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    How hard is it to prevent recurring blackouts in Puerto Rico?

    Researchers at MIT’s Laboratory for Information and Decision Systems (LIDS) have shown that using decision-making software and dynamic monitoring of weather and energy use can significantly improve resiliency in the face of weather-related outages, and can also help to efficiently integrate renewable energy sources into the grid.The researchers point out that the system they suggest might have prevented or at least lessened the kind of widespread power outage that Puerto Rico experienced last week by providing analysis to guide rerouting of power through different lines and thus limit the spread of the outage.The computer platform, which the researchers describe as DyMonDS, for Dynamic Monitoring and Decision Systems, can be used to enhance the existing operating and planning practices used in the electric industry. The platform supports interactive information exchange and decision-making between the grid operators and grid-edge users — all the distributed power sources, storage systems and software that contribute to the grid. It also supports optimization of available resources and controllable grid equipment as system conditions vary. It further lends itself to implementing cooperative decision-making by different utility- and non-utility-owned electric power grid users, including portfolios of mixed resources, users, and storage. Operating and planning the interactions of the end-to-end high-voltage transmission grid with local distribution grids and microgrids represents another major potential use of this platform.This general approach was illustrated using a set of publicly-available data on both meteorology and details of electricity production and distribution in Puerto Rico. An extended AC Optimal Power Flow software developed by SmartGridz Inc. is used for system-level optimization of controllable equipment. This provides real-time guidance for deciding how much power, and through which transmission lines, should be channeled by adjusting plant dispatch and voltage-related set points, and in extreme cases, where to reduce or cut power in order to maintain physically-implementable service for as many customers as possible. The team found that the use of such a system can help to ensure that the greatest number of critical services maintain power even during a hurricane, and at the same time can lead to a substantial decrease in the need for construction of new power plants thanks to more efficient use of existing resources.The findings are described in a paper in the journal Foundations and Trends in Electric Energy Systems, by MIT LIDS researchers Marija Ilic and Laurentiu Anton, along with recent alumna Ramapathi Jaddivada.“Using this software,” Ilic says, they show that “even during bad weather, if you predict equipment failures, and by using that information exchange, you can localize the effect of equipment failures and still serve a lot of customers, 50 percent of customers, when otherwise things would black out.”Anton says that “the way many grids today are operated is sub-optimal.” As a result, “we showed how much better they could do even under normal conditions, without any failures, by utilizing this software.” The savings resulting from this optimization, under everyday conditions, could be in the tens of percents, they say.The way utility systems plan currently, Ilic says, “usually the standard is that they have to build enough capacity and operate in real time so that if one large piece of equipment fails, like a large generator or transmission line, you still serve customers in an uninterrupted way. That’s what’s called N-minus-1.” Under this policy, if one major component of the system fails, they should be able to maintain service for at least 30 minutes. That system allows utilities to plan for how much reserve generating capacity they need to have on hand. That’s expensive, Ilic points out, because it means maintaining this reserve capacity all the time, even under normal operating conditions when it’s not needed.In addition, “right now there are no criteria for what I call N-minus-K,” she says. If bad weather causes five pieces of equipment to fail at once, “there is no software to help utilities decide what to schedule” in terms of keeping the most customers, and the most important services such as hospitals and emergency services, provided with power. They showed that even with 50 percent of the infrastructure out of commission, it would still be possible to keep power flowing to a large proportion of customers.Their work on analyzing the power situation in Puerto Rico started after the island had been devastated by hurricanes Irma and Maria. Most of the electric generation capacity is in the south, yet the largest loads are in San Juan, in the north, and Mayaguez in the west. When transmission lines get knocked down, a lot of rerouting of power needs to happen quickly.With the new systems, “the software finds the optimal adjustments for set points,” for example, changing voltages can allow for power to be redirected through less-congested lines, or can be increased to lessen power losses, Anton says.The software also helps in the long-term planning for the grid. As many fossil-fuel power plants are scheduled to be decommissioned soon in Puerto Rico, as they are in many other places, planning for how to replace that power without having to resort to greenhouse gas-emitting sources is a key to achieving carbon-reduction goals. And by analyzing usage patterns, the software can guide the placement of new renewable power sources where they can most efficiently provide power where and when it’s needed.As plants are retired or as components are affected by weather, “We wanted to ensure the dispatchability of power when the load changes,” Anton says, “but also when crucial components are lost, to ensure the robustness at each step of the retirement schedule.”One thing they found was that “if you look at how much generating capacity exists, it’s more than the peak load, even after you retire a few fossil plants,” Ilic says. “But it’s hard to deliver.” Strategic planning of new distribution lines could make a big difference.Jaddivada, director of innovation at SmartGridz, says that “we evaluated different possible architectures in Puerto Rico, and we showed the ability of this software to ensure uninterrupted electricity service. This is the most important challenge utilities have today. They have to go through a computationally tedious process to make sure the grid functions for any possible outage in the system. And that can be done in a much more efficient way through the software that the company  developed.”The project was a collaborative effort between the MIT LIDS researchers and others at MIT Lincoln Laboratory, the Pacific Northwest National Laboratory, with overall help of SmartGridz software.  More

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    So you want to build a solar or wind farm? Here’s how to decide where.

