Under the right circumstances, the energy released is sufficient to induce further fusion reactions. When a deuterium nucleus (2H) and a tritium nucleus (3H) combine, the result is a helium nucleus and a very energetic neutron. The deuterium-tritium reaction is considered by most scientists to be the most promising for fusion energy. When confined at these temperatures, the nuclei can collide with sufficient speed to overcome Coulomb repulsion and fuse together.Ģ. Instead, terrestrial magnetic fusion experiments employ lower densities but far higher temperatures, around 100 million degrees Celsius. Thus, it’s not something that would be practical for energy production on earth. This gravity-powered reaction requires enormous densities and takes about a billion years to complete. Proton-proton fusion is the process that powers stars like our sun. This is why fusion fuels offer vastly higher energy density than chemical methods-about a million times denser than fossil fuels.Ī variety of fusion reactions are possible. These nuclear binding forces are far stronger than the forces that hold electrons in orbit around a nucleus and influence the energy of chemical processes. (Larger nuclei-those above iron-do not release energy when they fuse, as the higher number of protons increases Coulomb repulsion.) When small nuclei are fused together, this increases the strong force nuclear binding, releasing energy in the form of radiation and/or emission of subatomic particles. The fusion of light elements releases energy due to the interplay of two opposing forces: the “strong” nuclear force, which holds protons and neutrons together in the nucleus, and the Coulomb force, which causes positively charged protons to repel each other.Īt the very short distance scales of an atomic nucleus, the strong force overcomes Coulomb repulsion to bind the protons and neutrons together. Accordingly, power generation professionals can benefit from a clear understanding of the current fusion landscape and where things are likely to go over the next decade.įusion is a nuclear reaction in which two or more atomic nuclei combine to form one or more different atomic nuclei and often subatomic particles as well. Though it may be premature for utility resource planners to begin preparing for electricity from fusion, the time is growing closer when it becomes an option alongside other large generation projects. Meanwhile, the first reactor that should achieve “burn”-that is, self-sustaining fusion-is currently under construction in France, with operations set to begin within the next few years (Figure 1). and other nations, most of the key physics questions behind fusion have been answered.

As the result of decades of scientific advancement by the U.S. Yet that reality is considerably closer than many people realize. Practical, economic generation from fusion is not yet here, and it’s a solid bet that it will not arrive on the grid before the 2030s.

This photo shows the partly completed building that will house the fusion tokamak and its support systems. The ITER project, shown during construction in February 2020, will be the first experiment to create a “burning,” or self-sustaining, fusion plasma. Decades of overly enthusiastic predictions have led to a long-running joke that fusion is the energy source of the future-and always will be.ġ. Vastly more is understood about the physics of fusion energy than in Eddington’s day, yet commercial electricity generation from fusion still remains a goal rather than a reality. Obviously, these early predictions were more than a little off-base. It was not long before journalists and pulp fiction authors were predicting a time, surely not far away, when the world would be powered by simple fusion reactors requiring nothing more than abundant hydrogen from water. When British physicist Arthur Stanley Eddington first proposed in the 1920s that the sun and stars were powered by the fusion of hydrogen into helium, his idea sparked a rush of research and speculation into the possibility of bringing this energy source to earth. But significant recent advances in fusion science and technology could potentially put the first fusion power on the grid as soon as the 2040s. The joke about fusion energy is that it’s 30 years away and always will be.

Fission energy