From keeping warm in the winter to doing laundry, heat is crucial to daily life. But as the world grapples with climate change, buildings’ increasing energy consumption is a critical problem. Currently, heat is produced by burning fossil fuels like coal, oil, and gas, but that will need to change as the world shifts to clean energy. 

Georgia Tech researchers in the George W. Woodruff School of Mechanical Engineering (ME) are developing more efficient heating systems that don’t rely on fossil fuels. They demonstrated that combining two commonly found salts could help store clean energy as heat; this can be used for heating buildings or integrated with a heat pump for cooling buildings.

The researchers presented their research in “Thermochemical Energy Storage Using Salt Mixtures With Improved Hydration Kinetics and Cycling Stability,” in the Journal of Energy Storage.

Reaction Redux 

The fundamental mechanics of heat storage are simple and can be achieved through many methods. A basic reversible chemical reaction is the foundation for their approach: A forward reaction absorbs heat and then stores it, while a reverse reaction releases the heat, enabling a building to use it.

ME Assistant Professor Akanksha Menon has been interested in thermal energy storage since she began working on her Ph.D.  When she arrived at Georgia Tech and started the Water-Energy Research Lab (WERL), she became involved in not only developing storage technology and materials but also figuring out how to integrate them within a building. She thought understanding the fundamental material challenges could translate into creating better storage.

“I realized there are so many things that we don't understand, at a scientific level, about how these thermo-chemical materials work between the forward and reverse reactions,” she said.

The Superior Salt

The reactions Menon works with use salt. Each salt molecule can hold a certain number of water molecules within its structure. To instigate the chemical reaction, the researchers dehydrate the salt with heat, so it expels water vapor as a gas. To reverse the reaction, they hydrate the salt with water, forcing the salt structure’s expansion to accommodate those water molecules. 

It sounds like a simple process, but as this expansion/contraction process happens, the salt gets more stressed and will eventually mechanically fail, the same way lithium-ion batteries only have so many charge-discharge cycles. 

“You can start with something that's a nice spherical particle, but after it goes through a few of these dehydration-hydration cycles, it just breaks apart into tiny particles and completely pulverizes or it overhydrates and agglomerates into a block,” Menon explained. 

These changes aren’t necessarily catastrophic, but they do make the salt ineffective for long-term heat storage as the storage capacity decreases over time. 

Menon and her student, Erik Barbosa, a Ph.D. student in ME, began combining salts that react with water in different ways. After testing six salts over two years, they found two that complemented each other well. Magnesium chloride often fails because it absorbs too much water, whereas strontium chloride is very slow to hydrate. Together, their respective limitations can mutually benefit each other and lead to improved heat storage.

“We didn't plan to mix salts; it was just one of the experiments we tried,” Menon said. “Then we saw this interactive behavior and spent a whole year trying to understand why this was happening and if it was something we could generalize to use for thermal energy storage.”

The Energy Storage of the Future

Menon is just beginning with this research, which was supported by a National Science Foundation (NSF) CAREER Award. Her next step is developing the structures capable of containing these salts for heat storage, which is the focus of an Energy Earthshots project funded by the U.S. Department of Energy’s (DOE) Office of Basic Energy Sciences.

A system-level demonstration is also planned, where one solution is filling a drum with salts in a packed bed reactor. Then hot air would flow across the salts, dehydrating them and effectively charging the drum like a battery. To release that stored energy, humid air would be blown over the salts to rehydrate the crystals. The subsequently released heat can be used in a building instead of fossil fuels. While initiating the reaction needs electricity, this could come from off-peak (excess renewable electricity) and the stored thermal energy could be deployed at peak times. This is the focus of another ongoing project in the lab that is funded by the DOE’s  Building Technologies Office.

Ultimately, this technology could lead to climate-friendly energy solutions. Plus, unlike many alternatives like lithium batteries, salt is a widely available and cost-effective material, meaning its implementation could be swift. Salt-based thermal energy storage can help reduce carbon emissions, a vital strategy in the fight against climate change.

“Our research spans the range from fundamental science to applied engineering thanks to funding from the NSF and DOE,” Menon said. “This positions Georgia Tech to make a significant impact toward decarbonizing heat and enabling a renewable future.”

