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      Turning automotive engines into modular chemical plants to make green fuels

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      Reducing methane emissions is a top priority in the fight against climate change because of its propensity to trap heat in the atmosphere: Methane’s warming effects are 84 times more potent than CO2 over a 20-year timescale.And yet, as the main component of natural gas, methane is also a valuable fuel and a precursor to several important chemicals. The main barrier to using methane emissions to create carbon-negative materials is that human sources of methane gas — landfills, farms, and oil and gas wells — are relatively small and spread out across large areas, while traditional chemical processing facilities are huge and centralized. That makes it prohibitively expensive to capture, transport, and convert methane gas into anything useful. As a result, most companies burn or “flare” their methane at the site where it’s emitted, seeing it as a sunk cost and an environmental liability.The MIT spinout Emvolon is taking a new approach to processing methane by repurposing automotive engines to serve as modular, cost-effective chemical plants. The company’s systems can take methane gas and produce liquid fuels like methanol and ammonia on-site; these fuels can then be used or transported in standard truck containers.”We see this as a new way of chemical manufacturing,” Emvolon co-founder and CEO Emmanuel Kasseris SM ’07, PhD ’11 says. “We’re starting with methane because methane is an abundant emission that we can use as a resource. With methane, we can solve two problems at the same time: About 15 percent of global greenhouse gas emissions come from hard-to-abate sectors that need green fuel, like shipping, aviation, heavy heavy-duty trucks, and rail. Then another 15 percent of emissions come from distributed methane emissions like landfills and oil wells.”By using mass-produced engines and eliminating the need to invest in infrastructure like pipelines, the company says it’s making methane conversion economically attractive enough to be adopted at scale. The system can also take green hydrogen produced by intermittent renewables and turn it into ammonia, another fuel that can also be used to decarbonize fertilizers.“In the future, we’re going to need green fuels because you can’t electrify a large ship or plane — you have to use a high-energy-density, low-carbon-footprint, low-cost liquid fuel,” Kasseris says. “The energy resources to produce those green fuels are either distributed, as is the case with methane, or variable, like wind. So, you cannot have a massive plant [producing green fuels] that has its own zip code. You either have to be distributed or variable, and both of those approaches lend themselves to this modular design.”From a “crazy idea” to a companyKasseris first came to MIT to study mechanical engineering as a graduate student in 2004, when he worked in the Sloan Automotive Lab on a report on the future of transportation. For his PhD, he developed a novel technology for improving internal combustion engine fuel efficiency for a consortium of automotive and energy companies, which he then went to work for after graduation.Around 2014, he was approached by Leslie Bromberg ’73, PhD ’77, a serial inventor with more than 100 patents, who has been a principal research engineer in MIT’s Plasma Science and Fusion Center for nearly 50 years.“Leslie had this crazy idea of repurposing an internal combustion engine as a reactor,” Kasseris recalls. “I had looked at that while working in industry, and I liked it, but my company at the time thought the work needed more validation.”Bromberg had done that validation through a U.S. Department of Energy-funded project in which he used a diesel engine to “reform” methane — a high-pressure chemical reaction in which methane is combined with steam and oxygen to produce hydrogen. The work impressed Kasseris enough to bring him back to MIT as a research scientist in 2016.“We worked on that idea in addition to some other projects, and eventually it had reached the point where we decided to license the work from MIT and go full throttle,” Kasseris recalls. “It’s very easy to work with MIT’s Technology Licensing Office when you are an MIT inventor. You can get a low-cost licensing option, and you can do a lot with that, which is important for a new company. Then, once you are ready, you can finalize the license, so MIT was instrumental.”Emvolon continued working with MIT’s research community, sponsoring projects with Professor Emeritus John Heywood and participating in the MIT Venture Mentoring Service and the MIT Industrial Liaison Program.An engine-powered chemical plantAt the core of Emvolon’s system is an off-the-shelf automotive engine that runs “fuel rich” — with a higher ratio of fuel to air than what is needed for complete combustion.“That’s easy to say, but it takes a lot of [intellectual property], and that’s what was developed at MIT,” Kasseris says. “Instead of burning the methane in the gas to carbon dioxide and water, you partially burn it, or partially oxidize it, to carbon monoxide and hydrogen, which are the building blocks to synthesize a variety of chemicals.”The hydrogen and carbon monoxide are intermediate products used to synthesize different chemicals through further reactions. Those processing steps take place right next to the engine, which makes its own power. Each of Emvolon’s standalone systems fits within a 40-foot shipping container and can produce about 8 tons of methanol per day from 300,000 standard cubic feet of methane gas.The company is starting with green methanol because it’s an ideal fuel for hard-to-abate sectors such as shipping and heavy-duty transport, as well as an excellent feedstock for other high-value chemicals, such as sustainable aviation fuel. Many shipping vessels have already converted to run on green methanol in an effort to meet decarbonization goals.This summer, the company also received a grant from the Department of Energy to adapt its process to produce clean liquid fuels from power sources like solar and wind.“We’d like to expand to other chemicals like ammonia, but also other feedstocks, such as biomass and hydrogen from renewable electricity, and we already have promising results in that direction” Kasseris says. “We think we have a good solution for the energy transition and, in the later stages of the transition, for e-manufacturing.”A scalable approachEmvolon has already built a system capable of producing up to six barrels of green methanol a day in its 5,000 square-foot headquarters in Woburn, Massachusetts.“For chemical technologies, people talk about scale up risk, but with an engine, if it works in a single cylinder, we know it will work in a multicylinder engine,” Kasseris says. “It’s just engineering.”Last month, Emvolon announced an agreement with Montauk Renewables to build a commercial-scale demonstration unit next to a Texas landfill that will initially produce up to 15,000 gallons of green methanol a year and later scale up to 2.5 million gallons. That project could be expanded tenfold by scaling across Montauk’s other sites.“Our whole process was designed to be a very realistic approach to the energy transition,” Kasseris says. “Our solution is designed to produce green fuels and chemicals at prices that the markets are willing to pay today, without the need for subsidies. Using the engines as chemical plants, we can get the capital expenditure per unit output close to that of a large plant, but at a modular scale that enables us to be next to low-cost feedstock. Furthermore, our modular systems require small investments — of $1 to 10 million — that are quickly deployed, one at a time, within weeks, as opposed to massive chemical plants that require multiyear capital construction projects and cost hundreds of millions.” More