    Deciding where to build new solar or wind installations is often left up to individual developers or utilities, with limited overall coordination. But a new study shows that regional-level planning using fine-grained weather data, information about energy use, and energy system modeling can make a big difference in the design of such renewable power installations. This also leads to more efficient and economically viable operations.The findings show the benefits of coordinating the siting of solar farms, wind farms, and storage systems, taking into account local and temporal variations in wind, sunlight, and energy demand to maximize the utilization of renewable resources. This approach can reduce the need for sizable investments in storage, and thus the total system cost, while maximizing availability of clean power when it’s needed, the researchers found.The study, appearing today in the journal Cell Reports Sustainability, was co-authored by Liying Qiu and Rahman Khorramfar, postdocs in MIT’s Department of Civil and Environmental Engineering, and professors Saurabh Amin and Michael Howland.Qiu, the lead author, says that with the team’s new approach, “we can harness the resource complementarity, which means that renewable resources of different types, such as wind and solar, or different locations can compensate for each other in time and space. This potential for spatial complementarity to improve system design has not been emphasized and quantified in existing large-scale planning.”Such complementarity will become ever more important as variable renewable energy sources account for a greater proportion of power entering the grid, she says. By coordinating the peaks and valleys of production and demand more smoothly, she says, “we are actually trying to use the natural variability itself to address the variability.”Typically, in planning large-scale renewable energy installations, Qiu says, “some work on a country level, for example saying that 30 percent of energy should be wind and 20 percent solar. That’s very general.” For this study, the team looked at both weather data and energy system planning modeling on a scale of less than 10-kilometer (about 6-mile) resolution. “It’s a way of determining where should we, exactly, build each renewable energy plant, rather than just saying this city should have this many wind or solar farms,” she explains.To compile their data and enable high-resolution planning, the researchers relied on a variety of sources that had not previously been integrated. They used high-resolution meteorological data from the National Renewable Energy Laboratory, which is publicly available at 2-kilometer resolution but rarely used in a planning model at such a fine scale. These data were combined with an energy system model they developed to optimize siting at a sub-10-kilometer resolution. To get a sense of how the fine-scale data and model made a difference in different regions, they focused on three U.S. regions — New England, Texas, and California — analyzing up to 138,271 possible siting locations simultaneously for a single region.By comparing the results of siting based on a typical method vs. their high-resolution approach, the team showed that “resource complementarity really helps us reduce the system cost by aligning renewable power generation with demand,” which should translate directly to real-world decision-making, Qiu says. “If an individual developer wants to build a wind or solar farm and just goes to where there is the most wind or solar resource on average, it may not necessarily guarantee the best fit into a decarbonized energy system.”That’s because of the complex interactions between production and demand for electricity, as both vary hour by hour, and month by month as seasons change. “What we are trying to do is minimize the difference between the energy supply and demand rather than simply supplying as much renewable energy as possible,” Qiu says. “Sometimes your generation cannot be utilized by the system, while at other times, you don’t have enough to match the demand.”In New England, for example, the new analysis shows there should be more wind farms in locations where there is a strong wind resource during the night, when solar energy is unavailable. Some locations tend to be windier at night, while others tend to have more wind during the day.These insights were revealed through the integration of high-resolution weather data and energy system optimization used by the researchers. When planning with lower resolution weather data, which was generated at a 30-kilometer resolution globally and is more commonly used in energy system planning, there was much less complementarity among renewable power plants. Consequently, the total system cost was much higher. The complementarity between wind and solar farms was enhanced by the high-resolution modeling due to improved representation of renewable resource variability.The researchers say their framework is very flexible and can be easily adapted to any region to account for the local geophysical and other conditions. In Texas, for example, peak winds in the west occur in the morning, while along the south coast they occur in the afternoon, so the two naturally complement each other.Khorramfar says that this work “highlights the importance of data-driven decision making in energy planning.” The work shows that using such high-resolution data coupled with carefully formulated energy planning model “can drive the system cost down, and ultimately offer more cost-effective pathways for energy transition.”One thing that was surprising about the findings, says Amin, who is a principal investigator in the MIT Laboratory of Information and Data Systems, is how significant the gains were from analyzing relatively short-term variations in inputs and outputs that take place in a 24-hour period. “The kind of cost-saving potential by trying to harness complementarity within a day was not something that one would have expected before this study,” he says.In addition, Amin says, it was also surprising how much this kind of modeling could reduce the need for storage as part of these energy systems. “This study shows that there is actually a hidden cost-saving potential in exploiting local patterns in weather, that can result in a monetary reduction in storage cost.”The system-level analysis and planning suggested by this study, Howland says, “changes how we think about where we site renewable power plants and how we design those renewable plants, so that they maximally serve the energy grid. It has to go beyond just driving down the cost of energy of individual wind or solar farms. And these new insights can only be realized if we continue collaborating across traditional research boundaries, by integrating expertise in fluid dynamics, atmospheric science, and energy engineering.”The research was supported by the MIT Climate and Sustainability Consortium and MIT Climate Grand Challenges. More

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    Is there enough land on Earth to fight climate change and feed the world?

