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      in Energy

      MIT researchers map the energy transition’s effects on jobs

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      A new analysis by MIT researchers shows the places in the U.S. where jobs are most linked to fossil fuels. The research could help policymakers better identify and support areas affected over time by a switch to renewable energy.

      While many of the places most potentially affected have intensive drilling and mining operations, the study also measures how areas reliant on other industries, such as heavy manufacturing, could experience changes. The research examines the entire U.S. on a county-by-county level.

      “Our result is that you see a higher carbon footprint for jobs in places that drill for oil, mine for coal, and drill for natural gas, which is evident in our maps,” says Christopher Knittel, an economist at the MIT Sloan School of Management and co-author of a new paper detailing the findings. “But you also see high carbon footprints in areas where we do a lot of manufacturing, which is more likely to be missed by policymakers when examining how the transition to a zero-carbon economy will affect jobs.”

      So, while certain U.S. areas known for fossil-fuel production would certainly be affected — including west Texas, the Powder River Basin of Montana and Wyoming, parts of Appalachia, and more — a variety of industrial areas in the Great Plains and Midwest could see employment evolve as well.

      The paper, “Assessing the distribution of employment vulnerability to the energy transition using employment carbon footprints,” is published this week in Proceedings of the National Academy of Sciences. The authors are Kailin Graham, a master’s student in MIT’s Technology and Policy Program and graduate research assistant at MIT’s Center for Energy and Environmental Policy Research; and Knittel, who is the George P. Shultz Professor at MIT Sloan.

      “Our results are unique in that we cover close to the entire U.S. economy and consider the impacts on places that produce fossil fuels but also on places that consume a lot of coal, oil, or natural gas for energy,” says Graham. “This approach gives us a much more complete picture of where communities might be affected and how support should be targeted.”

      Adjusting the targets

      The current study stems from prior research Knittel has conducted, measuring carbon footprints at the household level across the U.S. The new project takes a conceptually related approach, but for jobs in a given county. To conduct the study, the researchers used several data sources measuring energy consumption by businesses, as well as detailed employment data from the U.S. Census Bureau.

      The study takes advantage of changes in energy supply and demand over time to estimate how strongly a full range of jobs, not just those in energy production, are linked to use of fossil fuels. The sectors accounted for in the study comprise 86 percent of U.S. employment, and 94 percent of U.S. emissions apart from the transportation sector.

      The Inflation Reduction Act, passed by Congress and signed into law by President Joe Biden in August 2022, is the first federal legislation seeking to provide an economic buffer for places affected by the transition away from fossil fuels. The act provides expanded tax credits for economic projects located in “energy community” areas — defined largely as places with high fossil-fuel industry employment or tax revenue and with high unemployment. Areas with recently closed or downsized coal mines or power plants also qualify.

      Graham and Knittel measured the “employment carbon footprint” (ECF) of each county in the U.S., producing new results. Out of more than 3,000 counties in the U.S., the researchers found that 124 are at the 90th percentile or above in ECF terms, while not qualifying for Inflation Reduction Act assistance. Another 79 counties are eligible for Inflation Reduction Act assistance, while being in the bottom 20 percent nationally in ECF terms.

      Those may not seem like colossal differences, but the findings identify real communities potentially being left out of federal policy, and highlight the need for new targeting of such programs. The research by Graham and Knittel offers a precise way to assess the industrial composition of U.S. counties, potentially helping to target economic assistance programs.

      “The impact on jobs of the energy transition is not just going to be where oil and natural gas are drilled, it’s going to be all the way up and down the value chain of things we make in the U.S.,” Knittel says. “That’s a more extensive, but still focused, problem.”

      Graham adds: “It’s important that policymakers understand these economy-wide employment impacts. Our aim in providing these data is to help policymakers incorporate these considerations into future policies like the Inflation Reduction Act.”

      Adapting policy

      Graham and Knittel are still evaluating what the best policy measures might be to help places in the U.S. adapt to a move away from fossil fuels.

      “What we haven’t necessarily closed the loop on is the right way to build a policy that takes account of these factors,” Knittel says. “The Inflation Reduction Act is the first policy to think about a [fair] energy transition because it has these subsidies for energy-dependent counties.” But given enough political backing, there may be room for additional policy measures in this area.

      One thing clearly showing through in the study’s data is that many U.S. counties are in a variety of situations, so there may be no one-size-fits-all approach to encouraging economic growth while making a switch to clean energy. What suits west Texas or Wyoming best may not work for more manufacturing-based local economies. And even among primary energy-production areas, there may be distinctions, among those drilling for oil or natural gas and those producing coal, based on the particular economics of those fuels. The study includes in-depth data about each county, characterizing its industrial portfolio, which may help tailor approaches to a range of economic situations.

      “The next step is using this data more specifically to design policies to protect these communities,” Knittel says. More

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      in Environment

      New tool predicts flood risk from hurricanes in a warming climate

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      Coastal cities and communities will face more frequent major hurricanes with climate change in the coming years. To help prepare coastal cities against future storms, MIT scientists have developed a method to predict how much flooding a coastal community is likely to experience as hurricanes evolve over the next decades.

      When hurricanes make landfall, strong winds whip up salty ocean waters that generate storm surge in coastal regions. As the storms move over land, torrential rainfall can induce further flooding inland. When multiple flood sources such as storm surge and rainfall interact, they can compound a hurricane’s hazards, leading to significantly more flooding than would result from any one source alone. The new study introduces a physics-based method for predicting how the risk of such complex, compound flooding may evolve under a warming climate in coastal cities.

