American scientists have just announced a breakthrough in the field of fusion energy, but why is this time different from other times when a similar leap has been announced?
There is a common joke among nuclear physicists that “we are 30 years away from achieving nuclear fusion, and we will always be 30 years away”, referring to the fact that predictions of achieving a viable nuclear fusion reaction within the next three decades are They have been doing this since the middle of the last century.
Nuclear fusion is a process in which atomic nuclei combine to form a new, heavier nucleus. This process releases a huge amount of energy, which can be harnessed to generate electricity. It’s the same process that powers the Sun and other stars. Unlike nuclear fission, which is the process of splitting atomic nuclei, fusion is a much cleaner and more efficient source of energy. However, it is also much more difficult to achieve, as it requires extremely high temperatures and pressure to force atomic nuclei to fuse together.
Since the 1950s, this experiment has been described as the holy grail of nuclear fusion research. Until now, no group has managed to produce more energy than the reaction consumes… until now.
Why is nuclear fusion so complicated?
Achieving the extremely high temperatures and pressures necessary for fusion to occur is a technological challenge of enormous proportions. Furthermore, the materials used in fusion reactors must be able to withstand these extreme conditions, which is also a major challenge. Fusion reactions produce very energetic neutron emissions, which can cause significant damage to the reactor over time. Therefore, developing an efficient and durable fusion reactor is a difficult and expensive task.
But also, so far, the energy bills haven’t come out: the amount of energy produced by the reaction has been less than the amount of energy needed to start and maintain the reaction. In other words, the reaction produced no net energy gain. This is a major challenge for fusion researchers, as achieving a sustained and efficient fusion reaction is necessary for the development of a commercial fusion reactor. There are many factors that can affect the efficiency of a fusion reaction, such as the type of fuel used, the configuration of the fusion reactor, and the conditions inside the reactor. Researchers are constantly working to improve the efficiency of fusion reactions in order to make fusion a practical and viable energy source.
Scientists at the Lawrence Livermore National Library in California were the first to achieve fusion “ignition”, that is, creating more energy from fusion reactions than the energy used to start the process. It’s something they had already theoretically announced last August, and now they’ve managed to replicate it for the first time in history in a laboratory.
According to those responsible for the laboratory, “this is one of the most impressive scientific achievements of the 21st century”. These results indicate that it would finally be possible to develop a clean energy source that could revolutionize the world.
How energy from nuclear fusion is produced
In the $3.5 billion experiment in California, hydrogen is introduced into a capsule the size of a peppercorn. It then fires a 192-beam laser that heats and compresses the fuel, simulating conditions inside a star. The intense heat and pressure causes the capsule to implode, causing the hydrogen atoms to fuse and produce energy.
Although the experiment has been done hundreds of times, last week, for the first time, the fuel remained hot, dense and compact enough to catch fire. It produced more energy than the lasers had deposited: about two megajoules in and three megajoules out.
How long will it take to have fusion energy?
Around the world, huge amounts of money have been invested in an attempt to make nuclear fusion a viable alternative to more polluting energy sources such as fossil fuels. While this week’s breakthrough is an incredible scientific achievement, researchers say the technology is still at least 10 years away from becoming a commercial energy source. The American laboratory uses one of the largest lasers in the world, and the process requires materials that are difficult to produce.
The equipment needed to convert the energy produced by fusion into electricity that can be used on the grid has also yet to be developed. Some scientists indicate that, despite the importance of the discovery and the need to move in this direction, it may be too late to save the planet from the worst effects of climate change. Ed Lyman, director of nuclear safety at the Union of Concerned Scientists, says there will be no viable nuclear fusion power until 2040. However, the planet needs to be decarbonized immediately.