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    Energy storage important to creating affordable, reliable, deeply decarbonized electricity systems

    In deeply decarbonized energy systems utilizing high penetrations of variable renewable energy (VRE), energy storage is needed to keep the lights on and the electricity flowing when the sun isn’t shining and the wind isn’t blowing — when generation from these VRE resources is low or demand is high. The MIT Energy Initiative’s Future of Energy Storage study makes clear the need for energy storage and explores pathways using VRE resources and storage to reach decarbonized electricity systems efficiently by 2050.

    “The Future of Energy Storage,” a new multidisciplinary report from the MIT Energy Initiative (MITEI), urges government investment in sophisticated analytical tools for planning, operation, and regulation of electricity systems in order to deploy and use storage efficiently. Because storage technologies will have the ability to substitute for or complement essentially all other elements of a power system, including generation, transmission, and demand response, these tools will be critical to electricity system designers, operators, and regulators in the future. The study also recommends additional support for complementary staffing and upskilling programs at regulatory agencies at the state and federal levels. 

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    Why is energy storage so important?

    The MITEI report shows that energy storage makes deep decarbonization of reliable electric power systems affordable. “Fossil fuel power plant operators have traditionally responded to demand for electricity — in any given moment — by adjusting the supply of electricity flowing into the grid,” says MITEI Director Robert Armstrong, the Chevron Professor of Chemical Engineering and chair of the Future of Energy Storage study. “But VRE resources such as wind and solar depend on daily and seasonal variations as well as weather fluctuations; they aren’t always available to be dispatched to follow electricity demand. Our study finds that energy storage can help VRE-dominated electricity systems balance electricity supply and demand while maintaining reliability in a cost-effective manner — that in turn can support the electrification of many end-use activities beyond the electricity sector.”

    The three-year study is designed to help government, industry, and academia chart a path to developing and deploying electrical energy storage technologies as a way of encouraging electrification and decarbonization throughout the economy, while avoiding excessive or inequitable burdens.

    Focusing on three distinct regions of the United States, the study shows the need for a varied approach to energy storage and electricity system design in different parts of the country. Using modeling tools to look out to 2050, the study team also focuses beyond the United States, to emerging market and developing economy (EMDE) countries, particularly as represented by India. The findings highlight the powerful role storage can play in EMDE nations. These countries are expected to see massive growth in electricity demand over the next 30 years, due to rapid overall economic expansion and to increasing adoption of electricity-consuming technologies such as air conditioning. In particular, the study calls attention to the pivotal role battery storage can play in decarbonizing grids in EMDE countries that lack access to low-cost gas and currently rely on coal generation.

    The authors find that investment in VRE combined with storage is favored over new coal generation over the medium and long term in India, although existing coal plants may linger unless forced out by policy measures such as carbon pricing. 

    “Developing countries are a crucial part of the global decarbonization challenge,” says Robert Stoner, the deputy director for science and technology at MITEI and one of the report authors. “Our study shows how they can take advantage of the declining costs of renewables and storage in the coming decades to become climate leaders without sacrificing economic development and modernization.”

    The study examines four kinds of storage technologies: electrochemical, thermal, chemical, and mechanical. Some of these technologies, such as lithium-ion batteries, pumped storage hydro, and some thermal storage options, are proven and available for commercial deployment. The report recommends that the government focus R&D efforts on other storage technologies, which will require further development to be available by 2050 or sooner — among them, projects to advance alternative electrochemical storage technologies that rely on earth-abundant materials. It also suggests government incentives and mechanisms that reward success but don’t interfere with project management. The report calls for the federal government to change some of the rules governing technology demonstration projects to enable more projects on storage. Policies that require cost-sharing in exchange for intellectual property rights, the report argues, discourage the dissemination of knowledge. The report advocates for federal requirements for demonstration projects that share information with other U.S. entities.

    The report says many existing power plants that are being shut down can be converted to useful energy storage facilities by replacing their fossil fuel boilers with thermal storage and new steam generators. This retrofit can be done using commercially available technologies and may be attractive to plant owners and communities — using assets that would otherwise be abandoned as electricity systems decarbonize.  

    The study also looks at hydrogen and concludes that its use for storage will likely depend on the extent to which hydrogen is used in the overall economy. That broad use of hydrogen, the report says, will be driven by future costs of hydrogen production, transportation, and storage — and by the pace of innovation in hydrogen end-use applications. 

    The MITEI study predicts the distribution of hourly wholesale prices or the hourly marginal value of energy will change in deeply decarbonized power systems — with many more hours of very low prices and more hours of high prices compared to today’s wholesale markets. So the report recommends systems adopt retail pricing and retail load management options that reward all consumers for shifting electricity use away from times when high wholesale prices indicate scarcity, to times when low wholesale prices signal abundance. 

    The Future of Energy Storage study is the ninth in MITEI’s “Future of” series, exploring complex and vital issues involving energy and the environment. Previous studies have focused on nuclear power, solar energy, natural gas, geothermal energy, and coal (with capture and sequestration of carbon dioxide emissions), as well as on systems such as the U.S. electric power grid. The Alfred P. Sloan Foundation and the Heising-Simons Foundation provided core funding for MITEI’s Future of Energy Storage study. MITEI members Equinor and Shell provided additional support.  More

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    MIT expands research collaboration with Commonwealth Fusion Systems to build net energy fusion machine, SPARC

    MIT’s Plasma Science and Fusion Center (PSFC) will substantially expand its fusion energy research and education activities under a new five-year agreement with Institute spinout Commonwealth Fusion Systems (CFS).

    “This expanded relationship puts MIT and PSFC in a prime position to be an even stronger academic leader that can help deliver the research and education needs of the burgeoning fusion energy industry, in part by utilizing the world’s first burning plasma and net energy fusion machine, SPARC,” says PSFC director Dennis Whyte. “CFS will build SPARC and develop a commercial fusion product, while MIT PSFC will focus on its core mission of cutting-edge research and education.”

    Commercial fusion energy has the potential to play a significant role in combating climate change, and there is a concurrent increase in interest from the energy sector, governments, and foundations. The new agreement, administered by the MIT Energy Initiative (MITEI), where CFS is a startup member, will help PSFC expand its fusion technology efforts with a wider variety of sponsors. The collaboration enables rapid execution at scale and technology transfer into the commercial sector as soon as possible.

    This new agreement doubles CFS’ financial commitment to PSFC, enabling greater recruitment and support of students, staff, and faculty. “We’ll significantly increase the number of graduate students and postdocs, and just as important they will be working on a more diverse set of fusion science and technology topics,” notes Whyte. It extends the collaboration between PSFC and CFS that resulted in numerous advances toward fusion power plants, including last fall’s demonstration of a high-temperature superconducting (HTS) fusion electromagnet with record-setting field strength of 20 tesla.

    The combined magnetic fusion efforts at PSFC will surpass those in place during the operations of the pioneering Alcator C-Mod tokamak device that operated from 1993 to 2016. This increase in activity reflects a moment when multiple fusion energy technologies are seeing rapidly accelerating development worldwide, and the emergence of a new fusion energy industry that would require thousands of trained people.