      One example of compound flooding’s impact is the aftermath from Hurricane Sandy in 2012. The storm made landfall on the East Coast of the United States as heavy winds whipped up a towering storm surge that combined with rainfall-driven flooding in some areas to cause historic and devastating floods across New York and New Jersey.

      In their study, the MIT team applied the new compound flood-modeling method to New York City to predict how climate change may influence the risk of compound flooding from Sandy-like hurricanes over the next decades.  

      They found that, in today’s climate, a Sandy-level compound flooding event will likely hit New York City every 150 years. By midcentury, a warmer climate will drive up the frequency of such flooding, to every 60 years. At the end of the century, destructive Sandy-like floods will deluge the city every 30 years — a fivefold increase compared to the present climate.

      “Long-term average damages from weather hazards are usually dominated by the rare, intense events like Hurricane Sandy,” says study co-author Kerry Emanuel, professor emeritus of atmospheric science at MIT. “It is important to get these right.”

      While these are sobering projections, the researchers hope the flood forecasts can help city planners prepare and protect against future disasters. “Our methodology equips coastal city authorities and policymakers with essential tools to conduct compound flooding risk assessments from hurricanes in coastal cities at a detailed, granular level, extending to each street or building, in both current and future decades,” says study author Ali Sarhadi, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences.

      The team’s open-access study appears online today in the Bulletin of the American Meteorological Society. Co-authors include Raphaël Rousseau-Rizzi at MIT’s Lorenz Center, Kyle Mandli at Columbia University, Jeffrey Neal at the University of Bristol, Michael Wiper at the Charles III University of Madrid, and Monika Feldmann at the Swiss Federal Institute of Technology Lausanne.

      The seeds of floods

      To forecast a region’s flood risk, weather modelers typically look to the past. Historical records contain measurements of previous hurricanes’ wind speeds, rainfall, and spatial extent, which scientists use to predict where and how much flooding may occur with coming storms. But Sarhadi believes that the limitations and brevity of these historical records are insufficient for predicting future hurricanes’ risks.

      “Even if we had lengthy historical records, they wouldn’t be a good guide for future risks because of climate change,” he says. “Climate change is changing the structural characteristics, frequency, intensity, and movement of hurricanes, and we cannot rely on the past.”

      Sarhadi and his colleagues instead looked to predict a region’s risk of hurricane flooding in a changing climate using a physics-based risk assessment methodology. They first paired simulations of hurricane activity with coupled ocean and atmospheric models over time. With the hurricane simulations, developed originally by Emanuel, the researchers virtually scatter tens of thousands of “seeds” of hurricanes into a simulated climate. Most seeds dissipate, while a few grow into category-level storms, depending on the conditions of the ocean and atmosphere.

      When the team drives these hurricane simulations with climate models of ocean and atmospheric conditions under certain global temperature projections, they can see how hurricanes change, for instance in terms of intensity, frequency, and size, under past, current, and future climate conditions.

      The team then sought to precisely predict the level and degree of compound flooding from future hurricanes in coastal cities. The researchers first used rainfall models to simulate rain intensity for a large number of simulated hurricanes, then applied numerical models to hydraulically translate that rainfall intensity into flooding on the ground during landfalling of hurricanes, given information about a region such as its surface and topography characteristics. They also simulated the same hurricanes’ storm surges, using hydrodynamic models to translate hurricanes’ maximum wind speed and sea level pressure into surge height in coastal areas. The simulation further assessed the propagation of ocean waters into coastal areas, causing coastal flooding.

      Then, the team developed a numerical hydrodynamic model to predict how two sources of hurricane-induced flooding, such as storm surge and rain-driven flooding, would simultaneously interact through time and space, as simulated hurricanes make landfall in coastal regions such as New York City, in both current and future climates.  

      “There’s a complex, nonlinear hydrodynamic interaction between saltwater surge-driven flooding and freshwater rainfall-driven flooding, that forms compound flooding that a lot of existing methods ignore,” Sarhadi says. “As a result, they underestimate the risk of compound flooding.”

      Amplified risk

      With their flood-forecasting method in place, the team applied it to a specific test case: New York City. They used the multipronged method to predict the city’s risk of compound flooding from hurricanes, and more specifically from Sandy-like hurricanes, in present and future climates. Their simulations showed that the city’s odds of experiencing Sandy-like flooding will increase significantly over the next decades as the climate warms, from once every 150 years in the current climate, to every 60 years by 2050, and every 30 years by 2099.

      Interestingly, they found that much of this increase in risk has less to do with how hurricanes themselves will change with warming climates, but with how sea levels will increase around the world.

      “In future decades, we will experience sea level rise in coastal areas, and we also incorporated that effect into our models to see how much that would increase the risk of compound flooding,” Sarhadi explains. “And in fact, we see sea level rise is playing a major role in amplifying the risk of compound flooding from hurricanes in New York City.”

      The team’s methodology can be applied to any coastal city to assess the risk of compound flooding from hurricanes and extratropical storms. With this approach, Sarhadi hopes decision-makers can make informed decisions regarding the implementation of adaptive measures, such as reinforcing coastal defenses to enhance infrastructure and community resilience.

