Are we there yet?

Inside the billion-dollar race to harness fusion

The world needs renewable power more than ever. For those in the hunt to master nature’s most tantalizing and challenging energy source, the question is no longer how, but how soon?

History suggests that an energy revolution requires not just money and brains, but a guiding intuition about what the future will bring. In 1859, early backers of the oil industry were confident that the black fluid they were pumping out of the Pennsylvania countryside and the kerosene it made would find people ready to switch from burning camphene, whale oil or candles for indoor lighting.

More than a century later, in the early 2000s, renewable energy entrepreneur Richard Swanson correctly projected that the cost of solar panels would plummet according to a mathematical relationship with rising production capacity.

And at the Massachusetts Institute of Technology, Dennis Whyte had a hunch that if you design a nuclear fusion reactor with the strongest magnets possible, the exotic stuff required to make those magnets will become available by the time you need it.

That, too, has proved to be correct. High temperature superconductors, once brittle and hard to work with, can now be purchased in bulk, conveniently deposited on strips of tape. When wrapped around layers of metal, the material can be used to make the most powerful magnets on Earth.

As it turns out, this has huge implications for the quest to develop nuclear fusion, the physical process that powers the sun and stars, as a commercial energy source.

In 2012, Dr. Whyte, a Canadian scientist and engineer who directs fusion research at MIT, was among the first to see the possibilities. He put this challenge to a class of graduate students: Start by assuming you can have all high temperature superconductor you want, then figure out what kind of machine it will make.

“It was revealing,” he said.

Today, that machine is being built by Commonwealth Fusion Systems, a company set up in 2018 as a spinoff from the work begun in Dr. Whyte’s class. The site, where the company has based its new headquarters an hour’s drive west of Boston, saw its official opening this week.

Commonwealth is vying to become the first private company with a fusion reactor that achieves “net energy” – meaning the energy that comes out is greater than the energy going in.

There are signs that the nascent fusion industry is nearing a financial watershed as well – a make-orbreak moment that is drawing comparisons with the advent of commercial space flight some 20 years ago. Because of Commonwealth and a handful of other companies leading the push, an energy source seen as crucial to the world’s postcarbon development may finally be flickering to life.

In total, those companies have raised more than US$5-billion from investors (SEE CHART). Commonwealth is the leader, having collected more than US$2-billion from backers who include Bill Gates through his Breakthrough Energy group, which is seeking to accelerate the path to net-zero carbon emissions by 2050.

Another is Vancouver-based General Fusion, which has raised more than US$300-million from investors who include Jeff Bezos and Temasek Holdings, Singapore’s giant sovereign wealth fund.

Once Commonwealth or any other company pushes past the net-energy threshold, “everybody on the planet will know it’s a different world,” Dr. Whyte said.

The Promethean dream of nuclear fusion is about harnessing an abundant, uninterrupted, carbonfree source of electricity. Long the domain of large, government-backed projects, the pursuit has more recently expanded to include an array of private companies, particularly in the United States, Britain and Canada.

True, fusion has a long track record of being more difficult and costly than expected – a transformational technology that is just years away and always will be, according to one long-running joke. And unlike space flight, it is not a mature field that has simply to be emulated and streamlined by commercial players.

But recent breakthroughs in the underlying science of fusion have raised excitement that the viable path to fusion energy is beginning to materialize.

In December, the U.S. government’s National Ignition Facility in Livermore, Calif., achieved net energy for the first time. Scientists at the US $3.5-billion lab, whose primary purpose is nuclear weapons research, used the world’s most powerful laser to implode a two-millimetre-wide fuel pellet, triggering a fusion reaction that produced 1.5 times the energy that the pellet absorbed in laser light.

The caveat is that it took more than 30 times that amount of energy to run the laser. While the experiment was rightly hailed as a milestone, it also illustrates how far away the achievement is from delivering electricity to consumers.

The biggest fusion megaproject of all is the International Thermonuclear Experimental Reactor, a US$22-billion experiment based in France, where a nine-storey reactor is nearing completion. ITER is a tokamak, a device first conceived in the 1950s by Soviet physicist and dissident Andrei Sakharov, among others.

A tokamak is a doughnut-shaped vessel encased in magnets. The vessel contains a searingly hot plasma – a kind of electrified nuclear gas – which is suspended by the surrounding magnetic field so that the walls of the doughnut are not destroyed. Once the plasma is heated to over 100 million degrees, fusion reactions can take place.

A tokamak may offer a direct route to a working power plant, but when ITER was proposed in the 1980s, the magnets available at that point required that it be a large machine. ITER has now been under construction for 15 years and it is not expected to reach net energy until some time in the mid-2030s.

For Dr. Whyte, who once imagined that ITER would become his ultimate career destination, the project’s prolonged timeline and escalating cost became the impetus for looking at tokamaks differently.

“If fusion is so important,” he began asking himself a decade ago, “why do we have only one project in the world to do this?”

