then a lot of ideas will immediately appear on how they can be improved. One of the ideas already suggests using a different type of fuel, which, however, is not so much on Earth.
“Helium-3, which is abundant on the moon, has the advantage that fusion products from plasma react less with the reactor walls, so the wall becomes less radioactive and can have a longer life,” says Soren Bang Korsholm.
So far, extracting fuel on the Moon and delivering it to Earth is costly. But maybe the energy of thermonuclear fusion will be so efficient that these costs will pay off.
“If there are thoughts about delivering fuel from the moon, then fusion power plants can be incredibly efficient,” the scientist concludes.
Jeppe Kyhne Knudsen, Jonas Petri, Lasse From
