While the U.S. federal government has clean energy targets, they are not binding. Most economically developed countries have mandatory policies designed to bolster renewable electricity production. Because the U.S. lacks an enforceable federal mandate for renewable electricity, individual states are left to develop their own regulations. 

Marilyn Brown, Regents’ and Brook Byers Professor of Sustainable Systems in Georgia Tech’s School of Public Policy; Shan Zhou, an assistant professor at Purdue University and Georgia Tech Ph.D. alumna; and Barry Solomon, a professor emeritus of environmental policy at Michigan Technological University, investigated how clean electricity policies affect not only the states that adopt them, but neighboring states as well. Using data-driven comparisons, the researchers found that the impact of these subnational clean energy policies is far greater — and more nuanced — than previously known. 

Their research was recently published in the journal Proceedings of the National Academy of Sciences. 

“Analysts are asking if the U.S. should have a federal renewable mandate to put the whole country on the same page, or if individual state policies are sufficient,” Brown said. “To answer that question, it is useful to know if states with renewable energy policies are influencing those without them.”

Brown, Solomon, and Zhou examined a common clean energy policy tool: the Renewable Portfolio Standard (RPS). Adopted by more than half of U.S. states, RPSs are regulations requiring a state’s utility providers to generate a certain percentage of their electricity from renewable resources, such as wind or solar. Many of these standards are mandatory, with utility companies facing fines if they fail to reach targets within a given time.

To investigate the influence of these policies across state lines, the researchers first created a dataset that included 31 years (1991-2021) of annual renewable electricity generation data for 48 U.S. states and the District of Columbia. They then used the dataset to generate pairs of states linking each state to its geographic neighbors or electricity trading partners, allowing them to examine the influence of the RPS policy adopted by one of the pair on the renewable energy generation of the other — a total of 1,519 paired comparisons. 

“By only looking at the pairs, we can see if an RPS in one state directly affects renewable electricity generation in another state, and, if that’s the case, whether it is because they are geographic neighbors or if it’s because they are participating in the same wholesale electricity market,” Zhou said. 

Looking into the electricity market is important, because states often purchase electricity from other states through wholesale markets rather than exclusively producing their own power, and the purchased power can be generated from renewables. Utilities in some states may be allowed to meet their own RPS requirements by purchasing renewable energy credits based on the renewable electricity generated in other states. 

In their analyses, the team also considered the concept of “policy stringency.” A stringency measure evaluates a state’s renewable electricity targets relative to the amount currently produced in the state. For example, if a state requires electric utilities to generate 30% of their electricity from renewable sources by 2030 and the state already has 25%, it isn’t a very stringent policy. On the other hand, if a state has a 30% target and only uses 10% renewables currently, it has a more ambitious and stringent RPS.

Though policy experts have used the metric in related work for over a decade, the research team improved the design. 

“Our stringency variable includes interim targets as well as the existing share of renewable energy generation,” Solomon said.

The team found that the amount of renewable electricity generation in a state is not only influenced by whether that state has its own RPS, but also by the RPS policies of neighboring states. 

“We also learned that the stronger a neighboring state’s RPS policy is, the more likely a given state is to generate more renewable electricity,” Brown said. “It’s all a very interactive web with many co-benefits.”

The authors were surprised to find that a given state’s electricity trading partners did not hold the most influence over renewable generation, but rather the geographical proximity to RPS states. They suggest that past RPS policy research focusing on within-state impacts likely underestimated an RPS’s full impact. While the researchers have not yet identified all factors that can cause spillover effects, they plan to investigate this further. 

“The spillover effect is very significant and should not be overlooked by future research, especially for states without RPSs,” Zhou said. “For states without policies, their renewable electricity generation is very heavily influenced by their neighbors.”

 

Citation: Shan Zhou, Barry D. Solomon, and Marilyn A. Brown, “The spillover effect of mandatory renewable portfolio standards.” PNAS (June 2024). 
DOI: https://doi.org/10.1073/pnas.2313193121
 

 

The federally funded IAC program provides small to mid-sized industrial facilities in the region with free assessments for energy, productivity, and waste, while also supporting workforce development, recruitment, and training.

“This IAC is a great example of the ways in which Georgia Tech is serving all of Georgia and the Southeast,” said Tim Lieuwen, executive director of Georgia Tech’s Strategic Energy Institute (SEI) and Regents’ Professor and holder of the David S. Lewis, Jr. Chair in the Daniel Guggenheim School of Aerospace Engineering.

“We support numerous small and medium-sized enterprises in rural, suburban, and urban areas, bringing the technical expertise of Georgia Tech to bear in solving real-world problems faced by our small businesses.”

