Design Patterns in Python for AI and LLM Engineers: A Practical Guide

As AI engineers, crafting clean, efficient, and maintainable code is critical, especially when building complex systems. Design patterns are reusable solutions to common problems in software design. For AI and large language model (LLM) engineers, design patterns help build robust, scalable, and maintainable systems that handle…

The MIT Press releases report on the future of open access publishing and policy

The MIT Press has released a comprehensive report that addresses how open access policies shape research and what is needed to maximize their positive impact on the research ecosystem.

The report, entitled “Access to Science and Scholarship 2024: Building an Evidence Base to Support the Future of Open Research Policy,” is the outcome of a National Science Foundation-funded workshop held at the Washington headquarters of the American Association for the Advancement of Science on Sept. 20.

While open access aims to democratize knowledge, its implementation has been a factor in the consolidation of the academic publishing industry, an explosion in published articles with inconsistent review and quality control, and new costs that may be hard for researchers and universities to bear, with less-affluent schools and regions facing the greatest risk. The workshop examined how open access and other open science policies may affect research and researchers in the future, how to measure their impact, and how to address emerging challenges.

The event brought together leading experts to discuss critical issues in open scientific and scholarly publishing. These issues include:

  • the impact of open access policies on the research ecosystem;
  • the enduring role of peer review in ensuring research quality;
  • the challenges and opportunities of data sharing and curation; and
  • the evolving landscape of scholarly communications infrastructure.

The report identifies key research questions in order to advance open science and scholarship. These include:

  • How can we better model and anticipate the consequences of government policies on public access to science and scholarship?
  • How can research funders support experimentation with new and more equitable business models for scientific publishing? and
  • If the dissemination of scholarship is decoupled from peer review and evaluation, who is best suited to perform that evaluation, and how should that process be managed and funded?

“This workshop report is a crucial step in building a data-driven roadmap for the future of open science publishing and policy,” says Phillip Sharp, Institute Professor and professor of biology emeritus at MIT, and faculty lead of the working group behind the workshop and the report. “By identifying key research questions around infrastructure, training, technology, and business models, we aim to ensure that open science practices are sustainable and that they contribute to the highest quality research.”

The full report is available for download, along with video recordings of the workshop.

The MIT Press is a leading academic publisher committed to advancing knowledge and innovation. It publishes significant books and journals across a wide range of disciplines spanning science, technology, design, humanities, and social science.

Improving health, one machine learning system at a time

Captivated as a child by video games and puzzles, Marzyeh Ghassemi was also fascinated at an early age in health. Luckily, she found a path where she could combine the two interests. 

“Although I had considered a career in health care, the pull of computer science and engineering was stronger,” says Ghassemi, an associate professor in MIT’s Department of Electrical Engineering and Computer Science and the Institute for Medical Engineering and Science (IMES) and principal investigator at the Laboratory for Information and Decision Systems (LIDS). “When I found that computer science broadly, and AI/ML specifically, could be applied to health care, it was a convergence of interests.”

Today, Ghassemi and her Healthy ML research group at LIDS work on the deep study of how machine learning (ML) can be made more robust, and be subsequently applied to improve safety and equity in health.

Growing up in Texas and New Mexico in an engineering-oriented Iranian-American family, Ghassemi had role models to follow into a STEM career. While she loved puzzle-based video games — “Solving puzzles to unlock other levels or progress further was a very attractive challenge” — her mother also engaged her in more advanced math early on, enticing her toward seeing math as more than arithmetic.

“Adding or multiplying are basic skills emphasized for good reason, but the focus can obscure the idea that much of higher-level math and science are more about logic and puzzles,” Ghassemi says. “Because of my mom’s encouragement, I knew there were fun things ahead.”

Ghassemi says that in addition to her mother, many others supported her intellectual development. As she earned her undergraduate degree at New Mexico State University, the director of the Honors College and a former Marshall Scholar — Jason Ackelson, now a senior advisor to the U.S. Department of Homeland Security — helped her to apply for a Marshall Scholarship that took her to Oxford University, where she earned a master’s degree in 2011 and first became interested in the new and rapidly evolving field of machine learning. During her PhD work at MIT, Ghassemi says she received support “from professors and peers alike,” adding, “That environment of openness and acceptance is something I try to replicate for my students.”

While working on her PhD, Ghassemi also encountered her first clue that biases in health data can hide in machine learning models.