    MITEI director Robert Armstrong adds, “Our goal from the beginning was to create a membership model that would allow startups who have specific research challenges to leverage the MITEI ecosystem, including MIT faculty, students, and other MITEI members. The team at the PSFC and MITEI have worked seamlessly to support CFS, and we are excited for this next phase of the relationship.”

    PSFC is supporting CFS’ efforts toward realizing the SPARC fusion platform, which facilitates rapid development and refinement of elements (including HTS magnets) needed to build ARC, a compact, modular, high-field fusion power plant that would set the stage for commercial fusion energy production. The concepts originated in Whyte’s nuclear science and engineering class 22.63 (Principles of Fusion Engineering) and have been carried forward by students and PSFC staff, many of whom helped found CFS; the new activity will expand research into advanced technologies for the envisioned pilot plant.

    “This has been an incredibly effective collaboration that has resulted in a major breakthrough for commercial fusion with the successful demonstration of revolutionary fusion magnet technology that will enable the world’s first commercially relevant net energy fusion device, SPARC, currently under construction,” says Bob Mumgaard SM ’15, PhD ’15, CEO of Commonwealth Fusion Systems. “We look forward to this next phase in the collaboration with MIT as we tackle the critical research challenges ahead for the next steps toward fusion power plant development.”

    In the push for commercial fusion energy, the next five years are critical, requiring intensive work on materials longevity, heat transfer, fuel recycling, maintenance, and other crucial aspects of power plant development. It will need innovation from almost every engineering discipline. “Having great teams working now, it will cut the time needed to move from SPARC to ARC, and really unleash the creativity. And the thing MIT does so well is cut across disciplines,” says Whyte.

    “To address the climate crisis, the world needs to deploy existing clean energy solutions as widely and as quickly as possible, while at the same time developing new technologies — and our goal is that those new technologies will include fusion power,” says Maria T. Zuber, MIT’s vice president for research. “To make new climate solutions a reality, we need focused, sustained collaborations like the one between MIT and Commonwealth Fusion Systems. Delivering fusion power onto the grid is a monumental challenge, and the combined capabilities of these two organizations are what the challenge demands.”

    On a strategic level, climate change and the imperative need for widely implementable carbon-free energy have helped orient the PSFC team toward scalability. “Building one or 10 fusion plants doesn’t make a difference — we have to build thousands,” says Whyte. “The design decisions we make will impact the ability to do that down the road. The real enemy here is time, and we want to remove as many impediments as possible and commit to funding a new generation of scientific leaders. Those are critically important in a field with as much interdisciplinary integration as fusion.” More

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    Team creates map for production of eco-friendly metals

    In work that could usher in more efficient, eco-friendly processes for producing important metals like lithium, iron, and cobalt, researchers from MIT and the SLAC National Accelerator Laboratory have mapped what is happening at the atomic level behind a particularly promising approach called metal electrolysis.

    By creating maps for a wide range of metals, they not only determined which metals should be easiest to produce using this approach, but also identified fundamental barriers behind the efficient production of others. As a result, the researchers’ map could become an important design tool for optimizing the production of all these metals.

    The work could also aid the development of metal-air batteries, cousins of the lithium-ion batteries used in today’s electric vehicles.

    Most of the metals key to society today are produced using fossil fuels. These fuels generate the high temperatures necessary to convert the original ore into its purified metal. But that process is a significant source of greenhouse gases — steel alone accounts for some 7 percent of carbon dioxide emissions globally. As a result, researchers from around the world are working to identify more eco-friendly ways for the production of metals.

    One promising approach is metal electrolysis, in which a metal oxide, the ore, is zapped with electricity to create pure metal with oxygen as the byproduct. That is the reaction explored at the atomic level in new research reported in the April 8 issue of the journal Chemistry of Materials.

    Donald Siegel is department chair and professor of mechanical engineering at the University of Texas at Austin. Says Siegel, who was not involved in the Chemistry of Materials study: “This work is an important contribution to improving the efficiency of metal production from metal oxides. It clarifies our understanding of low-carbon electrolysis processes by tracing the underlying thermodynamics back to elementary metal-oxygen interactions. I expect that this work will aid in the creation of design rules that will make these industrially important processes less reliant on fossil fuels.”

    Yang Shao-Horn, the JR East Professor of Engineering in MIT’s Department of Materials Science and Engineering (DMSE) and Department of Mechanical Engineering, is a leader of the current work, with Michal Bajdich of SLAC.

    “Here we aim to establish some basic understanding to predict the efficiency of electrochemical metal production and metal-air batteries from examining computed thermodynamic barriers for the conversion between metal and metal oxides,” says Shao-Horn, who is on the research team for MIT’s new Center for Electrification and Decarbonization of Industry, a winner of the Institute’s first-ever Climate Grand Challenges competition. Shao-Horn is also affiliated with MIT’s Materials Research Laboratory and Research Laboratory of Electronics.

    In addition to Shao-Horn and Bajdich, other authors of the Chemistry of Materials paper are Jaclyn R. Lunger, first author and a DMSE graduate student; mechanical engineering senior Naomi Lutz; and DMSE graduate student Jiayu Peng.

    Other applications

    The work could also aid in developing metal-air batteries such as lithium-air, aluminum-air, and zinc-air batteries. These cousins of the lithium-ion batteries used in today’s electric vehicles have the potential to electrify aviation because their energy densities are much higher. However, they are not yet on the market due to a variety of problems including inefficiency.

    Charging metal-air batteries also involves electrolysis. As a result, the new atomic-level understanding of these reactions could not only help engineers develop efficient electrochemical routes for metal production, but also design more efficient metal-air batteries.

    Learning from water splitting

    Electrolysis is also used to split water into oxygen and hydrogen, which stores the resulting energy. That hydrogen, in turn, could become an eco-friendly alternative to fossil fuels. Since much more is known about water electrolysis, the focus of Bajdich’s work at SLAC, than the electrolysis of metal oxides, the team compared the two processes for the first time.

    The result: “Slowly, we uncovered the elementary steps involved in metal electrolysis,” says Bajdich. The work was challenging, says Lunger, because “it was unclear to us what those steps are. We had to figure out how to get from A to B,” or from a metal oxide to metal and oxygen.

    All of the work was conducted with supercomputer simulations. “It’s like a sandbox of atoms, and then we play with them. It’s a little like Legos,” says Bajdich. More specifically, the team explored different scenarios for the electrolysis of several metals. Each involved different catalysts, molecules that boost the speed of a reaction.

    Says Lunger, “To optimize the reaction, you want to find the catalyst that makes it most efficient.” The team’s map is essentially a guide for designing the best catalysts for each different metal.

    What’s next? Lunger noted that the current work focused on the electrolysis of pure metals. “I’m interested in seeing what happens in more complex systems involving multiple metals. Can you make the reaction more efficient if there’s sodium and lithium present, or cadmium and cesium?”

