Will fusion be the disruptive energy source of the 2030s?
The impact of climate change has increased the need for sustainable sources of energy that are both environmentally friendly and economically viable.
Renewable energies, including hydro, wind, solar, hydrogen, and associated technologies such as batteries, are the current tools available to meet the growing energy demand with a reduced carbon footprint. But while these technologies are reaching maturity, aided by data-driven intelligent energy management, these technologies will probably not be sufficient to handle the demand of an 8.5 billion population in 2030.
Nuclear fusion reactors stand out as potential candidates to change this. This energy production technology reproduces the power generation mechanism of the sun and the stars. At the core of these stellar bodies, the tremendous heat and gravity environment makes the nuclei of hydrogen isotopes collide at very high energy and fuse naturally into heavier helium atoms. When achieved, this nuclear reaction releases enormous amounts of energy.
Like nuclear fission, fusion is a nuclear reaction, but fusion has the advantage of releasing way more energy for the same mass of material involved than fission. Consequently, the nuclear fusion chamber contains only a few grams of the hydrogen isotopes needed to fuse: deuterium which is naturally present in seawater, and tritium. While tritium is a radioactive material, the quantities involved are small and it is low-level radioactive; tritium radioactivity decreases very rapidly compared to fission products like uranium so considerably limits the risk to the population.
The advantages of nuclear fusion as a source of energy are numerous. In summary, fusion is cleaner than fission because it produces no harmful long-life nuclear waste, it is greener than gas or coal plants because the fusion process emits no CO2, and it is safer than fission because it will stop by itself if it is unstable. The production capacity of a fusion reactor is envisioned to be equal to a fission power reactor, i.e., between one and three gigawatts. The objective for future fusion devices is to disrupt the energy market, providing a new sustainable solution for green and affordable energy.
But reproducing this fusion mechanism in a reactor on earth requires three challenging conditions: temperature, density, and confinement time. First, an extremely high temperature of 150,000,000 degrees Celsius is needed to provide the energy required for the atoms to collide with sufficient power. Second, the density of the plasma particle must be high enough so that the probability of collisions is high enough to be effective. Finally, the temperature and density conditions must be maintained for a sufficient confinement time to enable ignition and power generation.
The confinement in so-called "magnetic fusion devices" is realized by generating powerful magnetic fields, forcing particles to travel on specific trajectories called field lines and increasing their chances of generating fusion reactions considerably. However, not only is meeting the temperature, density, and confinement time requirements complex but designing a machine that will handle these conditions sustainably is an incredible technological challenge.
Thankfully, since the 60s, years of research have seen the scientific community making constant progress in controlling this energy source for future generations. The complexity of the science behind plasma physics, due to its non-linear and stochastic characteristics, requires the control of cutting-edge technologies once heard of only in science fiction films, such as superconductivity, high vacuum, and cryogenics.
The most significant prototype of a fusion device that will demonstrate the maturity of the technology is being assembled in France (ITER). Its first plasma is currently planned for the end of 2025. In parallel, more and more initiatives such as tech start-ups are raising funds to develop alternative fusion technologies and new prototypes.
The challenge is significant, and the path is long, but we are seeing promising progress, which could change our lives. There's no doubt, that in 2030, fusion will be a very, very hot topic.
The possibility of fusion power is no longer a dream of science fiction writers. It is here today, and the potential to control the power of the sun and stars on earth is only a few years away…