She had trained models to predict outcomes using health data, “and the mindset at the time was to use all available data. In neural networks for images, we had seen that the right features would be learned for good performance, eliminating the need to hand-engineer specific features.”

During a meeting with Leo Celi, principal research scientist at the MIT Laboratory for Computational Physiology and IMES and a member of Ghassemi’s thesis committee, Celi asked if Ghassemi had checked how well the models performed on patients of different genders, insurance types, and self-reported races.

Ghassemi did check, and there were gaps. “We now have almost a decade of work showing that these model gaps are hard to address — they stem from existing biases in health data and default technical practices. Unless you think carefully about them, models will naively reproduce and extend biases,” she says.

Ghassemi has been exploring such issues ever since.

Her favorite breakthrough in the work she has done came about in several parts. First, she and her research group showed that learning models could recognize a patient’s race from medical images like chest X-rays, which radiologists are unable to do. The group then found that models optimized to perform well “on average” did not perform as well for women and minorities. This past summer, her group combined these findings to show that the more a model learned to predict a patient’s race or gender from a medical image, the worse its performance gap would be for subgroups in those demographics. Ghassemi and her team found that the problem could be mitigated if a model was trained to account for demographic differences, instead of being focused on overall average performance — but this process has to be performed at every site where a model is deployed.

“We are emphasizing that models trained to optimize performance (balancing overall performance with lowest fairness gap) in one hospital setting are not optimal in other settings. This has an important impact on how models are developed for human use,” Ghassemi says. “One hospital might have the resources to train a model, and then be able to demonstrate that it performs well, possibly even with specific fairness constraints. However, our research shows that these performance guarantees do not hold in new settings. A model that is well-balanced in one site may not function effectively in a different environment. This impacts the utility of models in practice, and it’s essential that we work to address this issue for those who develop and deploy models.”

Ghassemi’s work is informed by her identity.

“I am a visibly Muslim woman and a mother — both have helped to shape how I see the world, which informs my research interests,” she says. “I work on the robustness of machine learning models, and how a lack of robustness can combine with existing biases. That interest is not a coincidence.”

Regarding her thought process, Ghassemi says inspiration often strikes when she is outdoors — bike-riding in New Mexico as an undergraduate, rowing at Oxford, running as a PhD student at MIT, and these days walking by the Cambridge Esplanade. She also says she has found it helpful when approaching a complicated problem to think about the parts of the larger problem and try to understand how her assumptions about each part might be incorrect.

“In my experience, the most limiting factor for new solutions is what you think you know,” she says. “Sometimes it’s hard to get past your own (partial) knowledge about something until you dig really deeply into a model, system, etc., and realize that you didn’t understand a subpart correctly or fully.”

As passionate as Ghassemi is about her work, she intentionally keeps track of life’s bigger picture.

“When you love your research, it can be hard to stop that from becoming your identity — it’s something that I think a lot of academics have to be aware of,” she says. “I try to make sure that I have interests (and knowledge) beyond my own technical expertise.

“One of the best ways to help prioritize a balance is with good people. If you have family, friends, or colleagues who encourage you to be a full person, hold on to them!”

Having won many awards and much recognition for the work that encompasses two early passions — computer science and health — Ghassemi professes a faith in seeing life as a journey.

“There’s a quote by the Persian poet Rumi that is translated as, ‘You are what you are looking for,’” she says. “At every stage of your life, you have to reinvest in finding who you are, and nudging that towards who you want to be.”

A blueprint for better cancer immunotherapies

Immune checkpoint blockade (ICB) therapies can be very effective against some cancers by helping the immune system recognize cancer cells that are masquerading as healthy cells. 

T cells are built to recognize specific pathogens or cancer cells, which they identify from the short fragments of proteins presented on their surface. These fragments are often referred to as antigens. Healthy cells will will not have the same short fragments or antigens on their surface, and thus will be spared from attack. 

Even with cancer-associated antigens studding their surfaces, tumor cells can still escape attack by presenting a checkpoint protein, which is built to turn off the T cell. Immune checkpoint blockade therapies bind to these “off-switch” proteins and allow the T cell to attack.