    This work was supported by a U.S. Department of Energy Office of Science Graduate Student Research award. It was also supported by an MIT Energy Initiative fellowship, the Toyota Research Institute through the Accelerated Materials Design and Discovery Program, the Catalysis Science Program of Department of Energy, Office of Basic Energy Sciences, and by the Differentiate Program through the U.S. Advanced Research Projects Agency — Energy.  More

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    New England renewables + Canadian hydropower

    The urgent need to cut carbon emissions has prompted a growing number of U.S. states to commit to achieving 100 percent clean electricity by 2040 or 2050. But figuring out how to meet those commitments and still have a reliable and affordable power system is a challenge. Wind and solar installations will form the backbone of a carbon-free power system, but what technologies can meet electricity demand when those intermittent renewable sources are not adequate?

    In general, the options being discussed include nuclear power, natural gas with carbon capture and storage (CCS), and energy storage technologies such as new and improved batteries and chemical storage in the form of hydrogen. But in the northeastern United States, there is one more possibility being proposed: electricity imported from hydropower plants in the neighboring Canadian province of Quebec.

    The proposition makes sense. Those plants can produce as much electricity as about 40 large nuclear power plants, and some power generated in Quebec already comes to the Northeast. So, there could be abundant additional supply to fill any shortfall when New England’s intermittent renewables underproduce. However, U.S. wind and solar investors view Canadian hydropower as a competitor and argue that reliance on foreign supply discourages further U.S. investment.

    Two years ago, three researchers affiliated with the MIT Center for Energy and Environmental Policy Research (CEEPR) — Emil Dimanchev SM ’18, now a PhD candidate at the Norwegian University of Science and Technology; Joshua Hodge, CEEPR’s executive director; and John Parsons, a senior lecturer in the MIT Sloan School of Management — began wondering whether viewing Canadian hydro as another source of electricity might be too narrow. “Hydropower is a more-than-hundred-year-old technology, and plants are already built up north,” says Dimanchev. “We might not need to build something new. We might just need to use those plants differently or to a greater extent.”

    So the researchers decided to examine the potential role and economic value of Quebec’s hydropower resource in a future low-carbon system in New England. Their goal was to help inform policymakers, utility decision-makers, and others about how best to incorporate Canadian hydropower into their plans and to determine how much time and money New England should spend to integrate more hydropower into its system. What they found out was surprising, even to them.

    The analytical methods

    To explore possible roles for Canadian hydropower to play in New England’s power system, the MIT researchers first needed to predict how the regional power system might look in 2050 — both the resources in place and how they would be operated, given any policy constraints. To perform that analysis, they used GenX, a modeling tool originally developed by Jesse Jenkins SM ’14, PhD ’18 and Nestor Sepulveda SM ’16, PhD ’20 while they were researchers at the MIT Energy Initiative (MITEI).

    The GenX model is designed to support decision-making related to power system investment and real-time operation and to examine the impacts of possible policy initiatives on those decisions. Given information on current and future technologies — different kinds of power plants, energy storage technologies, and so on — GenX calculates the combination of equipment and operating conditions that can meet a defined future demand at the lowest cost. The GenX modeling tool can also incorporate specified policy constraints, such as limits on carbon emissions.

    For their study, Dimanchev, Hodge, and Parsons set parameters in the GenX model using data and assumptions derived from a variety of sources to build a representation of the interconnected power systems in New England, New York, and Quebec. (They included New York to account for that state’s existing demand on the Canadian hydro resources.) For data on the available hydropower, they turned to Hydro-Québec, the public utility that owns and operates most of the hydropower plants in Quebec.

    It’s standard in such analyses to include real-world engineering constraints on equipment, such as how quickly certain power plants can be ramped up and down. With help from Hydro-Québec, the researchers also put hour-to-hour operating constraints on the hydropower resource.

    Most of Hydro-Québec’s plants are “reservoir hydropower” systems. In them, when power isn’t needed, the flow on a river is restrained by a dam downstream of a reservoir, and the reservoir fills up. When power is needed, the dam is opened, and the water in the reservoir runs through downstream pipes, turning turbines and generating electricity. Proper management of such a system requires adhering to certain operating constraints. For example, to prevent flooding, reservoirs must not be allowed to overfill — especially prior to spring snowmelt. And generation can’t be increased too quickly because a sudden flood of water could erode the river edges or disrupt fishing or water quality.

    Based on projections from the National Renewable Energy Laboratory and elsewhere, the researchers specified electricity demand for every hour of the year 2050, and the model calculated the cost-optimal mix of technologies and system operating regime that would satisfy that hourly demand, including the dispatch of the Hydro-Québec hydropower system. In addition, the model determined how electricity would be traded among New England, New York, and Quebec.

    Effects of decarbonization limits on technology mix and electricity trading

    To examine the impact of the emissions-reduction mandates in the New England states, the researchers ran the model assuming reductions in carbon emissions between 80 percent and 100 percent relative to 1990 levels. The results of those runs show that, as emissions limits get more stringent, New England uses more wind and solar and extends the lifetime of its existing nuclear plants. To balance the intermittency of the renewables, the region uses natural gas plants, demand-side management, battery storage (modeled as lithium-ion batteries), and trading with Quebec’s hydropower-based system. Meanwhile, the optimal mix in Quebec is mostly composed of existing hydro generation. Some solar is added, but new reservoirs are built only if renewable costs are assumed to be very high.

    The most significant — and perhaps surprising — outcome is that in all the scenarios, the hydropower-based system of Quebec is not only an exporter but also an importer of electricity, with the direction of flow on the Quebec-New England transmission lines changing over time.

    Historically, energy has always flowed from Quebec to New England. The model results for 2018 show electricity flowing from north to south, with the quantity capped by the current transmission capacity limit of 2,225 megawatts (MW).

    An analysis for 2050, assuming that New England decarbonizes 90 percent and the capacity of the transmission lines remains the same, finds electricity flows going both ways. Flows from north to south still dominate. But for nearly 3,500 of the 8,760 hours of the year, electricity flows in the opposite direction — from New England to Quebec. And for more than 2,200 of those hours, the flow going north is at the maximum the transmission lines can carry.

    The direction of flow is motivated by economics. When renewable generation is abundant in New England, prices are low, and it’s cheaper for Quebec to import electricity from New England and conserve water in its reservoirs. Conversely, when New England’s renewables are scarce and prices are high, New England imports hydro-generated electricity from Quebec.

    So rather than delivering electricity, Canadian hydro provides a means of storing the electricity generated by the intermittent renewables in New England.

    “We see this in our modeling because when we tell the model to meet electricity demand using these resources, the model decides that it is cost-optimal to use the reservoirs to store energy rather than anything else,” says Dimanchev. “We should be sending the energy back and forth, so the reservoirs in Quebec are in essence a battery that we use to store some of the electricity produced by our intermittent renewables and discharge it when we need it.”

    Given that outcome, the researchers decided to explore the impact of expanding the transmission capacity between New England and Quebec. Building transmission lines is always contentious, but what would be the impact if it could be done?