      “Another aspect highlighting the urgency of our research is the projected 25 percent increase in coastal populations by midcentury, leading to heightened exposure to damaging storms,” Sarhadi says. “Additionally, we have trillions of dollars in assets situated in coastal flood-prone areas, necessitating proactive strategies to reduce damages from compound flooding from hurricanes under a warming climate.”

      This research was supported, in part, by Homesite Insurance. More

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      in Energy

      Cobalt-free batteries could power cars of the future

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      Many electric vehicles are powered by batteries that contain cobalt — a metal that carries high financial, environmental, and social costs.

      MIT researchers have now designed a battery material that could offer a more sustainable way to power electric cars. The new lithium-ion battery includes a cathode based on organic materials, instead of cobalt or nickel (another metal often used in lithium-ion batteries).

      In a new study, the researchers showed that this material, which could be produced at much lower cost than cobalt-containing batteries, can conduct electricity at similar rates as cobalt batteries. The new battery also has comparable storage capacity and can be charged up faster than cobalt batteries, the researchers report.

      “I think this material could have a big impact because it works really well,” says Mircea Dincă, the W.M. Keck Professor of Energy at MIT. “It is already competitive with incumbent technologies, and it can save a lot of the cost and pain and environmental issues related to mining the metals that currently go into batteries.”

      Dincă is the senior author of the study, which appears today in the journal ACS Central Science. Tianyang Chen PhD ’23 and Harish Banda, a former MIT postdoc, are the lead authors of the paper. Other authors include Jiande Wang, an MIT postdoc; Julius Oppenheim, an MIT graduate student; and Alessandro Franceschi, a research fellow at the University of Bologna.

      Alternatives to cobalt

      Most electric cars are powered by lithium-ion batteries, a type of battery that is recharged when lithium ions flow from a positively charged electrode, called a cathode, to a negatively electrode, called an anode. In most lithium-ion batteries, the cathode contains cobalt, a metal that offers high stability and energy density.

      However, cobalt has significant downsides. A scarce metal, its price can fluctuate dramatically, and much of the world’s cobalt deposits are located in politically unstable countries. Cobalt extraction creates hazardous working conditions and generates toxic waste that contaminates land, air, and water surrounding the mines.

      “Cobalt batteries can store a lot of energy, and they have all of features that people care about in terms of performance, but they have the issue of not being widely available, and the cost fluctuates broadly with commodity prices. And, as you transition to a much higher proportion of electrified vehicles in the consumer market, it’s certainly going to get more expensive,” Dincă says.

      Because of the many drawbacks to cobalt, a great deal of research has gone into trying to develop alternative battery materials. One such material is lithium-iron-phosphate (LFP), which some car manufacturers are beginning to use in electric vehicles. Although still practically useful, LFP has only about half the energy density of cobalt and nickel batteries.

      Another appealing option are organic materials, but so far most of these materials have not been able to match the conductivity, storage capacity, and lifetime of cobalt-containing batteries. Because of their low conductivity, such materials typically need to be mixed with binders such as polymers, which help them maintain a conductive network. These binders, which make up at least 50 percent of the overall material, bring down the battery’s storage capacity.

      About six years ago, Dincă’s lab began working on a project, funded by Lamborghini, to develop an organic battery that could be used to power electric cars. While working on porous materials that were partly organic and partly inorganic, Dincă and his students realized that a fully organic material they had made appeared that it might be a strong conductor.

      This material consists of many layers of TAQ (bis-tetraaminobenzoquinone), an organic small molecule that contains three fused hexagonal rings. These layers can extend outward in every direction, forming a structure similar to graphite. Within the molecules are chemical groups called quinones, which are the electron reservoirs, and amines, which help the material to form strong hydrogen bonds.

      Those hydrogen bonds make the material highly stable and also very insoluble. That insolubility is important because it prevents the material from dissolving into the battery electrolyte, as some organic battery materials do, thereby extending its lifetime.

      “One of the main methods of degradation for organic materials is that they simply dissolve into the battery electrolyte and cross over to the other side of the battery, essentially creating a short circuit. If you make the material completely insoluble, that process doesn’t happen, so we can go to over 2,000 charge cycles with minimal degradation,” Dincă says.

      Strong performance

      Tests of this material showed that its conductivity and storage capacity were comparable to that of traditional cobalt-containing batteries. Also, batteries with a TAQ cathode can be charged and discharged faster than existing batteries, which could speed up the charging rate for electric vehicles.

      To stabilize the organic material and increase its ability to adhere to the battery’s current collector, which is made of copper or aluminum, the researchers added filler materials such as cellulose and rubber. These fillers make up less than one-tenth of the overall cathode composite, so they don’t significantly reduce the battery’s storage capacity.

      These fillers also extend the lifetime of the battery cathode by preventing it from cracking when lithium ions flow into the cathode as the battery charges.

      The primary materials needed to manufacture this type of cathode are a quinone precursor and an amine precursor, which are already commercially available and produced in large quantities as commodity chemicals. The researchers estimate that the material cost of assembling these organic batteries could be about one-third to one-half the cost of cobalt batteries.

      Lamborghini has licensed the patent on the technology. Dincă’s lab plans to continue developing alternative battery materials and is exploring possible replacement of lithium with sodium or magnesium, which are cheaper and more abundant than lithium. More

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      in Environment

      K. Lisa Yang Global Engineering and Research Center will prioritize innovations for resource-constrained communities

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      Billions of people worldwide face threats to their livelihood, health, and well-being due to poverty. These problems persist because solutions offered in developed countries often do not meet the requirements — related to factors like price, performance, usability, robustness, and culture — of poor or developing countries. Academic labs frequently try to tackle these challenges, but often to no avail because they lack real-world, on-the-ground knowledge from key stakeholders, and because they do not have an efficient, reliable means of converting breakthroughs to real-world impact.