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      Ensuring a durable transition

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      To fend off the worst impacts of climate change, “we have to decarbonize, and do it even faster,” said William H. Green, director of the MIT Energy Initiative (MITEI) and Hoyt C. Hottel Professor, MIT Department of Chemical Engineering, at MITEI’s Annual Research Conference.“But how the heck do we actually achieve this goal when the United States is in the middle of a divisive election campaign, and globally, we’re facing all kinds of geopolitical conflicts, trade protectionism, weather disasters, increasing demand from developing countries building a middle class, and data centers in countries like the U.S.?”Researchers, government officials, and business leaders convened in Cambridge, Massachusetts, Sept. 25-26 to wrestle with this vexing question at the conference that was themed, “A durable energy transition: How to stay on track in the face of increasing demand and unpredictable obstacles.”“In this room we have a lot of power,” said Green, “if we work together, convey to all of society what we see as real pathways and policies to solve problems, and take collective action.”The critical role of consensus-building in driving the energy transition arose repeatedly in conference sessions, whether the topic involved developing and adopting new technologies, constructing and siting infrastructure, drafting and passing vital energy policies, or attracting and retaining a skilled workforce.Resolving conflictsThere is “blowback and a social cost” in transitioning away from fossil fuels, said Stephen Ansolabehere, the Frank G. Thompson Professor of Government at Harvard University, in a panel on the social barriers to decarbonization. “Companies need to engage differently and recognize the rights of communities,” he said.Nora DeDontney, director of development at Vineyard Offshore, described her company’s two years of outreach and negotiations to bring large cables from ocean-based wind turbines onshore.“Our motto is, ‘community first,’” she said. Her company works to mitigate any impacts towns might feel because of offshore wind infrastructure construction with projects, such as sewer upgrades; provides workforce training to Tribal Nations; and lays out wind turbines in a manner that provides safe and reliable areas for local fisheries.Elsa A. Olivetti, professor in the Department of Materials Science and Engineering at MIT and the lead of the Decarbonization Mission of MIT’s new Climate Project, discussed the urgent need for rapid scale-up of mineral extraction. “Estimates indicate that to electrify the vehicle fleet by 2050, about six new large copper mines need to come on line each year,” she said. To meet the demand for metals in the United States means pushing into Indigenous lands and environmentally sensitive habitats. “The timeline of permitting is not aligned with the temporal acceleration needed,” she said.Larry Susskind, the Ford Professor of Urban and Environmental Planning in the MIT Department of Urban Studies and Planning, is trying to resolve such tensions with universities playing the role of mediators. He is creating renewable energy clinics where students train to participate in emerging disputes over siting. “Talk to people before decisions are made, conduct joint fact finding, so that facilities reduce harms and share the benefits,” he said.Clean energy boom and pressureA relatively recent and unforeseen increase in demand for energy comes from data centers, which are being built by large technology companies for new offerings, such as artificial intelligence.“General energy demand was flat for 20 years — and now, boom,” said Sean James, Microsoft’s senior director of data center research. “It caught utilities flatfooted.” With the expansion of AI, the rush to provision data centers with upwards of 35 gigawatts of new (and mainly renewable) power in the near future, intensifies pressure on big companies to balance the concerns of stakeholders across multiple domains. Google is pursuing 24/7 carbon-free energy by 2030, said Devon Swezey, the company’s senior manager for global energy and climate.“We’re pursuing this by purchasing more and different types of clean energy locally, and accelerating technological innovation such as next-generation geothermal projects,” he said. Pedro Gómez Lopez, strategy and development director, Ferrovial Digital, which designs and constructs data centers, incorporates renewable energy into their projects, which contributes to decarbonization goals and benefits to locales where they are sited. “We can create a new supply of power, taking the heat generated by a data center to residences or industries in neighborhoods through District Heating initiatives,” he said.The Inflation Reduction Act and other legislation has ramped up employment opportunities in clean energy nationwide, touching every region, including those most tied to fossil fuels. “At the start of 2024 there were about 3.5 million clean energy jobs, with ‘red’ states showing the fastest growth in clean energy jobs,” said David S. Miller, managing partner at Clean Energy Ventures. “The majority (58 percent) of new jobs in energy are now in clean energy — that transition has happened. And one-in-16 new jobs nationwide were in clean energy, with clean energy jobs growing more than three times faster than job growth economy-wide”In this rapid expansion, the U.S. Department of Energy (DoE) is prioritizing economically marginalized places, according to Zoe Lipman, lead for good jobs and labor standards in the Office of Energy Jobs at the DoE. “The community benefit process is integrated into our funding,” she said. “We are creating the foundation of a virtuous circle,” encouraging benefits to flow to disadvantaged and energy communities, spurring workforce training partnerships, and promoting well-paid union jobs. “These policies incentivize proactive community and labor engagement, and deliver community benefits, both of which are key to building support for technological change.”Hydrogen opportunity and challengeWhile engagement with stakeholders helps clear the path for implementation of technology and the spread of infrastructure, there remain enormous policy, scientific, and engineering challenges to solve, said multiple conference participants. In a “fireside chat,” Prasanna V. Joshi, vice president of low-carbon-solutions technology at ExxonMobil, and Ernest J. Moniz, professor of physics and special advisor to the president at MIT, discussed efforts to replace natural gas and coal with zero-carbon hydrogen in order to reduce greenhouse gas emissions in such major industries as steel and fertilizer manufacturing.“We have gone into an era of industrial policy,” said Moniz, citing a new DoE program offering incentives to generate demand for hydrogen — more costly than conventional fossil fuels — in end-use applications. “We are going to have to transition from our current approach, which I would call carrots-and-twigs, to ultimately, carrots-and-sticks,” Moniz warned, in order to create “a self-sustaining, major, scalable, affordable hydrogen economy.”To achieve net zero emissions by 2050, ExxonMobil intends to use carbon capture and sequestration in natural gas-based hydrogen and ammonia production. Ammonia can also serve as a zero-carbon fuel. Industry is exploring burning ammonia directly in coal-fired power plants to extend the hydrogen value chain. But there are challenges. “How do you burn 100 percent ammonia?”, asked Joshi. “That’s one of the key technology breakthroughs that’s needed.” Joshi believes that collaboration with MIT’s “ecosystem of breakthrough innovation” will be essential to breaking logjams around the hydrogen and ammonia-based industries.MIT ingenuity essentialThe energy transition is placing very different demands on different regions around the world. Take India, where today per capita power consumption is one of the lowest. But Indians “are an aspirational people … and with increasing urbanization and industrial activity, the growth in power demand is expected to triple by 2050,” said Praveer Sinha, CEO and managing director of the Tata Power Co. Ltd., in his keynote speech. For that nation, which currently relies on coal, the move to clean energy means bringing another 300 gigawatts of zero-carbon capacity online in the next five years. Sinha sees this power coming from wind, solar, and hydro, supplemented by nuclear energy.“India plans to triple nuclear power generation capacity by 2032, and is focusing on advancing small modular reactors,” said Sinha. “The country also needs the rapid deployment of storage solutions to firm up the intermittent power.” The goal is to provide reliable electricity 24/7 to a population living both in large cities and in geographically remote villages, with the help of long-range transmission lines and local microgrids. “India’s energy transition will require innovative and affordable technology solutions, and there is no better place to go than MIT, where you have the best brains, startups, and technology,” he said.These assets were on full display at the conference. Among them a cluster of young businesses, including:the MIT spinout Form Energy, which has developed a 100-hour iron battery as a backstop to renewable energy sources in case of multi-day interruptions;startup Noya that aims for direct air capture of atmospheric CO2 using carbon-based materials;the firm Active Surfaces, with a lightweight material for putting solar photovoltaics in previously inaccessible places;Copernic Catalysts, with new chemistry for making ammonia and sustainable aviation fuel far more inexpensively than current processes; andSesame Sustainability, a software platform spun out of MITEI that gives industries a full financial analysis of the costs and benefits of decarbonization.The pipeline of research talent extended into the undergraduate ranks, with a conference “slam” competition showcasing students’ summer research projects in areas from carbon capture using enzymes to 3D design for the coils used in fusion energy confinement.“MIT students like me are looking to be the next generation of energy leaders, looking for careers where we can apply our engineering skills to tackle exciting climate problems and make a tangible impact,” said Trent Lee, a junior in mechanical engineering researching improvements in lithium-ion energy storage. “We are stoked by the energy transition, because it’s not just the future, but our chance to build it.” More