    Their model results shows that when transmission capacity is increased from 2,225 MW to 6,225 MW, flows in both directions are greater, and in both cases the flow is at the new maximum for more than 1,000 hours.

    Results of the analysis thus confirm that the economic response to expanded transmission capacity is more two-way trading. To continue the battery analogy, more transmission capacity to and from Quebec effectively increases the rate at which the battery can be charged and discharged.

    Effects of two-way trading on the energy mix

    What impact would the advent of two-way trading have on the mix of energy-generating sources in New England and Quebec in 2050?

    Assuming current transmission capacity, in New England, the change from one-way to two-way trading increases both wind and solar power generation and to a lesser extent nuclear; it also decreases the use of natural gas with CCS. The hydro reservoirs in Canada can provide long-duration storage — over weeks, months, and even seasons — so there is less need for natural gas with CCS to cover any gaps in supply. The level of imports is slightly lower, but now there are also exports. Meanwhile, in Quebec, two-way trading reduces solar power generation, and the use of wind disappears. Exports are roughly the same, but now there are imports as well. Thus, two-way trading reallocates renewables from Quebec to New England, where it’s more economical to install and operate solar and wind systems.

    Another analysis examined the impact on the energy mix of assuming two-way trading plus expanded transmission capacity. For New England, greater transmission capacity allows wind, solar, and nuclear to expand further; natural gas with CCS all but disappears; and both imports and exports increase significantly. In Quebec, solar decreases still further, and both exports and imports of electricity increase.

    Those results assume that the New England power system decarbonizes by 99 percent in 2050 relative to 1990 levels. But at 90 percent and even 80 percent decarbonization levels, the model concludes that natural gas capacity decreases with the addition of new transmission relative to the current transmission scenario. Existing plants are retired, and new plants are not built as they are no longer economically justified. Since natural gas plants are the only source of carbon emissions in the 2050 energy system, the researchers conclude that the greater access to hydro reservoirs made possible by expanded transmission would accelerate the decarbonization of the electricity system.

    Effects of transmission changes on costs

    The researchers also explored how two-way trading with expanded transmission capacity would affect costs in New England and Quebec, assuming 99 percent decarbonization in New England. New England’s savings on fixed costs (investments in new equipment) are largely due to a decreased need to invest in more natural gas with CCS, and its savings on variable costs (operating costs) are due to a reduced need to run those plants. Quebec’s savings on fixed costs come from a reduced need to invest in solar generation. The increase in cost — borne by New England — reflects the construction and operation of the increased transmission capacity. The net benefit for the region is substantial.

    Thus, the analysis shows that everyone wins as transmission capacity increases — and the benefit grows as the decarbonization target tightens. At 99 percent decarbonization, the overall New England-Quebec region pays about $21 per megawatt-hour (MWh) of electricity with today’s transmission capacity but only $18/MWh with expanded transmission. Assuming 100 percent reduction in carbon emissions, the region pays $29/MWh with current transmission capacity and only $22/MWh with expanded transmission.

    Addressing misconceptions

    These results shed light on several misconceptions that policymakers, supporters of renewable energy, and others tend to have.

    The first misconception is that the New England renewables and Canadian hydropower are competitors. The modeling results instead show that they’re complementary. When the power systems in New England and Quebec work together as an integrated system, the Canadian reservoirs are used part of the time to store the renewable electricity. And with more access to hydropower storage in Quebec, there’s generally more renewable investment in New England.

    The second misconception arises when policymakers refer to Canadian hydro as a “baseload resource,” which implies a dependable source of electricity — particularly one that supplies power all the time. “Our study shows that by viewing Canadian hydropower as a baseload source of electricity — or indeed a source of electricity at all — you’re not taking full advantage of what that resource can provide,” says Dimanchev. “What we show is that Quebec’s reservoir hydro can provide storage, specifically for wind and solar. It’s a solution to the intermittency problem that we foresee in carbon-free power systems for 2050.”

    While the MIT analysis focuses on New England and Quebec, the researchers believe that their results may have wider implications. As power systems in many regions expand production of renewables, the value of storage grows. Some hydropower systems have storage capacity that has not yet been fully utilized and could be a good complement to renewable generation. Taking advantage of that capacity can lower the cost of deep decarbonization and help move some regions toward a decarbonized supply of electricity.

    This research was funded by the MIT Center for Energy and Environmental Policy Research, which is supported in part by a consortium of industry and government associates.

    This article appears in the Autumn 2021 issue of Energy Futures, the magazine of the MIT Energy Initiative. More

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    Finding the questions that guide MIT fusion research

    “One of the things I learned was, doing good science isn’t so much about finding the answers as figuring out what the important questions are.”

    As Martin Greenwald retires from the responsibilities of senior scientist and deputy director of the MIT Plasma Science and Fusion Center (PSFC), he reflects on his almost 50 years of science study, 43 of them as a researcher at MIT, pursuing the question of how to make the carbon-free energy of fusion a reality.

    Most of Greenwald’s important questions about fusion began after graduating from MIT with a BS in both physics and chemistry. Beginning graduate work at the University of California at Berkeley, he felt compelled to learn more about fusion as an energy source that could have “a real societal impact.” At the time, researchers were exploring new ideas for devices that could create and confine fusion plasmas. Greenwald worked on Berkeley’s “alternate concept” TORMAC, a Toroidal Magnetic Cusp. “It didn’t work out very well,” he laughs. “The first thing I was known for was making the measurements that shut down the program.”

    Believing the temperature of the plasma generated by the device would not be as high as his group leader expected, Greenwald developed hardware that could measure the low temperatures predicted by his own “back of the envelope calculations.” As he anticipated, his measurements showed that “this was not a fusion plasma; this was hardly a confined plasma at all.”

    With a PhD from Berkeley, Greenwald returned to MIT for a research position at the PSFC, attracted by the center’s “esprit de corps.”

    He arrived in time to participate in the final experiments on Alcator A, the first in a series of tokamaks built at MIT, all characterized by compact size and featuring high-field magnets. The tokamak design was then becoming favored as the most effective route to fusion: its doughnut-shaped vacuum chamber, surrounded by electromagnets, could confine the turbulent plasma long enough, while increasing its heat and density, to make fusion occur.

    Alcator A showed that the energy confinement time improves in relation to increasing plasma density. MIT’s succeeding device, Alcator C, was designed to use higher magnetic fields, boosting expectations that it would reach higher densities and better confinement. To attain these goals, however, Greenwald had to pursue a new technique that increased density by injecting pellets of frozen fuel into the plasma, a method he likens to throwing “snowballs in hell.” This work was notable for the creation of a new regime of enhanced plasma confinement on Alcator C. In those experiments, a confined plasma surpassed for the first time one of the two Lawson criteria — the minimum required value for the product of the plasma density and confinement time — for making net power from fusion. This had been a milestone for fusion research since their publication by John Lawson in 1957.

    Greenwald continued to make a name for himself as part of a larger study into the physics of the Compact Ignition Tokamak — a high-field burning plasma experiment that the U.S. program was proposing to build in the late 1980s. The result, unexpectedly, was a new scaling law, later known as the “Greenwald Density Limit,” and a new theory for the mechanism of the limit. It has been used to accurately predict performance on much larger machines built since.

