Alongside A.I., I can think of no more promising an innovation than nuclear fusion energy. For a detailed introduction to nuclear fusion, you can refer back to episode #533, wherein former fusion researcher Dr. Brett Tully gives us an overview of nuclear fusion with a particular focus on how data science is making an impact on energy technology. In a nutshell, our current nuclear reactors work in a completely different way: Today’s reactors rely on nuclear fission, where very heavy atoms release energy when they split into smaller, lighter atoms. Nuclear fusion relies on the inverse: In it, very light atoms release energy when they combine into larger atoms. Specifically, the leading nuclear fusion approaches of today use hydrogen atoms (which we have in abundance on earth) as an input and produce helium (which we are in short supply of) as an output. Thus, fusion energy would be super sustainable, but not only that — it could produce an enormous amount of energy: Fusion reactions power stars including our very own sun, so having fusion reactors would be like harnessing the energy of miniature suns right here on earth. With nuclear fusion, we’d be able to supply energy to everyone on the planet without burning fossil fuels — indeed, we could use surplus energy to decarbonize our atmosphere and reverse some of the climate change damage humans have caused since the dawn of our industrial revolution.
So if fusion is such a game-changer for humanity, why haven’t we been focusing our enormous amounts of resources on it to obtain it? Well, governments have been investing billions of dollars a year in nuclear fusion prototypes and this year, for the first time, private investment in fusion energy exceeded public investment, with $5 billion dollars of private money flowing into fusion energy companies this year alone. This suggests to me that the market has sensed that commercially viable fusion energy stations might not be too far away and so it’s worth staking multi-billion-dollar bets on it.
The thing about harnessing a miniature sun right here on earth is that — guess what — it’s hard to do. For several decades now, most of the progress toward realizing nuclear fusion has been made by gigantic operations that are funded by federal governments — operations that have the specific intent of realizing specific intermediate steps on the road to eventually achieving stable, commercial fusion energy. That brings me to the reason why I’m focused on all of this today: A paper published earlier this month in a journal called Physical Review Letters — a paper with over a thousand authors — showed that one of the most critical intermediate steps toward nuclear fusion has been achieved, something called nuclear fusion ignition.
Ignition is significant because it’s the point in a nuclear fusion reaction where the reaction becomes self-sustaining. At that point, external energy inputs that created the fusion reaction are no longer needed. This major event was achieved at the aptly-named National Ignition Facility in California, construction of which began 25 years ago, and the successful ignition experiment yielded many times more energy than all preceding experiments there.
Relative to earlier experiments at the National Ignition Facility, the experiment on the right achieved nuclear fusion ignition and resulted in many times more energy being yielded.
So that’s the encouraging news. To temper your excitement about the realization of fusion power in the near-term, the National Ignition Facility has thus far been unable to successfully replicate its ignition experiment. And, even though ignition was briefly achieved that one time, far more energy went into running the experiment than was produced by the fusion reaction.
Nevertheless, this is a big deal. The folks at the NIF are working to improve their facility and procedural designs to more reliably attain ignition and to sustain nuclear fusion for longer. And other major projects elsewhere are making progress as well. The International Thermonuclear Experimental Reactor (ITER, for short), for example, a facility in France that is funded by 35 countries — including European ones, China, India, Japan, South Korea, Russia, the US, and others — hope to attain another major benchmark called breakeven — where a fusion reaction outputs more total energy than it takes to run the experiment — by 2025.
If you’d like to learn more about the exciting prospect of private investment realizing commercial nuclear fusion in the hopefully-not-too-distant future, I’ve included a link to a documentary by Bloomberg that’s available for free on YouTube.