    Capping global warming at 1.5 degrees Celsius is a tall order. Achieving that goal will not only require a massive reduction in greenhouse gas emissions from human activities, but also a substantial reallocation of land to support that effort and sustain the biosphere, including humans. More land will be needed to accommodate a growing demand for bioenergy and nature-based carbon sequestration while ensuring sufficient acreage for food production and ecological sustainability.The expanding role of land in a 1.5 C world will be twofold — to remove carbon dioxide from the atmosphere and to produce clean energy. Land-based carbon dioxide removal strategies include bioenergy with carbon capture and storage; direct air capture; and afforestation/reforestation and other nature-based solutions. Land-based clean energy production includes wind and solar farms and sustainable bioenergy cropland. Any decision to allocate more land for climate mitigation must also address competing needs for long-term food security and ecosystem health.Land-based climate mitigation choices vary in terms of costs — amount of land required, implications for food security, impact on biodiversity and other ecosystem services — and benefits — potential for sequestering greenhouse gases and producing clean energy.Now a study in the journal Frontiers in Environmental Science provides the most comprehensive analysis to date of competing land-use and technology options to limit global warming to 1.5 C. Led by researchers at the MIT Center for Sustainability Science and Strategy (CS3), the study applies the MIT Integrated Global System Modeling (IGSM) framework to evaluate costs and benefits of different land-based climate mitigation options in Sky2050, a 1.5 C climate-stabilization scenario developed by Shell.Under this scenario, demand for bioenergy and natural carbon sinks increase along with the need for sustainable farming and food production. To determine if there’s enough land to meet all these growing demands, the research team uses the global hectare (gha) — an area of 10,000 square meters, or 2.471 acres — as the standard unit of measurement, and current estimates of the Earth’s total habitable land area (about 10 gha) and land area used for food production and bioenergy (5 gha).The team finds that with transformative changes in policy, land management practices, and consumption patterns, global land is sufficient to provide a sustainable supply of food and ecosystem services throughout this century while also reducing greenhouse gas emissions in alignment with the 1.5 C goal. These transformative changes include policies to protect natural ecosystems; stop deforestation and accelerate reforestation and afforestation; promote advances in sustainable agriculture technology and practice; reduce agricultural and food waste; and incentivize consumers to purchase sustainably produced goods.If such changes are implemented, 2.5–3.5 gha of land would be used for NBS practices to sequester 3–6 gigatonnes (Gt) of CO2 per year, and 0.4–0.6 gha of land would be allocated for energy production — 0.2–0.3 gha for bioenergy and 0.2–0.35 gha for wind and solar power generation.“Our scenario shows that there is enough land to support a 1.5 degree C future as long as effective policies at national and global levels are in place,” says CS3 Principal Research Scientist Angelo Gurgel, the study’s lead author. “These policies must not only promote efficient use of land for food, energy, and nature, but also be supported by long-term commitments from government and industry decision-makers.” More

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    Consortium led by MIT, Harvard University, and Mass General Brigham spurs development of 408 MW of renewable energy

    MIT is co-leading an effort to enable the development of two new large-scale renewable energy projects in regions with carbon-intensive electrical grids: Big Elm Solar in Bell County, Texas, came online this year, and the Bowman Wind Project in Bowman County, North Dakota, is expected to be operational in 2026. Together, they will add a combined 408 megawatts (MW) of new renewable energy capacity to the power grid. This work is a critical part of MIT’s strategy to achieve its goal of net-zero carbon emissions by 2026.The Consortium for Climate Solutions, which includes MIT and 10 other Massachusetts organizations, seeks to eliminate close to 1 million metric tons of greenhouse gases each year — more than five times the annual direct emissions from MIT’s campus — by committing to purchase an estimated 1.3-million-megawatt hours of new solar and wind electricity generation annually.