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      Preparing Taiwan for a decarbonized economy

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      The operations of Taiwan’s electronics, manufacturing, and financial firms vary widely, but their leaders all have at least one thing in common: They recognize the role that a changing energy landscape will play in their future success, and they’re actively planning for that transition.“They’re all interested in how Taiwan can supply energy for its economy going forward — energy that meets global goals for decarbonization,” says Robert C. Armstrong, the Chevron Professor of Chemical Engineering Emeritus at MIT, as well as a principal investigator for the Taiwan Innovative Green Economy Roadmap (TIGER) program. “Each company is going to have its own particular needs. For example, financial companies have data centers that need energy 24/7, with no interruptions. But the need for a robust, reliable, resilient energy system is shared among all of them.”Ten Taiwanese companies are participating in TIGER, a two-year program with the MIT Energy Initiative (MITEI) to explore various ways that industry and government can promote and adopt technologies, practices, and policies that will keep Taiwan competitive amid a quickly changing energy landscape. MIT research teams are exploring a set of six topics during the first year of the program, with plans to tackle a second set of topics during the second year, eventually leading to a roadmap to green energy security for Taiwan.“We are helping them to understand green energy technologies, we are helping them to understand how policies around the world might affect supply chains, and we are helping them to understand different pathways for their domestic policies,” says Sergey Paltsev, a principal investigator for the TIGER program, as well as a deputy director of the MIT Center for Sustainability Science and Strategy and a senior research scientist at MITEI. “We are looking at how Taiwan will be affected in terms of the cost of doing business and how to preserve the competitive advantage of its export-oriented industries.”“The biggest question,” Paltsev adds, “is how Taiwanese companies can decarbonize their energy in a sustainable manner.”Why Taiwan?Paul Hsu, founding partner of the Taiwanese business consultancy Paul Hsu and Partners (one of the 10 participating TIGER companies), as well as founding chair and current board member of the Epoch Foundation, has been working for more than 30 years to forge collaborations between business leaders in Taiwan and MIT researchers. The energy challenges facing Taiwanese businesses, as well as their place in the global supply chain, make the TIGER program critical not only to improve environmental sustainability, but also to ensure future competitiveness, he says. “The energy field is facing revolution,” Hsu says. “Taiwanese companies are not operating in Taiwan alone, but also operating worldwide, and we are affected by the global supply chain. We need to diversify our businesses and our energy resources, and the first thing we’re looking for in this partnership is education — an understanding about how to orient Taiwanese industry toward the future of energy.”Wendy Duan, the program director of the Asia Pacific program at MITEI, notes that Taiwan has a number of similarities to places such as Singapore and Japan. The lessons learned through the TIGER program, she says, will likely be applicable — at least on some level — to other markets throughout Asia, and even around the world.“Taiwan is very much dependent on imported energy,” Duan notes. “Many countries in East Asia are facing similar challenges, and if Taiwan has a good roadmap for the future of energy, it can be a good role model.”“Taiwan is a great place for this sort of collaboration,” Armstrong says. “Their industry is very innovative, and it’s a place where businesses are willing to implement new, important ideas. At the same time, their economy is highly dependent on trade, and they import a lot of fossil fuels today. To compete in a decarbonized global economy, they’re going to have to find alternatives to that. If you can develop a path from today’s economy in Taiwan to a future manufacturing economy that is decarbonized, then that gives you a lot of interesting tools you could bring to bear in other economies.”Uncovering solutionsStakeholders from MIT and the participating companies meet for monthly webinars and biannual in-person workshops (alternating between Cambridge, Massachusetts, and Taipei) to discuss progress. The research addresses options for Taiwan to increase its supply of green energy, methods for storing and distributing that energy more efficiently, policy levers for implementing these changes, and Taiwan’s place in the global energy economy.“The project on the electric grid, the project on storage, and the project on hydrogen — all three of those are related to the issue of how to decarbonize power generation and delivery,” notes Paltsev. “But we also need to understand how things in other parts of the world are going to affect demand for the products that are produced in Taiwan. If there is a huge change in demand for certain products due to decarbonization, Taiwanese companies are going to feel it. Therefore, the companies want to understand where the demand is going to be coming from, and how to adjust their business strategies.”One of the research projects is looking closely at advanced nuclear power. There are significant political roadblocks standing in the way, but business leaders are intrigued by the prospect of nuclear energy in Taiwan, where available land for wind and solar power generation is sparse.“So far, Taiwan government policy is anti-nuclear,” Hsu says. “The current ruling party is against it. They are still thinking about what happened in the 1960s and 1970s, and they think nuclear is very dangerous. But if you look into it, nuclear generation technology has really improved.”Implementing a green economy roadmapTIGER participants’ interest in green energy solutions is, of course, not merely academic. Ultimately, the success of the program will be determined not only by the insights from the research produced over these two years, but by how these findings constructively inform both the private and public sectors.“MIT and TIGER participants are united in their commitment to advancing regional industrial and economic development, while championing decarbonization and sustainability efforts in Taiwan,” Duan says. “MIT researchers are informed by insights and domain expertise contributed by TIGER participants, believing that their collaborative efforts can help other nations facing similar geo-economic challenges.”“We are helping the companies understand how to stay leaders in this changing world,” says Paltsev. “We want to make sure that we are not painting an unrealistically rosy picture, or conveying that it will be easy to decarbonize. On the contrary, we want to stay realistic and try to show them both where they can make advances and where we see challenges.”The goal, Armstrong says, is not energy independence for Taiwan, but rather energy security. “Energy security requires diversity of supply,” he says. “So, you have a diverse set of suppliers, who are trusted trading partners, but it doesn’t mean you’re on your own. That’s the goal for Taiwan.”What will that mean, more specifically? Well, that’s what TIGER researchers aim to learn. “It probably means a mix of energy sources,” Armstrong says. “It could be that nuclear fission provides a core of energy that companies need for their industrial operations, it could be that they can import hydrogen in the form of ammonia or another carrier, and it could be that they leverage the renewable resources they have, together with storage technologies, to provide some pretty inexpensive energy for their manufacturing sector.”“We don’t know,” Armstrong adds. “But that’s what we’re looking at, to see if we can figure out a pathway that gets them to their goals. We are optimistic that we can get there.”The companies participating in the TIGER program include AcBel Polytech Inc., CDIB Capital Group / KGI Bank Co., Ltd.; Delta Electronics, Inc.; Fubon Financial Holding Co., Ltd.; Paul Hsu and Partners Co., Ltd.; Ta Ya Electric Wire & Cable Co., Ltd.; TCC Group Holdings Co. Ltd.; Walsin Lihwa Corporation; Wistron Corporation; and Zhen Ding Technology Holding, Ltd. More

