Within 15 years, MIT expects to produce energy from fusion
Within 15 years, MIT expects to produce energy from fusion. MIT and Commonwealth Fusion Systems (CFS) collaborate in a new US initiative and decided to take a radically different approach to other efforts to transform fusion fram an exensive science experiment into a viable commercial energy source.
The team intend to use a new class of high-temperature superconductors they predict will allow them to create the world’s first fusion reactor that produces more energy than needs to be put in to get the fusion reaction going.
Carbon-free fusion power
CFS is announcing today that it has attracted an investment of $50 million in support of this effort from the Italian energy company Eni. In addition, CFS continues to seek the support of additional investors. CFS will fund fusion research at MIT as part of this collaboration, with an ultimate goal of rapidly commercializing fusion energy and establishing a new industry.
Bob Mumgaard, CEO of\CFS: “The aspiration is to have a working power plant in time to combat climate change. We think we have the science, speed and scale to put carbon-free fusion power on the grid in 15 years.”
“Everyone agrees on the eventual impact and the commercial potential of fusion power, but then the question is: How do you get there?” adds Commonwealth Fusion Systems CEO Robert Mumgaard SM ’15, PhD ’15. “We get there by leveraging the science that’s already developed, collaborating with the right partners, and tackling the problems step by step.”
Superconducting magnets are key
Fusion, the process that powers the sun and stars, involves light elements, such as hydrogen, smashing together to form heavier elements, such as helium — releasing prodigious amounts of energy in the process. This process produces net energy only at extreme temperatures of hundreds of millions of degrees Celsius, too hot for any solid material to withstand. To get around that, fusion researchers use magnetic fields to hold in place the hot plasma — a kind of gaseous soup of subatomic particles — keeping it from coming into contact with any part of the donut-shaped chamber.
The new effort aims to build a compact device capable of generating 100 million watts, or 100 megawatts (MW), of fusion power. This device will, if all goes according to plan, demonstrate key technical milestones needed to ultimately achieve a full-scale prototype of a fusion power plant that could set the world on a path to low-carbon energy. If widely disseminated, such fusion power plants could meet a substantial fraction of the world’s growing energy needs while drastically curbing the greenhouse gas emissions that are causing global climate change.
CFS will support more than $30 million of MIT research over the next three years through investments by Eni and others. This work will aim to develop the world’s most powerful large-bore superconducting electromagnets — the key component that will enable construction of a much more compact version of a fusion device called a tokamak.
The magnets, based on a superconducting material that has only recently become available commercially, will produce a magnetic field four times as strong as that employed in any existing fusion experiment, enabling a more than tenfold increase in the power produced by a tokamak of a given size.
Conceived at PSFC
The project was conceived by researchers from MIT’s Plasma Science and Fusion Center, led by PSFC Director Dennis Whyte, Deputy Director Martin Greenwald, and a team that grew to include representatives from across MIT, involving disciplines from engineering to physics to architecture to economics. The core PSFC team included Mumgaard, Dan Brunner PhD ’13, and Brandon Sorbom PhD ’17 — all now leading CFS — as well as Zach Hartwig PhD ’14, now an assistant professor of nuclear science and engineering at MIT.
Once the superconducting electromagnets are developed by researchers at MIT and CFS — expected to occur within three years — MIT and CFS will design and build a compact and powerful fusion experiment, called SPARC, using those magnets. The experiment will be used for what is expected to be a final round of research enabling design of the world’s first commercial power-producing fusion plants.
SPARC is designed to produce about 100 MW of heat. While it will not turn that heat into electricity, it will produce, in pulses of about 10 seconds, as much power as is used by a small city. That output would be more than twice the power used to heat the plasma, achieving the ultimate technical milestone: positive net energy from fusion.
This demonstration would establish that a new power plant of about twice SPARC’s diameter, capable of producing commercially viable net power output, could go ahead toward final design and construction.
Such a plant would become the world’s first true fusion power plant, with a capacity of 200 MW of electricity, comparable to that of most modern commercial electric power plants. At that point, its implementation could proceed rapidly and with little risk, and such power plants could be demonstrated within 15 years, say Whyte, Greenwald, and Hartwig.
Complementary to ITER
The project is expected to complement the research planned for a large international collaboration called ITER, currently under construction as the world’s largest fusion experiment at a site in southern France. If successful, ITER is expected to begin producing fusion energy around 2035.
“Fusion is way too important for only one track,” says Greenwald, who is a senior research scientist at PSFC.
By using magnets made from the newly available superconducting material — a steel tape coated with a compound called yttrium-barium-copper oxide (YBCO) — SPARC is designed to produce a fusion power output about a fifth that of ITER, but in a device that is only about 1/65 the volume, Hartwig says. The ultimate benefit of the YBCO tape is that it drastically reduces the cost, timeline, and organizational complexity required to build net fusion energy devices, enabling new players and new approaches to fusion energy at university and private company scale.
The way these high-field magnets slash the size of plants needed to achieve a given level of power has repercussions that reverberate through every aspect of the design. Components that would otherwise be so large that they would have to be manufactured on-site could instead be factory-built and trucked in; ancillary systems for cooling and other functions would all be scaled back proportionately; and the total cost and time for design and construction would be drastically reduced.
“What you’re looking for is power production technologies that are going to play nicely within the mix that’s going to be integrated on the grid in 10 to 20 years,” Hartwig says. “The grid right now is moving away from these two- or three-gigawatt monolithic coal or fission power plants. The range of a large fraction of power production facilities in the U.S. is now is in the 100 to 500 megawatt range. Your technology has to be amenable with what sells to compete robustly in a brutal marketplace.”
Because the magnets are the key technology for the new fusion reactor, and because their development carries the greatest uncertainties, work on the magnets will be the initial three-year phase of the project — building upon the strong foundation of federally funded research conducted at MIT and elsewhere. Once the magnet technology is proven, the next step of designing the SPARC tokamak is based on a relatively straightforward evolution from existing tokamak experiments, he says.
“By putting the magnet development up front,” says Whyte, the Hitachi America Professor of Engineering and head of MIT’s Department of Nuclear Science and Engineering, “we think that this gives you a really solid answer in three years, and gives you a great amount of confidence moving forward that you’re giving yourself the best possible chance of answering the key question, which is: Can you make net energy from a magnetically confined plasma?”
The research project aims to leverage the scientific knowledge and expertise built up over decades of government-funded research — including MIT’s work, from 1971 to 2016, with its Alcator C-Mod experiment, as well as its predecessors — in combination with the intensity of a well-funded startup company. Whyte, Greenwald, and Hartwig say that this approach could greatly shorten the time to bring fusion technology to the marketplace — while there’s still time for fusion to make a real difference in climate change.