Generating nearly limitless, clean, carbon-free energy from nuclear fusion—a vision that seems to be perpetually out of reach—has taken major steps in the past several years toward becoming a reality.
On the heels of major recent breakthroughs in physics labs in generating nuclear fusion, the quest has now expanded into the private sector, where a proliferation of start-up companies are racing to make the process commercially viable, and profitable.
If they succeed, the prize would be an abundant source of virtually carbon-free energy that does not consume vast acres of natural landscapes and coastal areas, as do solar panels and wind turbines. And, unlike today’s nuclear-fission reactors, fusion energy produces relatively little radioactive waste.
Tritium and deuterium, isotopes of hydrogen, are the elements used in fusion, rather than heavy elements like uranium and plutonium that are used in fission. The final products of a fusion reaction are helium and neutrons.
Besides producing less waste, nuclear fusion does not entail the risk of runaway chain reactions like Chernobyl, scientists say.
If a fission plant shuts down during an emergency, “it can still produce a lot of power for a while from the leftover activity in the reactor, and this is why it melts,” Jean Barrette, physics professor emeritus at McGill University, told The Epoch Times.
“Whereas with nuclear fusion, you turn the switch off and it’s over; it doesn’t have any leftover radiation.”
While the potential benefits from fusion are manifold, harnessing it for electricity remains a daunting task.
“The fundamental process is well known, and of course, that’s what powers the stars,” Robert Fedosejevs, professor of electrical engineering at the University of Alberta and a specialist in laser technology, told The Epoch Times. But “fusion is the most technologically challenging approach to making energy that mankind has ever attempted.”
Within stars, immense gravity creates intense heat and pressure that causes several hydrogen nuclei to fuse into a single helium nucleus. There is a slight loss of mass in this process, and that “missing” mass is converted into enormous amounts of energy according to Albert Einstein’s famous equation, e = mc².
Absent the gravity of the sun, however, the challenge on earth is not only creating continuous fusion, but doing it in a way that doesn’t require more energy than it produces.
In December 2022, the Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) in California crossed this threshold. Through the work of about 1,000 U.S. and international scientists, the NIF created a fusion reaction that, for the first time, produced more energy than it consumed.
Staff pose for a photo at the heart of the National Ignition Facility at Lawrence Livermore National Laboratory in Livermore, Calif., in this file photo. Steve Jurvetson/CC BY 2.0
It was done by firing 192 simultaneous laser beams into a tiny peppercorn-sized capsule of deuterium and tritium (DT) to compress and heat it to temperatures between 50-100 million degrees Kelvin until it fused, with the product being a helium ion, a neutron, and energy.
“They’ve basically produced multi mega joules of fusion energy, with only two mega joules of laser energy going in,” Fedosejevs said. “That’s the scientific benchmark that people have been working toward for the last 50 to 60 years, to at least show that in the laboratory you can generate more energy out than in.
“So there’s no question fusion works. It’s really, how can we technically achieve it in a sustainable fashion as a power source?”
Moving From Labs to Functional Reactors
Going from a one-off, nano-second reaction in a laboratory to the reliable and cost-effective production of electricity is where scientists, engineers, and investors around the globe are turning their focus. “We are very, very far away from working plants,” Barrette said. “You need success in many, many directions.
“It’s not one thing they’re missing. They’re missing many things right now that all have to work to make an efficient reactor.”
The first is how to create sustained reactions through fusion, in order to generate base-load electricity. Development in this area is going down one of two paths: laser inertial confinement fusion, the process used by NIF, and magnetic confinement fusion, which uses a magnetic field to simulate the intense gravity within stars.
Laser fusion, which Fedosejevs describes as a “micro-implosion in a vacuum vessel driven by an ultra-short laser pulse,” has taken the lead in terms of producing net energy gains from the reaction. The DT fuel targets are meticulously arranged, and the lasers are all aimed precisely at a space about the width of a human hair.
They are then fired once before having to be recharged and re-aimed. The process allows for about one reaction per day.
To become viable for electricity generation, lasers would have to fire at least 100 times per second, Barrette said, and although solving this and other problems is not impossible, “they are now still very much in the research phase.”