      The new K. Lisa Yang Global Engineering and Research (GEAR) Center at MIT, founded with a $28 million gift from philanthropist and investor Lisa Yang, aims to rethink how products and technologies for resource-constrained communities are conceived, designed, and commercialized. A collaboration between MIT’s School of Engineering and School of Science, the Yang GEAR Center will bring together a multidisciplinary team of MIT researchers to assess today’s most pressing global challenges in three critical areas: global health, climate change mitigation and adaptation, and the water-energy-food nexus.

      “As she has shown over and over through her philanthropy, Lisa Yang shares MIT’s passion for connecting fundamental research and real-world data to create positive impact,” says MIT president Sally Kornbluth. “I’m grateful for her powerful vision and incredible generosity in founding the K. Lisa Yang GEAR Center. I can’t imagine a better use of MIT’s talents than working to improve the lives and health of people around the world.”

      Yang’s gift expands her exceptional philanthropic support of human health and basic science research at MIT over the past six years. Yang GEAR Center will join MIT’s Yang Tan Collective, an assemblage of six major research centers focused on accelerating collaboration in basic science, research, and engineering to realize translational strategies that improve human health and well-being at a global scale.

      “Billions of people face daily life-or-death challenges that could be improved with elegant technologies,” says Yang. “And yet I’ve learned how many products and tools created by top engineers don’t make it out of the lab. They may look like clever ideas during the prototype phase, but they are entirely ill-suited to the communities they were designed for. I am very excited about the potential of a deliberate and thoughtful engineering effort that will prioritize the design of technologies for use in impoverished communities.”

      Cost, material availability, cultural suitability, and other market mismatches hinder many major innovations in global health, food, and water from being translated to use in resource-constrained communities. Yang GEAR Center will support a major research and design program with its mission to strategically identify compelling challenges and associated scientific knowledge gaps in resource-constrained communities then address them through academic innovation to create and translate transformative technologies.

      The center will be led by Amos Winter, associate professor of mechanical engineering, whose lab focuses on creating technologies that marry innovative, low-cost design with an in-depth understanding of the unique socioeconomic constraints of emerging markets.

      “Academia has a key role to play in solving the historically unsolvable challenges in resource-constrained communities,” says Winter. “However, academic research is often disconnected from the real-world requirements that must be satisfied to make meaningful change. Yang GEAR Center will be a catalyst for innovation to impact by helping colleagues identify compelling problems and focus their talents on realizing real-world solutions, and by providing mechanisms for commercial dissemination. I am extremely grateful to find in Lisa a partner who shares a vision for how academic research can play a more efficient and targeted role in addressing the needs of the world’s most disadvantaged populations.”

      The backbone of the Yang GEAR Center will be a team of seasoned research scientists and engineers. These individuals will scout real-world problems and distill the relevant research questions then help assemble collaborative teams. As projects develop, center staff will mentor students, build and conduct field pilots, and foster relationships with stakeholders around the world. They will be strategically positioned to translate technology at the end of projects through licensing and startups. Center staff and collaborators will focus on creating products and services for climate-driven migrants, such as solar-powered energy and water networks; technologies for reducing atmospheric carbon and promoting the hydrogen economy; brackish water desalination and irrigation solutions; and high-performance, global health diagnostics and devices.

      For instance, a Yang GEAR Center team focused on creating water-saving and solar-powered irrigation solutions for farmers in the Middle East and North Africa will continue its work in the region. They will conduct exploratory research; build a team of stakeholders, including farmers, agricultural outreach organizations, irrigation hardware manufacturers, retailers, water and agriculture scientists, and local government officials; design, rigorously test, and iterate prototypes both in the lab and in the field; and conduct large-scale field trials to garner user feedback and pave the way to product commercialization.

      “Grounded in foundational scientific research and blended with excellence in the humanities, MIT provides a framework that integrates people, economics, research, and innovation. By incorporating multiple perspectives — and being attentive to the needs and cultures of the people who will ultimately rely on research outcomes — MIT can have the greatest impact in areas of health, climate science, and resource security,” says Nergis Mavalvala, dean of the School of Science and the Curtis and Kathleen Marble Professor of Astrophysics.

      An overarching aim for the center will be to educate graduates who are global engineers, designers, and researchers positioned for a career of addressing compelling, high-impact challenges. The center includes four endowed Hock E. Tan GEAR Center Fellowships that will support graduate students and/or postdoctoral fellows eager to enter the field of global engineering. The fellowships are named for MIT alumnus and Broadcom CEO Hock E. Tan ’75 SM ’75.

      “I am thrilled that the Yang GEAR Center is taking a leading role in training problem-solvers who will rethink how products and inventions can help communities facing the most pressing challenges of our time,” adds Anantha Chandrakasan, dean of the School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science. “These talented young students,  postdocs, and staff have the potential to reach across disciplines — and across the globe — to truly transform the impact engineering can have in the future.” More

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      in Energy

      Study reveals a reaction at the heart of many renewable energy technologies

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      A key chemical reaction — in which the movement of protons between the surface of an electrode and an electrolyte drives an electric current — is a critical step in many energy technologies, including fuel cells and the electrolyzers used to produce hydrogen gas.