Born and raised in Saskatchewan, Dr. Whyte has deep roots in fusion. After studying as an engineering physicist, he did his PhD work using a tokamak built by Hydro-Québec in Varennes, near Montreal. In the 1990s, he was on a Canadian-sponsored fellowship with General Atomics in San Diego when Ottawa cancelled its support for fusion research.

Without a program to return home to, Dr. Whyte and his wife stayed on in the U.S. After stints at the University of California and the University of Wisconsin, he found his way to MIT in 2006.

There, Dr. Whyte began to see a different path. He prodded his students to consider whether the advent of stronger magnets than those used by ITER could make a tokamak that could reach net energy but that was smaller and therefore cheaper to build.

Other players have made similar calculations. Among the more than 30 companies now pursuing commercial fusion worldwide, a common theme is that ideas once considered technically infeasible are now benefiting from new technologies that could fast track fusion energy at a scale and cost that is realistic for consumer power generation.

General Fusion in Vancouver, co-founded in 2002 by physicist Michel Laberge, has been developing an approach called targeted magnetic fusion, first explored by the U.S. Naval Research Laboratory in the 1970s. Like Commonwealth in Massachusetts, the Canadian company is preparing to build a device that will demonstrate its reactor concept.

After reaching an agreement with the UK Atomic Energy Authority, General Fusion has selected a site at Culham, Oxfordshire, in England for its demonstration reactor. Nearby is the Joint European Torus, or JET, currently the world’s largest operating tokamak, which set a record in 2021 for the most energy produced in a fusion reaction.

With construction slated to begin this year, General Fusion aims to have its machine up and running by 2027.

“It’s really about executing on our plan over the next few years to demonstrate at large scale and ultimately get energy on the grid in the early 2030s,” said Greg Twinney, the company’s chief executive officer.

In addition to the money it has raised from investors, this week General Fusion confirmed that it is asking the Canadian government for $335-million more to support its commercialization strategy. The company has said that the funding could be part of a larger government investment in a Canadian fusion hub, and it has gathered industry and academic support for the idea in advance of the coming federal budget.

In a world looking to meet growing energy demands while also shifting away from fossil fuels, the pitch for commercial fusion is obvious. “When you look at the long term, when you do the math, you need something like fusion,” said Brandon Sorbom, a former student of Dr. Whyte who is now chief scientific officer at Commonwealth.

“In the shorter term,” he said, “I think it makes sense that we get to it as soon as possible.”

The great irony of fusion energy is that it is so ubiquitous and yet so hard to replicate. A dazzling view of the Milky Way on a moonless night is simply the light of billions of fusion reactors blazing away without human assistance.

Down on Earth, conventional nuclear power plants run on fission, a nuclear reaction that relies on the splitting of uranium, the heaviest naturally occurring element, to produce enough heat to drive a generator.

By contrast, fusion turns light elements into heavier ones. Igniting the process requires a challenging combination of high temperature, pressure and timing. For that reason, a fusion reaction demands a vast amount of energy input up front, but the result releases about 10 times more energy than fission does per weight of the atoms involved, and several million times more than oil or coal.

The easiest way to achieve fusion in a reactor is by bringing together two forms of hydrogen – deuterium and tritium. If the two nuclei collide with enough force to overcome the positive electrical charge that pushes them apart, they can produce a single nucleus of helium.

This so-called D-T reaction also releases a neutron, a subatomic particle, which carries away about 80 per cent of the energy gained in the reaction. When the neutron collides with its surroundings, the energy of its motion is converted to heat.

Deuterium occurs naturally, and accounts for about one out of every 5,000 hydrogen atoms found in seawater. Tritium, which is radioactive with a half-life of a little more than 12 years, is another matter. Currently, Canada has much of the world’s nonmilitary supply of tritium because it is a byproduct of the country’s 19 Candu nuclear reactors, which provide power in Ontario and New Brunswick.

As fusion companies seek to realize their plans, there is the potential for a tritium shortage, particularly once ITER comes online in the 2030s. But most fusion reactor plans include using neutrons from fusion reactions to turn a surrounding layer of lithium into additional tritium, so that fusion can be self-sustaining.

If all of this works, fusion comes with the same upsides as conventional nuclear power with fewer of the downsides. Fusion does not release carbon dioxide or other harmful emissions, and, unlike renewables, it can deliver energy without interruption and be set up virtually anywhere. Because fusion is hard to sustain, it also shuts itself off without continuous encouragement, like a match trying to light wet wood. So, in a fusion reactor, there is no equivalent to a meltdown – the kind of runaway reaction that led to disasters at Chernobyl and Fukushima.

Nevertheless, fusion requires some handling of radioactive materials, including tritium. Over time, parts of a fusion reactor would become radioactive through absorbing neutrons and would require safe disposal and long-term storage. Exactly how much material would need to be stored, and for how long, depends on the particular approach.

All of these considerations have long been a feature of fusion. What has changed lately is the potential for new advances to lower the cost of fusion just as the climate crisis has put a new premium on reducing carbon emissions.