    The center’s next tokamak, Alcator C-Mod, started operation in 1993 and ran for more than 20 years, with Greenwald as the chair of its Experimental Program Committee. Larger than Alcator C, the new device supported a highly shaped plasma, strong radiofrequency heating, and an all-metal plasma-facing first wall. All of these would eventually be required in a fusion power system.

    C-Mod proved to be MIT’s most enduring fusion experiment to date, producing important results for 20 years. During that time Greenwald contributed not only to the experiments, but to mentoring the next generation. Research scientist Ryan Sweeney notes that “Martin quickly gained my trust as a mentor, in part due to his often casual dress and slightly untamed hair, which are embodiments of his transparency and his focus on what matters. He can quiet a room of PhDs and demand attention not by intimidation, but rather by his calmness and his ability to bring clarity to complicated problems, be they scientific or human in nature.”

    Greenwald worked closely with the group of students who, in PSFC Director Dennis Whyte’s class, came up with the tokamak concept that evolved into SPARC. MIT is now pursuing this compact, high-field tokamak with Commonwealth Fusion Systems, a startup that grew out of the collective enthusiasm for this concept, and the growing realization it could work. Greenwald now heads the Physics Group for the SPARC project at MIT. He has helped confirm the device’s physics basis in order to predict performance and guide engineering decisions.

    “Martin’s multifaceted talents are thoroughly embodied by, and imprinted on, SPARC” says Whyte. “First, his leadership in its plasma confinement physics validation and publication place SPARC on a firm scientific footing. Secondly, the impact of the density limit he discovered, which shows that fuel density increases with magnetic field and decreasing the size of the tokamak, is critical in obtaining high fusion power density not just in SPARC, but in future power plants. Third, and perhaps most impressive, is Martin’s mentorship of the SPARC generation of leadership.”

    Greenwald’s expertise and easygoing personality have made him an asset as head of the PSFC Office for Computer Services and group leader for data acquisition and computing, and sought for many professional committees. He has been an APS Fellow since 2000, and was an APS Distinguished Lecturer in Plasma Physics (2001-02). He was also presented in 2014 with a Leadership Award from Fusion Power Associates. He is currently an associate editor for Physics of Plasmas and a member of the Lawrence Livermore National Laboratory Physical Sciences Directorate External Review Committee.

    Although leaving his full-time responsibilities, Greenwald will remain at MIT as a visiting scientist, a role he says will allow him to “stick my nose into everything without being responsible for anything.”

    “At some point in the race you have to hand off the baton,“ he says. “And it doesn’t mean you’re not interested in the outcome; and it doesn’t mean you’re just going to walk away into the stands. I want to be there at the end when we succeed.” More

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    MIT Energy Conference focuses on climate’s toughest challenges

    This year’s MIT Energy Conference, the largest student-led event of its kind, included keynote talks and panels that tackled some of the thorniest remaining challenges in the global effort to cut back on climate-altering emissions. These include the production of construction materials such as steel and cement, and the role of transportation including aviation and shipping. While the challenges are formidable, approaches incorporating methods such as fusion, heat pumps, energy efficiency, and the use of hydrogen hold promise, participants said.

    The two-day conference, held on March 31 and April 1 for more than 900 participants, included keynote lectures, 14 panel discussions, a fireside chat, networking events, and more. The event this year included the final round of the annual MIT Climate and Energy Prize, whose winning team receives $100,000 and other support. The prize, awarded since 2007, has led to the creation of more than 220 companies and $1.1 billion in investments.

    This year’s winner is a project that hopes to provide an innovative, efficient waterless washing machine aimed at the vast majority of the world’s people, who still do laundry by hand.

    “A truly consequential moment in history”

    In his opening keynote address Fatih Birol, executive director of the International Energy Agency, noted that this year’s conference was taking place during the unprovoked invasion of Ukraine by Russia, a leading gas and oil exporter. As a result, “global oil markets are going through a major turmoil,” he said.

    He said that Russian oil exports are expected to drop by 3 million barrels a day, and that international efforts to release reserves and promote increased production elsewhere will help, but will not suffice. “We have to look to other measures” to make up the shortfall, he said, noting that his agency has produced a 10-point plan of measures to help reduce global demand for oil.

    Europe gets 45 percent of its natural gas from Russia, and the agency also has developed a 10-point plan to help alleviate expected shortages there, including measures to improve energy efficiency in homes and industries, promote renewable heating sources, and postpone retirement of some nuclear plants. But he emphasized that “our goals to reach our climate targets should not be yet another victim of Mr. Putin and his allies.”  Unfortunately, Birol said, “I see that addressing climate change is sliding down in the policy agenda of many governments.”

    But he sees reasons for optimism as well, in terms of the feasibility of achieving the global emissions reduction target, agreed to by countries representing 80 percent of the global economy, of reaching net zero carbon dioxide emissions by 2050. The IEA has developed a roadmap for the entire energy sector to get there, which is now used by many governments as a benchmark, according to Birol.

    In addition, the trend is already clear, he said. “More than 90 percent of all power plants installed in the world [last year] were renewable energy,” mainly solar and wind. And 10 percent of cars sold worldwide last year, and 20 percent in Europe, were electric cars. “Please remember that in 2019 it was only 2 percent!” he said. He also predicted that “nuclear is going to make a comeback in many countries,” both in terms of large plants and newer small modular reactors.

    Birol said that “I hope that the current crisis gives governments the impetus to address the energy security concerns, to reach our climate goals, and … [to] choose the right direction at this very important turning point.”

    The conference’s second day began with keynote talks by Gina McCarthy, national climate advisor at the White House Office of Domestic Climate Policy, and Maria Zuber, MIT’s vice president for research. In her address, Zuber said, “This conference comes at a truly consequential moment in history — a moment that puts into stark relief the enormous risks created by our current fossil-fuel based energy system — risks we cannot continue to accept.”

    She added that “time is not on our side.” To meet global commitments for limiting climate impacts, the world needs to reduce emissions by about half by 2030, and get to net zero by 2050. “In other words, we need to transform our entire global energy system in a few decades,” she said. She cited MIT’s “Fast Forward” climate action plan, issued last year, as presenting the two tracks that the world needs to pursue simultaneously: going as far as possible, as fast as possible, with the tools that exist now, while also innovating and investing in new ideas, technologies, practices, and institutions that may be needed to reach the net-zero goal.

    On the first track, she said, citing an IEA report, “from here until 2040, we can get most of the emissions reductions we need with technologies that are currently available or on the verge of becoming commercially available.” These include electrifying and boosting efficiency in buildings, industry, and transportation; increasing the portion of electricity coming from emissions-free sources; and investing in new infrastructure such as electric vehicle charging stations.

    But more than that is needed, she pointed out. For example, the amount of methane that leaks away into the atmosphere from fossil fuel operations is equivalent to all the natural gas used in Europe’s power sector, Zuber said. Recovering and selling that methane can dramatically reduce global methane emissions, often at little or no cost.