      For the first time, MIT chemists have mapped out in detail how these proton-coupled electron transfers happen at an electrode surface. Their results could help researchers design more efficient fuel cells, batteries, or other energy technologies.

      “Our advance in this paper was studying and understanding the nature of how these electrons and protons couple at a surface site, which is relevant for catalytic reactions that are important in the context of energy conversion devices or catalytic reactions,” says Yogesh Surendranath, a professor of chemistry and chemical engineering at MIT and the senior author of the study.

      Among their findings, the researchers were able to trace exactly how changes in the pH of the electrolyte solution surrounding an electrode affect the rate of proton motion and electron flow within the electrode.

      MIT graduate student Noah Lewis is the lead author of the paper, which appears today in Nature Chemistry. Ryan Bisbey, a former MIT postdoc; Karl Westendorff, an MIT graduate student; and Alexander Soudackov, a research scientist at Yale University, are also authors of the paper.

      Passing protons

      Proton-coupled electron transfer occurs when a molecule, often water or an acid, transfers a proton to another molecule or to an electrode surface, which stimulates the proton acceptor to also take up an electron. This kind of reaction has been harnessed for many energy applications.

      “These proton-coupled electron transfer reactions are ubiquitous. They are often key steps in catalytic mechanisms, and are particularly important for energy conversion processes such as hydrogen generation or fuel cell catalysis,” Surendranath says.

      In a hydrogen-generating electrolyzer, this approach is used to remove protons from water and add electrons to the protons to form hydrogen gas. In a fuel cell, electricity is generated when protons and electrons are removed from hydrogen gas and added to oxygen to form water.

      Proton-coupled electron transfer is common in many other types of chemical reactions, for example, carbon dioxide reduction (the conversion of carbon dioxide into chemical fuels by adding electrons and protons). Scientists have learned a great deal about how these reactions occur when the proton acceptors are molecules, because they can precisely control the structure of each molecule and observe how electrons and protons pass between them. However, when proton-coupled electron transfer occurs at the surface of an electrode, the process is much more difficult to study because electrode surfaces are usually very heterogenous, with many different sites that a proton could potentially bind to.

      To overcome that obstacle, the MIT team developed a way to design electrode surfaces that gives them much more precise control over the composition of the electrode surface. Their electrodes consist of sheets of graphene with organic, ring-containing compounds attached to the surface. At the end of each of these organic molecules is a negatively charged oxygen ion that can accept protons from the surrounding solution, which causes an electron to flow from the circuit into the graphitic surface.

      “We can create an electrode that doesn’t consist of a wide diversity of sites but is a uniform array of a single type of very well-defined sites that can each bind a proton with the same affinity,” Surendranath says. “Since we have these very well-defined sites, what this allowed us to do was really unravel the kinetics of these processes.”

      Using this system, the researchers were able to measure the flow of electrical current to the electrodes, which allowed them to calculate the rate of proton transfer to the oxygen ion at the surface at equilibrium — the state when the rates of proton donation to the surface and proton transfer back to solution from the surface are equal. They found that the pH of the surrounding solution has a significant effect on this rate: The highest rates occurred at the extreme ends of the pH scale — pH 0, the most acidic, and pH 14, the most basic.

      To explain these results, researchers developed a model based on two possible reactions that can occur at the electrode. In the first, hydronium ions (H3O+), which are in high concentration in strongly acidic solutions, deliver protons to the surface oxygen ions, generating water. In the second, water delivers protons to the surface oxygen ions, generating hydroxide ions (OH-), which are in high concentration in strongly basic solutions.

      However, the rate at pH 0 is about four times faster than the rate at pH 14, in part because hydronium gives up protons at a faster rate than water.

      A reaction to reconsider

      The researchers also discovered, to their surprise, that the two reactions have equal rates not at neutral pH 7, where hydronium and hydroxide concentrations are equal, but at pH 10, where the concentration of hydroxide ions is 1 million times that of hydronium. The model suggests this is because the forward reaction involving proton donation from hydronium or water contributes more to the overall rate than the backward reaction involving proton removal by water or hydroxide.

      Existing models of how these reactions occur at electrode surfaces assume that the forward and backward reactions contribute equally to the overall rate, so the new findings suggest that those models may need to be reconsidered, the researchers say.

      “That’s the default assumption, that the forward and reverse reactions contribute equally to the reaction rate,” Surendranath says. “Our finding is really eye-opening because it means that the assumption that people are using to analyze everything from fuel cell catalysis to hydrogen evolution may be something we need to revisit.”

      The researchers are now using their experimental setup to study how adding different types of ions to the electrolyte solution surrounding the electrode may speed up or slow down the rate of proton-coupled electron flow.

      “With our system, we know that our sites are constant and not affecting each other, so we can read out what the change in the solution is doing to the reaction at the surface,” Lewis says.

      The research was funded by the U.S. Department of Energy Office of Basic Energy Sciences. More

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      in Environment

      Researchers release open-source space debris model

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      MIT’s Astrodynamics, Space Robotics, and Controls Laboratory (ARCLab) announced the public beta release of the MIT Orbital Capacity Assessment Tool (MOCAT) during the 2023 Organization for Economic Cooperation and Development (OECD) Space Forum Workshop on Dec. 14. MOCAT enables users to model the long-term future space environment to understand growth in space debris and assess the effectiveness of debris-prevention mechanisms.

