[Scientists have been working on nuclear fusion—the process of recreating the atomic reactions that power the sun and stars right here on Earth. Their goal is to harness the process to produce a clean and limitless source of energy. Image from Nasa/Solar Dynamics Observatory]
Which is the hottest place in the solar system?
A nuclear scientist who had been my classmate posed this question to me when I had enquired about her work. It must be the centre of the sun, I blurted out. Then, I turned to Wikipedia for details. It said solar core temperatures hover around 15 million degrees Celsius. It's so incredibly hot in there that nothing survives in its true state. Everything gets ionised into a nebulous froth called plasma, where atoms meld into each other and produce endless bursts of energy. The answer, obviously, is the sun's core.
She smiled at me. She didn't say I was wrong but said there was another right answer.
According to her, the hottest place in the entire solar system is actually about an hour’s drive (50 miles) from my home in West London, in an idyllic village called Culham in Oxfordshire. There, inside a research facility, scientists cook up temperatures of 150 million degrees Celsius, or 10 times as hot as the sun. Since no physical material can hold this heat, they use powerful magnetic fields to contain the plasma and then they do their experiments.
That’s where my friend works. She is one among a rare breed of scientists who work on nuclear fusion—the process of recreating the atomic reactions that power the sun and stars right here on Earth. Their goal is to harness the process to produce a clean and limitless source of energy—the Holy Grail of science for more than seven decades. If and when their mission succeeds, and commercial nuclear fusion becomes a reality, the world will forever become free of fossil fuels. The war on human-induced climate change, and those pesky power cuts, can at last be won. That’s the promise.
But for the most part, these exotic scientists remain obscure, pecking away at nerdy problems, with little success to report for years at a time. True fusion, on a repeatable and commercial scale, has not been achieved yet. It is an elusive field of research, where project milestones stretch across generations. My friend and her colleagues are most likely to retire without any merit badges. They almost never make newspaper headlines.
I, too, soon forgot about our conversation, with any knowledge I had gathered about fusion stashed away in the attic of my brain. Until one day, I heard a buzz sweeping through London’s scientific establishment about a world record. EuroFusion, the Oxfordshire research programme, had generated the most amount of energy that ever came from a nuclear-fusion machine. It was a breakthrough, the experts said, one that took humanity one baby step closer to building a commercial fusion power plant.
Suddenly, this moribund field has come alive again. Fusion scientists have become rock stars in Britain. Their photos are being seen in newspapers. YouTubers interview them. Congratulations are pouring in from around the world, including rival scientists. My friend’s career doesn’t look so hopeless now.
For all this brouhaha, EuroFusion merely succeeded in producing 59 megajoules of energy, enough to power an average home for half a day. The tiny amount of thermal output was generated by injecting a lot more heat into the system, meaning net energy loss. Now, that doesn’t sound like an achievement for a bunch of scientists who had been working on this for 40 years!
But ask insiders, and they say this is an earthquake in their field. Fusion, as a scientific concept, has been proven since the 1950s but has eluded an engineering design that could make it a useful technology in real life. Now, EuroFusion’s experiment has shown it can be done viably and sustainably. The experiment lasted only five seconds, but that’s the evidence scientists needed to know that it can be done for five hours, five weeks, or five months.
More importantly, the Oxford energy record hasn’t come in isolation. It is just the latest in a string of successes in fusion research reported from around the world over the past year. In fact, more technological breakthroughs have been announced in these 12 months than in the past 40 years. The vexatious problems that have kept fusion energy from becoming a reality all this time are looking closer than ever to being resolved. Governments and private financial backers, who had balked at funding a failing science, are now returning and offering billions.
In other words, nuclear fusion is at last moving from the theoretical-research mode to the mission mode.
So nuclear, yet so far
All the nuclear energy we produce today comes from fission—which works by splitting atoms to release large amounts of energy. It’s a risky and controversial technology, and its poor safety record is sparking a rethink about its continued use. By definition, fission has to work with unstable atoms that are expensive to mine and hard to store safely. It releases radioactivity lasting millions of years and is prone to uncontrolled chain reactions causing major loss of life. Accidents like the 1979 Three Mile Island radioactive escape in Pennsylvania, the Chernobyl reactor meltdown in 1986, as well as the tsunami-induced Fukushima blowout in 2011 have highlighted this danger. That’s why the world is already moving on from this technology, retiring old reactors but not replacing them. The peak of fission may be already behind us. (Though fission faithfuls might dispute that. They say it is cleaner than fossil fuel and helps to reduce our dependence on the Middle East and Russia. Even Germany, which is on the verge of shutting down its last fission power plant, is now thinking of extending its life after Russia invaded Ukraine).