    For the longer run, “we need track-two solutions to decarbonize tough industries like aviation, shipping, chemicals, concrete, and steel,” and to remove carbon dioxide from the atmosphere. She described some of the promising technologies that are in the pipeline. Fusion, for example, has moved from being a scientific challenge to an engineering problem whose solution seems well underway, she said.

    Another important area is food-related systems, which currently account for a third of all global emissions. For example, fertilizer production uses a very energy-intensive process, but work on plants engineered to fix nitrogen directly could make a significant dent.

    These and several other advanced research areas may not all pan out, but some undoubtedly will, and will help curb climate change as well as create new jobs and reduce pollution.

    Though the problems we face are complex, they are not insurmountable, Zuber said. “We don’t need a miracle. What we need is to move along the two tracks I’ve outlined with determination, ingenuity, and fierce urgency.”

    The promise and challenges of hydrogen

    Other conference speakers took on some of the less-discussed but crucial areas that also need to be addressed in order to limit global warming to 1.5 degrees. Heavy transportation, and aviation in particular, have been considered especially challenging. In his keynote address, Glenn Llewellyn, vice president for zero-emission aircraft at Airbus, outlined several approaches his company is working on to develop competitive midrange alternative airliners by 2035 that use either batteries or fuel cells powered by hydrogen. The early-stage designs demonstrate that, contrary to some projections, there is a realistic pathway to weaning that industry from its present reliance on fossil fuel, chiefly kerosene.

    Hydrogen has real potential as an aviation fuel, he said, either directly for use in fuel cells for power or burned directly for propulsion, or indirectly as a feedstock for synthetic fuels. Both are being studied by the company, he said, including a hybrid model that uses both hydrogen fuel cells and hydrogen-fueled jet engines. The company projects a range of 2,000 nautical miles for a jet carrying 200 to 300 passengers, he said — all with no direct emissions and no contrails.

    But this vision will not be practical, Llewellyn said, unless economies of scale help to significantly lower the cost of hydrogen production. “Hydrogen is at the hub of aviation decarbonization,” he said. But that kind of price reduction seems quite feasible, he said, given that other major industries are also seriously looking at the use of hydrogen for their own decarbonization plans, including the production of steel and cement.

    Such uses were the subject of a panel discussion entitled “Deploying the Hydrogen Economy.” Hydrogen production technology exists, but not nearly at the scale that’s needed, which is about 500 million tons a year, pointed out moderator Dharik Mallapragada of the MIT Energy Initiative.

    Yet in some applications, the use of hydrogen both reduces emissions and is economically competitive. Preeti Pande of Plug Power said that her company, which produces hydrogen fuel cells, has found a significant market in an unexpected place: fork lifts, used in warehouses and factories worldwide. It turns out that replacing current battery-operated versions with fuel cell versions is a win-win for the companies that use them, saving money while helping to meet decarbonization goals.

    Lindsay Ashby of Avangrid Renewables said that the company has installed fuel-cell buses in Barcelona that run entirely on hydrogen generated by solar panels. The company is also building a 100-megawatt solar facility to produce hydrogen for the production of fertilizer, another major industry in need of decarbonization because of its large emissions footprint. And Brett Perleman of the Center for Houston’s Future said of his city that “we’re already a hydrogen hub today, just not green hydrogen” since the gas is currently mostly produced as a byproduct of fossil fuels. But that is changing rapidly, he said, and Houston, along with several other cities, aims to be a center of activity for hydrogen produced from renewable, non-carbon-emitting sources. They aim to be producing 1,000 tons a day by 2028, “and I think we’ll end up exceeding that,” he said.

    For industries that can switch to renewably generated electricity, that is typically the best choice, Perleman said. “But for those that can’t, hydrogen is a great option,” and that includes aviation, shipping, and rail. “The big oil companies all have plans in place” to develop clean hydrogen production, he said. “It’s not just a dream, but a reality.”

    For shipping, which tends to rely on bunker fuel, a particularly high-emissions fossil fuel, another potential option could be a new generation of small nuclear plants, said Jeff Navin of Terrapower, a company currently developing such units. “Finding replacements for coal, oil, or natural gas for industrial purposes is very hard,” he said, but often what these processes require is consistent high heat, which nuclear can deliver, as long as costs and regulatory issues can be resolved.  

    MIT professor of nuclear engineering Jacopo Buongiorno pointed out that the primary reasons for delays and cost overruns in nuclear plants have had to do with issues at the construction site, many of which could be alleviated by having smaller, factory-built modular plants, or by building multiple units at a time of a standardized design. If the government would take on the nuclear waste disposal, as some other countries have done, then nuclear power could play an important part in the decarbonization of many industries, he said.

    Student-led startups

    The two-day conference concluded with the final round of the annual MIT Climate and Energy Prize, consisting of the five finalist teams presenting brief pitches for their startup company ideas, followed by questions from the panel of judges. This year’s finalists included a team called Muket, dedicated to finding ways of reducing methane emissions from cattle and dairy farms. Feed additives or other measures could cut the emissions by 50 percent, the team estimates.

    A team called Ivu Biologics described a system for incorporating nitrogen-fixing microbes into the coatings of seeds, thereby reducing the need for added fertilizers, whose production is a major greenhouse gas source. The company is making use of seed-coating technology developed at MIT over the last few years. Another team, called Mesophase, also based on MIT-developed technology, aims to replace the condensers used in power plants and other industrial systems with much more efficient versions, thus increasing the energy output from a given amount of fuel or other heat source.

    A team called TerraTrade aims to facilitate the adoption of power purchase agreements by companies, institutions and governments, by acting as a kind of broker to create and administer such agreements, making it easier for even smaller entities to take part in these plans, which help to enable rapid development of renewable fossil-fuel-free energy production.

    The grand prize of $100,000 was awarded to a team called Ultropia, which is developing a combined clothes washer and drier that uses ultrasound instead of water for its cleaning. The system does use a small amount of water, but this can be recycled, making these usable even in areas where water availability is limited. The devices could have a great impact on the estimated 6 billion people in the world today who are still limited to washing clothes by hand, the team says, and because the machines would be so efficient, they would require very little energy to run — a significant improvement over the wider adoption of conventional washers and driers. More

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    Chemical reactions for the energy transition

    One challenge in decarbonizing the energy system is knowing how to deal with new types of fuels. Traditional fuels such as natural gas and oil can be combined with other materials and then heated to high temperatures so they chemically react to produce other useful fuels or substances, or even energy to do work. But new materials such as biofuels can’t take as much heat without breaking down.

    A key ingredient in such chemical reactions is a specially designed solid catalyst that is added to encourage the reaction to happen but isn’t itself consumed in the process. With traditional materials, the solid catalyst typically interacts with a gas; but with fuels derived from biomass, for example, the catalyst must work with a liquid — a special challenge for those who design catalysts.