“MIT has mobilized on multiple fronts to expedite solutions to climate change,” says Glen Shor, executive vice president and treasurer. “Catalyzing these large-scale renewable projects is an important part of our comprehensive efforts to reduce carbon emissions from generating energy. We are pleased to work in partnership with other local enterprises and organizations to amplify the impact we could achieve individually.”The two new projects complement MIT’s existing 25-year power purchase agreement established with Summit Farms in 2016, which enabled the construction of a roughly 650-acre, 60 MW solar farm on farmland in North Carolina, leading to the early retirement of a coal-fired plant nearby. Its success has inspired other institutions to implement similar aggregation models.A collective approach to enable global impactMIT, Harvard University, and Mass General Brigham formed the consortium in 2020 to provide a structure to accelerate global emissions reductions through the development of large-scale renewable energy projects — accelerating and expanding the impact of each institution’s greenhouse gas reduction initiatives. As the project’s anchors, they collectively procured the largest volume of energy through the aggregation.  The consortium engaged with PowerOptions, a nonprofit energy-buying consortium, which offered its members the opportunity to participate in the projects. The City of Cambridge, Beth Israel Lahey, Boston Children’s Hospital, Dana-Farber Cancer Institute, Tufts University, the Mass Convention Center Authority, the Museum of Fine Arts, and GBH later joined the consortium through PowerOptions.  The consortium vetted over 125 potential projects against its rigorous project evaluation criteria. With faculty and MIT stakeholder input on a short list of the highest-ranking projects, it ultimately chose Bowman Wind and Big Elm Solar. Collectively, these two projects will achieve large greenhouse gas emissions reductions in two of the most carbon-intensive electrical grid regions in the United States and create clean energy generation sources to reduce negative health impacts.“Enabling these projects in regions where the grids are most carbon-intensive allows them to have the greatest impact. We anticipate these projects will prevent two times more emissions per unit of generated electricity than would a similar-scale project in New England,” explains Vice President for Campus Services and Stewardship Joe Higgins.By all consortium institutions making significant 15-to-20-year financial commitments to buy electricity, the developer was able to obtain critical external project financing to build the projects. Owned and operated by Apex Clean Energy, the projects will add new renewable electricity to the grid equivalent to powering 130,000 households annually, displacing over 950,000 metric tons of greenhouse gas emissions each year from highly carbon-intensive power plants in the region. Complementary decarbonization work underway In addition to investing in offsite renewable energy projects, many consortium members have developed strategies to reduce and eliminate their own direct emissions. At MIT, accomplishing this requires transformative change in how energy is generated, distributed, and used on campus. Efforts underway include the installation of solar panels on campus rooftops that will increase renewable energy generation four-fold by 2026; continuing to transition our heat distribution infrastructure from steam-based to hot water-based; utilizing design and construction that minimizes emissions and increases energy efficiency; employing AI-enabled sensors to optimize temperature set points and reduce energy use in buildings; and converting MIT’s vehicle fleet to all-electric vehicles while adding more electric car charging stations.The Institute has also upgraded the Central Utilities Plant, which uses advanced co-generation technology to produce power that is up to 20 percent less carbon-intensive than that from the regional power grid. MIT is charting the course toward a next-generation district energy system, with a comprehensive planning initiative to revolutionize its campus energy infrastructure. The effort is exploring leading-edge technology, including industrial-scale heat pumps, geothermal exchange, micro-reactors, bio-based fuels, and green hydrogen derived from renewable sources as solutions to achieve full decarbonization of campus operations by 2050.“At MIT, we are focused on decarbonizing our own campus as well as the role we can play in solving climate at the largest of scales, including supporting a cleaner grid in line with the call to triple renewables globally by 2030. By enabling these large-scale renewable projects, we can have an immediate and significant impact of reducing emissions through the urgently needed decarbonization of regional power grids,” says Julie Newman, MIT’s director of sustainability.   More