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      Nanoscale transistors could enable more efficient electronics

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      Silicon transistors, which are used to amplify and switch signals, are a critical component in most electronic devices, from smartphones to automobiles. But silicon semiconductor technology is held back by a fundamental physical limit that prevents transistors from operating below a certain voltage.This limit, known as “Boltzmann tyranny,” hinders the energy efficiency of computers and other electronics, especially with the rapid development of artificial intelligence technologies that demand faster computation.In an effort to overcome this fundamental limit of silicon, MIT researchers fabricated a different type of three-dimensional transistor using a unique set of ultrathin semiconductor materials.Their devices, featuring vertical nanowires only a few nanometers wide, can deliver performance comparable to state-of-the-art silicon transistors while operating efficiently at much lower voltages than conventional devices.“This is a technology with the potential to replace silicon, so you could use it with all the functions that silicon currently has, but with much better energy efficiency,” says Yanjie Shao, an MIT postdoc and lead author of a paper on the new transistors.The transistors leverage quantum mechanical properties to simultaneously achieve low-voltage operation and high performance within an area of just a few square nanometers. Their extremely small size would enable more of these 3D transistors to be packed onto a computer chip, resulting in fast, powerful electronics that are also more energy-efficient.“With conventional physics, there is only so far you can go. The work of Yanjie shows that we can do better than that, but we have to use different physics. There are many challenges yet to be overcome for this approach to be commercial in the future, but conceptually, it really is a breakthrough,” says senior author Jesús del Alamo, the Donner Professor of Engineering in the MIT Department of Electrical Engineering and Computer Science (EECS).They are joined on the paper by Ju Li, the Tokyo Electric Power Company Professor in Nuclear Engineering and professor of materials science and engineering at MIT; EECS graduate student Hao Tang; MIT postdoc Baoming Wang; and professors Marco Pala and David Esseni of the University of Udine in Italy. The research appears today in Nature Electronics.Surpassing siliconIn electronic devices, silicon transistors often operate as switches. Applying a voltage to the transistor causes electrons to move over an energy barrier from one side to the other, switching the transistor from “off” to “on.” By switching, transistors represent binary digits to perform computation.A transistor’s switching slope reflects the sharpness of the “off” to “on” transition. The steeper the slope, the less voltage is needed to turn on the transistor and the greater its energy efficiency.But because of how electrons move across an energy barrier, Boltzmann tyranny requires a certain minimum voltage to switch the transistor at room temperature.To overcome the physical limit of silicon, the MIT researchers used a different set of semiconductor materials — gallium antimonide and indium arsenide — and designed their devices to leverage a unique phenomenon in quantum mechanics called quantum tunneling.Quantum tunneling is the ability of electrons to penetrate barriers. The researchers fabricated tunneling transistors, which leverage this property to encourage electrons to push through the energy barrier rather than going over it.“Now, you can turn the device on and off very easily,” Shao says.But while tunneling transistors can enable sharp switching slopes, they typically operate with low current, which hampers the performance of an electronic device. Higher current is necessary to create powerful transistor switches for demanding applications.Fine-grained fabricationUsing tools at MIT.nano, MIT’s state-of-the-art facility for nanoscale research, the engineers were able to carefully control the 3D geometry of their transistors, creating vertical nanowire heterostructures with a diameter of only 6 nanometers. They believe these are the smallest 3D transistors reported to date.Such precise engineering enabled them to achieve a sharp switching slope and high current simultaneously. This is possible because of a phenomenon called quantum confinement.Quantum confinement occurs when an electron is confined to a space that is so small that it can’t move around. When this happens, the effective mass of the electron and the properties of the material change, enabling stronger tunneling of the electron through a barrier.Because the transistors are so small, the researchers can engineer a very strong quantum confinement effect while also fabricating an extremely thin barrier.“We have a lot of flexibility to design these material heterostructures so we can achieve a very thin tunneling barrier, which enables us to get very high current,” Shao says.Precisely fabricating devices that were small enough to accomplish this was a major challenge.“We are really into single-nanometer dimensions with this work. Very few groups in the world can make good transistors in that range. Yanjie is extraordinarily capable to craft such well-functioning transistors that are so extremely small,” says del Alamo.When the researchers tested their devices, the sharpness of the switching slope was below the fundamental limit that can be achieved with conventional silicon transistors. Their devices also performed about 20 times better than similar tunneling transistors.“This is the first time we have been able to achieve such sharp switching steepness with this design,” Shao adds.The researchers are now striving to enhance their fabrication methods to make transistors more uniform across an entire chip. With such small devices, even a 1-nanometer variance can change the behavior of the electrons and affect device operation. They are also exploring vertical fin-shaped structures, in addition to vertical nanowire transistors, which could potentially improve the uniformity of devices on a chip.“This work definitively steps in the right direction, significantly improving the broken-gap tunnel field effect transistor (TFET) performance. It demonstrates steep-slope together with a record drive-current. It highlights the importance of small dimensions, extreme confinement, and low-defectivity materials and interfaces in the fabricated broken-gap TFET. These features have been realized through a well-mastered and nanometer-size-controlled process,” says Aryan Afzalian, a principal member of the technical staff at the nanoelectronics research organization imec, who was not involved with this work.This research is funded, in part, by Intel Corporation. More