    For nearly a decade, Yogesh Surendranath, an associate professor of chemistry at MIT, has been focusing on chemical reactions between solid catalysts and liquids, but in a different situation: rather than using heat to drive reactions, he and his team input electricity from a battery or a renewable source such as wind or solar to give chemically inactive molecules more energy so they react. And key to their research is designing and fabricating solid catalysts that work well for reactions involving liquids.

    Recognizing the need to use biomass to develop sustainable liquid fuels, Surendranath wondered whether he and his team could take the principles they have learned about designing catalysts to drive liquid-solid reactions with electricity and apply them to reactions that occur at liquid-solid interfaces without any input of electricity.

    To their surprise, they found that their knowledge is directly relevant. Why? “What we found — amazingly — is that even when you don’t hook up wires to your catalyst, there are tiny internal ‘wires’ that do the reaction,” says Surendranath. “So, reactions that people generally think operate without any flow of current actually do involve electrons shuttling from one place to another.” And that means that Surendranath and his team can bring the powerful techniques of electrochemistry to bear on the problem of designing catalysts for sustainable fuels.

    A novel hypothesis

    Their work has focused on a class of chemical reactions important in the energy transition that involve adding oxygen to small organic (carbon-containing) molecules such as ethanol, methanol, and formic acid. The conventional assumption is that the reactant and oxygen chemically react to form the product plus water. And a solid catalyst — often a combination of metals — is present to provide sites on which the reactant and oxygen can interact.

    But Surendranath proposed a different view of what’s going on. In the usual setup, two catalysts, each one composed of many nanoparticles, are mounted on a conductive carbon substrate and submerged in water. In that arrangement, negatively charged electrons can flow easily through the carbon, while positively charged protons can flow easily through water.

    Surendranath’s hypothesis was that the conversion of reactant to product progresses by means of two separate “half-reactions” on the two catalysts. On one catalyst, the reactant turns into a product, in the process sending electrons into the carbon substrate and protons into the water. Those electrons and protons are picked up by the other catalyst, where they drive the oxygen-to-water conversion. So, instead of a single reaction, two separate but coordinated half-reactions together achieve the net conversion of reactant to product.

    As a result, the overall reaction doesn’t actually involve any net electron production or consumption. It is a standard “thermal” reaction resulting from the energy in the molecules and maybe some added heat. The conventional approach to designing a catalyst for such a reaction would focus on increasing the rate of that reactant-to-product conversion. And the best catalyst for that kind of reaction could turn out to be, say, gold or palladium or some other expensive precious metal.

    However, if that reaction actually involves two half-reactions, as Surendranath proposed, there is a flow of electrical charge (the electrons and protons) between them. So Surendranath and others in the field could instead use techniques of electrochemistry to design not a single catalyst for the overall reaction but rather two separate catalysts — one to speed up one half-reaction and one to speed up the other half-reaction. “That means we don’t have to design one catalyst to do all the heavy lifting of speeding up the entire reaction,” says Surendranath. “We might be able to pair up two low-cost, earth-abundant catalysts, each of which does half of the reaction well, and together they carry out the overall transformation quickly and efficiently.”

    But there’s one more consideration: Electrons can flow through the entire catalyst composite, which encompasses the catalyst particle(s) and the carbon substrate. For the chemical conversion to happen as quickly as possible, the rate at which electrons are put into the catalyst composite must exactly match the rate at which they are taken out. Focusing on just the electrons, if the reaction-to-product conversion on the first catalyst sends the same number of electrons per second into the “bath of electrons” in the catalyst composite as the oxygen-to-water conversion on the second catalyst takes out, the two half-reactions will be balanced, and the electron flow — and the rate of the combined reaction — will be fast. The trick is to find good catalysts for each of the half-reactions that are perfectly matched in terms of electrons in and electrons out.

    “A good catalyst or pair of catalysts can maintain an electrical potential — essentially a voltage — at which both half-reactions are fast and are balanced,” says Jaeyune Ryu PhD ’21, a former member of the Surendranath lab and lead author of the study; Ryu is now a postdoc at Harvard University. “The rates of the reactions are equal, and the voltage in the catalyst composite won’t change during the overall thermal reaction.”

    Drawing on electrochemistry

    Based on their new understanding, Surendranath, Ryu, and their colleagues turned to electrochemistry techniques to identify a good catalyst for each half-reaction that would also pair up to work well together. Their analytical framework for guiding catalyst development for systems that combine two half-reactions is based on a theory that has been used to understand corrosion for almost 100 years, but has rarely been applied to understand or design catalysts for reactions involving small molecules important for the energy transition.

    Key to their work is a potentiostat, a type of voltmeter that can either passively measure the voltage of a system or actively change the voltage to cause a reaction to occur. In their experiments, Surendranath and his team use the potentiostat to measure the voltage of the catalyst in real time, monitoring how it changes millisecond to millisecond. They then correlate those voltage measurements with simultaneous but separate measurements of the overall rate of catalysis to understand the reaction pathway.

    For their study of the conversion of small, energy-related molecules, they first tested a series of catalysts to find good ones for each half-reaction — one to convert the reactant to product, producing electrons and protons, and another to convert the oxygen to water, consuming electrons and protons. In each case, a promising candidate would yield a rapid reaction — that is, a fast flow of electrons and protons out or in.

    To help identify an effective catalyst for performing the first half-reaction, the researchers used their potentiostat to input carefully controlled voltages and measured the resulting current that flowed through the catalyst. A good catalyst will generate lots of current for little applied voltage; a poor catalyst will require high applied voltage to get the same amount of current. The team then followed the same procedure to identify a good catalyst for the second half-reaction.

    To expedite the overall reaction, the researchers needed to find two catalysts that matched well — where the amount of current at a given applied voltage was high for each of them, ensuring that as one produced a rapid flow of electrons and protons, the other one consumed them at the same rate.

    To test promising pairs, the researchers used the potentiostat to measure the voltage of the catalyst composite during net catalysis — not changing the voltage as before, but now just measuring it from tiny samples. In each test, the voltage will naturally settle at a certain level, and the goal is for that to happen when the rate of both reactions is high.

    Validating their hypothesis and looking ahead

    By testing the two half-reactions, the researchers could measure how the reaction rate for each one varied with changes in the applied voltage. From those measurements, they could predict the voltage at which the full reaction would proceed fastest. Measurements of the full reaction matched their predictions, supporting their hypothesis.

    The team’s novel approach of using electrochemistry techniques to examine reactions thought to be strictly thermal in nature provides new insights into the detailed steps by which those reactions occur and therefore into how to design catalysts to speed them up. “We can now use a divide-and-conquer strategy,” says Ryu. “We know that the net thermal reaction in our study happens through two ‘hidden’ but coupled half-reactions, so we can aim to optimize one half-reaction at a time” — possibly using low-cost catalyst materials for one or both.

    Adds Surendranath, “One of the things that we’re excited about in this study is that the result is not final in and of itself. It has really seeded a brand-new thrust area in our research program, including new ways to design catalysts for the production and transformation of renewable fuels and chemicals.”

    This research was supported primarily by the Air Force Office of Scientific Research. Jaeyune Ryu PhD ’21 was supported by a Samsung Scholarship. Additional support was provided by a National Science Foundation Graduate Research Fellowship.