      With the escalating congestion in low Earth orbit, driven by a surge in satellite deployments, the risk of collisions and space debris proliferation is a pressing concern. Conducting thorough space environment studies is critical for developing effective strategies for fostering responsible and sustainable use of space resources. 

      MOCAT stands out among orbital modeling tools for its capability to model individual objects, diverse parameters, orbital characteristics, fragmentation scenarios, and collision probabilities. With the ability to differentiate between object categories, generalize parameters, and offer multi-fidelity computations, MOCAT emerges as a versatile and powerful tool for comprehensive space environment analysis and management.

      MOCAT is intended to provide an open-source tool to empower stakeholders including satellite operators, regulators, and members of the public to make data-driven decisions. The ARCLab team has been developing these models for the last several years, recognizing that the lack of open-source implementation of evolutionary modeling tools limits stakeholders’ ability to develop consensus on actions to help improve space sustainability. This beta release is intended to allow users to experiment with the tool and provide feedback to help guide further development.

      Richard Linares, the principal investigator for MOCAT and an MIT associate professor of aeronautics and astronautics, expresses excitement about the tool’s potential impact: “MOCAT represents a significant leap forward in orbital capacity assessment. By making it open-source and publicly available, we hope to engage the global community in advancing our understanding of satellite orbits and contributing to the sustainable use of space.”

      MOCAT consists of two main components. MOCAT-MC evaluates space environment evolution with individual trajectory simulation and Monte Carlo parameter analysis, providing both a high-level overall view for the environment and a fidelity analysis into the individual space objects evolution. MOCAT Source Sink Evolutionary Model (MOCAT-SSEM), meanwhile, uses a lower-fidelity modeling approach that can run on personal computers within seconds to minutes. MOCAT-MC and MOCAT-SSEM can be accessed separately via GitHub.

      MOCAT’s initial development has been supported by the Defense Advanced Research Projects Agency (DARPA) and NASA’s Office of Technology and Strategy.

      “We are thrilled to support this groundbreaking orbital debris modeling work and the new knowledge it created,” says Charity Weeden, associate administrator for the Office of Technology, Policy, and Strategy at NASA headquarters in Washington. “This open-source modeling tool is a public good that will advance space sustainability, improve evidence-based policy analysis, and help all users of space make better decisions.” More

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      in Energy

      The future of motorcycles could be hydrogen

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      MIT’s Electric Vehicle Team, which has a long record of building and racing innovative electric vehicles, including cars and motorcycles, in international professional-level competitions, is trying something very different this year: The team is building a hydrogen-powered electric motorcycle, using a fuel cell system, as a testbed for new hydrogen-based transportation.

      The motorcycle successfully underwent its first full test-track demonstration in October. It is designed as an open-source platform that should make it possible to swap out and test a variety of different components, and for others to try their own versions based on plans the team is making freely available online.

      Aditya Mehrotra, who is spearheading the project, is a graduate student working with mechanical engineering professor Alex Slocum, the Walter M. May  and A. Hazel May Chair in Emerging Technologies. Mehrotra was studying energy systems and happened to also really like motorcycles, he says, “so we came up with the idea of a hydrogen-powered bike. We did an evaluation study, and we thought that this could actually work. We [decided to] try to build it.”

      Team members say that while battery-powered cars are a boon for the environment, they still face limitations in range and have issues associated with the mining of lithium and resulting emissions. So, the team was interested in exploring hydrogen-powered vehicles as a clean alternative, allowing for vehicles that could be quickly refilled just like gasoline-powered vehicles.

      Unlike past projects by the team, which has been part of MIT since 2005, this vehicle will not be entering races or competitions but will be presented at a variety of conferences. The team, consisting of about a dozen students, has been working on building the prototype since January 2023. In October they presented the bike at the Hydrogen Americas Summit, and in May they will travel to the Netherlands to present it at the World Hydrogen Summit. In addition to the two hydrogen summits, the team plans to show its bike at the Consumer Electronics Show in Las Vegas this month.

      “We’re hoping to use this project as a chance to start conversations around ‘small hydrogen’ systems that could increase demand, which could lead to the development of more infrastructure,” Mehrotra says. “We hope the project can help find new and creative applications for hydrogen.” In addition to these demonstrations and the online information the team will provide, he adds, they are also working toward publishing papers in academic journals describing their project and lessons learned from it, in hopes of making “an impact on the energy industry.”

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      For the love of speed: Building a hydrogen-powered motorcycle

      The motorcycle took shape over the course of the year piece by piece. “We got a couple of industry sponsors to donate components like the fuel cell and a lot of the major components of the system,” he says. They also received support from the MIT Energy Initiative, the departments of Mechanical Engineering and Electrical Engineering and Computer Science, and the MIT Edgerton Center.

      Initial tests were conducted on a dynamometer, a kind of instrumented treadmill Mehrotra describes as “basically a mock road.” The vehicle used battery power during its development, until the fuel cell, provided by South Korean company Doosan, could be delivered and installed. The space the group has used to design and build the prototype, the home of the Electric Vehicle Team, is in MIT’s Building N51 and is well set up to do detailed testing of each of the bike’s components as it is developed and integrated.

      Elizabeth Brennan, a senior in mechanical engineering, says she joined the team in January 2023 because she wanted to gain more electrical engineering experience, “and I really fell in love with it.” She says group members “really care and are very excited to be here and work on this bike and believe in the project.”