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      Smart handling of neutrons is crucial to fusion power success

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      In fall 2009, when Ethan Peterson ’13 arrived at MIT as an undergraduate, he already had some ideas about possible career options. He’d always liked building things, even as a child, so he imagined his future work would involve engineering of some sort. He also liked physics. And he’d recently become intent on reducing our dependence on fossil fuels and simultaneously curbing greenhouse gas emissions, which made him consider studying solar and wind energy, among other renewable sources.Things crystallized for him in the spring semester of 2010, when he took an introductory course on nuclear fusion, taught by Anne White, during which he discovered that when a deuterium nucleus and a tritium nucleus combine to produce a helium nucleus, an energetic (14 mega electron volt) neutron — traveling at one-sixth the speed of light — is released. Moreover, 1020 (100 billion billion) of these neutrons would be produced every second that a 500-megawatt fusion power plant operates. “It was eye-opening for me to learn just how energy-dense the fusion process is,” says Peterson, who became the Class of 1956 Career Development Professor of nuclear science and engineering in July 2024. “I was struck by the richness and interdisciplinary nature of the fusion field. This was an engineering discipline where I could apply physics to solve a real-world problem in a way that was both interesting and beautiful.”He soon became a physics and nuclear engineering double major, and by the time he graduated from MIT in 2013, the U.S. Department of Energy (DoE) had already decided to cut funding for MIT’s Alcator C-Mod fusion project. In view of that facility’s impending closure, Peterson opted to pursue graduate studies at the University of Wisconsin. There, he acquired a basic science background in plasma physics, which is central not only to nuclear fusion but also to astrophysical phenomena such as the solar wind.When Peterson received his PhD from Wisconsin in 2019, nuclear fusion had rebounded at MIT with the launch, a year earlier, of the SPARC project — a collaborative effort being carried out with the newly founded MIT spinout Commonwealth Fusion Systems. He returned to his alma mater as a postdoc and then a research scientist in the Plasma Science and Fusion Center, taking his time, at first, to figure out how to best make his mark in the field.Minding your neutronsAround that time, Peterson was participating in a community planning process, sponsored by the DoE, that focused on critical gaps that needed to be closed for a successful fusion program. In the course of these discussions, he came to realize that inadequate attention had been paid to the handling of neutrons, which carry 80 percent of the energy coming out of a fusion reaction — energy that needs to be harnessed for electrical generation. However, these neutrons are so energetic that they can penetrate through many tens of centimeters of material, potentially undermining the structural integrity of components and damaging vital equipment such as superconducting magnets. Shielding is also essential for protecting humans from harmful radiation.One goal, Peterson says, is to minimize the number of neutrons that escape and, in so doing, to reduce the amount of lost energy. A complementary objective, he adds, “is to get neutrons to deposit heat where you want them to and to stop them from depositing heat where you don’t want them to.” These considerations, in turn, can have a profound influence on fusion reactor design. This branch of nuclear engineering, called neutronics — which analyzes where neutrons are created and where they end up going — has become Peterson’s specialty.It was never a high-profile area of research in the fusion community — as plasma physics, for example, has always garnered more of the spotlight and more of the funding. That’s exactly why Peterson has stepped up. “The impacts of neutrons on fusion reactor design haven’t been a high priority for a long time,” he says. “I felt that some initiative needed to be taken,” and that prompted him to make the switch from plasma physics to neutronics. It has been his principal focus ever since — as a postdoc, a research scientist, and now as a faculty member.A code to design byThe best way to get a neutron to transfer its energy is to make it collide with a light atom. Lithium, with an atomic number of three, or lithium-containing materials are normally good choices — and necessary for producing tritium fuel. The placement of lithium “blankets,” which are intended to absorb energy from neutrons and produce tritium, “is a critical part of the design of fusion reactors,” Peterson says. High-density materials, such as lead and tungsten, can be used, conversely, to block the passage of neutrons and other types of radiation. “You might want to layer these high- and low-density materials in a complicated way that isn’t immediately intuitive” he adds. Determining which materials to put where — and of what thickness and mass — amounts to a tricky optimization problem, which will affect the size, cost, and efficiency of a fusion power plant.To that end, Peterson has developed modelling tools that can make analyses of these sorts easier and faster, thereby facilitating the design process. “This has traditionally been the step that takes the longest time and causes the biggest holdups,” he says. The models and algorithms that he and his colleagues are devising are general enough, moreover, to be compatible with a diverse range of fusion power plant concepts, including those that use magnets or lasers to confine the plasma.Now that he’s become a professor, Peterson is in a position to introduce more people to nuclear engineering, and to neutronics in particular. “I love teaching and mentoring students, sharing the things I’m excited about,” he says. “I was inspired by all the professors I had in physics and nuclear engineering at MIT, and I hope to give back to the community in the same way.”He also believes that if you are going to work on fusion, there is no better place to be than MIT, “where the facilities are second-to-none. People here are extremely innovative and passionate. And the sheer number of people who excel in their fields is staggering.” Great ideas can sometimes be sparked by off-the-cuff conversations in the hallway — something that happens more frequently than you expect, Peterson remarks. “All of these things taken together makes MIT a very special place.” More

