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      The answer may be blowing in the wind

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      Capturing energy from the winds gusting off the coasts of the United States could more than double the nation’s electricity generation. It’s no wonder the Biden administration views this immense, clean-energy resource as central to its ambitious climate goals of 100 percent carbon-emissions-free electricity by 2035 and a net-zero emissions economy by 2050. The White House is aiming for 30 gigawatts of offshore wind by 2030 — enough to power 10 million homes.

      At the MIT Energy Initiative’s Spring Symposium, academic experts, energy analysts, wind developers, government officials, and utility representatives explored the immense opportunities and formidable challenges of tapping this titanic resource, both in the United States and elsewhere in the world.

      “There’s a lot of work to do to figure out how to use this resource economically — and sooner rather than later,” said Robert C. Armstrong, MITEI director and the Chevron Professor of Chemical Engineering, in his introduction to the event. 

      In sessions devoted to technology, deployment and integration, policy, and regulation, participants framed the issues critical to the development of offshore wind, described threats to its rapid rollout, and offered potential paths for breaking through gridlock.

      R&D advances

      Moderating a panel on MIT research that is moving the industry forward, Robert Stoner, MITEI’s deputy director for science and technology, provided context for the audience about the industry.

      “We have a high degree of geographic coincidence between where that wind capacity is and where most of us are, and it’s complementary to solar,” he said. Turbines sited in deeper, offshore waters gain the advantage of higher-velocity winds. “You can make these machines huge, creating substantial economies of scale,” said Stoner. An onshore turbine generates approximately 3 megawatts; offshore structures can each produce 15 to 17 megawatts, with blades the length of a football field and heights greater than the Washington Monument.

      To harness the power of wind farms spread over hundreds of nautical miles in deep water, Stoner said, researchers must first address some serious issues, including building and maintaining these massive rigs in harsh environments, laying out wind farms to optimize generation, and creating reliable and socially acceptable connections to the onshore grid. MIT scientists described how they are tackling a number of these problems.

      “When you design a floating structure, you have to prepare for the worst possible conditions,” said Paul Sclavounos, a professor of mechanical engineering and naval architecture who is developing turbines that can withstand severe storms that batter turbine blades and towers with thousands of tons of wind force. Sclavounos described systems used in the oil industry for tethering giant, buoyant rigs to the ocean floor that could be adapted for wind platforms. Relatively inexpensive components such as polyester mooring lines and composite materials “can mitigate the impact of high waves and big, big wind loads.”

      To extract the maximum power from individual turbines, developers must take into account the aerodynamics among turbines in a single wind farm and between adjacent wind farms, according to Michael Howland, the Esther and Harold E. Edgerton Assistant Professor of Civil and Environmental Engineering. Howland’s work modeling turbulence in the atmosphere and wind speeds has demonstrated that angling turbines by just a small amount relative to each other can increase power production significantly for offshore installations, dramatically improving their efficiencies. Howland hopes his research will promote “changing the design of wind farms from the beginning of the process.”

      There’s a staggering complexity to integrating electricity from offshore wind into regional grids such as the one operated by ISO New England, whether converting voltages or monitoring utility load. Steven B. Leeb, a professor of electrical engineering and computer science and of mechanical engineering, is developing sensors that can indicate electronic failures in a micro grid connected to a wind farm. And Marija Ilić, a joint adjunct professor in the Department of Electrical Engineering and Computer Science and a senior research scientist at the Laboratory for Information and Decision Systems, is developing software that would enable real-time scheduling of controllable equipment to compensate for the variable power generated by wind and other variable renewable resources. She is also working on adaptive distributed automation of this equipment to ensure a stable electric power grid.

      “How do we get from here to there?”

      Symposium speakers provided snapshots of the emerging offshore industry, sharing their sense of urgency as well as some frustrations.

      Climate poses “an existential crisis” that calls for “a massive war-footing undertaking,” said Melissa Hoffer, who occupies the newly created cabinet position of climate chief for the Commonwealth of Massachusetts. She views wind power “as the backbone of electric sector decarbonization.” With the Vineyard Wind project, the state will be one of the first in the nation to add offshore wind to the grid. “We are actually going to see the first 400 megawatts … likely interconnected and coming online by the end of this year, which is a fantastic milestone for us,” said Hoffer.

      The journey to completing Vineyard Wind involved a plethora of painstaking environmental reviews, lawsuits over lease siting, negotiations over the price of the electricity it will produce, buy-in from towns where its underground cable comes ashore, and travels to an Eversource substation. It’s a familiar story to Alla Weinstein, founder and CEO of Trident Winds, Inc. On the West Coast, where deep waters (greater than 60 meters) begin closer to shore, Weinstein is trying to launch floating offshore wind projects. “I’ve been in marine renewables for 20 years, and when people ask why I do what I do, I tell them it’s because it matters,” she said. “Because if we don’t do it, we may not have a planet that’s suitable for humans.”

      Weinstein’s “picture of reality” describes a multiyear process during which Trident Winds must address the concerns of such stakeholders as tribal communities and the fishing industry and ensure compliance with, among other regulations, the Marine Mammal Protection Act and the Migratory Bird Species Act. Construction of these massive floating platforms, when it finally happens, will require as-yet unbuilt specialized port infrastructure and boats, and a large skilled labor force for assembly and transmission. “This is a once-in-a-lifetime opportunity to create a new industry,” she said, but “how do we get from here to there?”

      Danielle Jensen, technical manager for Shell’s Offshore Wind Americas, is working on a project off of Rhode Island. The blueprint calls for high-voltage, direct-current cable snaking to landfall in Massachusetts, where direct-current lines switch to alternating current to connect to the grid. “None of this exists, so we have to find a space, the lands, and the right types of cables, tie into the interconnection point, and work with interconnection operators to do that safely and reliably,” she said.

      Utilities are partnering with developers to begin clearing some of these obstacles. Julia Bovey, director of offshore wind for Eversource, described her firm’s redevelopment or improvement of five ports, and new transport vessels for offshore assembly of wind farm components in Atlantic waters. The utility is also digging under roads to lay cables for new power lines. Bovey notes that snags in supply chains and inflation have been driving up costs. This makes determining future electricity rates more complex, especially since utility contracts and markets work differently in each state.

      Just seven up

      Other nations hold a commanding lead in offshore wind: To date, the United States claims just seven operating turbines, while Denmark boasts 6,200 and the U.K. 2,600. Europe’s combined offshore power capacity stands at 30 gigawatts — which, as MITEI Research Scientist Tim Schittekatte notes, is the U.S. goal for 2030.

      The European Union wants 400 gigawatts of offshore wind by 2050, a target made all the more urgent by threats to Europe’s energy security from the war in Ukraine. “The idea is to connect all those windmills, creating a mesh offshore grid,” Schittekatte said, aided by E.U. regulations that establish “a harmonized process to build cross-border infrastructure.”

      Morten Pindstrup, the international chief engineer at Energinet, Denmark’s state-owned energy enterprise, described one component of this pan-European plan: a hybrid Danish-German offshore wind network. Energinet is also constructing energy islands in the North Sea and the Baltic to pool power from offshore wind farms and feed power to different countries.