-Written by Benjamin Wright-

Ameet Pinto, who is the Carlton S. Wilder Associate Professor in the School of Civil and Environmental Engineering, was drawn to Georgia Tech because of the depth and breadth of the research expertise on campus, as well as the collaborative atmosphere.

“I know that if I want to write a research proposal next week for a new idea and I lack expertise in one area, I can find a collaborator on campus with the necessary skillset,” they say. “We have a critical mass of highly skilled researchers across disciplines, and that’s truly amazing.” Helping others tap into that critical mass will be their primary role as one of two associate co-directors for interdisciplinary research in the Brook Byers Institute for Sustainable Systems. Ameet will work with associate professor Yuanzhi Tang from the School of Earth and Atmospheric Sciences to help bring like-minded researchers within the sustainability field together and shepherd them through the grant-writing process.

“My role, as I see it, is to help faculty from across the campus find synergies in their research and then amplify the impact of those synergies by assisting them in going after large thematic proposals with bid support,” says Ameet. “I’m super excited to help make those connections, and where those connections already exist, provide the support to help them take off.”

With degrees in chemical engineering, environmental engineering, and civil engineering and a personal research area that falls under environmental engineering, Ameet is used to working across interdisciplinary lines. Ameet uses their background in chemical engineering to develop sustainable methods to produce drinking water and treat wastewater.

“A major goal for my research group is to look at the microorganisms within the engineered water cycle. We can leverage them, beneficially, to make water treatment, wastewater treatment, and water delivery, both safe and sustainable,” he explains. “If we can use biological processes to remove contaminants, or to produce safe water, then we are not using chemicals.”

After stints teaching at Northeastern University and University of Glasgow, Ameet joined the Georgia Tech faculty in 2021 when the campus community was largely remote during Covid restrictions. Ameet is excited to use this new leadership role within BBISS to connect with others and help build a vibrant community of sustainability researchers.

“My personal vision is closely aligned with BBISS so I was excited to join the leadership team. I know there are other researchers like me looking to make connections with sustainability fields and I know I can help in that area. This is an amazing opportunity to get to know the campus community and connect with like-minded researchers while realizing a shared vision and mission.”

Outside of work Ameet loves to cook. They also have three cats, nine chickens, and their wife is an avid gardener who keeps them fully stocked in fresh produce. Originally from India, Ameet earned a bachelor’s degree in chemical engineering from the Institute of Chemical Technology (University of Mumbai), master’s from the University of Alaska Fairbanks, and Ph.D. from Virginia Tech.

Chaouki Abdallah, Georgia Tech's executive vice president for Research (EVPR), has been named the new president of the Lebanese American University in Beirut.  

Abdallah, MSECE 1982, Ph.D. ECE 1988, has served as EVPR since 2018; in this role, he led extraordinary growth in Georgia Tech's research enterprise. Through the work of the Georgia Tech Research Institute, 10 interdisciplinary research institutes (IRIs), and a broad portfolio of faculty research, Georgia Tech now stands at No. 17 in the nation in research expenditures — and No. 1 among institutions without a medical school.  

Additionally, Abdallah has also overseen Tech's economic development activities through the Enterprise Innovation Institute and such groundbreaking entrepreneurship programs as CREATE-X, VentureLab, and the Advanced Technology Development Center. 

Under Abdallah's strategic, thoughtful leadership, Georgia Tech strengthened its research partnerships with historically Black colleges and universities, launched the New York Climate Exchange with a focus on accelerating climate change solutions, established an AI Hub to boost research and commercialization in artificial intelligence, advanced biomedical research (including three research awards from ARPA-H), and elevated the Institute's annual impact on Georgia's economy to a record $4.5 billion.  

Prior to Georgia Tech, Abdallah served as the 22nd president of the University of New Mexico (UNM), where he also had been provost, executive vice president of academic affairs, and chair of the electrical and computer engineering department. At UNM, he oversaw long-range academic planning, student success initiatives, and improvements in retention and graduation rates. 

A national search will be conducted for Abdallah's replacement. In the coming weeks, President Ángel Cabrera will name an interim EVPR. 

Georgia Institute of Technology has been named a Center for Sustainability Across the Curriculum by the Association for the Advancement of Sustainability in Higher Education (AASHE). Georgia Tech is one of only 21 Centers worldwide, reflecting a continued commitment to incorporating sustainability education through courses and co-curricular experiences.