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      Study: Fusion energy could play a major role in the global response to climate change

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      For many decades, fusion has been touted as the ultimate source of abundant, clean electricity. Now, as the world faces the need to reduce carbon emissions to prevent catastrophic climate change, making commercial fusion power a reality takes on new importance. In a power system dominated by low-carbon variable renewable energy sources (VREs) such as solar and wind, “firm” electricity sources are needed to kick in whenever demand exceeds supply — for example, when the sun isn’t shining or the wind isn’t blowing and energy storage systems aren’t up to the task. What is the potential role and value of fusion power plants (FPPs) in such a future electric power system — a system that is not only free of carbon emissions but also capable of meeting the dramatically increased global electricity demand expected in the coming decades?Working together for a year-and-a-half, investigators in the MIT Energy Initiative (MITEI) and the MIT Plasma Science and Fusion Center (PSFC) have been collaborating to answer that question. They found that — depending on its future cost and performance — fusion has the potential to be critically important to decarbonization. Under some conditions, the availability of FPPs could reduce the global cost of decarbonizing by trillions of dollars. More than 25 experts together examined the factors that will impact the deployment of FPPs, including costs, climate policy, operating characteristics, and other factors. They present their findings in a new report funded through MITEI and entitled “The Role of Fusion Energy in a Decarbonized Electricity System.”“Right now, there is great interest in fusion energy in many quarters — from the private sector to government to the general public,” says the study’s principal investigator (PI) Robert C. Armstrong, MITEI’s former director and the Chevron Professor of Chemical Engineering, Emeritus. “In undertaking this study, our goal was to provide a balanced, fact-based, analysis-driven guide to help us all understand the prospects for fusion going forward.” Accordingly, the study takes a multidisciplinary approach that combines economic modeling, electric grid modeling, techno-economic analysis, and more to examine important factors that are likely to shape the future deployment and utilization of fusion energy. The investigators from MITEI provided the energy systems modeling capability, while the PSFC participants provided the fusion expertise.Fusion technologies may be a decade away from commercial deployment, so the detailed technology and costs of future commercial FPPs are not known at this point. As a result, the MIT research team focused on determining what cost levels fusion plants must reach by 2050 to achieve strong market penetration and make a significant contribution to the decarbonization of global electricity supply in the latter half of the century.The value of having FPPs available on an electric grid will depend on what other options are available, so to perform their analyses, the researchers needed estimates of the future cost and performance of those options, including conventional fossil fuel generators, nuclear fission power plants, VRE generators, and energy storage technologies, as well as electricity demand for specific regions of the world. To find the most reliable data, they searched the published literature as well as results of previous MITEI and PSFC analyses.Overall, the analyses showed that — while the technology demands of harnessing fusion energy are formidable — so are the potential economic and environmental payoffs of adding this firm, low-carbon technology to the world’s portfolio of energy options.Perhaps the most remarkable finding is the “societal value” of having commercial FPPs available. “Limiting warming to 1.5 degrees C requires that the world invest in wind, solar, storage, grid infrastructure, and everything else needed to decarbonize the electric power system,” explains Randall Field, executive director of the fusion study and MITEI’s director of research. “The cost of that task can be far lower when FPPs are available as a source of clean, firm electricity.” And the benefit varies depending on the cost of the FPPs. For example, assuming that the cost of building a FPP is $8,000 per kilowatt (kW) in 2050 and falls to $4,300/kW in 2100, the global cost of decarbonizing electric power drops by $3.6 trillion. If the cost of a FPP is $5,600/kW in 2050 and falls to $3,000/kW in 2100, the savings from having the fusion plants available would be $8.7 trillion. (Those calculations are based on differences in global gross domestic product and assume a discount rate of 6 percent. The undiscounted value is about 20 times larger.)The goal of other analyses was to determine the scale of deployment worldwide at selected FPP costs. Again, the results are striking. For a deep decarbonization scenario, the total global share of electricity generation from fusion in 2100 ranges from less than 10 percent if the cost of fusion is high to more than 50 percent if the cost of fusion is low.Other analyses showed that the scale and timing of fusion deployment vary in different parts of the world. Early deployment of fusion can be expected in wealthy nations such as European countries and the United States that have the most aggressive decarbonization policies. But certain other locations — for example, India and the continent of Africa — will have great growth in fusion deployment in the second half of the century due to a large increase in demand for electricity during that time. “In the U.S. and Europe, the amount of demand growth will be low, so it’ll be a matter of switching away from dirty fuels to fusion,” explains Sergey Paltsev, deputy director of the MIT Center for Sustainability Science and Strategy and a senior research scientist at MITEI. “But in India and Africa, for example, the tremendous growth in overall electricity demand will be met with significant amounts of fusion along with other low-carbon generation resources in the later part of the century.”A set of analyses focusing on nine subregions of the United States showed that the availability and cost of other low-carbon technologies, as well as how tightly carbon emissions are constrained, have a major impact on how FPPs would be deployed and used. In a decarbonized world, FPPs will have the highest penetration in locations with poor diversity, capacity, and quality of renewable resources, and limits on carbon emissions will have a big impact. For example, the Atlantic and Southeast subregions have low renewable resources. In those subregions, wind can produce only a small fraction of the electricity needed, even with maximum onshore wind buildout. Thus, fusion is needed in those subregions, even when carbon constraints are relatively lenient, and any available FPPs would be running much of the time. In contrast, the Central subregion of the United States has excellent renewable resources, especially wind. Thus, fusion competes in the Central subregion only when limits on carbon emissions are very strict, and FPPs will typically be operated only when the renewables can’t meet demand.An analysis of the power system that serves the New England states provided remarkably detailed results. Using a modeling tool developed at MITEI, the fusion team explored the impact of using different assumptions about not just cost and emissions limits but even such details as potential land-use constraints affecting the use of specific VREs. This approach enabled them to calculate the FPP cost at which fusion units begin to be installed. They were also able to investigate how that “threshold” cost changed with changes in the cap on carbon emissions. The method can even show at what price FPPs begin to replace other specific generating sources. In one set of runs, they determined the cost at which FPPs would begin to displace floating platform offshore wind and rooftop solar.“This study is an important contribution to fusion commercialization because it provides economic targets for the use of fusion in the electricity markets,” notes Dennis G. Whyte, co-PI of the fusion study, former director of the PSFC, and the Hitachi America Professor of Engineering in the Department of Nuclear Science and Engineering. “It better quantifies the technical design challenges for fusion developers with respect to pricing, availability, and flexibility to meet changing demand in the future.”The researchers stress that while fission power plants are included in the analyses, they did not perform a “head-to-head” comparison between fission and fusion, because there are too many unknowns. Fusion and nuclear fission are both firm, low-carbon electricity-generating technologies; but unlike fission, fusion doesn’t use fissile materials as fuels, and it doesn’t generate long-lived nuclear fuel waste that must be managed. As a result, the regulatory requirements for FPPs will be very different from the regulations for today’s fission power plants — but precisely how they will differ is unclear. Likewise, the future public perception and social acceptance of each of these technologies cannot be projected, but could have a major influence on what generation technologies are used to meet future demand.The results of the study convey several messages about the future of fusion. For example, it’s clear that regulation can be a potentially large cost driver. This should motivate fusion companies to minimize their regulatory and environmental footprint with respect to fuels and activated materials. It should also encourage governments to adopt appropriate and effective regulatory policies to maximize their ability to use fusion energy in achieving their decarbonization goals. And for companies developing fusion technologies, the study’s message is clearly stated in the report: “If the cost and performance targets identified in this report can be achieved, our analysis shows that fusion energy can play a major role in meeting future electricity needs and achieving global net-zero carbon goals.” More