Researchers have established that how cancer-associated antigens are distributed throughout a tumor determines how it will respond to checkpoint therapies. Tumors with the same antigen signal across most of its cells respond well, but heterogeneous tumors with subpopulations of cells that each have different antigens, do not. The overwhelming majority of tumors fall into the latter category and are characterized by heterogenous antigen expression. Because the mechanisms behind antigen distribution and tumor response are poorly understood, efforts to improve ICB therapy response in heterogenous tumors have been hindered.

In a new study, MIT researchers analyzed antigen expression patterns and associated T cell responses to better understand why patients with heterogenous tumors respond poorly to ICB therapies. In addition to identifying specific antigen architectures that determine how immune systems respond to tumors, the team developed an RNA-based vaccine that, when combined with ICB therapies, was effective at controlling tumors in mouse models of lung cancer.

Stefani Spranger, associate professor of biology and member of MIT’s Koch Institute for Integrative Cancer Research, is the senior author of the study, appearing recently in the Journal for Immunotherapy of Cancer. Other contributors include Koch Institute colleague Forest White, the Ned C. (1949) and Janet Bemis Rice Professor and professor of biological engineering at MIT, and Darrell Irvine, professor of immunology and microbiology at Scripps Research Institute and a former member of the Koch Institute.

While RNA vaccines are being evaluated in clinical trials, current practice of antigen selection is based on the predicted stability of antigens on the surface of tumor cells. 

“It’s not so black-and-white,” says Spranger. “Even antigens that don’t make the numerical cut-off could be really valuable targets. Instead of just focusing on the numbers, we need to look inside the complex interplays between antigen hierarchies to uncover new and important therapeutic strategies.”

Spranger and her team created mouse models of lung cancer with a number of different and well-defined expression patterns of cancer-associated antigens in order to analyze how each antigen impacts T cell response. They created both “clonal” tumors, with the same antigen expression pattern across cells, and “subclonal” tumors that represent a heterogenous mix of tumor cell subpopulations expressing different antigens. In each type of tumor, they tested different combinations of antigens with strong or weak binding affinity to MHC.

The researchers found that the keys to immune response were how widespread an antigen is expressed across a tumor, what other antigens are expressed at the same time, and the relative binding strength and other characteristics of antigens expressed by multiple cell populations in the tumor

As expected, mouse models with clonal tumors were able to mount an immune response sufficient to control tumor growth when treated with ICB therapy, no matter which combinations of weak or strong antigens were present. However, the team discovered that the relative strength of antigens present resulted in dynamics of competition and synergy between T cell populations, mediated by immune recognition specialists called cross-presenting dendritic cells in tumor-draining lymph nodes. In pairings of two weak or two strong antigens, one resulting T cell population would be reduced through competition. In pairings of weak and strong antigens, overall T cell response was enhanced. 

In subclonal tumors, with different cell populations emitting different antigen signals, competition rather than synergy was the rule, regardless of antigen combination. Tumors with a subclonal cell population expressing a strong antigen would be well-controlled under ICB treatment at first, but eventually parts of the tumor lacking the strong antigen began to grow and developed the ability evade immune attack and resist ICB therapy.

Incorporating these insights, the researchers then designed an RNA-based vaccine to be delivered in combination with ICB treatment with the goal of strengthening immune responses suppressed by antigen-driven dynamics. Strikingly, they found that no matter the binding affinity or other characteristics of the antigen targeted, the vaccine-ICB therapy combination was able to control tumors in mouse models. The widespread availability of an antigen across tumor cells determined the vaccine’s success, even if that antigen was associated with weak immune response.

Analysis of clinical data across tumor types showed that the vaccine-ICB therapy combination may be an effective strategy for treating patients with tumors with high heterogeneity. Patterns of antigen architectures in patient tumors correlated with T cell synergy or competition in mice models and determined responsiveness to ICB in cancer patients. In future work with the Irvine laboratory at the Scripps Research Institute, the Spranger laboratory will further optimize the vaccine with the aim of testing the therapy strategy in the clinic. 

To design better water filters, MIT engineers look to manta rays

Filter feeders are everywhere in the animal world, from tiny crustaceans and certain types of coral and krill, to various molluscs, barnacles, and even massive basking sharks and baleen whales. Now, MIT engineers have found that one filter feeder has evolved to sift food in ways that could improve the design of industrial water filters.