Innovators in this space are working to develop more powerful lasers that can operate at a much higher repetition rate in order to produce energy continuously.
An August
report in Physics Today written by nuclear scientists Stefano Atzeni and Debra Callahan, however, notes that the NIF’s laser-based fusion was conducted with 30-year-old laser technology and that progress in laser and target technology has now advanced to the point that laser fusion continues to be seen as potentially commercially viable.
(Top) Technicians work on a target (R) at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. (Bottom L) An illustrative rendering shows a NIF target pellet inside a hohlraum capsule with laser beams entering through the openings on both end. The beams compress and heat the target to the necessary conditions for nuclear fusion to occur. (Bottom R) A view of the cryogenically cooled target as seen by the laser through the hohlraum capsule's laser entrance point. U.S. Department of Energy
By contrast to laser fusion, magnetic fusion relies on a powerful magnetic field to create the conditions necessary for fusion to take place.
With magnetic fusion, a machine called a tokamak, a design that originated in the Soviet Union in the 1950s, uses magnetic fields to confine, compress, and heat DT plasma within a donut-shaped reactor called a torus. Once fusion occurs, the product is a helium ion and a neutron. These neutrons are able to pass through the magnetic field, and as they do they are captured by a “blanket” outside the wall; this is the primary source of the heat that would ultimately generate electricity.
Over the decades since its invention, scientists have worked to develop ever-stronger magnets to generate more energy for longer durations.
In 1982, Princeton Plasma Physics Laboratory created its Tokamak Fusion Test Reactor (TFTR), which set a number of world records, including heating plasma to 510 million degrees centigrade, well beyond the 100 million degrees required for commercial fusion. These temperatures exceed those at the center of the sun, which NASA estimates are about 15 million degrees centigrade.
In 1994, the TFTR generated a record 10.7 million watts of controlled fusion energy, which would power more than 3,000 homes.
England also operates a tokamak, called the Joint European Torus (JET), which has also succeeded in generating record amounts of fusion energy. In addition, scientists from 35 countries collaborated on the ITER tokamak in France, which will be the largest superconducting magnet ever built and is scheduled to begin operating in 2034.
“It will produce a field of 13 tesla, equivalent to 280,000 times the Earth’s magnetic field,” a U.S. Department of Energy (DOE) report states. While laser fusion currently leads in terms of demonstrated energy output, magnetic fusion may hold more promise for generating the continuous energy output necessary for base-load electricity.
“Tokamaks can sustain plasma currents at the mega-ampere level, which is equivalent to the electric current in the most powerful bolts of lightning,” the DOE states. “Fusion energy scientists believe that tokamaks are the leading plasma confinement concept for future fusion power plants.”
Not to be left behind, China has built the Experimental Advanced Superconducting Tokamak (EAST) in Hefei, which has also operated successfully.
(Top) The Princeton Plasma Physics Laboratory's tokamak, called the National Spherical Torus Experiment-Upgrade (NSTX-U), in this file photo. (Bottom) The ITER tokamak machine in Saint-Paul-Lez-Durance, France, on Sept. 9, 2021. Michael Livingston/PPPL Communications, Daniel Cole/AP Photo
The Challenges of the ‘Wall’
Alongside the quest to develop commercially viable fusion reactions, an equally tall hurdle is figuring out how to build a functional, durable physical structure to contain and draw energy from the reactions. “We had the idea of ‘let’s put the sun in a bottle,’ and it turns out the hard part was not really creating the sun,” Eric Emdee, a research physicist at the Princeton Plasma Physics Laboratory (PPPL), told The Epoch Times.
“We’ve created very high temperature plasmas, temperatures that are optimal for fusion to happen,” he said. “The hard part is creating the bottle.”
Within a tokamak reactor, the DT plasma, contained within a magnetic field, is surrounded by a physical wall, called a plasma facing component (PFC) that must withstand the 100 million-degree heat from the reaction.
Similar to solar flares, some plasma escapes the magnetic field during reactions, threatening to damage the vessel wall. In addition, materials from the wall can interact with the plasma, diluting it and reducing the DT’s ability to fuse.
