In this podcast from the MIT Energy Initiative (MITEI) Dennis Whyte, director of the MIT Plasma Science and Fusion Center discusses the history and future of fusion.
Francis O’Sullivan: From MIT, this is the Energy Initiative and I'm Francis O'Sullivan. Welcome to today's podcast, one of a series we're carrying out on game-changing energy technologies. Today, as part of the series, we're speaking to Professor Dennis Whyte(link is external), head of MIT's Nuclear Science and Engineering Department(link is external) and director of the MIT Plasma Science and Fusion Center(link is external). Dennis, welcome to the podcast.
Dennis Whyte: Hi, thanks for having me.
FO: Dennis, this podcast, as I mentioned, is one of a series that we've been carrying out, looking at game-changing technologies in energy that colleagues here on campus at MIT are focused on. We're so excited to be here to speak to you because what you're doing and what you're working on really represents truly, I think, a game-changer. That's the whole topic of nuclear fusion. Tell me a little bit about where we are today with respect to nuclear fusion, your vision for its role in transforming the energy system, and the challenges indeed that we're going to have to face in kind of realizing the potential that we all kind of feel fusion might have.
DW: We'll start with what it is. Fusion is the process that powers all the stars, including our own sun. Stars are huge balls of hydrogen and fusion is the fusing of hydrogen nuclei together to make a different element. They fuse together to produce helium. This is how stars work. When that happens, it releases staggering amounts of energy. This was a mystery, actually, until the 1930s when basically these processes were understood. Before that, Lord Kelvin, very famous British scientist, the originator of the Kelvin and the temperature scale, calculated–they knew the sun was hydrogen and how fast you would use up the energy of hydrogen, burning it in the chemical sense–the sun could only be about 5000 years old. That was wrong. It's actually about five billion years old. That tells you about the efficiency of actually converting hydrogen into helium. It's basically a million times more energy-intensive than hydrogen burning. So that is fusing. That's what we're trying to bring down to earth. What we have to do on earth is actually collapse this into a much more powerful star. We use these heavier isotopes or versions of hydrogen because they react at millions of times higher level than what our star does. What does that require? It requires a temperature of about 100 million degrees. We basically have to push enough of it together that it has a pressure which is about five to ten atmospheres of pressure. Sort of like the pressure that's in the tires in your car. Once you do those, that system starts to make net energy. It starts to keep itself hot like a sun does. And you're rocking and rolling. We haven't achieved that yet, but just to give you an indication how close are we, we routinely actually hit that 100-million-degree temperature. In terms of that pressure, about how much stuff we've pushed together, we actually set the record here at MIT. It was about two atmospheres. Recognizing that you have to get to five or ten. It's just like, yeah, we're not that far away.
FO: On that point–because I think people will find this fascinating–we're sitting here in your office at MIT, and across the street there has been, not far from us, maybe like 100 meters, maybe less, a temperature of 100 million degrees Celsius has been realized. People are going to say, well, that seems hot. And it is pretty hot. How do we go about actually achieving that? What are the bits and pieces that you guys have brought together here to make that happen?
DW: What you actually need is a containment system that actually doesn't consist of a physical container. Which sounds, what, what are you talking about? What we use is a magnetic container. That magnetic container is a virtual container in the sense that it's not a physical object, but actually holds together the–you said that I was Director of the Plasma Science and Fusion Center. Plasma, what is that? I saw that on MASH one time, "I need more plasma for the patient." It's not that kind of plasma; blood plasma. It's actually the fourth state of matter. This is what stars are. When things get very hot, above about 5000 degrees, they all turn into plasma. Plasmas get contained by magnetic fields because of the charges that the particles contain, and that holds it.
FO: This is really what's so remarkable about what you guys have been doing over the past few years. First, great new science, and that's tremendous, of course. But as you know well, a salient characteristic of today's energy sector has been a movement towards greater decentralization. This is one of the huge hurdles, obviously, the at-scale fusion paradigm has struggled against. With the new technology, coupled now with this concept that you've brought for the development of the technology and the go-to-market, there's now a feasible pathway, I think, to really unlock that potential. I think people have acknowledged that's really remarkable. Tell us a little bit about how that idea has come about, what the challenges have been in realizing the support that's been needed to get this start-up concept up and running, where we are today, and tell us then how many years fusion is away, Dennis. [Laughter]
DW: I knew that was coming. That's okay, that's fine. I have to attribute this to being a professor here at MIT. I came here 12 years ago, and I immediately started teaching the fusion energy class here, which basically touches on all the things that we've just been talking about, plus other technologies. This goes through all the basics. I always ended this class with a review of conceptual power plant designs that were being produced primarily here in the United States, but also abroad as well, too. Because if we're working on this idea, we should be conceptualizing, what does it look like? What does the possible economic profile look like of these things? I'm always suspicious of whole numbers as a scientist. It was fascinating that actually every single design was designed at one gigawatt, one billion watts electric. I was reporting this to the students, and we would go through the challenges of this. I asked, "What's the deal? Why are you doing this?” The people who ran those studies, they said they went to EPRI–which the Electric Power Research Institute–they said they wanted to get the idea, “What should be the unit size? How much power should we be making?” Because they were proposing multiple gigawatt ones, and EPRI said absolutely not. This has to be at least, at maximum a gigawatt. Okay, we're going to just design everything at a gigawatt. As an academic, I was very suspicious of this. I thought, is this really true? Do you actually have to design everything? Is this economy of scale true? We started exploring different things in the class about why that might not be true. The answer became pretty apparent. It was actually in the physics was, if you were at a higher magnetic field than what they were assuming, you would actually start bringing down the unit size. This then all formulated altogether in the ARC design, which actually in the end became a surprise to me about how coherent this story became, of applying this new technology, the new high magnetic field. That class was, like, four years ago. It was still kind of speculative, while getting a little bit more solid technology. But you could see the pathway coming towards it. Then the exciting part, the most exciting part of that class, was when we finished all this intense technical work about using the magnetic fields, about shrinking the size. I basically told the students, "We're going to make this unit as small as possible." We pushed and pushed on both the science and the technology. It's hard to make fusion small. Then we ended up with this thing that had a certain size and volume. We did a quick estimate of its cost and how much power it made per cost. I almost fell off my chair. Maybe I did fall off my chair. It was basically the same as the first fission power plants that were produced. I never believed in my lifetime that basically fusion would have just a pure economic profile versus fission that would be competitive. Since because fission is, in many ways, it's complicated enough, but it's a lot simpler to deploy than fusion. It happens at room temperature, using uranium that you dig up from the ground. You put it in, you got a thing of water, you get the heat out, and man. That changed my mind. That was actually the trigger moment for me, personally, was that this means our duty isn't just a scientific duty anymore to advance this field. This means this technology now applied to this science means that fusion can make a difference. Because it did with fission. In a very short period of time, they took that technology from almost nothing to actually deploying it. As you well know, in a span of about 12 to 15 years, it was producing a staggering percentage of the electricity in the United States, and basically almost all–outside of hydropower–basically all of the carbon-free energy. We can do that again with fusion after I saw that. But we have to make it work.