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      MIT Energy and Climate Club mobilizes future leaders to address global climate issues

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      One of MIT’s missions is helping to solve the world’s greatest problems — with a large focus on one of the most pressing topics facing the world today, climate change.The MIT Energy and Climate Club, (MITEC) formerly known as the MIT Energy Club, has been working since 2004 to inform and educate the entire MIT community about this urgent issue and other related matters.MITEC, one of the largest clubs on campus, has hundreds of active members from every major, including both undergraduate and graduate students. With a broad reach across the Institute, MITEC is the hub for thought leadership and relationship-building across campus.The club’s co-presidents Laurențiu Anton, doctoral candidate in electrical engineering and computer science; Rosie Keller, an MBA student in the MIT Sloan School of Management; and Thomas Lee, doctoral candidate in the Institute for Data, Systems, and Society, say that faculty, staff, and alumni are also welcome to join and interact with the continuously growing club.While they closely collaborate on all aspects of the club, each of the co-presidents has a focus area to support the student managing directors and vice presidents for several of the club’s committees. Keller oversees the External Relations, Social, Launchpad, and Energy and Climate Hackathon leadership teams. Lee supports the leadership team for next spring’s Energy Conference. He also assists the club treasurer on budget and finance and guides the industry Sponsorships team. Anton oversees marketing, community and education as well as the Energy and Climate Night and Energy and Climate Career Fair leadership teams.“We think of MITEC as the umbrella of all things related to energy and climate on campus. Our goal is to share actionable information and not just have discussions. We work with other organizations on campus, including the MIT Environmental Solutions Initiative, to bring awareness,” says Anton. “Our Community and Education team is currently working with the MIT ESI [Environmental Solutions Initiative] to create an ecosystem map that we’re excited to produce for the MIT community.”To share their knowledge and get more people interested in solving climate and energy problems, each year MITEC hosts a variety of events including the MIT Energy and Climate Night, the MIT Energy and Climate Hack, the MIT Energy and Climate Career Fair, and the MIT Energy Conference to be held next spring March 3-4. The club also offers students the opportunity to gain valuable work experience while engaging with top companies, such as Constellation Energy and GE Vernova, on real climate and energy issues through their Launchpad Program.Founded in 2006, the annual MIT Energy Conference is the largest student-run conference in North America focused on energy and climate issues, where hundreds of participants gather every year with the CEOs, policymakers, investors, and scholars at the forefront of the global energy transition.“The 2025 MIT Energy Conference’s theme is ‘Breakthrough to Deployment: Driving Climate Innovation to Market’ — which focuses on the importance of both cutting-edge research innovation as well as large-scale commercial deployment to successfully reach climate goals,” says Lee.Anton notes that the first of four MITEC flagship events the MIT Energy and Climate Night. This research symposium that takes place every year in the fall at the MIT Museum will be held on Nov. 8. The club invites a select number of keynote speakers and several dozen student posters. Guests are allowed to walk around and engage with students, and in return students get practice showcasing their research. The club’s career fair will take place in the spring semester, shortly after Independent Activities Period.MITEC also provides members opportunities to meet with companies that are working to improve the energy sector, which helps to slow down, as well as adapt to, the effects of climate change.“We recently went to Provincetown and toured Eversource’s battery energy storage facility. This helped open doors for club members,” says Keller. “The Provincetown battery helps address grid reliability problems after extreme storms on Cape Cod — which speaks to energy’s connection to both the mitigation and adaptation aspects of climate change,” adds Lee.“MITEC is also a great way to meet other students at MIT that you might not otherwise have a chance to,” says Keller.“We’d always welcome more undergraduate students to join MITEC. There are lots of leadership opportunities within the club for them to take advantage of and build their resumes. We also have good and growing collaboration between different centers on campus such as the Sloan Sustainability Initiative and the MIT Energy Initiative. They support us with resources, introductions, and help amplify what we’re doing. But students are the drivers of the club and set the agendas,” says Lee.All three co-presidents are excited to hear that MIT President Sally Kornbluth wants to bring climate change solutions to the next level, and that she recently launched The Climate Project at MIT to kick off the Institute’s major new effort to accelerate and scale up climate change solutions.“We look forward to connecting with the new directors of the Climate Project at MIT and Interim Vice President for Climate Change Richard Lester in the near future. We are eager to explore how MITEC can support and collaborate with the Climate Project at MIT,” says Anton.Lee, Keller, and Anton want MITEC to continue fostering solutions to climate issues. They emphasized that while individual actions like bringing your own thermos, using public transportation, or recycling are necessary, there’s a bigger picture to consider. They encourage the MIT community to think critically about the infrastructure and extensive supply chains behind the products everyone uses daily.“It’s not just about bringing a thermos; it’s also understanding the life cycle of that thermos, from production to disposal, and how our everyday choices are interconnected with global climate impacts,” says Anton.“Everyone should get involved with this worldwide problem. We’d like to see more people think about how they can use their careers for change. To think how they can navigate the type of role they can play — whether it’s in finance or on the technical side. I think exploring what that looks like as a career is also a really interesting way of thinking about how to get involved with the problem,” says Keller.“MITEC’s newsletter reaches more than 4,000 people. We’re grateful that so many people are interested in energy and climate change,” says Anton. More