In a paper appearing this week in the Proceedings of the National Academy of Sciences, the team characterizes the filter-feeding mechanism of the mobula ray — a family of aquatic rays that includes two manta species and seven devil rays. Mobula rays feed by swimming open-mouthed through plankton-rich regions of the ocean and filtering plankton particles into their gullet as water streams into their mouths and out through their gills.

The floor of the mobula ray’s mouth is lined on either side with parallel, comb-like structures, called plates, that siphon water into the ray’s gills. The MIT team has shown that the dimensions of these plates may allow for incoming plankton to bounce all the way across the plates and further into the ray’s cavity, rather than out through the gills. What’s more, the ray’s gills absorb oxygen from the outflowing water, helping the ray to simultaneously breathe while feeding.

“We show that the mobula ray has evolved the geometry of these plates to be the perfect size to balance feeding and breathing,” says study author Anette “Peko” Hosoi, the Pappalardo Professor of Mechanical Engineering at MIT.

The engineers fabricated a simple water filter modeled after the mobula ray’s plankton-filtering features. They studied how water flowed through the filter when it was fitted with 3D-printed plate-like structures. The team took the results of these experiments and drew up a blueprint, which they say designers can use to optimize industrial cross-flow filters, which are broadly similar in configuration to that of the mobula ray.

“We want to expand the design space of traditional cross-flow filtration with new knowledge from the manta ray,” says lead author and MIT postdoc Xinyu Mao PhD ’24. “People can choose a parameter regime of the mobula ray so they could potentially improve overall filter performance.”

Hosoi and Mao co-authored the new study with Irmgard Bischofberger, associate professor of mechanical engineering at MIT.

A better trade-off

The new study grew out of the group’s focus on filtration during the height of the Covid pandemic, when the researchers were designing face masks to filter out the virus. Since then, Mao has shifted focus to study filtration in animals and how certain filter-feeding mechanisms might improve filters used in industry, such as in water treatment plants.

Mao observed that any industrial filter must strike a balance between permeability (how easily fluid can flow through a filter), and selectivity (how successful a filter is at keeping out particles of a target size). For instance, a membrane that is studded with large holes might be highly permeable, meaning a lot of water can be pumped through using very little energy. However, the membrane’s large holes would let many particles through, making it very low in selectivity. Likewise, a membrane with much smaller pores would be more selective yet also require more energy to pump the water through the smaller openings.

“We asked ourselves, how do we do better with this tradeoff between permeability and selectivity?” Hosoi says.

As Mao looked into filter-feeding animals, he found that the mobula ray has struck an ideal balance between permeability and selectivity: The ray is highly permeable, in that it can let water into its mouth and out through its gills quickly enough to capture oxygen to breathe. At the same time, it is highly selective, filtering and feeding on plankton rather than letting the particles stream out through the gills.

The researchers realized that the ray’s filtering features are broadly similar to that of industrial cross-flow filters. These filters are designed such that fluid flows across a permeable membrane that lets through most of the fluid, while any polluting particles continue flowing across the membrane and eventually out into a reservoir of waste.

The team wondered whether the mobula ray might inspire design improvements to industrial cross-flow filters. For that, they took a deeper dive into the dynamics of mobula ray filtration.

A vortex key

As part of their new study, the team fabricated a simple filter inspired by the mobula ray. The filter’s design is what engineers refer to as a “leaky channel” — effectively, a pipe with holes along its sides. In this case, the team’s “channel” consists of two flat, transparent acrylic plates that are glued together at the edges, with a slight opening between the plates through which fluid can be pumped. At one end of the channel, the researchers inserted 3D-printed structures resembling the grooved plates that run along the floor of the mobula ray’s mouth.

The team then pumped water through the channel at various rates, along with colored dye to visualize the flow. They took images across the channel and observed an interesting transition: At slow pumping rates, the flow was “very peaceful,” and fluid easily slipped through the grooves in the printed plates and out into a reservoir. When the researchers increased the pumping rate, the faster-flowing fluid did not slip through, but appeared to swirl at the mouth of each groove, creating a vortex, similar to a small knot of hair between the tips of a comb’s teeth.

“This vortex is not blocking water, but it is blocking particles,” Hosoi explains. “Whereas in a slower flow, particles go through the filter with the water, at higher flow rates, particles try to get through the filter but are blocked by this vortex and are shot down the channel instead. The vortex is helpful because it prevents particles from flowing out.”