This title is awarded to institutions with demonstrated experience in organizing sustainability education professional development opportunities for faculty and reflects the Institute’s efforts to increase the accessibility and diversity of education for sustainability, including community-engaged sustainability learning and teaching with the United Nations Sustainable Development Goals (SDGs). As a designated Center, Georgia Tech will host annual professional development events open to faculty from other institutions.

Read the full story on the Center for Teaching and Learning blog.

Georgia Tech’s School of Public Policy has named its first Byers Family Pathways to Policy Fellows and the offices where they will spend their internships in Washington.

Why it matters: These fellowships, funded by a transformative gift from Brook Byers and family, aim to develop future leaders in energy policy. The recipients will gain invaluable experience through year-long internships in Washington while expanding the School’s network and reach in the nation’s capital. The program also gives crucial support for students to live in Washington for a year.

“One of my key missions is to highlight the critical role of data in shaping effective policy,” said Jazmin Rivera, who will be working on decarbonization policy in U.S. Sen. Bill Cassidy’s office. “I believe that educated policymakers are essential for creating robust, evidence-based legislation. Through this fellowship, I aim to see legislation passed that is informed by my work, learn more about energy policy from the source, make bipartisan connections, and gain insights from productive activism."

Joining Rivera in Washington:

• Taylor Clarke: Focusing on environmental policy in the office of Sen. Jon Ossoff.
• Vincent Gu: Ph.D. student serving on the Senate Budget Committee, representing Sen. Sheldon Whitehouse of Rhode Island.

“Working with the Senate Budget Committee offers unique opportunities to interact with various government agencies and understand the collaborative efforts on climate issues,” Gu said. “Through this fellowship, I hope to gain a deeper understanding of the technical requirements for implementing climate solutions like hydrogen and electric vehicles and the work needed to make them feasible."

The big picture: Energy policy expertise is critical as the nation and world navigates the climate crisis, and programs like this show Georgia Tech’s School of Public Policy is delivering transformative learning experiences to prepare students for success.

“I am looking forward to what the next year holds and seeing what my peers will accomplish,” said Clarke. “Having adequate support for opportunities on the Hill is rare, so I am happy to see a program begin that can remove the cost barrier for passionate students.”

What they’re saying: “Georgia Tech students are problem solvers,” said Cassidy R. Sugimoto, Tom and Marie Patton Chair. “We're putting students in positions where they can work with national leaders in solving one of the most pressing problems of our time. We believe in education that makes a difference. This fellowship exemplifies our dedication to this value."

When people think of greenhouse gas emissions from transportation, what often comes to mind are airplanes and land vehicles like cars or trucks. But as efforts to slow climate change are ramping up, the spotlight is on another form of transport: ships. 

The U.N.’s International Maritime Organization (IMO) has set targets to reduce shipping greenhouse gas emissions by at least 40% by 2030 and 70% by 2040, aiming for net-zero by 2050. Shipping currently accounts for about 3% of global annual greenhouse gas emissions, and the pressure is on shipping companies to meet these ambitious goals.

Across Georgia Tech, researchers are working toward a sustainable future for ocean shipping. This includes Valerie Thomas, the Anderson-Interface Chair of Natural Systems Professor in the H. Milton Stewart School of Industrial and Systems Engineering, and in the School of Public Policy. She is scholar of energy systems, sustainability, assessment, and low-carbon transportation fuels, and her work touches many aspects of the maritime industry. 

Finding Sustainable Solutions

“Today, we ship a lot of goods by ocean freight, and there is certainly an environmental impact with shipping,” Thomas said.  “But the emissions from shipping a product from East Asia to the U.S. on a bulk carrier vessel are significantly lower than trucking a product across the U.S. When ships are filled to the brim with cargo and are moving slowly across oceans, this is energy efficient, fuel efficient, and even cost efficient per ton of ‘stuff’ transported.” 

While ocean shipping is significantly more energy efficient than air or land transport and contributes far fewer emissions, Thomas says cutting down on ocean freight emissions will require a great deal more effort. One way is to find more eco-friendly fuels. 

“I look at big systems, and one of those areas is investigating alternative fuels,” Thomas said. “I’m often trying to figure out how much greenhouse gas various fuels emit, what other types of emissions or matter are coming out, and how to compare different fuel options.”