FO: So today there is a start-up that has been established called Commonwealth Fusion Systems(link is external).
DW: That's right.
FO: And Commonwealth has achieved funding.
FO: And there's a pathway towards development that's been laid out. Tell us a little bit about how Commonwealth has come together, who's involved in Commonwealth, and what the vision is over the next few years for Commonwealth realizing this opportunity.
DW: Commonwealth, very appropriately, was spun out of MIT and the leadership of that company came from the students and the postdocs who were students in those classes. It's a great story for MIT.
FO: Yeah, that's fantastic.
DW: It's a real company now. What we did was, we thought very hard about the kind of organization and the structure of the organization. Can a start-up really do fusion? There are a few examples out there of other start-ups who have raised significant amounts of funds, who've launched themselves, who are doing really interesting work. We looked at it and said, is that optimum? It wasn't necessarily optimum because you need a really, what I call, deep bench of engineering and scientific expertise. Here we had, at MIT, at the Plasma Science and Fusion Center, a lot of that expertise. What were we going to do? We basically said, what we're going to do is imagine a new model for developing this very exciting energy source. Organization-wise, part of this core group is going to go out and spin it out into the company and we're going to attract high-level investors, serious investors, in this. Yet at the same time, from MIT, the hat I wear, we are going to be fully supportive of accomplishing the hard R&D around this and basically be an R&D and development partner for the company. That's what we did. We took this out into the world, into the energy world and said, this is what we're committed to. From the MIT side, we're committed to clean energy, carbon-free energy, and providing the R&D and the science around that. From the company side, we're committed to commercialization that, namely, this is deployed in a way that people are using fusion to better their lives, and we're using clean energy. That was a pretty powerful combination. In fact, indeed, the company, the project, has very serious investors, from ENI, which is one of the world's largest energy companies, the Italian supermajor energy company, to Breakthrough Energy Ventures, which was started by Bill Gates, which you're well-aware of, and several others. With the idea that we have a commitment from them that they share our vision, that it's not an easy path, and we want an aggressive timeline actually towards doing this. But it is doable. We're executing on this now. The company basically came out in public about seven or eight months ago. We attracted that investment. We established a research agreement between the company and MIT. Right now, I have 50+ people working on that, literally across the street right now, on developing this new technology. It is a fantastic partnership between MIT and CFS. CFS does the things that we can't do. We can't do direct commercialization, but their goal is to see fusion be a commercial product. MIT's goal is, like all of this work that we've done, to establish the scientific and technical pinnings of fusion be out there in the real world. The joke about this is, I would say, we had this great idea. It was born in many ways out of the intellectual juices flowing at MIT and through education, students, and the interaction with the broader community, including the Energy Initiative, which was a real eye-opener about introducing us to people, understanding what the energy market needed. It was a pretty sad thing, actually, I would say, is that, I was a person who worked in energy–I'm putting up air quotes–“energy research”, but I never really talked to people in the energy sector. Now we did, and we understood the kind of product that needed to be made. We did a very MIT thing, we had this great idea that we should go and possibly license to the industry or something like that. There is no fusion industry, so we created one. [Laughter]
FO: Dennis, let me just say, it’s been such a fascinating discussion. But perhaps more importantly, what you just described really brings together all of what I think we at MIT are about. It's about amazing science. It's about really pushing the frontier of the scientific knowledge forward. But it's about then taking that and applying it. That's the goal. To see you guys do this and to see the progress that's being made and, crucially, to see the potential, truly game-changing potential that is coming with this effort is really remarkable. Thank you so very much for taking the time. I'm going to thank you for the audience. I'm sure everyone who listens to this will say that was great, thanks so much.
DW: Thank you. And thanks, no kidding, thanks to the Energy Initiative, actually. The Energy Initiative was an absolutely key part in fact of making this happen. That's another great partnership at MIT.
FO: I think it's a great example of what can be done. Fingers crossed, progress just continues to build momentum.
DW: We're working hard at it.
FO: Show notes and links to this and other episodes are available at energy.mit.edu/podcast(link is external). Please tweet us @mitenergy(link is external) with your questions and comments, and of course, show ideas, and do also please subscribe and review us where you get your podcasts. From the MIT Energy Initiative, I’m Francis O’Sullivan and thank you for listening today.