The team surmised that vortices are the key to mobula rays’ filter-feeding ability. The ray is able to swim at just the right speed that water, streaming into its mouth, can form vortices between the grooved plates. These vortices effectively block any plankton particles — even those that are smaller than the space between plates. The particles then bounce across the plates and head further into the ray’s cavity, while the rest of the water can still flow between the plates and out through the gills.

The researchers used the results of their experiments, along with dimensions of the filtering features of mobula rays, to develop a blueprint for cross-flow filtration.

“We have provided practical guidance on how to actually filter as the mobula ray does,” Mao offers.

“You want to design a filter such that you’re in the regime where you generate vortices,” Hosoi says. “Our guidelines tell you: If you want your plant to pump at a certain rate, then your filter has to have a particular pore diameter and spacing to generate vortices that will filter out particles of this size. The mobula ray is giving us a really nice rule of thumb for rational design.”

This work was supported, in part, by the U.S. National Institutes of Health, and the Harvey P. Greenspan Fellowship Fund. 

Professor Emeritus James Harris, a scholar of Spanish language, dies at 92

James Wesley “Jim” Harris PhD ’67, professor emeritus of Spanish and linguistics, passed away on Nov. 10. He was 92.

Harris attended the University of Georgia, the Instituto Tecnológico de Estudios Superiores de Monterrey, and the Universidad Nacional Autónoma de México. He later earned a master’s degree in linguistics from Louisiana State University and a PhD in linguistics from MIT.

Harris joined the MIT faculty as an assistant professor in 1967, where he remained until his retirement in 1996. During his tenure, he served as head of what was then called the Department of Foreign Languages and Literatures.

“I met Jim when I came to MIT in 1977 as department head of the neonatal Department of Linguistics and Philosophy,” says Samuel Jay Keyser, MIT professor emeritus of linguistics. “Throughout his career in the department, he never relinquished his connection to the unit that first employed him at MIT.”

In his early days at MIT, when French, German, and Russian dominated as elite “languages of science and world literature,” Harris championed, over some opposition, the introduction of Spanish language and literature courses.

He later oversaw the inclusion of Japanese and Chinese courses as language offerings at MIT. He promoted undergraduate courses in linguistics, leading to a full undergraduate degree program and later broadening the focus of the prestigious PhD program. 

His research in linguistics centered on theoretical phonology and morphology. His books, presentations at professional meetings, and articles in peer-reviewed journals were among the most discussed — in both positive and negative assessments, as he noted — by prominent scholars in the field. The ability to teach complex technical material comfortably in Spanish, plus the status of an MIT professorship, resulted in invitations to teach at universities across Spain and Latin America. He was also highly valued as a member of the editorial boards of several professional journals.

“I remember Jim most of all for being the consummate scholar,” Keyser says. “His articles were models of argumentation. They were assembled with all the precision of an Inca wall and all the beauty of a Faberge Egg. You couldn’t slip a credit card through any of its arguments, they were so superbly sculpted.”

Having achieved national recognition as an English-Spanish bilingual teacher and teacher-trainer, Harris was engaged as a writer at the Modern Language Materials Development Center in New York. Later, he co-authored, with Guillermo Segreda, a series of popular college-level Spanish textbooks.

“Harris belonged to Noam Chomsky and Morris Halle’s first generation of graduate students,” says MIT linguist Michael John Kenstowicz. “Together they overturned the distributionalist model of the structuralists in favor of ordered generative rules.”

After retiring from MIT, he remained internationally recognized as a highly influential figure in the area of Romance linguistics, and “el decano” (“the dean”) of Spanish phonology.

Harris was married to Florence Warshawsky Harris for 50 years until her passing in 2020. In 2011, in celebration of the program’s 50th anniversary, they partnered to prepare and publish a detailed history of the linguistics program’s origins. Warshawsky Harris, formerly an MIT graduate student, also edited Chomsky and Halle’s influential “The Sound Pattern on English” and numerous other important linguistic texts.

Harris’ scholarship was widely recognized in a diverse group of scholarly articles and textbooks he authored, co-authored, edited, and published.

Harris was born outside Atlanta, Georgia, in 1932. During the Korean War, he performed his military service as the clarinet and saxophone instructor at the U.S. Naval School of Music in Washington. After his discharge, he directed the band at the Charlotte Hall School in Maryland, where he also taught Spanish, French, and Latin.