      The European wind industry benefits from centralized planning, regulation, and markets, said Johannes P. Pfeifenberger, a principal of The Brattle Group. “The grid planning process in the U.S. is not suitable today to find cost-effective solutions to get us to a clean energy grid in time,” he said. Pfeifenberger recommended that the United States immediately pursue a series of moves including a multistate agreement for cooperating on offshore wind and establishment by grid operators of compatible transmission technologies.

      Symposium speakers expressed sharp concerns that complicated and prolonged approvals, as well as partisan politics, could hobble the nation’s nascent offshore industry. “You can develop whatever you want and agree on what you’re doing, and then the people in charge change, and everything falls apart,” said Weinstein. “We can’t slow down, and we actually need to accelerate.”

      Larry Susskind, the Ford Professor of Urban and Environmental Planning, had ideas for breaking through permitting and political gridlock. A negotiations expert, he suggested convening confidential meetings for stakeholders with competing interests for collaborative problem-solving sessions. He announced the creation of a Renewable Energy Facility Siting Clinic at MIT. “We get people to agree that there is a problem, and to accept that without a solution, the system won’t work in the future, and we have to start fixing it now.”

      Other symposium participants were more sanguine about the success of offshore wind. “Trust me, floating wind is not a pie-in-the-sky, exotic technology that is difficult to implement,” said Sclavounos. “There will be companies investing in this technology because it produces huge amounts of energy, and even though the process may not be streamlined, the economics will work itself out.” More

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      Exploring new sides of climate and sustainability research

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      When the MIT Climate and Sustainability Consortium (MCSC) launched its Climate and Sustainability Scholars Program in fall 2022, the goal was to offer undergraduate students a unique way to develop and implement research projects with the strong support of each other and MIT faculty. Now into its second semester, the program is underscoring the value of fostering this kind of network — a community with MIT students at its core, exploring their diverse interests and passions in the climate and sustainability realms.Inspired by MIT’s successful SuperUROP [Undergraduate Research Opportunities Program], the yearlong MCSC Climate and Sustainability Scholars Program includes a classroom component combined with experiential learning opportunities and mentorship, all centered on climate and sustainability topics.“Harnessing the innovation, passion, and expertise of our talented students is critical to MIT’s mission of tackling the climate crisis,” says Anantha P. Chandrakasan, dean of the School of Engineering, Vannevar Bush Professor of Electrical Engineering and Computer Science, and chair of the MCSC. “The program is helping train students from a variety of disciplines and backgrounds to be effective leaders in climate and sustainability-focused roles in the future.”

      “What we found inspiring about MIT’s existing SuperUROP program was how it provides students with the guidance, training, and resources they need to investigate the world’s toughest problems,” says Elsa Olivetti, the Esther and Harold E. Edgerton Associate Professor in Materials Science and Engineering and MCSC co-director. “This incredible level of support and mentorship encourages students to think and explore in creative ways, make new connections, and develop strategies and solutions that propel their work forward.”The first and current cohort of Climate and Sustainability Scholars consists of 19 students, representing MIT’s School of Engineering, MIT Schwarzman College of Computing, School of Science, School of Architecture and Planning, and MIT Sloan School of Management. These students are learning new perspectives, approaches, and angles in climate and sustainability — from each other, MIT faculty, and industry professionals.Projects with real-world applicationsStudents in the program work directly with faculty and principal investigators across MIT to develop their research projects focused on a large scope of sustainability topics.

      “This broad scope is important,” says Desirée Plata, MIT’s Gilbert W. Winslow Career Development Professor in Civil and Environmental Engineering, “because climate and sustainability solutions are needed in every facet of society. For a long time, people were searching for a ‘silver bullet’ solution to the climate change problems, but we didn’t get to this point with a single technological decision. This problem was created across a spectrum of sociotechnological activities, and fundamentally different thinking across a spectrum of solutions is what’s needed to move us forward. MCSC students are working to provide those solutions.”

      Undergraduate student and physics major M. (MG) Geogdzhayeva is working with Raffaele Ferrari, Cecil and Ida Green Professor of Oceanography in the Department of Earth, Atmospheric and Planetary Sciences, and director of the Program in Atmospheres, Oceans, and Climate, on their project “Using Continuous Time Markov Chains to Project Extreme Events under Climate.” Geogdzhayeva’s research supports the Flagship Climate Grand Challenges project that Ferrari is leading along with Professor Noelle Eckley Selin.

      “The project I am working on has a similar approach to the Climate Grand Challenges project entitled “Bringing computation to the climate challenge,” says Geogdzhayeva. “I am designing an emulator for climate extremes. Our goal is to boil down climate information to what is necessary and to create a framework that can deliver specific information — in order to develop valuable forecasts. As someone who comes from a physics background, the Climate and Sustainability Scholars Program has helped me think about how my research fits into the real world, and how it could be implemented.”

      Investigating technology and stakeholders

      Within technology development, Jade Chongsathapornpong, also a physics major, is diving into photo-modulated catalytic reactions for clean energy applications. Chongsathapornpong, who has worked with the MCSC on carbon capture and sequestration through the Undergraduate Research Opportunities Program (UROP), is now working with Harry Tuller, MIT’s R.P. Simmons Professor of Ceramics and Electronic Materials. Louise Anderfaas, majoring in materials science and engineering, is also working with Tuller on her project “Robust and High Sensitivity Detectors for Exploration of Deep Geothermal Wells.”Two other students who have worked with the MCSC through UROP include Paul Irvine, electrical engineering and computer science major, who is now researching American conservatism’s current relation to and views about sustainability and climate change, and Pamela Duke, management major, now investigating the use of simulation tools to empower industrial decision-makers around climate change action.Other projects focusing on technology development include the experimental characterization of poly(arylene ethers) for energy-efficient propane/propylene separations by Duha Syar, who is a chemical engineering major and working with Zachary Smith, the Robert N. Noyce Career Development Professor of Chemical Engineering; developing methods to improve sheet steel recycling by Rebecca Lizarde, who is majoring in materials science and engineering; and ion conduction in polymer-ceramic composite electrolytes by Melissa Stok, also majoring in materials science and engineering.

      Melissa Stok, materials science and engineering major, during a classroom discussion.

      Photo: Andrew Okyere

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      “My project is very closely connected to developing better Li-Ion batteries, which are extremely important in our transition towards clean energy,” explains Stok, who is working with Bilge Yildiz, MIT’s Breene M. Kerr (1951) Professor of Nuclear Science and Engineering. “Currently, electric cars are limited in their range by their battery capacity, so working to create more effective batteries with higher energy densities and better power capacities will help make these cars go farther and faster. In addition, using safer materials that do not have as high of an environmental toll for extraction is also important.” Claire Kim, a chemical engineering major, is focusing on batteries as well, but is honing in on large form factor batteries more relevant for grid-scale energy storage with Fikile Brushett, associate professor of chemical engineering.Some students in the program chose to focus on stakeholders, which, when it comes to climate and sustainability, can range from entities in business and industry to farmers to Indigenous people and their communities. Shivani Konduru, an electrical engineering and computer science major, is exploring the “backfire effects” in climate change communication, focusing on perceptions of climate change and how the messenger may change outcomes, and Einat Gavish, mathematics major, on how different stakeholders perceive information on driving behavior.Two students are researching the impact of technology on local populations. Anushree Chaudhuri, who is majoring in urban studies and planning, is working with Lawrence Susskind, Ford Professor of Urban and Environmental Planning, on community acceptance of renewable energy siting, and Amelia Dogan, also an urban studies and planning major, is working with Danielle Wood, assistant professor of aeronautics and astronautics and media arts and sciences, on Indigenous data sovereignty in environmental contexts.