      Brennan, who is the team’s safety lead, has been learning about the safe handling methods required for the bike’s hydrogen fuel, including the special tanks and connectors needed. The team initially used a commercially available electric motor for the prototype but is now working on an improved version, designed from scratch, she says, “which gives us a lot more flexibility.”

      As part of the project, team members are developing a kind of textbook describing what they did and how they carried out each step in the process of designing and fabricating this hydrogen electric fuel-cell bike. No such motorcycle yet exists as a commercial product, though a few prototypes have been built.

      That kind of guidebook to the process “just doesn’t exist,” Brennan says. She adds that “a lot of the technology development for hydrogen is either done in simulation or is still in the prototype stages, because developing it is expensive, and it’s difficult to test these kinds of systems.” One of the team’s goals for the project is to make everything available as an open-source design, and “we want to provide this bike as a platform for researchers and for education, where researchers can test ideas in both space- and funding-constrained environments.”

      Unlike a design built as a commercial product, Mehrotra says, “our vehicle is fully designed for research, so you can swap components in and out, and get real hardware data on how good your designs are.” That can help people work on implementing their new design ideas and help push the industry forward, he says.

      The few prototypes developed previously by some companies were inefficient and expensive, he says. “So far as we know, we are the first fully open-source, rigorously documented, tested and released-as-a-platform, [fuel cell] motorcycle in the world. No one else has made a motorcycle and tested it to the level that we have, and documented to the point that someone might actually be able to take this and scale it in the future, or use it in research.”

      He adds that “at the moment, this vehicle is affordable for research, but it’s not affordable yet for commercial production because the fuel cell is a very big, expensive component.” Doosan Fuel Cell, which provided the fuel cell for the prototype bike, produces relatively small and lightweight fuel cells mostly for use in drones. The company also produces hydrogen storage and delivery systems.

      The project will continue to evolve, says team member Annika Marschner, a sophomore in mechanical engineering. “It’s sort of an ongoing thing, and as we develop it and make changes, make it a stronger, better bike, it will just continue to grow over the years, hopefully,” she says.

      While the Electric Vehicle Team has until now focused on battery-powered vehicles, Marschner says, “Right now we’re looking at hydrogen because it seems like something that’s been less explored than other technologies for making sustainable transportation. So, it seemed like an exciting thing for us to offer our time and effort to.”

      Making it all work has been a long process. The team is using a frame from a 1999 motorcycle, with many custom-made parts added to support the electric motor, the hydrogen tank, the fuel cell, and the drive train. “Making everything fit in the frame of the bike is definitely something we’ve had to think about a lot because there’s such limited space there. So, it required trying to figure out how to mount things in clever ways so that there are not conflicts,” she says.

      Marschner says, “A lot of people don’t really imagine hydrogen energy being something that’s out there being used on the roads, but the technology does exist.” She points out that Toyota and Hyundai have hydrogen-fueled vehicles on the market, and that some hydrogen fuel stations exist, mostly in California, Japan, and some European countries. But getting access to hydrogen, “for your average consumer on the East Coast, is a huge, huge challenge. Infrastructure is definitely the biggest challenge right now to hydrogen vehicles,” she says.

      She sees a bright future for hydrogen as a clean fuel to replace fossil fuels over time. “I think it has a huge amount of potential,” she says. “I think one of the biggest challenges with moving hydrogen energy forward is getting these demonstration projects actually developed and showing that these things can work and that they can work well. So, we’re really excited to bring it along further.” More

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      in Energy

      MIT researchers outline a path for scaling clean hydrogen production

      by

      Hydrogen is an integral component for the manufacture of steel, fertilizer, and a number of chemicals. Producing hydrogen using renewable electricity offers a way to clean up these and many other hard-to-decarbonize industries.

      But supporting the nascent clean hydrogen industry while ensuring it grows into a true force for decarbonization is complicated, in large part because of the challenges of sourcing clean electricity. To assist regulators and to clarify disagreements in the field, MIT researchers published a paper today in Nature Energy that outlines a path to scale the clean hydrogen industry while limiting emissions.

      Right now, U.S. electric grids are mainly powered by fossil fuels, so if scaling hydrogen production translates to greater electricity use, it could result in a major emissions increase. There is also the risk that “low-carbon” hydrogen projects could end up siphoning renewable energy that would have been built anyway for the grid. It is therefore critical to ensure that low-carbon hydrogen procures electricity from “additional” renewables, especially when hydrogen production is supported by public subsidies. The challenge is allowing hydrogen producers to procure renewable electricity in a cost-effective way that helps the industry grow, while minimizing the risk of high emissions.

      U.S. regulators have been tasked with sorting out this complexity. The Inflation Reduction Act (IRA) is offering generous production tax credits for low-carbon hydrogen. But the law didn’t specify exactly how hydrogen’s carbon footprint should be judged.

      To this end, the paper proposes a phased approach to qualify for the tax credits. In the first phase, hydrogen created from grid electricity can receive the credits under looser standards as the industry gets its footing. Once electricity demand for hydrogen production grows, the industry should be required to adhere to stricter standards for ensuring the electricity is coming from renewable sources. Finally, many years from now when the grid is mainly powered by renewable energy, the standards can loosen again.

      The researchers say the nuanced approach ensures the law supports the growth of clean hydrogen without coming at the expense of emissions.