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      The changing geography of “energy poverty”

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      A growing portion of Americans who are struggling to pay for their household energy live in the South and Southwest, reflecting a climate-driven shift away from heating needs and toward air conditioning use, an MIT study finds.The newly published research also reveals that a major U.S. federal program that provides energy subsidies to households, by assigning block grants to states, does not yet fully match these recent trends.The work evaluates the “energy burden” on households, which reflects the percentage of income needed to pay for energy necessities, from 2015 to 2020. Households with an energy burden greater than 6 percent of income are considered to be in “energy poverty.” With climate change, rising temperatures are expected to add financial stress in the South, where air conditioning is increasingly needed. Meanwhile, milder winters are expected to reduce heating costs in some colder regions.“From 2015 to 2020, there is an increase in burden generally, and you do also see this southern shift,” says Christopher Knittel, an MIT energy economist and co-author of a new paper detailing the study’s results. About federal aid, he adds, “When you compare the distribution of the energy burden to where the money is going, it’s not aligned too well.”The paper, “U.S. federal resource allocations are inconsistent with concentrations of energy poverty,” is published today in Science Advances.The authors are Carlos Batlle, a professor at Comillas University in Spain and a senior lecturer with the MIT Energy Initiative; Peter Heller SM ’24, a recent graduate of the MIT Technology and Policy Program; Knittel, the George P. Shultz Professor at the MIT Sloan School of Management and associate dean for climate and sustainability at MIT; and Tim Schittekatte, a senior lecturer at MIT Sloan.A scorching decadeThe study, which grew out of graduate research that Heller conducted at MIT, deploys a machine-learning estimation technique that the scholars applied to U.S. energy use data.Specifically, the researchers took a sample of about 20,000 households from the U.S. Energy Information Administration’s Residential Energy Consumption Survey, which includes a wide variety of demographic characteristics about residents, along with building-type and geographic information. Then, using the U.S. Census Bureau’s American Community Survey data for 2015 and 2020, the research team estimated the average household energy burden for every census tract in the lower 48 states — 73,057 in 2015, and 84,414 in 2020.That allowed the researchers to chart the changes in energy burden in recent years, including the shift toward a greater energy burden in southern states. In 2015, Maine, Mississippi, Arkansas, Vermont, and Alabama were the five states (ranked in descending order) with the highest energy burden across census bureau tracts. In 2020, that had shifted somewhat, with Maine and Vermont dropping on the list and southern states increasingly having a larger energy burden. That year, the top five states in descending order were Mississippi, Arkansas, Alabama, West Virginia, and Maine.The data also reflect a urban-rural shift. In 2015, 23 percent of the census tracts where the average household is living in energy poverty were urban. That figure shrank to 14 percent by 2020.All told, the data are consistent with the picture of a warming world, in which milder winters in the North, Northwest, and Mountain West require less heating fuel, while more extreme summer temperatures in the South require more air conditioning.“Who’s going to be harmed most from climate change?” asks Knittel. “In the U.S., not surprisingly, it’s going to be the southern part of the U.S. And our study is confirming that, but also suggesting it’s the southern part of the U.S that’s least able to respond. If you’re already burdened, the burden’s growing.”An evolution for LIHEAP?In addition to identifying the shift in energy needs during the last decade, the study also illuminates a longer-term change in U.S. household energy needs, dating back to the 1980s. The researchers compared the present-day geography of U.S. energy burden to the help currently provided by the federal Low Income Home Energy Assistance Program (LIHEAP), which dates to 1981.Federal aid for energy needs actually predates LIHEAP, but the current program was introduced in 1981, then updated in 1984 to include cooling needs such as air conditioning. When the formula was updated in 1984, two “hold harmless” clauses were also adopted, guaranteeing states a minimum amount of funding.Still, LIHEAP’s parameters also predate the rise of temperatures over the last 40 years, and the current study shows that, compared to the current landscape of energy poverty, LIHEAP distributes relatively less of its funding to southern and southwestern states.“The way Congress uses formulas set in the 1980s keeps funding distributions nearly the same as it was in the 1980s,” Heller observes. “Our paper illustrates the shift in need that has occurred over the decades since then.”Currently, it would take a fourfold increase in LIHEAP to ensure that no U.S. household experiences energy poverty. But the researchers tested out a new funding design, which would help the worst-off households first, nationally, ensuring that no household would have an energy burden of greater than 20.3 percent.“We think that’s probably the most equitable way to allocate the money, and by doing that, you now have a different amount of money that should go to each state, so that no one state is worse off than the others,” Knittel says.And while the new distribution concept would require a certain amount of subsidy reallocation among states, it would be with the goal of helping all households avoid a certain level of energy poverty, across the country, at a time of changing climate, warming weather, and shifting energy needs in the U.S.“We can optimize where we spend the money, and that optimization approach is an important thing to think about,” Knittel says.  More