      “I am interviewing Indigenous environmental activists for my project,” says Dogan. “This course is the first one directly related to sustainability that I have taken, and I am really enjoying it. It has opened me up to other aspects of climate beyond just the humanity side, which is my focus. I did MIT’s SuperUROP program and loved it, so was excited to do this similar opportunity with the climate and sustainability focus.”

      Other projects include in-field monitoring of water quality by Dahlia Dry, a physics major; understanding carbon release and accrual in coastal wetlands by Trinity Stallins, an urban studies and planning major; and investigating enzyme synthesis for bioremediation by Delight Nweneka, an electrical engineering and computer science major, each linked to the MCSC’s impact pathway work in nature-based solutions.

      The wide range of research topics underscores the Climate and Sustainability Program’s goal of bringing together diverse interests, backgrounds, and areas of study even within the same major. For example, Helena McDonald is studying pollution impacts of rocket launches, while Aviva Intveld is analyzing the paleoclimate and paleoenvironment background of the first peopling of the Americas. Both students are Earth, atmospheric and planetary sciences majors but are researching climate impacts from very different perspectives. Intveld was recently named a 2023 Gates Cambridge Scholar.

      “There are students represented from several majors in the program, and some people are working on more technical projects, while others are interpersonal. Both approaches are really necessary in the pursuit of climate resilience,” says Grace Harrington, who is majoring in civil and environmental engineering and whose project investigates ways to optimize the power of the wind farm. “I think it’s one of the few classes I’ve taken with such an interdisciplinary nature.”

      Shivani Konduru, electrical engineering and computer science major, during a classroom lecture

      Photo: Andrew Okyere

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      Perspectives and guidance from MIT and industry expertsAs students are developing these projects, they are also taking the program’s course (Climate.UAR), which covers key topics in climate change science, decarbonization strategies, policy, environmental justice, and quantitative methods for evaluating social and environmental impacts. The course is cross-listed in departments across all five schools and is taught by an experienced and interdisciplinary team. Desirée Plata was central to developing the Climate and Sustainability Scholars Programs and course with Associate Professor Elsa Olivetti, who taught the first semester. Olivetti is now co-teaching the second semester with Jeffrey C. Grossman, the Morton and Claire Goulder and Family Professor in Environmental Systems, head of the Department of Materials Science and Engineering, and MCSC co-director. The course’s writing instructors are Caroline Beimford and David Larson.  

      “I have been introduced to a lot of new angles in the climate space through the weekly guest lecturers, who each shared a different sustainability-related perspective,” says Claire Kim. “As a chemical engineering major, I have mostly looked into the technologies for decarbonization, and how to scale them, so learning about policy, for example, was helpful for me. Professor Black from the Department of History spoke about how we can analyze the effectiveness of past policy to guide future policy, while Professor Selin talked about framing different climate policies as having co-benefits. These perspectives are really useful because no matter how good a technology is, you need to convince other people to adopt it, or have strong policy in place to encourage its use, in order for it to be effective.”

      Bringing the industry perspective, guests have presented from MCSC member companies such as PepsiCo, Holcim, Apple, Cargill, and Boeing. As an example, in one class, climate leaders from three companies presented together on their approaches to setting climate goals, barriers to reaching them, and ways to work together. “When I presented to the class, alongside my counterparts at Apple and Boeing, the student questions pushed us to explain how can collaborate on ways to achieve our climate goals, reflecting the broader opportunity we find within the MCSC,” says Dana Boyer, sustainability manager at Cargill.

      Witnessing the cross-industry dynamics unfold in class was particularly engaging for the students. “The most beneficial part of the program for me is the number of guest lectures who have come in to the class, not only from MIT but also from the industry side,” Grace Harrington adds. “The diverse range of people talking about their own fields has allowed me to make connections between all my classes.”Bringing in perspectives from both academia and industry is a reflection of the MCSC’s larger mission of linking its corporate members with each other and with the MIT community to develop scalable climate solutions.“In addition to focusing on an independent research project and engaging with a peer community, we’ve had the opportunity to hear from speakers across the sustainability space who are also part of or closely connected to the MIT ecosystem,” says Anushree Chaudhuri. “These opportunities have helped me make connections and learn about initiatives at the Institute that are closely related to existing or planned student sustainability projects. These connections — across topics like waste management, survey best practices, and climate communications — have strengthened student projects and opened pathways for future collaborations.

      Basuhi Ravi, MIT PhD candidate, giving a guest lecture

      Photo: Andrew Okyere

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      Having a positive impact as students and after graduation

      At the start of the program, students identified several goals, including developing focused independent research questions, drawing connections and links with real-world challenges, strengthening their critical thinking skills, and reflecting on their future career ambitions. A common thread throughout them all: the commitment to having a meaningful impact on climate and sustainability challenges both as students now, and as working professionals after graduation.“I’ve absolutely loved connecting with like-minded peers through the program. I happened to know most of the students coming in from various other communities on campus, so it’s been a really special experience for all of these people who I couldn’t connect with as a cohesive cohort before to come together. Whenever we have small group discussions in class, I’m always grateful for the time to learn about the interdisciplinary research projects everyone is involved with,” concludes Chaudhuri. “I’m looking forward to staying in touch with this group going forward, since I think most of us are planning on grad school and/or careers related to climate and sustainability.”

      The MCSC Climate and Sustainability Scholars Program is representative of MIT’s ambitious and bold initiatives on climate and sustainability — bringing together faculty and students across MIT to collaborate with industry on developing climate and sustainability solutions in the context of undergraduate education and research. Learn about how you can get involved. More

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      Engineers solve a mystery on the path to smaller, lighter batteries

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      A discovery by MIT researchers could finally unlock the door to the design of a new kind of rechargeable lithium battery that is more lightweight, compact, and safe than current versions, and that has been pursued by labs around the world for years.

      The key to this potential leap in battery technology is replacing the liquid electrolyte that sits between the positive and negative electrodes with a much thinner, lighter layer of solid ceramic material, and replacing one of the electrodes with solid lithium metal. This would greatly reduce the overall size and weight of the battery and remove the safety risk associated with liquid electrolytes, which are flammable. But that quest has been beset with one big problem: dendrites.

      Dendrites, whose name comes from the Latin for branches, are projections of metal that can build up on the lithium surface and penetrate into the solid electrolyte, eventually crossing from one electrode to the other and shorting out the battery cell. Researchers haven’t been able to agree on what gives rise to these metal filaments, nor has there been much progress on how to prevent them and thus make lightweight solid-state batteries a practical option.

      The new research, being published today in the journal Joule in a paper by MIT Professor Yet-Ming Chiang, graduate student Cole Fincher, and five others at MIT and Brown University, seems to resolve the question of what causes dendrite formation. It also shows how dendrites can be prevented from crossing through the electrolyte.