“We’re at the point where we are transitioning from experiments to reactor prototype designs, but we still need to determine how to have acceptable plasma-material interactions,” Emdee said. “How do we come up with a design for the vessel walls that will be economical? What are the materials we could use that are best for the plasma?”
Emdee’s research focuses on the materials for the PFC that could resolve these issues and divert the heat to prevent damage to the reactor. He is investigating the use of liquid metals to dissipate the heat, such as liquid lithium, which would flow along the wall of the tokamak.
Aside from reaction and containment issues, producing the fuel for fusion also has its challenges, which are magnified by the need to generate it in large quantities.
For laser fusion, Atzeni and Callahan write, fuel targets are currently created by hand in a labor-intensive process. For this technology to become commercially viable, however, millions of fuel targets would have to be used in a reactor every day that it operates, and the ability to mass produce DT fuel has not yet been demonstrated.
Deuterium is abundant and can be found in seawater, but tritium must be “bred” from elements like lithium. With magnetic fusion, tritium can be produced within the tokamak itself.
“To do that, you need to have a fuel cycle where the neutrons from your fusion energy are captured in lithium to breed the tritium, and then you have to extract the tritium and use it as a fuel,” Fedosejevs said.
“So there are a number of details which are still a major challenge, but which, as far as the science is concerned, seem tractable, though nobody’s done it yet on a scale size that one would need to do for a reactor.”
(Top) A staff member checks the Tokamak Fusion Test Reactor, in this file photo. (Bottom L) The Saturn target design aims to explore the possibly of demonstrating ignition in the National Ignition Facility using the Polar-Direct-Drive configuration, in this file photo. The capsule is mounted on a specifically designed ring by means of spider-silk strands. (Bottom Right) An illustration shows simulation that uses Weixing Wang's GTS code to show core turbulence in a Tokamak at Argonne National Laboratory. Researchers aim to push fusion computer codes and associated algorithms closer to defining plasma confinement properties required to ignite the ITER experimental fusion reactor. U.S. Department of Energy
Investment Capital on the Rise
An additional element necessary for the development of fusion-based electricity is money. But here, too, there is reason for optimism.In recent years a proliferation of start-up companies have been looking to develop commercial fusion. They are often offshoots of universities engaged in fusion research, such as MIT and Princeton, and frequently collaborate with academia on research and development.
Many of them have received government subsidies. In May 2023, the DOE announced $46 million in grants for commercial fusion development, given to eight companies across seven states. Recipients were Commonwealth Fusion Systems, Focused Energy Inc., Princeton Stellarators Inc., Realta Fusion Inc., Tokamak Energy Inc., Type One Energy Group, Xcimer Energy Inc. and Zap Energy Inc.
“Within five to 10 years, the eight awardees will resolve scientific and technological challenges to create designs for a fusion pilot plant that will help bring fusion to both technical and commercial viability,” the DOE stated in a press release.
In June, the DOE announced its “Fusion Energy Strategy 2024,” which will provide an additional $180 million toward the development of fusion-based electricity.
“The development of fusion energy as a clean, safe, abundant energy source has become a global race, and the U.S. will stay in the lead,” DOE Deputy Secretary David Turk said in a statement.
At the same time, private investment capital into nuclear fusion has doubled over the past two years, reaching a total of nearly $6 billion as of 2023, according to EnergyWorld.
Last year, Helion Energy, a start-up based in Washington state, signed an agreement with Microsoft to deliver 50 megawatts of fusion-based electricity by 2028.
“There is no doubt we still have a lot of work to do, but we are confident in our ability to deliver the world’s first fusion power facility,” Helion co-founder and CEO David Kirtly said in a statement.
While investors express ambitions that commercial fusion could become a reality within a decade, many insiders see a longer road ahead.
“If they can sustain that rate [of investment], then I think we are on track to seeing demos by mid-2030s, and hopefully engineering reactors by early 2040s,” Fedosejevs said.
Emdee takes a more cautious view.
“I would say optimistic estimates of fusion providing power to the grid are maybe the 2040s,” he said. “But the more conservative estimates, that I personally believe are more realistic, are the 2060s or 2070s.”