“I think the big difference right now is the interest in energy from the perspective of low greenhouse gas emissions and anything that falls into that category,” said Axel Meisen, president of the Fusion Energy Council of Canada, a non-profit organization established in 2016 to promote Canadian participation in the development of fusion.

While companies driving the current wave of enthusiasm are diverse, what separates most of them is mostly how they propose to bring together deuterium and tritium.

Among the oldest is TAE, a California-based company co-founded in 1998 by Canadian physicist Norman Rostoker. Instead of a tokamak, the company is developing a system that involves firing plasma into a cylindrical chamber where it forms a smoke-ringlike structure that generates its own self-confining magnetic field. The principle, known as field-reversed configuration, is also favoured by Helion Energy Inc., based in Everett, Wash.

In contrast, First Light Fusion, based in Britain, is foregoing plasma and seeking to trigger fusion through the rapid compression of specially-designed fuel targets. The idea is like the one employed by the National Ignition Facility, except that it replaces a costly laser with a giant gun that fires projectiles at the targets with velocities approaching 20 times the speed of sound.

In Canada, General Fusion has bet on a hybrid model in which hot magnetized plasma is confined inside a spinning vortex of liquid metal. The vortex is surrounded by powerful pistons which can apply a sudden squeeze to the metal, in turn compressing the plasma to a point at which fusion can momentarily occur. The cycle then repeats, like an engine.

A key feature of the design is that it requires only conventional electromagnets, without the need for superconducting materials, thereby reducing costs.

In December, General Fusion announced that the results it has achieved so far suggest the process can achieve fusion when scaled up to the size of the demonstration machine the company is preparing to build at Culham in Britain. The test device will aim for a type of fusion that uses deuterium plasma only. While it will not achieve net energy, its success would set the stage for a deuterium-tritium reactor, about 40-per-cent larger, that would cross that threshold and form the basis for a commercial reactor.

Mr. Twinney, who joined General Fusion in 2020 and became CEO last year, acknowledged the quickening pace of developments in commercial fusion as more players enter the area, aiming to bring similar demonstrations online at about the same time.

“The prize is huge,” he said. “So much work has gone into this for a lot of decades that we are all confident we’ve got the right ingredients now to put it all together.”

As part of its plans, General Fusion has signed a memorandum of understanding with Canadian Nuclear Laboratories in Chalk River, Ont. The research facility is equipped to work with, and test, technologies related to tritium handling that will be needed in a future pilot power plant. First Light Fusion has announced a similar arrangement.

Ian Castillo, who leads CNL’s hydrogen and tritium technologies directorate, said the agreements show that companies recognize that “there are other parts of the puzzle beyond the reactor.”

Commonwealth’s new headquarters are on a 47acre property tucked in the rolling countryside around Devens, Mass. Over the past year, the company has grown to more than 400 staff. Many of them work in the main building, which also houses the manufacturing facility for building the hightemperature superconducting magnets that will encase the company’s first reactor, dubbed SPARC.

Through a picture window in a NASA-like control room, a second building that will house the reactor can be seen in the final stages of construction.

“We want this to be a very boring device,” said Dr. Sorbom, meaning the fewer surprises the better. Apart from its use of high-temperature superconducting magnets, the reactor was designed along the well-studied lines of a traditional tokamak.

The company has the 10 grams of tritium it will need to run SPARC, but it has not divulged the supplier. The primary goal of the project is to test the various aspects of the reactor’s compact design, including how it will remove the helium that will otherwise build up as fusion takes place and dampen the reactor’s ability to sustain its energy output.

Along the way, the machine will have other important hurdles to clear. For example, its ultrapowerful magnets could still face technical obstacles at the extremes at which the machine needs to operate. But if all goes to plan, the machine will achieve net energy at some point after it begins operating in 2025 – perhaps reaching 10 times that based on the company’s calculation. After that, the next step is a prototype power plant that uses the heat from fusion energy to generate electricity, ready some time in the 2030s.

But as exciting as it will be if the commercial players reach their goals, it is unlikely that fusion reactors will have significant presence on power grids before 2040, let alone deliver the world from carbon by 2050.

“It would be extremely premature to start putting fusion into electricity supply assumptions, at any point through the middle of this century,” analysts with the U.S. investment firm Raymond James Financial Inc. wrote in a December brief.

Other veteran fusion analysts agree. Despite recent progress, fusion energy is not a ready-made escape hatch from dealing with tough choices around carbon emissions. Rather, fusion could be an attractive option after those choices have been made.

For Dr. Sorbom, who is 36 and who began thinking about the world’s energy dilemma and its impact on his generation when he was in high school, the real motivation for working on fusion is bigger than climate change, it’s about what it takes to power a global civilization for centuries to come.

“If you look at quality of life metrics – at literacy and infant mortality and life span and things like that. You can basically correlate all of those to energy, and they all get better.”

For his part, Dr. Whyte is just happy to see so much action after so many years of limited progress.

“I’m working on a wider variety of topics in fusion than I’ve ever worked on in my career,” the MIT professor said. “I’ve never been more energized.”