Georgia Tech’s IAC, which serves Georgia, South Carolina, and North Florida, is administered jointly by the George W. Woodruff School of Mechanical Engineering and the Georgia Manufacturing Extension Partnership (GaMEP), part of the Enterprise Innovation Institute (EI2). The organization has performed thousands of assessments since its inception in the 1980s – usually at the rate of 15 to 20 per year – and typically identifies upwards of 10% in energy savings for clients.

The assessment team, overseen by IAC associate director Kelly Grissom, comprises faculty and student engineers from Georgia Tech and the Florida A&M University/Florida State University College of Engineering.

In addition, Georgia Tech leads the Southeastern IACs Center of Excellence, which partners the institution with fellow University System of Georgia (USG) entity Kennesaw State University, local HBCU Clark Atlanta University, and neighboring state capital HBCU Florida A&M University.

Although mechanical engineering has historically been the chief area of concentration for IAC’s interns, the program currently accepts students across a range of disciplines. “Increased diversity from that standpoint enriches the potential of the recommendations we can make,” said Grissom.

Students are integral to the program, as is Grissom’s role in facilitating their experiences with client engagement and technical recommendations.

“Kelly is the reason our program has been recognized,” said Randy Green, energy and sustainability services group manager at GaMEP. “He works tirelessly to ensure that assessments are accomplished with success for our manufacturers and students.”

“We also recognize our partnership with the Woodruff School of Mechanical Engineering and with IAC program lead Comas Haynes, Ph.D., who works diligently to keep us on track and connected with our sponsors at the U.S. Department of Energy,” Green added.

The DoE accolade represents “a ‘one Georgia Tech’ win,” symbolic of the synergistic relationships forged across the Institute, said Haynes, who also serves as the Hydrogen Initiative Lead at Georgia Tech’s Strategic Energy Institute (SEI) and Energy branch head in the Intelligent Sustainable Technologies Division at the Georgia Tech Research Institute. Haynes specifically cited Green’s “technical prowess and managerial oversight” as another key to the IAC program’s success.

Said Devesh Ranjan, Eugene C. Gwaltney, Jr. School Chair and professor in the George W. Woodruff School of Mechanical Engineering, “It is truly an honor for Georgia Tech to be named the Department of Energy Industrial (Training and) Assessment Center of the Year. Clean energy and manufacturing have been a focus for the Institute and the Woodruff School for a long time, and GTRI, EI2, and SEI have collaboratively done phenomenal work in helping manufacturers save energy, improve productivity, and reduce waste.”

To check eligibility and apply for assistance from Georgia Tech’s IAC, click here.

When the door to the Mars Dune Alpha habitat at NASA's Johnson Space Center in Houston, Texas, closed behind the crew members of the first Crew Health and Performance Exploration Analog (CHAPEA) mission, Georgia Tech graduate Ross Brockwell was transported 152 million simulated miles to the Red Planet.  

For the next 378 days, Brockwell, a 1999 civil engineering graduate, and three other crew members participated in the study designed to gain insights into the challenges of deep space exploration and its effects on human health and performance. The crew performed robotic operations, habitat maintenance, agricultural activities, and simulated surface walks in the "sandbox" with the assistance of virtual reality while enduring intentional resource limitations, isolation, and confinement. 

A structural engineer by day, he has always dreamed of space travel, and when a fellow Yellow Jacket alerted Brockwell to the application for the CHAPEA mission, he seized the opportunity.  

"Sometimes, you get chances in your lifetime, and if I don't get a chance to actually go to Mars, if I can take this chance to help us get there as a planet, I'm honored," he said. 

Once inside the 1,700-square-foot habitat, Brockwell's role as the CHAPEA mission's flight engineer focused on infrastructure, building design, and organizational leadership. As much as he learned from his tasks throughout the mission, like anticipating possible failure points and contingency planning, NASA learned even more through physical and cognitive monitoring.  

"There was a lot of science, but some of the science was focused on us as the participants — our physiology and our performance — to make the mission as realistic as possible," he said.  

Communication is a key element in space travel. Getting a message from Mars back to family and friends or mission control on Earth took 20 minutes on average for the crew inside the habitat, testing their ability to isolate. Without constant communication with the outside world, the crew fostered camaraderie through team activities and celebrated birthdays and holidays together. Brockwell's ingenuity wasn't limited to official tasks; he used a 3D printer to create a bracket for mounting a mini-basketball hoop.  

Meals inside the habitat mirrored the shelf-stable food system of the International Space Station. While cultivated crops like tomatoes supplemented their main supply, Brockwell says there is a common misconception about astronaut food.  