      Chiang says in the group’s earlier work, they made a “surprising and unexpected” finding, which was that the hard, solid electrolyte material used for a solid-state battery can be penetrated by lithium, which is a very soft metal, during the process of charging and discharging the battery, as ions of lithium move between the two sides.

      This shuttling back and forth of ions causes the volume of the electrodes to change. That inevitably causes stresses in the solid electrolyte, which has to remain fully in contact with both of the electrodes that it is sandwiched between. “To deposit this metal, there has to be an expansion of the volume because you’re adding new mass,” Chiang says. “So, there’s an increase in volume on the side of the cell where the lithium is being deposited. And if there are even microscopic flaws present, this will generate a pressure on those flaws that can cause cracking.”

      Those stresses, the team has now shown, cause the cracks that allow dendrites to form. The solution to the problem turns out to be more stress, applied in just the right direction and with the right amount of force.

      While previously, some researchers thought that dendrites formed by a purely electrochemical process, rather than a mechanical one, the team’s experiments demonstrate that it is mechanical stresses that cause the problem.

      The process of dendrite formation normally takes place deep within the opaque materials of the battery cell and cannot be observed directly, so Fincher developed a way of making thin cells using a transparent electrolyte, allowing the whole process to be directly seen and recorded. “You can see what happens when you put a compression on the system, and you can see whether or not the dendrites behave in a way that’s commensurate with a corrosion process or a fracture process,” he says.

      The team demonstrated that they could directly manipulate the growth of dendrites simply by applying and releasing pressure, causing the dendrites to zig and zag in perfect alignment with the direction of the force.

      Applying mechanical stresses to the solid electrolyte doesn’t eliminate the formation of dendrites, but it does control the direction of their growth. This means they can be directed to remain parallel to the two electrodes and prevented from ever crossing to the other side, and thus rendered harmless.

      In their tests, the researchers used pressure induced by bending the material, which was formed into a beam with a weight at one end. But they say that in practice, there could be many different ways of producing the needed stress. For example, the electrolyte could be made with two layers of material that have different amounts of thermal expansion, so that there is an inherent bending of the material, as is done in some thermostats.

      Another approach would be to “dope” the material with atoms that would become embedded in it, distorting it and leaving it in a permanently stressed state. This is the same method used to produce the super-hard glass used in the screens of smart phones and tablets, Chiang explains. And the amount of pressure needed is not extreme: The experiments showed that pressures of 150 to 200 megapascals were sufficient to stop the dendrites from crossing the electrolyte.

      The required pressure is “commensurate with stresses that are commonly induced in commercial film growth processes and many other manufacturing processes,” so should not be difficult to implement in practice, Fincher adds.

      In fact, a different kind of stress, called stack pressure, is often applied to battery cells, by essentially squishing the material in the direction perpendicular to the battery’s plates — somewhat like compressing a sandwich by putting a weight on top of it. It was thought that this might help prevent the layers from separating. But the experiments have now demonstrated that pressure in that direction actually exacerbates dendrite formation. “We showed that this type of stack pressure actually accelerates dendrite-induced failure,” Fincher says.

      What is needed instead is pressure along the plane of the plates, as if the sandwich were being squeezed from the sides. “What we have shown in this work is that when you apply a compressive force you can force the dendrites to travel in the direction of the compression,” Fincher says, and if that direction is along the plane of the plates, the dendrites “will never get to the other side.”

      That could finally make it practical to produce batteries using solid electrolyte and metallic lithium electrodes. Not only would these pack more energy into a given volume and weight, but they would eliminate the need for liquid electrolytes, which are flammable materials.

      Having demonstrated the basic principles involved, the team’s next step will be to try to apply these to the creation of a functional prototype battery, Chiang says, and then to figure out exactly what manufacturing processes would be needed to produce such batteries in quantity. Though they have filed for a patent, the researchers don’t plan to commercialize the system themselves, he says, as there are already companies working on the development of solid-state batteries. “I would say this is an understanding of failure modes in solid-state batteries that we believe the industry needs to be aware of and try to use in designing better products,” he says.

      The research team included Christos Athanasiou and Brian Sheldon at Brown University, and Colin Gilgenbach, Michael Wang, and W. Craig Carter at MIT. The work was supported by the U.S. National Science Foundation, the U.S. Department of Defense, the U.S. Defense Advanced Research Projects Agency, and the U.S. Department of Energy. More

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      Advancing the energy transition amidst global crises

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      “The past six years have been the warmest on the planet, and our track record on climate change mitigation is drastically short of what it needs to be,” said Robert C. Armstrong, MIT Energy Initiative (MITEI) director and the Chevron Professor of Chemical Engineering, introducing MITEI’s 15th Annual Research Conference.

      At the symposium, participants from academia, industry, and finance acknowledged the deepening difficulties of decarbonizing a world rocked by geopolitical conflicts and suffering from supply chain disruptions, energy insecurity, inflation, and a persistent pandemic. In spite of this grim backdrop, the conference offered evidence of significant progress in the energy transition. Researchers provided glimpses of a low-carbon future, presenting advances in such areas as long-duration energy storage, carbon capture, and renewable technologies.

      In his keynote remarks, Ernest J. Moniz, the Cecil and Ida Green Professor of Physics and Engineering Systems Emeritus, founding director of MITEI, and former U.S. secretary of energy, highlighted “four areas that have materially changed in the last year” that could shake up, and possibly accelerate, efforts to address climate change.

      Extreme weather seems to be propelling the public and policy makers of both U.S. parties toward “convergence … at least in recognition of the challenge,” Moniz said. He perceives a growing consensus that climate goals will require — in diminishing order of certainty — firm (always-on) power to complement renewable energy sources, a fuel (such as hydrogen) flowing alongside electricity, and removal of atmospheric carbon dioxide (CO2).

      Russia’s invasion of Ukraine, with its “weaponization of natural gas” and global energy impacts, underscores the idea that climate, energy security, and geopolitics “are now more or less recognized widely as one conversation.” Moniz pointed as well to new U.S. laws on climate change and infrastructure that will amplify the role of science and technology and “address the drive to technological dominance by China.”

      The rapid transformation of energy systems will require a comprehensive industrial policy, Moniz said. Government and industry must select and rapidly develop low-carbon fuels, firm power sources (possibly including nuclear power), CO2 removal systems, and long-duration energy storage technologies. “We will need to make progress on all fronts literally in this decade to come close to our goals for climate change mitigation,” he concluded.

      Global cooperation?

      Over two days, conference participants delved into many of the issues Moniz raised. In one of the first panels, scholars pondered whether the international community could forge a coordinated climate change response. The United States’ rift with China, especially over technology trade policies, loomed large.

      “Hatred of China is a bipartisan hobby and passion, but a blanket approach isn’t right, even for the sake of national security,” said Yasheng Huang, the Epoch Foundation Professor of Global Economics and Management at the MIT Sloan School of Management. “Although the United States and China working together would have huge effects for both countries, it is politically unpalatable in the short term,” said F. Taylor Fravel, the Arthur and Ruth Sloan Professor of Political Science and director of the MIT Security Studies Program. John E. Parsons, deputy director for research at the MIT Center for Energy and Environmental Policy Research, suggested that the United States should use this moment “to get our own act together … and start doing things,” such as building nuclear power plants in a cost-effective way.