Fusion, on the other hand, works by bringing together atoms to produce a larger element, also releasing energy in the process. In many ways, it is the perfect energy source. First of all, it’s dirt cheap as the fuel that drives fusion is sea water, which we aren’t likely to run out of ever. Second, it can produce four times as much energy as fission, and four million times as much as coal or gas for the same volume of fuel. Third, the process is safe as it uses hydrogen, a stable atom with zero chance of out-of-control reactions. The reactor stops when fuel stops. Finally, there’s little radioactivity from fusion. In the most popular method, where deuterium and tritium (isotopes of hydrogen) are fused, the former is non-radioactive and the latter has a half-life of just 12.3 years. Tritium’s radioactivity can’t even penetrate paper and dissipates quickly.
Given these virtues, it’s a pity that fusion isn’t already our primary source of energy. But that’s not for want of trying. Around the world, dozens of experimental reactors conduct fusion regularly, but none of them has yielded a design for a functional reactor which can supply electricity to the grid. Fusion is native to the stars and is made possible by the extreme gravity and heat in them. The settled and cooled earth doesn’t provide the conditions conducive for the celestial process. We must create the conditions artificially. In fact, the experimental machines have to produce heat that’s several times the solar temperatures, in order to compensate for our low gravitational force. That’s where the 150 million degrees Celsius comes in.
But there’s one hurdle. Current technologies require more energy to start fusion than they can generate out of it. Their struggle, then, is to figure out how to produce more with less. That ratio of energy produced to energy consumed is called the Q value. All the great fusion experiments around the world, including Oxfordshire, are focused on achieving a Q value of 1. It has not been done yet, but is the baby step we need before thinking of commercially viable ratios such as 10 or 25 or even 100, when fusion will achieve grid electricity.
Once we understand this scientific dilemma, it’s possible for us to appreciate the significance of the breakthroughs that have happened in the past year. Dozens of experiments around the world, while all aiming for a Q value of 1, have taken different approaches to reach there. Some are trying to increase the energy generated, while others are trying to achieve fusion at lower temperatures so that the input can be minimized. Some are trying to make fusion self-sustaining by drawing its energy from the plasma rather than an external source. Still others are working on the materials and structures that make the whole thing more efficient.
All these researchers have ploughed on for years, making small improvements at a time, learning from each other and tinkering with the science as a collective. As luck would have it, all these efforts came to a head sometime starting February 2021 when project after project achieved new milestones that had eluded them previously. That they are all happening within a short span of 12 months is only an illusion. They are the result of decades of patient research carried out in obscurity, amid financial constraints and derision from fellow scientists who said the whole thing was a waste of time.
Heroes and happy twists
In 2004, Annie Kritcher was a student at the University of Michigan when she was looking for a summer placement in nuclear science. When she got an opportunity at the National Ignition Facility, a fusion programme at the Lawrence Livermore National Laboratory in California, she grabbed it. The same year, in England, Ian Chapman passed from Durham University and joined the Culham Science Centre, where the EuroFusion research experiment was taking shape, as a graduate scientist. Meanwhile, at the Massachusetts Institute of Technology, veteran fusion scientist Martin Greenwald was poring over a Nobel Prize-winning paper by two IBM scientists on High Temperature Superconducting Materials for its potential application in his research.
Their paths would eventually converge but they didn’t know it then. Each of them was ploughing a lonely furrow in a field that was little more than the backwaters of science. They didn’t have much to go on with in the beginning. Little had been achieved by way of practical design, and a functional fusion reactor looked as far away as the stars it was supposed to mimic. Still, they dared to be in the business in the belief, against all odds, that fusion was the future of energy.
Cut back 17 years later, to 2021, and all their careers hit jackpot. Kritcher had risen to be the design lead for NIF’s laser-based fusion experiment at Lawrence Livermore. Her team had made hundreds of design changes over the years and were ready to test the result of their improved system. Chapman was now the Chief Executive Officer of the UK Atomic Energy Authority, having been promoted to the country’s top nuclear-science job and the leadership of the Culham facility. Greenwald had successfully built the world’s most powerful magnet with the high-temperature superconducting materials he had been obsessed with for years. He was ready to test and demonstrate it. All of them were now part of a global ecosystem of fusion research, lending their knowledge to each other’s missions.
On August 8, Kritcher’s team at NIF concentrated 192 laser beams on a tiny pellet of fuel, sparking a fusion reaction for 100 trillionth of a second. And almost at once, they knew it was a massive success. It set a world record Q value of 0.7, meaning a 70% energy yield. It wasn’t 1, the state of “ignition” when the output energy equals the input, but it broke a 24-year record (0.67 achieved by the Oxfordshire experiment). This signalled that her team was making the right changes to the experiment’s design and true ignition could well be a matter of time.
But that wasn’t the best part.