      “If we can scale low-carbon hydrogen production, we can cut some significant sources of existing emissions and enable decarbonization of other critical industries,” says paper co-author Michael Giovanniello, a graduate student in MIT’s Technology and Policy Program. “At the same time, there’s a real risk of implementing the wrong requirements and wasting lots of money to subsidize carbon-intensive hydrogen production. So, you have to balance scaling the industry with reducing the risk of emissions. I hope there’s clarity and foresight in how this policy is implemented, and I hope our paper makes the argument clear for policymakers.”

      Giovanniello’s co-authors on the paper are MIT Energy Initiative (MITEI) Principal Research Scientist Dharik Mallapragada, MITEI Research Assistant Anna Cybulsky, and MIT Sloan School of Management Senior Lecturer Tim Schittekatte.

      On definitions and disagreements

      When renewable electricity from a wind farm or solar array flows through the grid, it’s mixed with electricity from fossil fuels. The situation raises a question worth billions of dollars in federal tax credits: What are the carbon dioxide emissions of grid users who are also signing agreements to procure electricity from renewables?

      One way to answer this question is via energy system models that can simulate various scenarios related to technology configurations and qualifying requirements for receiving the credit.

      To date, many studies using such models have come up with very different emissions estimates for electrolytic hydrogen production. One source of disagreement is over “time matching,” which refers to how strictly to align the timing of electric hydrogen production with the generation of clean electricity. One proposed approach, known as hourly time matching, would require that electricity consumption to produce hydrogen is accounted for by procured clean electricity at every hour.

      A less stringent approach, called annual time matching, would offer more flexibility in hourly electricity consumption for hydrogen production, so long as the annual consumption matches the annual generation from the procured clean electricity generation. The added flexibility could reduce the cost of hydrogen production, which is critical for scaling its use, but could lead to greater emissions per unit of hydrogen produced.

      Another point of disagreement stems from how hydrogen producers purchase renewable electricity. If an electricity user procures energy from an existing solar farm, it’s simply increasing overall electricity demand and taking clean energy away from other users. But if the tax credits only go to electric hydrogen producers that sign power purchase agreements with new renewable suppliers, they’re supporting clean electricity that wouldn’t have otherwise been contributing to the grid. This concept is known as “additionality.”

      The researchers analyzed previous studies that reached conflicting conclusions, and identified different interpretations of additionality underlying their methodologies. One interpretation of additionality is that new electrolytic hydrogen projects do not compete with nonhydrogen demand for renewable energy resources. The other assumes that they do compete for all newly deployed renewables — and, because of low-carbon hydrogen subsidies, the electrolyzers take priority.

      Using DOLPHYN, an open-source energy systems model, the researchers tested how these two interpretations of additionality (the “compete” and “noncompete” scenarios) impact the cost and emissions of the alternative time-matching requirements (hourly and annual) associated with grid-interconnected hydrogen production. They modeled two regional U.S. grids — in Texas and Florida — which represent the high and low end of renewables deployment. They further tested the interaction of four critical policy factors with the hydrogen tax credits, including renewable portfolio standards, constraints of renewables and energy storage deployment, limits on hydrogen electrolyzer capacity factors, and competition with natural gas-based hydrogen with carbon capture.

      They show that the different modeling interpretations of additionality are the primary factor explaining the vastly different estimates of emissions from electrolyzer hydrogen under annual time-matching.

      Getting policy right

      The paper concludes that the right way to implement the production tax credit qualifying requirements depends on whether you believe we live in a “compete” or “noncompete” world. But reality is not so binary.

      “What framework is more appropriate is going to change with time as we deploy more hydrogen and the grid decarbonizes, so therefore the policy has to be adaptive to those changes,” Mallapragada says. “It’s an evolving story that’s tied to what’s happening in the rest of the energy system, and in particular the electric grid, both from the technological as policy perspective.”

      Today, renewables deployment is driven, in part, by binding factors, such as state renewable portfolio standards and corporate clean-energy commitments, as well as by purely market forces. Since the electrolyzer is so nascent, and today resembles a “noncompete” world, the researchers argue for starting with the less strict annual requirement. But as hydrogen demand for renewable electricity grows, and market competition drives an increasing quantity of renewables deployment, transitioning to hourly matching will be necessary to avoid high emissions.

      This phased approach necessitates deliberate, long-term planning from regulators. “If regulators make a decision and don’t outline when they’ll reassess that decision, they might never reassess that decision, so we might get locked into a bad policy,” Giovanniello explains. In particular, the paper highlights the risk of locking in an annual time-matching requirement that leads to significant emissions in future.

      The researchers hope their findings will contribute to upcoming policy decisions around the Inflation Reduction Act’s tax credits. They started looking into this question around a year ago, making it a quick turnaround by academic standards.

      “There was definitely a sense to be timely in our analysis so as to be responsive to the needs of policy,” Mallapragada says.

      The researchers say the paper can also help policymakers understand the emissions impacts of companies procuring renewable energy credits to meet net-zero targets and electricity suppliers attempting to sell “green” electricity.

      “This question is relevant in a lot of different domains,” Schittekatte says. “Other popular examples are the emission impacts of data centers that procure green power, or even the emission impacts of your own electric car sourcing power from your rooftop solar and the grid. There are obviously differences based on the technology in question, but the underlying research question we’ve answered is the same. This is an extremely important topic for the energy transition.” More