      Debating carbon removal

      Several panels took up the matter of carbon emissions and the most promising technologies for contending with them. Charles Harvey, MIT professor of civil and environmental engineering, and Howard Herzog, a senior research engineer at MITEI, set the stage early, debating whether capturing carbon was essential to reaching net-zero targets.

      “I have no trouble getting to net zero without carbon capture and storage,” said David Keith, the Gordon McKay Professor of Applied Physics at Harvard University, in a subsequent roundtable. Carbon capture seems more risky to Keith than solar geoengineering, which involves injecting sulfur into the stratosphere to offset CO2 and its heat-trapping impacts.

      There are new ways of moving carbon from where it’s a problem to where it’s safer. Kripa K. Varanasi, MIT professor of mechanical engineering, described a process for modulating the pH of ocean water to remove CO2. Timothy Krysiek, managing director for Equinor Ventures, talked about construction of a 900-kilometer pipeline transporting CO2 from northern Germany to a large-scale storage site located in Norwegian waters 3,000 meters below the seabed. “We can use these offshore Norwegian assets as a giant carbon sink for Europe,” he said.

      A startup showcase featured additional approaches to the carbon challenge. Mantel, which received MITEI Seed Fund money, is developing molten salt material to capture carbon for long-term storage or for use in generating electricity. Verdox has come up with an electrochemical process for capturing dilute CO2 from the atmosphere.

      But while much of the global warming discussion focuses on CO2, other greenhouse gases are menacing. Another panel discussed measuring and mitigating these pollutants. “Methane has 82 times more warming power than CO2 from the point of emission,” said Desirée L. Plata, MIT associate professor of civil and environmental engineering. “Cutting methane is the strongest lever we have to slow climate change in the next 25 years — really the only lever.”

      Steven Hamburg, chief scientist and senior vice president of the Environmental Defense Fund, cautioned that emission of hydrogen molecules into the atmosphere can cause increases in other greenhouse gases such as methane, ozone, and water vapor. As researchers and industry turn to hydrogen as a fuel or as a feedstock for commercial processes, “we will need to minimize leakage … or risk increasing warming,” he said.

      Supply chains, markets, and new energy ventures

      In panels on energy storage and the clean energy supply chain, there were interesting discussions of challenges ahead. High-density energy materials such as lithium, cobalt, nickel, copper, and vanadium for grid-scale energy storage, electric vehicles (EVs), and other clean energy technologies, can be difficult to source. “These often come from water-stressed regions, and we need to be super thoughtful about environmental stresses,” said Elsa Olivetti, the Esther and Harold E. Edgerton Associate Professor in Materials Science and Engineering. She also noted that in light of the explosive growth in demand for metals such as lithium, recycling EVs won’t be of much help. “The amount of material coming back from end-of-life batteries is minor,” she said, until EVs are much further along in their adoption cycle.

      Arvind Sanger, founder and managing partner of Geosphere Capital, said that the United States should be developing its own rare earths and minerals, although gaining the know-how will take time, and overcoming “NIMBYism” (not in my backyard-ism) is a challenge. Sanger emphasized that we must continue to use “denser sources of energy” to catalyze the energy transition over the next decade. In particular, Sanger noted that “for every transition technology, steel is needed,” and steel is made in furnaces that use coal and natural gas. “It’s completely woolly-headed to think we can just go to a zero-fossil fuel future in a hurry,” he said.

      The topic of power markets occupied another panel, which focused on ways to ensure the distribution of reliable and affordable zero-carbon energy. Integrating intermittent resources such as wind and solar into the grid requires a suite of retail markets and new digital tools, said Anuradha Annaswamy, director of MIT’s Active-Adaptive Control Laboratory. Tim Schittekatte, a postdoc at the MIT Sloan School of Management, proposed auctions as a way of insuring consumers against periods of high market costs.

      Another panel described the very different investment needs of new energy startups, such as longer research and development phases. Hooisweng Ow, technology principal at Eni Next LLC Ventures, which is developing drilling technology for geothermal energy, recommends joint development and partnerships to reduce risk. Michael Kearney SM ’11, PhD ’19, SM ’19 is a partner at The Engine, a venture firm built by MIT investing in path-breaking technology to solve the toughest challenges in climate and other problems. Kearney believes the emergence of new technologies and markets will bring on “a labor transition on an order of magnitude never seen before in this country,” he said. “Workforce development is not a natural zone for startups … and this will have to change.”

      Supporting the global South

      The opportunities and challenges of the energy transition look quite different in the developing world. In conversation with Robert Armstrong, Luhut Binsar Pandjaitan, the coordinating minister for maritime affairs and investment of the Republic of Indonesia, reported that his “nation is rich with solar, wind, and energy transition minerals like nickel and copper,” but cannot on its own tackle developing renewable energy or reducing carbon emissions and improving grid infrastructure. “Education is a top priority, and we are very far behind in high technologies,” he said. “We need help and support from MIT to achieve our target,” he said.

      Technologies that could springboard Indonesia and other nations of the global South toward their climate goals are emerging in MITEI-supported projects and at young companies MITEI helped spawn. Among the promising innovations unveiled at the conference are new materials and designs for cooling buildings in hot climates and reducing the environmental costs of construction, and a sponge-like substance that passively sucks moisture out of the air to lower the energy required for running air conditioners in humid climates.

      Other ideas on the move from lab to market have great potential for industrialized nations as well, such as a computational framework for maximizing the energy output of ocean-based wind farms; a process for using ammonia as a renewable fuel with no CO2 emissions; long-duration energy storage derived from the oxidation of iron; and a laser-based method for unlocking geothermal steam to drive power plants. More

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      Machine learning facilitates “turbulence tracking” in fusion reactors

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      Fusion, which promises practically unlimited, carbon-free energy using the same processes that power the sun, is at the heart of a worldwide research effort that could help mitigate climate change.

      A multidisciplinary team of researchers is now bringing tools and insights from machine learning to aid this effort. Scientists from MIT and elsewhere have used computer-vision models to identify and track turbulent structures that appear under the conditions needed to facilitate fusion reactions.

      Monitoring the formation and movements of these structures, called filaments or “blobs,” is important for understanding the heat and particle flows exiting from the reacting fuel, which ultimately determines the engineering requirements for the reactor walls to meet those flows. However, scientists typically study blobs using averaging techniques, which trade details of individual structures in favor of aggregate statistics. Individual blob information must be tracked by marking them manually in video data. 

      The researchers built a synthetic video dataset of plasma turbulence to make this process more effective and efficient. They used it to train four computer vision models, each of which identifies and tracks blobs. They trained the models to pinpoint blobs in the same ways that humans would.

      When the researchers tested the trained models using real video clips, the models could identify blobs with high accuracy — more than 80 percent in some cases. The models were also able to effectively estimate the size of blobs and the speeds at which they moved.

      Because millions of video frames are captured during just one fusion experiment, using machine-learning models to track blobs could give scientists much more detailed information.