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    Startup turns mining waste into critical metals for the U.S.

    At the heart of the energy transition is a metal transition. Wind farms, solar panels, and electric cars require many times more copper, zinc, and nickel than their gas-powered alternatives. They also require more exotic metals with unique properties, known as rare earth elements, which are essential for the magnets that go into things like wind turbines and EV motors.Today, China dominates the processing of rare earth elements, refining around 60 percent of those materials for the world. With demand for such materials forecasted to skyrocket, the Biden administration has said the situation poses national and economic security threats.Substantial quantities of rare earth metals are sitting unused in the United States and many other parts of the world today. The catch is they’re mixed with vast quantities of toxic mining waste.Phoenix Tailings is scaling up a process for harvesting materials, including rare earth metals and nickel, from mining waste. The company uses water and recyclable solvents to collect oxidized metal, then puts the metal into a heated molten salt mixture and applies electricity.The company, co-founded by MIT alumni, says its pilot production facility in Woburn, Massachusetts, is the only site in the world producing rare earth metals without toxic byproducts or carbon emissions. The process does use electricity, but Phoenix Tailings currently offsets that with renewable energy contracts.The company expects to produce more than 3,000 tons of the metals by 2026, which would have represented about 7 percent of total U.S. production last year.Now, with support from the Department of Energy, Phoenix Tailings is expanding the list of metals it can produce and accelerating plans to build a second production facility.For the founding team, including MIT graduates Tomás Villalón ’14 and Michelle Chao ’14 along with Nick Myers and Anthony Balladon, the work has implications for geopolitics and the planet.“Being able to make your own materials domestically means that you’re not at the behest of a foreign monopoly,” Villalón says. “We’re focused on creating critical materials for the next generation of technologies. More broadly, we want to get these materials in ways that are sustainable in the long term.”Tackling a global problemVillalón got interested in chemistry and materials science after taking Course 3.091 (Introduction to Solid-State Chemistry) during his first year at MIT. In his senior year, he got a chance to work at Boston Metal, another MIT spinoff that uses an electrochemical process to decarbonize steelmaking at scale. The experience got Villalón, who majored in materials science and engineering, thinking about creating more sustainable metallurgical processes.But it took a chance meeting with Myers at a 2018 Bible study for Villalón to act on the idea.“We were discussing some of the major problems in the world when we came to the topic of electrification,” Villalón recalls. “It became a discussion about how the U.S. gets its materials and how we should think about electrifying their production. I was finally like, ‘I’ve been working in the space for a decade, let’s go do something about it.’ Nick agreed, but I thought he just wanted to feel good about himself. Then in July, he randomly called me and said, ‘I’ve got [$7,000]. When do we start?’”Villalón brought in Chao, his former MIT classmate and fellow materials science and engineering major, and Myers brought Balladon, a former co-worker, and the founders started experimenting with new processes for producing rare earth metals.“We went back to the base principles, the thermodynamics I learned with MIT professors Antoine Allanore and Donald Sadoway, and understanding the kinetics of reactions,” Villalón says. “Classes like Course 3.022 (Microstructural Evolution in Materials) and 3.07 (Introduction to Ceramics) were also really useful. I touched on every aspect I studied at MIT.”The founders also received guidance from MIT’s Venture Mentoring Service (VMS) and went through the U.S. National Science Foundation’s I-Corps program. Sadoway served as an advisor for the company.After drafting one version of their system design, the founders bought an experimental quantity of mining waste, known as red sludge, and set up a prototype reactor in Villalón’s backyard. The founders ended up with a small amount of product, but they had to scramble to borrow the scientific equipment needed to determine what exactly it was. It turned out to be a small amount of rare earth concentrate along with pure iron.Today, at the company’s refinery in Woburn, Phoenix Tailings puts mining waste rich in rare earth metals into its mixture and heats it to around 1,300 degrees Fahrenheit. When it applies an electric current to the mixture, pure metal collects on an electrode. The process leaves minimal waste behind.“The key for all of this isn’t just the chemistry, but how everything is linked together, because with rare earths, you have to hit really high purities compared to a conventionally produced metal,” Villalón explains. “As a result, you have to be thinking about the purity of your material the entire way through.”From rare earths to nickel, magnesium, and moreVillalón says the process is economical compared to conventional production methods, produces no toxic byproducts, and is completely carbon free when renewable energy sources are used for electricity.The Woburn facility is currently producing several rare earth elements for customers, including neodymium and dysprosium, which are important in magnets. Customers are using the materials for things likewind turbines, electric cars, and defense applications.The company has also received two grants with the U.S. Department of Energy’s ARPA-E program totaling more than $2 million. Its 2023 grant supports the development of a system to extract nickel and magnesium from mining waste through a process that uses carbonization and recycled carbon dioxide. Both nickel and magnesium are critical materials for clean energy applications like batteries.The most recent grant will help the company adapt its process to produce iron from mining waste without emissions or toxic byproducts. Phoenix Tailings says its process is compatible with a wide array of ore types and waste materials, and the company has plenty of material to work with: Mining and processing mineral ores generates about 1.8 billion tons of waste in the U.S. each year.“We want to take our knowledge from processing the rare earth metals and slowly move it into other segments,” Villalón explains. “We simply have to refine some of these materials here. There’s no way we can’t. So, what does that look like from a regulatory perspective? How do we create approaches that are economical and environmentally compliant not just now, but 30 years from now?” More