    This article appears in the Autumn 2021 issue of Energy Futures, the magazine of the MIT Energy Initiative. More

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    Q&A: Latifah Hamzah ’12 on creating sustainable solutions in Malaysia and beyond

    Latifah Hamzah ’12 graduated from MIT with a BS in mechanical engineering and minors in energy studies and music. During their time at MIT, Latifah participated in various student organizations, including the MIT Symphony Orchestra, Alpha Phi Omega, and the MIT Design/Build/Fly team. They also participated in the MIT Energy Initiative’s Undergraduate Research Opportunities Program (UROP) in the lab of former professor of mechanical engineering Alexander Mitsos, examining solar-powered thermal and electrical co-generation systems.

    After graduating from MIT, Latifah worked as a subsea engineer at Shell Global Solutions and co-founded Engineers Without Borders – Malaysia, a nonprofit organization dedicated to finding sustainable and empowering solutions that impact disadvantaged populations in Malaysia. More recently, Latifah received a master of science in mechanical engineering from Stanford University, where they are currently pursuing a PhD in environmental engineering with a focus on water and sanitation in developing contexts.

    Q: What inspired you to pursue energy studies as an undergraduate student at MIT?

    A: I grew up in Malaysia, where I was at once aware of both the extent to which the oil and gas industry is a cornerstone of the economy and the need to transition to a lower-carbon future. The Energy Studies minor was therefore enticing because it gave me a broader view of the energy space, including technical, policy, economic, and other viewpoints. This was my first exposure to how things worked in the real world — in that many different fields and perspectives had to be considered cohesively in order to have a successful, positive, and sustained impact. Although the minor was predominantly grounded in classroom learning, what I learned drove me to want to discover for myself how the forces of technology, society, and policy interacted in the field in my subsequent endeavors.

    In addition to the breadth that the minor added to my education, it also provided a structure and focus for me to build on my technical fundamentals. This included taking graduate-level classes and participating in UROPs that had specific energy foci. These were my first forays into questions that, while still predominantly technical, were more open-ended and with as-yet-unknown answers that would be substantially shaped by the framing of the question. This shift in mindset required from typical undergraduate classes and problem sets took a bit of adjusting to, but ultimately gave me the confidence and belief that I could succeed in a more challenging environment.

    Q: How did these experiences with energy help shape your path forward, particularly in regard to your work with Engineers Without Borders – Malaysia and now at Stanford?

    A: When I returned home after graduation, I was keen to harness my engineering education and explore in practice what the Energy Studies minor curriculum had taught by theory and case studies: to consider context, nuance, and interdisciplinary and myriad perspectives to craft successful, sustainable solutions. Recognizing that there were many underserved communities in Malaysia, I co-founded Engineers Without Borders – Malaysia with some friends with the aim of working with these communities to bring simple and sustainable engineering solutions. Many of these projects did have an energy focus. For example, we designed, sized, and installed micro-hydro or solar-power systems for various indigenous communities, allowing them to continue living on their ancestral lands while reducing energy poverty. Many other projects incorporated other aspects of engineering, such as hydrotherapy pools for folks with special needs, and water and sanitation systems for stateless maritime communities.

    Through my work with Engineers Without Borders – Malaysia, I found a passion for the broader aspects of sustainability, development, and equity. By spending time with communities in the field and sharing in their experiences, I recognized gaps in my skill set that I could work on to be more effective in advocating for social and environmental justice. In particular, I wanted to better understand communities and their perspectives while being mindful of my positionality. In addition, I wanted to address the more systemic aspects of the problems they faced, which I felt in many cases would only be possible through a combination of research, evidence, and policy. To this end, I embarked on a PhD in environmental engineering with a minor in anthropology and pursued a Community-Based Research Fellowship with Stanford’s Haas Center for Public Service. I have also participated in the Rising Environmental Leaders Program (RELP), which helps graduate students “hone their leadership and communications skills to maximize the impact of their research.” RELP afforded me the opportunity to interact with representatives from government, NGOs [nongovernmental organizations], think tanks, and industry, from which I gained a better understanding of the policy and adjacent ecosystems at both the federal and state levels.

    Q: What are you currently studying, and how does it relate to your past work and educational experiences?

    A: My dissertation investigates waste management and monitoring for improved planetary health in three distinct projects. Suboptimal waste management can lead to poor outcomes, including environmental contamination, overuse of resources, and lost economic and environmental opportunities in resource recovery. My first project showed that three combinations of factors resulted in ruminant feces contaminating the stored drinking water supplies of households in rural Kenya, and the results were published in the International Journal of Environmental Research and Public Health. Consequently, water and sanitation interventions must also consider animal waste for communities to have safe drinking water.

    My second project seeks to establish a circular economy in the chocolate industry with indigenous Malaysian farmers and the Chocolate Concierge, a tree-to-bar social enterprise. Having designed and optimized apparatuses and processes to create biochar from cacao husk waste, we are now examining its impact on the growth of cacao saplings and their root systems. The hope is that biochar will increase the resilience of saplings for when they are transplanted from the nursery to the farm. As biochar can improve soil health and yield while reducing fertilizer inputs and sequestering carbon, farmers can accrue substantial economic and environmental benefits, especially if they produce, use, and sell it themselves.

    My third project investigates the gap in sanitation coverage worldwide and potential ways of reducing it. Globally, 46 percent of the population lacks access to safely managed sanitation, while the majority of the 54 percent who do have access use on-site sanitation facilities such as septic tanks and latrines. Given that on-site, decentralized systems typically have a lower space and resource footprint, are cheaper to build and maintain, and can be designed to suit various contexts, they could represent the best chance of reaching the sanitation Sustainable Development Goal. To this end, I am part of a team of researchers at the Criddle Group at Stanford working to develop a household-scale system as part of the Gates Reinvent the Toilet Challenge, an initiative aimed at developing new sanitation and toilet technologies for developing contexts.

    The thread connecting these projects is a commitment to investigating both the technical and socio-anthropological dimensions of an issue to develop sustainable, reliable, and environmentally sensitive solutions, especially in low- and middle-income countries (LMICs). I believe that an interdisciplinary approach can provide a better understanding of the problem space, which will hopefully lead to effective potential solutions that can have a greater community impact.

    Q: What do you plan to do once you obtain your PhD?

    A: I hope to continue working in the spheres of water and sanitation and/or sustainability post-PhD. It is a fascinating moment to be in this space as a person of color from an LMIC, especially as ideas such as community-based research and decolonizing fields and institutions are becoming more widespread and acknowledged. Even during my time at Stanford, I have noticed some shifts in the discourse, although we still have a long way to go to achieve substantive and lasting change. Folks like me are underrepresented in forums where the priorities, policies, and financing of aid and development are discussed at the international or global scale. I hope I’ll be able to use my qualifications, experience, and background to advocate for more just outcomes.

    This article appears in the Autumn 2021 issue of Energy Futures, the magazine of the MIT Energy Initiative More