      “Before, we could get a macroscopic picture of what these structures are doing on average. Now, we have a microscope and the computational power to analyze one event at a time. If we take a step back, what this reveals is the power available from these machine-learning techniques, and ways to use these computational resources to make progress,” says Theodore Golfinopoulos, a research scientist at the MIT Plasma Science and Fusion Center and co-author of a paper detailing these approaches.

      His fellow co-authors include lead author Woonghee “Harry” Han, a physics PhD candidate; senior author Iddo Drori, a visiting professor in the Computer Science and Artificial Intelligence Laboratory (CSAIL), faculty associate professor at Boston University, and adjunct at Columbia University; as well as others from the MIT Plasma Science and Fusion Center, the MIT Department of Civil and Environmental Engineering, and the Swiss Federal Institute of Technology at Lausanne in Switzerland. The research appears today in Nature Scientific Reports.

      Heating things up

      For more than 70 years, scientists have sought to use controlled thermonuclear fusion reactions to develop an energy source. To reach the conditions necessary for a fusion reaction, fuel must be heated to temperatures above 100 million degrees Celsius. (The core of the sun is about 15 million degrees Celsius.)

      A common method for containing this super-hot fuel, called plasma, is to use a tokamak. These devices utilize extremely powerful magnetic fields to hold the plasma in place and control the interaction between the exhaust heat from the plasma and the reactor walls.

      However, blobs appear like filaments falling out of the plasma at the very edge, between the plasma and the reactor walls. These random, turbulent structures affect how energy flows between the plasma and the reactor.

      “Knowing what the blobs are doing strongly constrains the engineering performance that your tokamak power plant needs at the edge,” adds Golfinopoulos.

      Researchers use a unique imaging technique to capture video of the plasma’s turbulent edge during experiments. An experimental campaign may last months; a typical day will produce about 30 seconds of data, corresponding to roughly 60 million video frames, with thousands of blobs appearing each second. This makes it impossible to track all blobs manually, so researchers rely on average sampling techniques that only provide broad characteristics of blob size, speed, and frequency.

      “On the other hand, machine learning provides a solution to this by blob-by-blob tracking for every frame, not just average quantities. This gives us much more knowledge about what is happening at the boundary of the plasma,” Han says.

      He and his co-authors took four well-established computer vision models, which are commonly used for applications like autonomous driving, and trained them to tackle this problem.

      Simulating blobs

      To train these models, they created a vast dataset of synthetic video clips that captured the blobs’ random and unpredictable nature.

      “Sometimes they change direction or speed, sometimes multiple blobs merge, or they split apart. These kinds of events were not considered before with traditional approaches, but we could freely simulate those behaviors in the synthetic data,” Han says.

      Creating synthetic data also allowed them to label each blob, which made the training process more effective, Drori adds.

      Using these synthetic data, they trained the models to draw boundaries around blobs, teaching them to closely mimic what a human scientist would draw.

      Then they tested the models using real video data from experiments. First, they measured how closely the boundaries the models drew matched up with actual blob contours.

      But they also wanted to see if the models predicted objects that humans would identify. They asked three human experts to pinpoint the centers of blobs in video frames and checked to see if the models predicted blobs in those same locations.

      The models were able to draw accurate blob boundaries, overlapping with brightness contours which are considered ground-truth, about 80 percent of the time. Their evaluations were similar to those of human experts, and successfully predicted the theory-defined regime of the blob, which agrees with the results from a traditional method.

      Now that they have shown the success of using synthetic data and computer vision models for tracking blobs, the researchers plan to apply these techniques to other problems in fusion research, such as estimating particle transport at the boundary of a plasma, Han says.

      They also made the dataset and models publicly available, and look forward to seeing how other research groups apply these tools to study the dynamics of blobs, says Drori.

      “Prior to this, there was a barrier to entry that mostly the only people working on this problem were plasma physicists, who had the datasets and were using their methods. There is a huge machine-learning and computer-vision community. One goal of this work is to encourage participation in fusion research from the broader machine-learning community toward the broader goal of helping solve the critical problem of climate change,” he adds.

      This research is supported, in part, by the U.S. Department of Energy and the Swiss National Science Foundation. More

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      Finding community in high-energy-density physics

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      Skylar Dannhoff knew one thing: She did not want to be working alone.

      As an undergraduate at Case Western Reserve University, she had committed to a senior project that often felt like solitary lab work, a feeling heightened by the pandemic. Though it was an enriching experience, she was determined to find a graduate school environment that would foster community, one “with lots of people, lots of collaboration; where it’s impossible to work until 3 a.m. without anyone noticing.” A unique group at the Plasma Science and Fusion Center (PSFC) looked promising: the High-Energy-Density Physics (HEDP) division, a lead partner in the National Nuclear Security Administration’s Center for Excellence at MIT.

      “It was a shot in the dark, just more of a whim than anything,” she says of her request to join HEDP on her application to MIT’s Department of Physics. “And then, somehow, they reached out to me. I told them I’m willing to learn about plasma. I didn’t know anything about it.”

      What she did know was that the HEDP group collaborates with other U.S. laboratories on an approach to creating fusion energy known as inertial confinement fusion (ICF). One version of the technique, known as direct-drive ICF, aims multiple laser beams symmetrically onto a spherical capsule filled with nuclear fuel. The other, indirect-drive ICF, instead aims multiple lasers beams into a gold cylindrical cavity called a hohlraum, within which the spherical fuel capsule is positioned. The laser beams are configured to hit the inner hohlraum wall, generating a “bath” of X-rays, which in turn compress the fuel capsule.

      Imploding the capsule generates intense fusion energy within a tiny fraction of a second (an order of tens of picoseconds). In August 2021, the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) used this method to produce an historic fusion yield of 1.3 megajoules, putting researchers within reach of “ignition,” the point where the self-sustained fusion burn spreads into the surrounding fuel, leading to a high fusion-energy gain.  

      Joining the group just a month before this long-sought success, Dannhoff was impressed more with the response of her new teammates and the ICF community than with the scientific milestone. “I got a better appreciation for people who had spent their entire careers working on this project, just chugging along doing their best, ignoring the naysayers. I was excited for the people.”

      Dannhoff is now working toward extending the success of NIF and other ICF experiments, like the OMEGA laser at the University of Rochester’s Laboratory for Laser Energetics. Under the supervision of Senior Research Scientist Chikang Li, she is studying what happens to the flow of plasma within the hohlraum cavity during indirect ICF experiments, particularly for hohlraums with inner-wall aerogel foam linings. Experiments, over the last decade, have shown just how excruciatingly precise the symmetry in ICF targets must be. The more symmetric the X-ray drive, the more effective the implosion, and it is possible that these foam linings will improve the X-ray symmetry and drive efficiency.

      Dannhoff is specifically interested in studying the behavior of silicon and tantalum-based foam liners. She is as concerned with the challenges of the people at General Atomics (GA) and LLNL who are creating these targets as she is with the scientific outcome.

      “I just had a meeting with GA yesterday,” she notes. “And it’s a really tricky process. It’s kind of pushing the boundaries of what is doable at the moment. I got a much better sense of how demanding this project is for them, how much we’re asking of them.”