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    MIT engineers’ new theory could improve the design and operation of wind farms

    The blades of propellers and wind turbines are designed based on aerodynamics principles that were first described mathematically more than a century ago. But engineers have long realized that these formulas don’t work in every situation. To compensate, they have added ad hoc “correction factors” based on empirical observations.Now, for the first time, engineers at MIT have developed a comprehensive, physics-based model that accurately represents the airflow around rotors even under extreme conditions, such as when the blades are operating at high forces and speeds, or are angled in certain directions. The model could improve the way rotors themselves are designed, but also the way wind farms are laid out and operated. The new findings are described today in the journal Nature Communications, in an open-access paper by MIT postdoc Jaime Liew, doctoral student Kirby Heck, and Michael Howland, the Esther and Harold E. Edgerton Assistant Professor of Civil and Environmental Engineering.“We’ve developed a new theory for the aerodynamics of rotors,” Howland says. This theory can be used to determine the forces, flow velocities, and power of a rotor, whether that rotor is extracting energy from the airflow, as in a wind turbine, or applying energy to the flow, as in a ship or airplane propeller. “The theory works in both directions,” he says.Because the new understanding is a fundamental mathematical model, some of its implications could potentially be applied right away. For example, operators of wind farms must constantly adjust a variety of parameters, including the orientation of each turbine as well as its rotation speed and the angle of its blades, in order to maximize power output while maintaining safety margins. The new model can provide a simple, speedy way of optimizing those factors in real time.“This is what we’re so excited about, is that it has immediate and direct potential for impact across the value chain of wind power,” Howland says.Modeling the momentumKnown as momentum theory, the previous model of how rotors interact with their fluid environment — air, water, or otherwise — was initially developed late in the 19th century. With this theory, engineers can start with a given rotor design and configuration, and determine the maximum amount of power that can be derived from that rotor — or, conversely, if it’s a propeller, how much power is needed to generate a given amount of propulsive force.Momentum theory equations “are the first thing you would read about in a wind energy textbook, and are the first thing that I talk about in my classes when I teach about wind power,” Howland says. From that theory, physicist Albert Betz calculated in 1920 the maximum amount of energy that could theoretically be extracted from wind. Known as the Betz limit, this amount is 59.3 percent of the kinetic energy of the incoming wind.But just a few years later, others found that the momentum theory broke down “in a pretty dramatic way” at higher forces that correspond to faster blade rotation speeds or different blade angles, Howland says. It fails to predict not only the amount, but even the direction of changes in thrust force at higher rotation speeds or different blade angles: Whereas the theory said the force should start going down above a certain rotation speed or blade angle, experiments show the opposite — that the force continues to increase. “So, it’s not just quantitatively wrong, it’s qualitatively wrong,” Howland says.The theory also breaks down when there is any misalignment between the rotor and the airflow, which Howland says is “ubiquitous” on wind farms, where turbines are constantly adjusting to changes in wind directions. In fact, in an earlier paper in 2022, Howland and his team found that deliberately misaligning some turbines slightly relative to the incoming airflow within a wind farm significantly improves the overall power output of the wind farm by reducing wake disturbances to the downstream turbines.In the past, when designing the profile of rotor blades, the layout of wind turbines in a farm, or the day-to-day operation of wind turbines, engineers have relied on ad hoc adjustments added to the original mathematical formulas, based on some wind tunnel tests and experience with operating wind farms, but with no theoretical underpinnings.Instead, to arrive at the new model, the team analyzed the interaction of airflow and turbines using detailed computational modeling of the aerodynamics. They found that, for example, the original model had assumed that a drop in air pressure immediately behind the rotor would rapidly return to normal ambient pressure just a short way downstream. But it turns out, Howland says, that as the thrust force keeps increasing, “that assumption is increasingly inaccurate.”And the inaccuracy occurs very close to the point of the Betz limit that theoretically predicts the maximum performance of a turbine — and therefore is just the desired operating regime for the turbines. “So, we have Betz’s prediction of where we should operate turbines, and within 10 percent of that operational set point that we think maximizes power, the theory completely deteriorates and doesn’t work,” Howland says.Through their modeling, the researchers also found a way to compensate for the original formula’s reliance on a one-dimensional modeling that assumed the rotor was always precisely aligned with the airflow. To do so, they used fundamental equations that were developed to predict the lift of three-dimensional wings for aerospace applications.The researchers derived their new model, which they call a unified momentum model, based on theoretical analysis, and then validated it using computational fluid dynamics modeling. In followup work not yet published, they are doing further validation using wind tunnel and field tests.Fundamental understandingOne interesting outcome of the new formula is that it changes the calculation of the Betz limit, showing that it’s possible to extract a bit more power than the original formula predicted. Although it’s not a significant change — on the order of a few percent — “it’s interesting that now we have a new theory, and the Betz limit that’s been the rule of thumb for a hundred years is actually modified because of the new theory,” Howland says. “And that’s immediately useful.” The new model shows how to maximize power from turbines that are misaligned with the airflow, which the Betz limit cannot account for.The aspects related to controlling both individual turbines and arrays of turbines can be implemented without requiring any modifications to existing hardware in place within wind farms. In fact, this has already happened, based on earlier work from Howland and his collaborators two years ago that dealt with the wake interactions between turbines in a wind farm, and was based on the existing, empirically based formulas.“This breakthrough is a natural extension of our previous work on optimizing utility-scale wind farms,” he says, because in doing that analysis, they saw the shortcomings of the existing methods for analyzing the forces at work and predicting power produced by wind turbines. “Existing modeling using empiricism just wasn’t getting the job done,” he says.In a wind farm, individual turbines will sap some of the energy available to neighboring turbines, because of wake effects. Accurate wake modeling is important both for designing the layout of turbines in a wind farm, and also for the operation of that farm, determining moment to moment how to set the angles and speeds of each turbine in the array.Until now, Howland says, even the operators of wind farms, the manufacturers, and the designers of the turbine blades had no way to predict how much the power output of a turbine would be affected by a given change such as its angle to the wind without using empirical corrections. “That’s because there was no theory for it. So, that’s what we worked on here. Our theory can directly tell you, without any empirical corrections, for the first time, how you should actually operate a wind turbine to maximize its power,” he says.Because the fluid flow regimes are similar, the model also applies to propellers, whether for aircraft or ships, and also for hydrokinetic turbines such as tidal or river turbines. Although they didn’t focus on that aspect in this research, “it’s in the theoretical modeling naturally,” he says.The new theory exists in the form of a set of mathematical formulas that a user could incorporate in their own software, or as an open-source software package that can be freely downloaded from GitHub. “It’s an engineering model developed for fast-running tools for rapid prototyping and control and optimization,” Howland says. “The goal of our modeling is to position the field of wind energy research to move more aggressively in the development of the wind capacity and reliability necessary to respond to climate change.”The work was supported by the National Science Foundation and Siemens Gamesa Renewable Energy. More

