2024 ended with a bang for a couple of companies working to bring fusion from an idea for a faraway future to technology that could be accessible within the next decade. We’ll do a quick walkthrough of the leading theory behind turning fusion into power and what the “state of the union” is for this trending niche.
In very basic terms, fusion happens when two atoms come together and release a bunch of energy. Complications arise, however, because atoms don’t want to come together: Much like siblings in a fight, there are repulsive forces at play that have always proven quite difficult to overcome, as the conditions needed require extreme heat and pressure.
The goal of most of the work in this space centers around how to strip the atoms of their electrons so that their nuclei can unite. Atoms really like their electrons, though (or maybe electrons really like their atoms!) so a lot of persuasion is required in the form of heat. By “a lot,” I mean the temperature needed is roughly 100 million degrees Celsius.
Once the electrons are gone, you now have a plasma of positrons, but positrons also don’t want to come together, so high pressures are required to squeeze them together and high speeds increase the possibility of a collision. The pressures needed are roughly more than 100 billion times that of Earth’s atmosphere. Most of us don’t regularly experience even 1 atmosphere, and most materials can’t withstand that kind of pressure, so creating those conditions is quite the tall order.
Creating the Right Conditions
As I discussed in a previous Enspired article, magnetic fields are used to contain the plasma in a fusion reaction within a reaction chamber. The chamber is shaped like a giant doughnut, but its fancier, scientific name is a toroid. The magnets are on the outside of the toroid and the plasma is on the inside.
A common starting material for fusion reactions is hydrogen that is broken down into deuterium and tritium during the plasma generation process. Another option is to source deuterium and tritium directly, since deuterium can be extracted from seawater and tritium can be extracted from lithium.
The magnets, starter materials and toroids traditionally used have been around for a while, so why is fusion technology trending now? Part of that interest results from a breakthrough three years ago (see sidebar) but 2024 also proved to be a year of innovation and groundbreaking in nuclear fusion.
Generating that much heat and pressure takes a lot of energy, and until the past few years, any nuclear fusion reaction required more energy than it produced, and those that produced “more” energy have output very little: Certain aspects of the process had to be ignored in the final input/output calculations. Recently, companies have begun breaking new ground in remedying these challenges.
One company, Commonwealth Fusion Systems, has focused on improving the performance of the magnets to prevent them from heating up too much (sending currents through magnets to generate the magnetic field heats up the magnets and can damage them). CFS tweaked the design of the magnets, including adding internal electrical insulation to minimize heating.
In November 2024, the company succeeded. “This is an important milestone on the road to commercialization,” said Brandon Sorbom, co-founder and chief science officer at CFS. “When we hit the button and put current through the magnet, it performed like a champ and hit all its major test objectives. The fact that our team was able to develop this technology all the way from benchtop to a fully integrated, at-scale superconducting magnet in just a couple of years is huge.”
Another company, OpenStar Technologies, is flipping the design of a nuclear fusion reactor on its head by moving the magnet inside the plasma field. This idea is less tested, but OpenStar claims its new design, referred to as a “levitated dipole,” is easier to repair and adjust than a traditional toroid. This enables more adjustments to magnet and experimental design in less time. OpenStar achieved its first plasma only a week after CFS had its breakthrough, so it seems the race is on!
If companies such as these can help nuclear fusion become a reality, the impact could be extensive: Society could soon have access to abundant, safe and carbon-free energy that is relatively easily sourced and produces no radioactive waste.
Where do geoscientists come in? We have roles to play in sourcing the deuterium and tritium needed during fusion reactions, but I also see paths forward in the magnetics (field generation and materials sourcing) required.