      What excites Dannhoff is the teamwork she observes, both at MIT and between ICF institutions around the United States. With roughly 10 graduate students and postdocs down the hall, each with an assigned lead role in lab management, she knows she can consult an expert on almost any question. And collaborators across the country are just an email away. “Any information that people can give you, they will give you, and usually very freely,” she notes. “Everyone just wants to see this work.”

      That Dannhoff is a natural team player is also evidenced in her hobbies. A hockey goalie, she prioritizes playing with MIT’s intramural teams, “because goalies are a little hard to come by. I just play with whoever needs a goalie on that night, and it’s a lot of fun.”

      She is also a member of the radio community, a fellowship she first embraced at Case Western — a moment she describes as a turning point in her life. “I literally don’t know who I would be today if I hadn’t figured out radio is something I’m interested in,” she admits. The MIT Radio Society provided the perfect landing pad for her arrival in Cambridge, full of the kinds of supportive, interesting, knowledgeable students she had befriended as an undergraduate. She credits radio with helping her realize that she could make her greatest contributions to science by focusing on engineering.

      Danhoff gets philosophical as she marvels at the invisible waves that surround us.

      “Not just radio waves: every wave,” she asserts. “The voice is the everywhere. Music, signal, space phenomena: it’s always around. And all we have to do is make the right little device and have the right circuit elements put in the right order to unmix and mix the signals and amplify them. And bada-bing, bada-boom, we’re talking with the universe.”

      “Maybe that epitomizes physics to me,” she adds. “We’re trying to listen to the universe, and it’s talking to us. We just have to come up with the right tools and hear what it’s trying to say.” More

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      3 Questions: Blue hydrogen and the world’s energy systems

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      In the past several years, hydrogen energy has increasingly become a more central aspect of the clean energy transition. Hydrogen can produce clean, on-demand energy that could complement variable renewable energy sources such as wind and solar power. That being said, pathways for deploying hydrogen at scale have yet to be fully explored. In particular, the optimal form of hydrogen production remains in question.

      MIT Energy Initiative Research Scientist Emre Gençer and researchers from a wide range of global academic and research institutions recently published “On the climate impacts of blue hydrogen production,” a comprehensive life-cycle assessment analysis of blue hydrogen, a term referring to natural gas-based hydrogen production with carbon capture and storage. Here, Gençer describes blue hydrogen and the role that hydrogen will play more broadly in decarbonizing the world’s energy systems.

      Q: What are the differences between gray, green, and blue hydrogen?

      A: Though hydrogen does not generate any emissions directly when it is used, hydrogen production can have a huge environmental impact. Colors of hydrogen are increasingly used to distinguish different production methods and as a proxy to represent the associated environmental impact. Today, close to 95 percent of hydrogen production comes from fossil resources. As a result, the carbon dioxide (CO2) emissions from hydrogen production are quite high. Gray, black, and brown hydrogen refer to fossil-based production. Gray is the most common form of production and comes from natural gas, or methane, using steam methane reformation but without capturing CO2.

      There are two ways to move toward cleaner hydrogen production. One is applying carbon capture and storage to the fossil fuel-based hydrogen production processes. Natural gas-based hydrogen production with carbon capture and storage is referred to as blue hydrogen. If substantial amounts of CO2 from natural gas reforming are captured and permanently stored, such hydrogen could be a low-carbon energy carrier. The second way to produce cleaner hydrogen is by using electricity to produce hydrogen via electrolysis. In this case, the source of the electricity determines the environmental impact of the hydrogen, with the lowest impact being achieved when electricity is generated from renewable sources, such as wind and solar. This is known as green hydrogen.

      Q: What insights have you gleaned with a life cycle assessment (LCA) of blue hydrogen and other low-carbon energy systems?

      A: Mitigating climate change requires significant decarbonization of the global economy. Accurate estimation of cumulative greenhouse gas (GHG) emissions and its reduction pathways is critical irrespective of the source of emissions. An LCA approach allows the quantification of the environmental life cycle of a commercial product, process, or service impact with all the stages (cradle-to-grave). The LCA-based comparison of alternative energy pathways, fuel options, etc., provides an apples-to-apples comparison of low-carbon energy choices. In the context of low-carbon hydrogen, it is essential to understand the GHG impact of supply chain options. Depending on the production method, contribution of life-cycle stages to the total emissions might vary. For example, with natural gas–based hydrogen production, emissions associated with production and transport of natural gas might be a significant contributor based on its leakage and flaring rates. If these rates are not precisely accounted for, the environmental impact of blue hydrogen can be underestimated. However, the same rationale is also true for electricity-based hydrogen production. If the electricity is not supplied from low-
carbon sources such as wind, solar, or nuclear, the carbon intensity of hydrogen can be significantly underestimated. In the case of nuclear, there are also other environmental impact considerations.

      An LCA approach — if performed with consistent system boundaries — can provide an accurate environmental impact comparison. It should also be noted that these estimations can only be as good as the assumptions and correlations used unless they are supported by measurements. 

      Q: What conditions are needed to make blue hydrogen production most effective, and how can it complement other decarbonization pathways?

      A: Hydrogen is considered one of the key vectors for the decarbonization of hard-to-abate sectors such as heavy-duty transportation. Currently, more than 95 percent of global hydrogen production is fossil-fuel based. In the next decade, massive amounts of hydrogen must be produced to meet this anticipated demand. It is very hard, if not impossible, to meet this demand without leveraging existing production assets. The immediate and relatively cost-effective option is to retrofit existing plants with carbon capture and storage (blue hydrogen).

      The environmental impact of blue hydrogen may vary over large ranges but depends on only a few key parameters: the methane emission rate of the natural gas supply chain, the CO2 removal rate at the hydrogen production plant, and the global warming metric applied. State-of-the-art reforming with high CO2 capture rates, combined with natural gas supply featuring low methane emissions, substantially reduces GHG emissions compared to conventional natural gas reforming. Under these conditions, blue hydrogen is compatible with low-carbon economies and exhibits climate change impacts at the upper end of the range of those caused by hydrogen production from renewable-based electricity. However, neither current blue nor green hydrogen production pathways render fully “net-zero” hydrogen without additional CO2 removal.

      This article appears in the Spring 2022 issue of Energy Futures, the magazine of the MIT Energy Initiative. More

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      Processing waste biomass to reduce airborne emissions

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      To prepare fields for planting, farmers the world over often burn corn stalks, rice husks, hay, straw, and other waste left behind from the previous harvest. In many places, the practice creates huge seasonal clouds of smog, contributing to air pollution that kills 7 million people globally a year, according to the World Health Organization.

      Annually, $120 billion worth of crop and forest residues are burned in the open worldwide — a major waste of resources in an energy-starved world, says Kevin Kung SM ’13, PhD ’17. Kung is working to transform this waste biomass into marketable products — and capitalize on a billion-dollar global market — through his MIT spinoff company, Takachar.

      Founded in 2015, Takachar develops small-scale, low-cost, portable equipment to convert waste biomass into solid fuel using a variety of thermochemical treatments, including one known as oxygen-lean torrefaction. The technology emerged from Kung’s PhD project in the lab of Ahmed Ghoniem, the Ronald C. Crane (1972) Professor of Mechanical Engineering at MIT.