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    Going Dutch on climate

    When MIT senior Rudiba Laiba saw that stores in the Netherlands eschewed plastic bags to save the planet, her first thought was, “that doesn’t happen in Bangladesh.”Laiba is one of eight MIT students who traveled to the Netherlands in June as part of an MIT Energy Initiative (MITEI)-sponsored trip to experience first-hand the country’s approach to the energy transition. The Netherlands aims to be carbon neutral by 2050, making it one of the top 10 countries leading the charge on climate change, according to U.S. News and World Report.MITEI sponsored the week-long trip to allow undergraduate and graduate students to collaboratively explore clean energy efforts with researchers, corporate leaders, and nongovernmental organizations. The students heard about projects ranging from creating hydrogen pipelines in the North Sea to climate-proofing a fuel-guzzling, asphalt-dense neighborhood.Felipe Abreu from Kissimmee, Florida, a rising second-year student studying materials science and engineering, is working this summer on ways to melt and reuse metal scraps discarded in manufacturing processes. “When MITEI put out this notice about visiting the Netherlands, I wanted to see if there were more advanced approaches to renewable energy that I’d never been exposed to,” Abreu says.Laiba notes that her native Bangladesh has not yet achieved the Netherlands’ nearly universal buy-in to tackling climate change, even though this South Asian country, like the Netherlands, is particularly vulnerable to rising sea levels due to topography and high population density.Laiba, who spent part of her childhood in New York City and lived in Bangladesh from ages 8 to 18, calls Bangladesh “on the front lines of climate change.“Even if I didn’t want to care about climate change, I had to, because I would see the effects of it,” she says.Key playersThe MIT students conducted hands-on exercises on how to switch from traditional energy sources to zero-carbon technologies. “We talked a lot about infrastructure, particularly how to repurpose natural gas infrastructure for hydrogen,” says Antje Danielson, director of education at MITEI, who led the trip with Em Schule, MITEI research and programming assistant. “The students were challenged to grapple with real-world decision-making.”The northern section of the Netherlands is known as the “hydrogen valley” of Europe. At the University of Groningen and Hanze University School of Applied Sciences, also in Groningen, the students heard about how the region profiles itself as a world capital for the energy transition through its push toward a hydrogen-based economy and its state-of-the-art global climate models.Erick Liang, a rising junior from Boston’s Roslindale neighborhood pursuing a dual major in nuclear science and engineering and physics, was intrigued by a massive wind farm in the port city of Eemshaven, one of the group’s first stops in the north of the country. “It was impressive as an engineering challenge, because they must have figured out ways to cheaply and effectively manufacture all these wind turbines,” he says.They visited German energy company RWE, which is generating 15 percent of Eemshaven’s electricity from biomass, replacing coal.Laiba, who is majoring in molecular biology and electrical engineering and computer science with a minor in business management, was intrigued by a presentation on biofuels. “It piqued my interest to see if they would use biomass on a large scale” because of the challenges and unpredictability associated with it as a fuel source.In Paddepoel, the students toured the first of several neighborhoods that once lacked greenery and used fossil fuel-based heating systems and now aim to generate more energy than they consume.“The students got to see what the size of the district heating pipes would be, and how they go through people’s gardens into the houses. We talked about the physical impact on the neighborhood of installing these pipes, as well as the potential social and political implications connected to a really difficult transition like this,” Danielson says.Going greenGreen hydrogen promises to be a key player in the energy transition, and Netherlands officials say they have committed to the new infrastructure and business models needed to move ahead with hydrogen as a fuel source.The students explored how green hydrogen differs from fossil fuel-generated hydrogen. They saw how Dutch companies grappled with siting hydrogen production facilities and handling hydrogen as a gas, which, unlike natural gas, does not yet have a detectable artificial odor. The students heard from energy network operator Gasunie about the science and engineering behind repurposing existing natural gas pipelines for a hydrogen network in the North Sea, and were challenged to solve the puzzle of combining hydrogen production with offshore wind energy. In the port of Rotterdam, they saw how the startup Battolyser Systems — which is working with Delft University of Technology on an electrolysis device that splits water into hydrogen and oxygen and doubles as a battery — is transitioning from lab bench to market.Laiba was impressed by how much capital was going into high-risk ventures and startups, “not only because they’re trying to make something revolutionary, but also because society needs to accept and use” their products.Abreu says that at Battolyser Systems, “I saw people my age on the forefront of green hydrogen, trying to make a difference.”The students visited the Global Center on Adaptation’s carbon-neutral floating offices and learned how this international organization supports climate adaptation actions around the world and the practice of mitigation.Also in Rotterdam, international marine contractor Van Oord took students to view a ship that installs wind turbines and explained how their new technology reduces the sound shockwave impact of the installations on marine life.At the Port of Rotterdam, the students heard about the challenges faced by Europe’s largest port in terms of global shipping and choosing the fuels of the future. The speaker tasked the MIT students with coming up with a plan to transition the privately owned, owner-inhabited barges that ply the region’s inland waterways to a zero-carbon system.“The Port Authority uses this exercise to illustrate the enormous complexity faced by companies in the energy transition,” Danielson says. “The fact that our students performed really well on the spot shows that we are doing something right at MIT.”Defining a path forwardLiang, Abreu, and Laiba were struck by how the Netherlands has come together as a country over climate change. “In the U.S., a lot of people disagree with the concept of climate change as a whole,” Liang says. “But in the Netherlands, everyone is on the same page that this is an issue that we should be working toward. They’re capable of seeing a path forward and trying to take action whenever possible.”Liang, a member of the MIT Solar Electric Vehicle Team, is doing undergraduate research sponsored by MITEI this summer, working to accelerate fusion manufacturing and development at the MIT Plasma Science and Fusion Center. He’s improving 3D printing processes to manufacture components that can accommodate the high temperatures and small space within a tokamak reactor, which uses magnetic fields to confine plasma and produce controlled thermonuclear fusion.“I personally would like to try finding a new solution” to achieving carbon neutrality, he says. That solution, to Liang, is fusion energy, with some entities hoping to demonstrate net energy gain through fusion in the next five years.Laiba is a researcher with the MIT Office of Sustainability, looking at ways to quantify and reduce the level of MIT’s Scope 3 greenhouse gas emissions. Scope 3 emissions are tied to the purchase of goods that use fossil fuels in their manufacture. She says, ​“Whatever I decide to do in the future will involve making a more sustainable future. And to me, renewable energy is the driving force behind that.”In the Netherlands, she says, “what we learned through the entire trip was that renewable energy powers the country to a large amount. Things I could see tangibly was Starbucks having paper cups even for our iced drinks, which I think would flop very hard in the U.S. I don’t think society’s ready for that yet.”Abreu says, “In America, sustainability has always been in the back seat while other things take the forefront. So going to a country where everybody you talk to has a stake (in sustainability) and actually cares, and they’re all pushing together for this common goal, it was inspiring. It gave me hope.” More

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    Making the clean energy transition work for everyone

    The clean energy transition is already underway, but how do we make sure it happens in a manner that is affordable, sustainable, and fair for everyone?

    That was the overarching question at this year’s MIT Energy Conference, which took place March 11 and 12 in Boston and was titled “Short and Long: A Balanced Approach to the Energy Transition.”