Harris is survived by ​​his daughter, Lynn Corinne Harris, his son-in-law, Rabbi David Adelson, and his grandchildren, Bee Adelson and Sam Harris.

Elevating Video Production – Unlocking the Power of NDI with Kiloview

On this installment of NDI November, Gary is joined by Judy from Kiloview to discover how Kiloview can elevate your video production by unlocking the power of NDI. Enhance your workflow with expert insights and live demonstrations of Kiloview’s latest innovations.

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The N60, Kiloview’s flagship 4K UHD device, sets a new standard for professional broadcast with cutting-edge FPGA technology and efficient AVC/ HEVC/ NDI codecs. It supports both NDI High Bandwidth and NDI HX/HX3, along with SRT/ RTMP/ HLS/ TS-UDP/ RTP/ RTSP.
The N50 supports both NDI High Bandwidth and NDI HX, offering bidirectional conversion and SRT for seamless transmission across LAN and the internet. It delivers 4:2:2 10-bit HDR video quality and includes features like Tally, PoE, PTZ control, KIS Pro intercom, and 3.5mm audio embedding. The N50 is built to meet the highest standards of professional IP transmission, ensuring exceptional performance.
The N50 supports both NDI High Bandwidth and NDI HX, offering bidirectional conversion and SRT for seamless transmission across LAN and the internet. It delivers 4:2:2 10-bit HDR video quality and includes features like Tally, PoE, PTZ control, KIS Pro intercom, and 3.5mm audio embedding. The N50 is built to meet the highest standards of professional IP transmission, ensuring exceptional performance.
Kiloview CUBE R1 is an award-winning NDI recorder system designed to capture and store high-quality video content from multiple NDI video sources. With its user-friendly design, CUBE R1 is ideal for on-the-go recording in live events, post-production and content creation scenarios. It supports simultaneous multi-channel NDI recording with custom layouts, providing compatibility with a wide range of NDI formats. This recorder system offers flexible recording formats and storage options, enabling users to save their footage in the expected quality and file type. With its user-friendly interface and reliable performance, Kiloview CUBE R1 is a valuable tool for professional live event organizers and content creators seeking efficient video recording solutions for high-profile post-production
Kiloview P3 is the next-gen of 5G wireless bonding encoder based on KiloLink technology, supporting six network connections: 4-channel 5G cellular, WiFi (2.4G/5G dual-band) and Gigabit Ethernet. With a 3500mAh built-in battery and a 7000mAh external battery, it can guarantee your all-day use. In addition, P3 adopts a modular design, allowing users to choose between 5G/4G modules (WiFi/SD module is included in the package) and battery modules to meet the diversified business scenarios. The P3 features 3G-SDI and 4K HDMI video inputs, supporting video inputs up to 4KP30 with H.265/H.264 encoding. With the permanent-free/ private-hostable KiloLink Server Pro, it truly achieves unlimited bonding and seamless streaming experience.
The P3 Mini 4G Wireless Bonding Encoder is the perfect outdoor live streaming device built on patented KiloLink bonding transmission technology, serving also as the upgraded version of P1/ P2. The P3 Mini features professional-grade antenna isolation design, allowing for the effective bonding and connection of multiple channels (supporting 3*4G cellular network + 1WiFi + 1*RJ45 Ethernet port), boasting exceptional anti-interference capability and stable transmission performance. It is equipped with dual input interfaces for 3G-SDI and HDMI, supporting up to 1080P60 video resolution. Additionally, the P3 mini is equipped with a 5000mAh battery with 4-hours continuous operation and supports PD fast charging, fully meeting versatile application scenarios.

New solar projects will grow renewable energy generation for four major campus buildings

In the latest step to implement commitments made in MIT’s Fast Forward climate action plan, staff from the Department of Facilities; Office of Sustainability; and Environment, Health and Safety Office are advancing new solar panel installations this fall and winter on four major campus buildings: The Stratton Student Center (W20), the Dewey Library building (E53), and two newer buildings, New Vassar (W46) and the Theater Arts building (W97).

These four new installations, in addition to existing rooftop solar installations on campus, are “just one part of our broader strategy to reduce MIT’s carbon footprint and transition to clean energy,” says Joe Higgins, vice president for campus services and stewardship.