      Biomass fuels, including wood, peat, and animal dung, are a major source of carbon emissions — but billions of people rely on such fuels for cooking, heating, and other household needs. “Currently, burning biomass generates 10 percent of the primary energy used worldwide, and the process is used largely in rural, energy-poor communities. We’re not going to change that overnight. There are places with no other sources of energy,” Ghoniem says.

      What Takachar’s technology provides is a way to use biomass more cleanly and efficiently by concentrating the fuel and eliminating contaminants such as moisture and dirt, thus creating a “clean-burning” fuel — one that generates less smoke. “In rural communities where biomass is used extensively as a primary energy source, torrefaction will address air pollution head-on,” Ghoniem says.

      Thermochemical treatment densifies biomass at elevated temperatures, converting plant materials that are typically loose, wet, and bulky into compact charcoal. Centralized processing plants exist, but collection and transportation present major barriers to utilization, Kung says. Takachar’s solution moves processing into the field: To date, Takachar has worked with about 5,500 farmers to process 9,000 metric tons of crops.

      Takachar estimates its technology has the potential to reduce carbon dioxide equivalent emissions by gigatons per year at scale. (“Carbon dioxide equivalent” is a measure used to gauge global warming potential.) In recognition, in 2021 Takachar won the first-ever Earthshot Prize in the clean air category, a £1 million prize funded by Prince William and Princess Kate’s Royal Foundation.

      Roots in Kenya

      As Kung tells the story, Takachar emerged from a class project that took him to Kenya — which explains the company’s name, a combination of takataka, which mean “trash” in Swahili, and char, for the charcoal end product.

      It was 2011, and Kung was at MIT as a biological engineering grad student focused on cancer research. But “MIT gives students big latitude for exploration, and I took courses outside my department,” he says. In spring 2011, he signed up for a class known as 15.966 (Global Health Delivery Lab) in the MIT Sloan School of Management. The class brought Kung to Kenya to work with a nongovernmental organization in Nairobi’s Kibera, the largest urban slum in Africa.

      “We interviewed slum households for their views on health, and that’s when I noticed the charcoal problem,” Kung says. The problem, as Kung describes it, was that charcoal was everywhere in Kibera — piled up outside, traded by the road, and used as the primary fuel, even indoors. Its creation contributed to deforestation, and its smoke presented a serious health hazard.

      Eager to address this challenge, Kung secured fellowship support from the MIT International Development Initiative and the Priscilla King Gray Public Service Center to conduct more research in Kenya. In 2012, he formed Takachar as a team and received seed money from the MIT IDEAS Global Challenge, MIT Legatum Center for Development and Entrepreneurship, and D-Lab to produce charcoal from household organic waste. (This work also led to a fertilizer company, Safi Organics, that Kung founded in 2016 with the help of MIT IDEAS. But that is another story.)

      Meanwhile, Kung had another top priority: finding a topic for his PhD dissertation. Back at MIT, he met Alexander Slocum, the Walter M. May and A. Hazel May Professor of Mechanical Engineering, who on a long walk-and-talk along the Charles River suggested he turn his Kenya work into a thesis. Slocum connected him with Robert Stoner, deputy director for science and technology at the MIT Energy Initiative (MITEI) and founding director of MITEI’s Tata Center for Technology and Design. Stoner in turn introduced Kung to Ghoniem, who became his PhD advisor, while Slocum and Stoner joined his doctoral committee.

      Roots in MIT lab

      Ghoniem’s telling of the Takachar story begins, not surprisingly, in the lab. Back in 2010, he had a master’s student interested in renewable energy, and he suggested the student investigate biomass. That student, Richard Bates ’10, SM ’12, PhD ’16, began exploring the science of converting biomass to more clean-burning charcoal through torrefaction.

      Most torrefaction (also known as low-temperature pyrolysis) systems use external heating sources, but the lab’s goal, Ghoniem explains, was to develop an efficient, self-sustained reactor that would generate fewer emissions. “We needed to understand the chemistry and physics of the process, and develop fundamental scaling models, before going to the lab to build the device,” he says.

      By the time Kung joined the lab in 2013, Ghoniem was working with the Tata Center to identify technology suitable for developing countries and largely based on renewable energy. Kung was able to secure a Tata Fellowship and — building on Bates’ research — develop the small-scale, practical device for biomass thermochemical conversion in the field that launched Takachar.

      This device, which was patented by MIT with inventors Kung, Ghoniem, Stoner, MIT research scientist Santosh Shanbhogue, and Slocum, is self-contained and scalable. It burns a little of the biomass to generate heat; this heat bakes the rest of the biomass, releasing gases; the system then introduces air to enable these gases to combust, which burns off the volatiles and generates more heat, keeping the thermochemical reaction going.

      “The trick is how to introduce the right amount of air at the right location to sustain the process,” Ghoniem explains. “If you put in more air, that will burn the biomass. If you put in less, there won’t be enough heat to produce the charcoal. That will stop the reaction.”

      About 10 percent of the biomass is used as fuel to support the reaction, Kung says, adding that “90 percent is densified into a form that’s easier to handle and utilize.” He notes that the research received financial support from the Abdul Latif Jameel Water and Food Systems Lab and the Deshpande Center for Technological Innovation, both at MIT. Sonal Thengane, another postdoc in Ghoniem’s lab, participated in the effort to scale up the technology at the MIT Bates Lab (no relation to Richard Bates).

      The charcoal produced is more valuable per ton and easier to transport and sell than biomass, reducing transportation costs by two-thirds and giving farmers an additional income opportunity — and an incentive not to burn agricultural waste, Kung says. “There’s more income for farmers, and you get better air quality.”

      Roots in India

      When Kung became a Tata Fellow, he joined a program founded to take on the biggest challenges of the developing world, with a focus on India. According to Stoner, Tata Fellows, including Kung, typically visit India twice a year and spend six to eight weeks meeting stakeholders in industry, the government, and in communities to gain perspective on their areas of study.

      “A unique part of Tata is that you’re considering the ecosystem as a whole,” says Kung, who interviewed hundreds of smallholder farmers, met with truck drivers, and visited existing biomass processing plants during his Tata trips to India. (Along the way, he also connected with Indian engineer Vidyut Mohan, who became Takachar’s co-founder.)

      “It was very important for Kevin to be there walking about, experimenting, and interviewing farmers,” Stoner says. “He learned about the lives of farmers.”

      These experiences helped instill in Kung an appreciation for small farmers that still drives him today as Takachar rolls out its first pilot programs, tinkers with the technology, grows its team (now up to 10), and endeavors to build a revenue stream. So, while Takachar has gotten a lot of attention and accolades — from the IDEAS award to the Earthshot Prize — Kung says what motivates him is the prospect of improving people’s lives.

      The dream, he says, is to empower communities to help both the planet and themselves. “We’re excited about the environmental justice perspective,” he says. “Our work brings production and carbon removal or avoidance to rural communities — providing them with a way to convert waste, make money, and reduce air pollution.”

      This article appears in the Spring 2022 issue of Energy Futures, the magazine of the MIT Energy Initiative. More