"I say with all sincerity, it was delicious." His favorite dish was a peanut chicken and wild rice mix, but the crew often got creative by mixing soups and proteins to create new dishes. 

Other than the food, the biggest surprise to Brockwell was how quickly the mission was completed.    

"I hoped and thought it would be that way, but we proved that a well-comprised crew can have a good time while doing this. There were a lot of clichéd expectations that there would be issues that we just didn't have. I think we demonstrated that a mission like this can be a huge success and an enjoyable, positive experience, not just something to be endured," he said.  

Brockwell says that his time at Georgia Tech allowed him to learn the fundamentals of engineering principles and taught him to keep an open mind when exploring how things work. After receiving a master's degree in aeronautics from the California Institute of Technology and completing the CHAPEA mission, he believes systems engineering can aid deep space exploration efforts for the next generation.  

"Thinking about the effect of every component on every other component and the emergent properties from complex systems is crucial. I think that systems thinking is going to become increasingly important. Ecology and ecological thinking need to be part of it, especially for aerospace. If you're thinking about deep space exploration, an understanding of ecological principles and closed-loop systems will be key," he said.  

At the end of the mission, Brockwell savored the sights and smells of Earth for the first time in over a year, saying that's what he missed the most. But if the opportunity arose to take the 152-million-mile flight to Mars, he'd be on the first ship out.   

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.”

When Blair Brettmann was a sophomore at the University of Texas at Austin, her advisor told her about the National Science Foundation’s Research Experience for Undergraduates (REU) program. The summer program enables undergraduates to conduct research at top institutions across the country. Brettmann spent the summer of 2005 at Cornell working in a national nanotechnology program — a defining experience that led to her current research in molecular engineering for integrated product development. 

“I didn't know for sure if I wanted to attend grad school until after the REU experience,” Brettmann said. “Through it, I went to high-level seminars for the first time, and working in a cleanroom was super cool.” 

Her experience was so positive that the following summer, Brettmann completed a second REU at the Massachusetts Institute of Technology, where she eventually earned her Ph.D. Now an associate professor in Georgia Tech’s School of Chemical and Biomolecular Engineering and School of Materials Science and Engineering and an Institute for Matter and Systems faculty member, Brettmann is an REU mentor for the current iteration of the nanotechnology program — now taking place at Georgia Tech. 

Brettmann’s mentee this summer, Marissa Moore, is having a similarly positive experience. A rising senior in chemical engineering at the University of Missouri-Columbia (Mizzou), Moore was already familiar with Georgia Tech because her father received his chemical engineering Ph.D. from the Institute; she hopes to do the same. Her passion for research began as she grew up with her sister, who had cerebral palsy and epilepsy. 

“We spent a lot of time in hospitals trying out new devices and looking for different medications that would help her, so I knew I wanted to make a difference in this area,” she said. 

But Moore wasn’t interested in being a doctor. Instead, she wanted to develop the materials that could be a solution for someone like her sister. Her undergraduate research focuses on materials and biomaterials for medical applications, and Georgia Tech is enabling her to deep-dive into pure materials science. 

“What I'm working on at both universities is biodegradable polymers, but at Mizzou I’m developing that polymer from the ground up, and at Tech I’m using the properties of the polymer and finding how to make them,” she explained. 

Having the opportunity to work in nanotechnology through the Institute for Materials and use Georgia Tech’s famous cleanroom made this REU stand out for Moore. 

“I had never been in the cleanroom before, so that was one of the most eye-opening experiences,” she said. “It was cool to gown up and learn all of the safety precautions.” 

For Brettmann, hands-on research experiences like this make the REU program unique — and crucial — for potential graduate students. 

“Having your experiments fail, or even having things not turn out as you expect them to is an important part of the graduate research experience,” she said. “One of the best things about REU is it can be a first experience for people and help them decide what to do in grad school later on.”

Georgia Tech will lead a consortium of 12 universities and 12 national labs as part of a $25 million U.S. Department of Energy National Nuclear Security Administration (NNSA) award. This is the second time Georgia Tech has won this award and led research and development efforts to aid NNSA’s nonproliferation, nuclear science, and security endeavors.

The Consortium for Enabling Technologies and Innovation (ETI) 2.0 will leverage the strong foundation of interdisciplinary, collaboration-driven technological innovation developed in the ETI Consortium funded in 2019. The technical mission of the ETI 2.0 team is to advance technologies across three core disciplines: data science and digital technologies in nuclear security and nonproliferation, precision environmental analysis for enhanced nuclear nonproliferation vigilance and emergency response, and emerging technologies. They will be advanced by research projects in novel radiation detectors, algorithms, testbeds, and digital twins.

