Fusion can unlock enough energy from a single glass of seawater to power the average U.S. home for two months. Believe it or not, a mere gram of seawater holds more than a quintillion atoms of deuterium - the key ingredient for nuclear fusion.
Nuclear fusion creates energy by smashing atoms together. This process is attractive for many reasons: no risk of nuclear meltdown, no carbon dioxide or long-lived nuclear waste, and it promises to be easily affordable. However, present fusion technology requires more energy to smash the atoms together than researchers can harvest from the fusion reaction. That’s akin to spending $10 to make $6. But a fusion reactor in Saint-Paul-lès-Durance, France called ITER (which translates to “the way” from Latin) promises to make an energy profit in the 2040’s, finally bringing humanity to the threshold of a fusion-powered future.
The basic concept of a fusion reactor is simple. Smash an atom of deuterium (one proton + one neutron) into an atom of tritium (one proton + two neutrons) with enough oomph, and voila, out comes Helium (two protons + two neutrons), one neutron, and energy in the form of heat. Heat like that boils water into steam, which turns turbines and powers your toaster.
Here’s the kicker: the atoms need to reach 150 million degrees Fahrenheit. Why? Because heating the atoms up imbues them with enough energy to actually fuse together. Anything less scalding and the atoms will bounce off one another like basketballs instead of merging together like chunks of Play-doh. So to fuse atoms - and thus make energy - researchers must create temperatures ten times hotter than the sun.
This insane temperature demands as much energy per second as a city like Fredericksburg, Virginia does. No fusion reactor thus far has been able to pay back those energy costs.
To get more energy out than they put in, researchers must reduce energy expenditures. The most promising design for energy-efficient fusion machines is a donut-shaped affair called a tokamak which facilitates magnetic fields and electric currents that simultaneously contain and heat the atoms. This fusion technology was pioneered by Soviet scientists in the mid 1960’s. In the 50 years since, scientists worldwide have honed the tokamak design, peeling back the curtain, inch by inch, equation by equation, to understand and utilize the complexities of fusion.
The next era of fusion research is scheduled to start in December 2025, France, when scientists from 35 nations power up ITER, the Hercules of tokamak fusion reactors. Not only will ITER be ten times larger than any present fusion reactor, but it will prove the viability of large-scale commercial fusion power and lay the groundwork for future power plants by testing fueling, safety, and more. In the 2040’s, ITER’s energy output will surge to 500 MW of power (enough to power Williamsburg, Virginia) to make an energy profit margin of 90%. That’s like investing $10 and getting $100 back.
The fun is just getting started; for the latest news on construction and experiments, look at ITER’s website. Although it may be a few years before you can use that seawater to fuel a fusion power plant with deuterium, it’s worth the wait. Clean, safe, unlimited energy is right around the corner... powered by atoms in the sea, inspired by atoms of the sun.