Further analysis of the results showed that the NIF’s August fusion event had achieved something that was thought to be in the realms of science fiction. It had reached the so-called burning plasma state, where the heat produced by fusion drove more fusion, thereby becoming self-sustaining without the need for external energy input. It was electrifying news when Nature magazine published a paper on the milestone.
The very next month, MIT dropped its happy bombshell. Greenwald and his colleagues had successfully demonstrated the world’s most powerful magnet, which produced a compression field of 20 tesla. Such a big magnet could contain the plasma heat so efficiently that the size of its container (called tokamak) can be reduced and thus made more efficient.
And in December, Chapman’s team in Europe achieved the five-second experiment that set a new benchmark for the maximum energy produced from a tokamak. It was a boost not just for the EuroFusion project, but for the much larger International Thermonuclear Experimental Reactor located in France. ITER is a multinational megaproject run by seven member-countries including India. It will use learnings from the UK experiment to build the world’s largest tokamak-based reactor with an aim to achieve a Q value of 10.
While government-funded projects like NIF, ITER and Culham are the leaders in the field, there’s also an explosion of private entrepreneurship challenging them with their own solutions. Greenwald and his colleagues at MIT have formed a startup, Commonwealth Fusion Energy, to build a full-fledged experimental reactor called SPARC, which they plan to commission by 2025. It will be a precursor to a commercial reactor called ARC, which they hope to build by 2030. (Those are enthusiastic deadlines by a fund-raising startup. Realistically, give them a few more years). The company has already got big backing, and has raised $2 billion from the likes of Bill Gates, Vinod Khosla and Temasek.
Washington-based Helion Energy last year became the first private company to achieve a temperature of 100 million degrees Celsius with its sixth prototype and began building a more powerful seventh prototype. Venture-capital money started flowing in almost instantaneously. The company has now raised almost $600 million, with milestone-linked commitments of another $1.7 billion, on the promise of building a reactor that extracts electricity directly from the fusion chamber, unlike other technologies where water is heated to turn a turbine. If it works, it will be far more thermal efficient.
These are just two examples of more than three dozen startups around the world that are taking part in the race to build the world’s first commercial fusion reactor. By some accounts, venture capitalists poured in $3 billion last year to fund such initiatives. It appears as though money is no longer a problem for fusion. That’s a far cry from the days when people like Greenwald had to lobby for a trickle of government funding and had to schedule experiments around the availability of cash.
A sobering thought
Nuclear scientists don’t tell many jokes, but there’s one that cracks them up interminably. You can hear it in seminars and workshops, in press interviews and YouTube videos. You can read it in almost every article on the subject. It goes like this: “Nuclear-fusion power is just 30 years away, and always will be.”
It’s not a great joke, but is quite descriptive of a field of science notorious for its failed promises and missed deadlines. Fusion is where the careers of three generations of scientists have gone to die. Billions of dollars spent on research have gone down the drain without producing even a functional prototype of a power plant, piling pressure on governments from the US to Europe to channel funds into other areas where results are more forthcoming. Fusion project managers, themselves, are guilty of overpromising and underdelivering. They are typically flashy characters, overly optimistic and constantly fund-seeking. They pledge unrealistically tight timelines and invariably disappoint when the results are due. Media hysteria over fusion erupts once a decade or so, mostly whipped up by these project managers, and then falls silent under the weight of failures.
Let us try to not fall into this pit. There’s no point in cheerleading the fusion-power ecosystem and then being proven wrong. One thing that frustrates me no end is the buzz around Q value, which evangelists tout as the panacea for fusion challenges. The issue with that is it only counts the energy used to excite the plasma, and not the total energy consumed by the entire reactor to keep the process going. When the overall energy input is considered, even a Q value of 25 can come up short. For a commercial reactor to be viable, it may have to achieve even higher Q values, which means there’s a very long road to traverse before this thing becomes a reality.
The current series of breakthroughs, while impressive in themselves, are just a baby step. Even if we assume that progress happens every day from now on, with full funding and no technical setbacks, it could take at least 30 years for us to switch on a light bulb or watch television powered by fusion energy. So, when I say nuclear fusion is coming within our grasp, take it to mean the middle of the century, not the end of this month.
That said, there’s plenty to get excited about nuclear fusion at this point. It can save the planet from climate change and energy crises. And it can do so in a safe, cheap and sustainable manner. A world where not a drop of oil is burned and no corner goes unlit is a prize so big that we can’t afford not to take this gamble. The latest breakthroughs are evidence that fusion is not fiction but a reality waiting to happen.
And when it does happen, we will owe huge gratitude to the men and women who staked their careers on a frustrating and failure-prone science—and never accepted defeat in the face of the most impossible odds.
About this series
A Letter from London is a new monthly newsletter, anchored by a leading strategic analyst and commentator of Indian origin, based in the heart of The City. It looks at what’s shifting at the intersection of business, markets, economy and society.