Thomas is a leading expert in life-cycle assessment. It is a method used to evaluate a fuel or technology's environmental impact throughout its entire cycle — from raw materials extraction, processing, manufacturing, distribution, and ultimately, use. Right now, basically all ships use petroleum fuels, which emit carbon dioxide and particulate matter into the air. 

Finding fuel alternatives is not a simple task: Just because a fuel might initially seem like a promising low-carbon option, that is not always the case in the end. Thomas’s expertise in life-cycle assessments helps her figure out whether these possible fuels are truly environmentally friendly.

“One such example is hydrogen: It doesn’t emit carbon dioxide when burned,” Thomas said. “But the manufacturing of hydrogen can emit carbon dioxide, and therefore, hydrogen is not always a low-carbon fuel on a lifecycle basis.”

Helping the Shipping Industry Cut Carbon 

Patricia Stathatou, a researcher at Georgia Tech’s Renewable Bioproducts Institute, specializes in sustainability assessment of chemical engineering processes and products, which includes lifecycle assessments and techno-economic assessments, evaluating both the environmental impacts and the economic viability of products and processes. Stathatou, who will join the School of Chemical and Biomolecular Engineering as an assistant professor in January 2025, also conducts experiments to support these assessments and guide the development of new technologies. 

“My contribution to the lifecycle assessment field is that I support assessments with in-field emission monitoring, taking samples, and performing chemical analyses,” Stathatou said. “This helps identify specific pollutants that might be emitted into the air or be present in water, wastewater, or solid waste streams.”

But as maritime shipping companies rise to the challenge of cutting emissions, they often do not know where to start. This is where Stathatou’s experience comes in. 

During her postdoctoral research at MIT, a major shipping company reached out to Stathatou and her colleagues asking for help in cutting emissions. They wanted to increase the energy efficiency of their fleet and investigate different strategies and technologies to eventually reach the IMO’s emissions goals.

Because of Stathatou’s expertise in alternative fuels, biofuels, and sustainable energy sources, she investigated potential solutions for the company, which included a six-day research trip monitoring emissions aboard one of the company’s bulk carrier vessels in East Asia. Her work involves designing experiments, measuring emissions, and evaluating the environmental impact of different fuels onboard bulk carrier vessels. 

“Ten years ago, there weren't rigorous goals or guidelines for reducing emissions in the shipping industry — and not much scientific collaboration in the process,” Stathatou said. “If we are to make a difference in the industry in regard to climate, we need partnerships with shipping companies to help guide their efforts.”

Stathatou plans to continue her collaborations with shipping companies and expects to carry out more on-ship evaluations soon. 

The Big Picture 

According to Thomas, a holistic approach is needed to make shipping more sustainable. "It's not just about the fuels we use; it's about optimizing supply chains, reducing empty freight, and leveraging multimodal transportation options," Thomas said. "By embracing net-zero freight initiatives and maximizing efficiency in logistics, we can achieve meaningful reductions in emissions while meeting the demands of global trade."

Encouraging shifts to ocean freight is another means of reducing emissions. For example, if a company wants to transport goods from Miami to Baltimore, they don’t need to go by road or rail. “You can ship your freight on the ocean along the coast, and that could be more environmentally efficient,” Thomas said. 

The work Thomas and Stathatou do is part of a broad portfolio of shipping sustainability research at Georgia Tech, which also includes the Georgia Tech Supply Chain and Logistics Institute, the Panama Logistics and Innovation Research Center, and the Net Zero Freight Systems Program, which Thomas co-leads. These partnerships aim to enhance the efficiency and sustainability of global supply chains, leveraging innovative research and practical applications.

“The work of evaluating different fuels, technologies, and strategies is not trivial, and figuring out these new methods does not happen quickly,” Thomas said. “These are difficult technologies, and it takes a long time to put them in place. That is why we need to do this work now.” 

Stathatou envisions that, with more shipping companies now looking to curb their emissions, there will be significant adoption of new fuels and technologies within the next decade.

“Ocean shipping is a transportation sector that we cannot go without, and so decarbonizing it is very important,” Stathatou said. “I believe the ability to perform these assessments and guide the development of future solutions will have a tremendous impact on humanity.”