The installations will not only meet but exceed the target set for total solar energy production on campus in the Fast Forward climate action plan that was issued in 2021. With an initial target of 500 kilowatts of installed solar capacity on campus, the new installations, along with those already in place, will bring the total output to roughly 650 kW, exceeding the goal. The solar installations are an important facet of MIT’s approach to eliminating all direct campus emissions by 2050.

The process of advancing to the stage of placing solar panels on campus rooftops is much more complex than just getting them installed on an ordinary house. The process began with a detailed assessment of the potential for reducing the campus greenhouse gas footprint. A first cut eliminated rooftops that were too shaded by trees or other buildings. Then, the schedule for regular replacement of roofs had to be taken into account — it’s better to put new solar panels on top of a roof that will not need replacement in a few years. Other roofs, especially lab buildings, simply had too much existing equipment on them to allow a large area of space for solar panels.

Randa Ghattas, senior sustainability project manager, and Taya Dixon, assistant director for capital budgets and contracts within the Department of Facilities, spearheaded the project. Their initial assessment showed that there were many buildings identified with significant solar potential, and it took the impetus of the Fast Forward plan to kick things into action. 

Even after winnowing down the list of campus buildings based on shading and the life cycle of roof replacements, there were still many other factors to consider. Some buildings that had ample roof space were of older construction that couldn’t bear the loads of a full solar installation without significant reconstruction. “That actually has proved trickier than we thought,” Ghattas says. For example, one building that seemed a good candidate, and already had some solar panels on it, proved unable to sustain the greater weight and wind loads of a full solar installation. Structural capacity, she says, turned out to be “probably the most important” factor in this case.

The roofs on the Student Center and on the Dewey Library building were replaced in the last few years with the intention of the later addition of solar panels. And the two newer buildings were designed from the beginning with solar in mind, even though the solar panels were not part of the initial construction. “The designs were built into them to accommodate solar,” Dixon says, “so those were easy options for us because we knew the buildings were solar-ready and could support solar being integrated into their systems, both the electrical system and the structural system of the roof.”

But there were also other considerations. The Student Center is considered a historically significant building, so the installation had to be designed so that it was invisible from street level, even including a safety railing that had to be built around the solar array. But that was not a problem. “It was fine for this building,” Ghattas says, because it turned out that the geometry of the building and the roofs hid the safety railing from view below.

Each installation will connect directly to the building’s electrical system, and thus into the campus grid. The power they produce will be used in the buildings they are on, though none will be sufficient to fully power its building. Overall, the new installations, in addition to the existing ones on the MIT Sloan School of Management building (E62) and the Alumni Pool (57) and the planned array on the new Graduate Junction dorm (W87-W88), will be enough to power 5 to 10 percent of the buildings’ electric needs, and offset about 190 metric tons of carbon dioxide emissions each year, Ghattas says. This is equivalent to the electricity use of 35 homes annually.

Each building installation is expected to take just a couple of weeks. “We’re hopeful that we’re going to have everything installed and operational by the end of this calendar year,” she says.

Other buildings could be added in coming years, as their roof replacement cycles come around. With the lessons learned along the way in getting to this point, Ghattas says, “now that we have a system in place, hopefully it’s going to be much easier in the future.”

Higgins adds that “in parallel with the solar projects, we’re working on expanding electric vehicle charging stations and the electric vehicle fleet and reducing energy consumption in campus buildings.”

Besides the on-campus improvements, he says, “MIT is focused on both the local and the global.” In addition to solar installations on campus buildings, which can only mitigate a small portion of campus emissions, “large-scale aggregation partnerships are key to moving the actual market landscape for adding cleaner energy generation to power grids,” which must ultimately lead to zero emissions, he says. “We are spurring the development of new utility-grade renewable energy facilities in regions with high carbon-intensive electrical grids. These projects have an immediate and significant impact in the urgently needed decarbonization of regional power grids.”

Higgins says that other technologies, strategies, and practices are being evaluated for heating, cooling, and power for the campus, “with zero carbon emissions by 2050, utilizing cleaner energy sources.” He adds that these campus initiatives “are part of MIT’s larger Climate Project, aiming to drive progress both on campus and beyond, advancing broader partnerships, new market models, and informing approaches to climate policy.” 

Alt Text: Not Always Needed

Most images require description for clarity, there are exceptions. This set of notes looks at different situations and contexts where alt text may not be needed and what to do in those cases.

Alt Text: Not Always Needed originally published on CSS-Tricks, which is part of the…