    Each year, the student-run conference brings together leaders in the energy sector to discuss the progress and challenges they see in their work toward a greener future. Participants come from research, industry, government, academia, and the investment community to network and exchange ideas over two whirlwind days of keynote talks, fireside chats, and panel discussions.

    Several participants noted that clean energy technologies are already cost-competitive with fossil fuels, but changing the way the world works requires more than just technology.

    “None of this is easy, but I think developing innovative new technologies is really easy compared to the things we’re talking about here, which is how to blend social justice, soft engineering, and systems thinking that puts people first,” Daniel Kammen, a distinguished professor of energy at the University of California at Berkeley, said in a keynote talk. “While clean energy has a long way to go, it is more than ready to transition us from fossil fuels.”

    The event also featured a keynote discussion between MIT President Sally Kornbluth and MIT’s Kyocera Professor of Ceramics Yet-Ming Chiang, in which Kornbluth discussed her first year at MIT as well as a recently announced, campus-wide effort to solve critical climate problems known as the Climate Project at MIT.

    “The reason I wanted to come to MIT was I saw that MIT has the potential to solve the world’s biggest problems, and first among those for me was the climate crisis,” Kornbluth said. “I’m excited about where we are, I’m excited about the enthusiasm of the community, and I think we’ll be able to make really impactful discoveries through this project.”

    Fostering new technologies

    Several panels convened experts in new or emerging technology fields to discuss what it will take for their solutions to contribute to deep decarbonization.

    “The fun thing and challenging thing about first-of-a-kind technologies is they’re all kind of different,” said Jonah Wagner, principal assistant director for industrial innovation and clean energy in the U.S. Office of Science and Technology Policy. “You can map their growth against specific challenges you expect to see, but every single technology is going to face their own challenges, and every single one will have to defy an engineering barrier to get off the ground.”

    Among the emerging technologies discussed was next-generation geothermal energy, which uses new techniques to extract heat from the Earth’s crust in new places.

    A promising aspect of the technology is that it can leverage existing infrastructure and expertise from the oil and gas industry. Many newly developed techniques for geothermal production, for instance, use the same drills and rigs as those used for hydraulic fracturing.

    “The fact that we have a robust ecosystem of oil and gas labor and technology in the U.S. makes innovation in geothermal much more accessible compared to some of the challenges we’re seeing in nuclear or direct-air capture, where some of the supply chains are disaggregated around the world,” said Gabrial Malek, chief of staff at the geothermal company Fervo Energy.

    Another technology generating excitement — if not net energy quite yet — is fusion, the process of combining, or fusing, light atoms together to form heavier ones for a net energy gain, in the same process that powers the sun. MIT spinout Commonwealth Fusion Systems (CFS) has already validated many aspects of its approach for achieving fusion power, and the company’s unique partnership with MIT was discussed in a panel on the industry’s progress.

    “We’re standing on the shoulders of decades of research from the scientific community, and we want to maintain those ties even as we continue developing our technology,” CFS Chief Science Officer Brandon Sorbom PhD ’17 said, noting that CFS is one of the largest company sponsors of research at MIT and collaborates with institutions around the world. “Engaging with the community is a really valuable lever to get new ideas and to sanity check our own ideas.”

    Sorbom said that as CFS advances fusion energy, the company is thinking about how it can replicate its processes to lower costs and maximize the technology’s impact around the planet.

    “For fusion to work, it has to work for everyone,” Sorbom said. “I think the affordability piece is really important. We can’t just build this technological jewel that only one class of nations can afford. It has to be a technology that can be deployed throughout the entire world.”

    The event also gave students — many from MIT — a chance to learn more about careers in energy and featured a startup showcase, in which dozens of companies displayed their energy and sustainability solutions.

    “More than 700 people are here from every corner of the energy industry, so there are so many folks to connect with and help me push my vision into reality,” says GreenLIB CEO Fred Rostami, whose company recycles lithium-ion batteries. “The good thing about the energy transition is that a lot of these technologies and industries overlap, so I think we can enable this transition by working together at events like this.”

    A focused climate strategy

    Kornbluth noted that when she came to MIT, a large percentage of students and faculty were already working on climate-related technologies. With the Climate Project at MIT, she wanted to help ensure the whole of those efforts is greater than the sum of its parts.

    The project is organized around six distinct missions, including decarbonizing energy and industry, empowering frontline communities, and building healthy, resilient cities. Kornbluth says the mission areas will help MIT community members collaborate around multidisciplinary challenges. Her team, which includes a committee of faculty advisors, has begun to search for the leads of each mission area, and Kornbluth said she is planning to appoint a vice president for climate at the Institute.

    “I want someone who has the purview of the whole Institute and will report directly to me to help make sure this project stays on track,” Kornbluth explained.

    In his conversation about the initiative with Kornbluth, Yet-Ming Chiang said projects will be funded based on their potential to reduce emissions and make the planet more sustainable at scale.

    “Projects should be very high risk, with very high impact,” Chiang explained. “They should have a chance to prove themselves, and those efforts should not be limited by resources, only by time.”

    In discussing her vision of the climate project, Kornbluth alluded to the “short and long” theme of the conference.

    “It’s about balancing research and commercialization,” Kornbluth said. “The climate project has a very variable timeframe, and I think universities are the sector that can think about the things that might be 30 years out. We have to think about the incentives across the entire innovation pipeline and how we can keep an eye on the long term while making sure the short-term things get out rapidly.” More