“What we're trying to do is bring those emergent technologies that are not implemented right now to fruition,” said Anna Erickson, Woodruff Professor and associate chair for research in the George W. Woodruff School of Mechanical Engineering, who leads both grants. “We want to understand what's ahead in the future for both the technology and the threats, which will help us determine how we can address it today.” 

While half the original collaborators remain, Erickson sought new institutional partners for their research expertise, including Abilene Christian University, University of Alaska Fairbanks, Stony Brook University, Rensselaer Polytechnic Institute, and Virginia Commonwealth University. Other university collaborators include the Colorado School of Mines, the Massachusetts Institute of Technology, Ohio State University, Texas A&M University, the University of Texas at Austin, and the University of Wisconsin–Madison.  

National lab partners are the Argonne National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Nevada National Security Site, Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Princeton Plasma Physics Laboratory, Sandia National Laboratories, and Savannah River National Laboratory.

The partners, along with the other NNSA Consortia, gathered at Texas A&M in June to present the new results of the research — NNSA DNN R&D University Program Review — and the kickoff will be hosted in Atlanta in February 2025. More than 300 collaborators, including 150 students, met for four days to share their research and develop new partnerships. 

Engaging students in research in the nuclear nonproliferation field is a key part of the award. The plan is to train over 50 graduate students, provide internships for graduate and undergraduate students, and offer faculty-student lab visit fellowships. This pipeline aims to develop well-rounded professionals equipped with the expertise to tackle future nonproliferation challenges.

“Because nuclear proliferation is a multifaceted problem, we try to bring together people from outside nuclear engineering to have a conversation about the problems and solutions,” Erickson said.

“One of the biggest accomplishments of ETI 1.0 is this incredible relationship that our university PIs have been able to forge with national labs,” she said. “Over five years, we've supported over 70 student internships at national labs, and we have already transitioned a number of Ph.D. students to careers at national labs.” 

As the consortium efforts continue, the team looks forward to the next phase of engagement with government, university, and national lab partners.

“With a united team and a focus on cutting-edge technologies, the ETI 2.0 consortium is poised to break new ground in nuclear nonproliferation,” Erickson said. “Collaboration is the fuel, and innovation is the engine.”

As the summer heat intensifies, with temperatures sometimes soaring to triple digits, the question of which fabrics are best for staying cool becomes particularly relevant. Sundaresan Jayaraman, a professor in Georgia Tech’s School of Materials Science and Engineering, offers insights into the properties of various fabrics and why some are more effective than others in hot, humid conditions.

Jayaraman, a renowned expert in fibers, polymers, and textiles, recognizes linen as the best fabric for hot and humid conditions. He explains that linen's effectiveness lies in its superior moisture management properties. The fiber structure of linen allows it to absorb moisture quickly and then transport it away from the body. This is due to linen's high moisture regain capacity, which means it can absorb a significant amount of moisture without feeling damp.

“The moisture vapor transport rate for linen is much greater than that for cotton or polyester,” he explained. Additionally, linen's bending rigidity prevents it from clinging to the body, allowing for better air circulation.

Cotton is another popular fabric for summer, known for its softness and breathability. However, Jayaraman points out that while cotton effectively absorbs moisture, it tends to retain it longer than linen, making it feel clammy in extreme heat. Cotton's moisture vapor transmission rate is lower than linen’s, meaning it doesn't dry as quickly.

The structure of cotton fibers, which are ribbon-like and can trap more water, also affects cotton’s performance. While it’s more prone to sticking to the body due to its lower bending rigidity, cotton is generally comfortable for less humid conditions or for shorter durations in the heat.

While polyester may not be the first fabric that comes to mind for summer, its performance can be significantly enhanced with chemical treatments. Dri-FIT technology, for instance, improves polyester’s moisture-wicking properties, making it a popular choice for athletic wear.

“Regular polyester is terrible when it comes to moisture absorption,” admitted Jayaraman. “But Dri-FIT polyester doesn’t feel clammy and is very comfortable for being physically active in the summer months.”

While functionality is crucial, aesthetics also play a role in fabric choice for the summer. Linen, despite its excellent cooling properties, is prone to wrinkling and may not drape as elegantly as cotton or treated polyester. Jayaraman notes that linen's natural stiffness, which contributes to its cooling benefits, also leads to its tendency to wrinkle. He says, “For a crisp appearance, linen garments often require ironing before wear.” For those prioritizing appearance, cotton offers a softer drape and a smoother look, albeit with slightly less cooling efficiency.

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.”