On a cloudy spring day in Atlanta, Rich Simmons, director of research and studies at the Georgia Tech Strategic Energy Institute (SEI), led a group of a dozen student volunteers to the roof of the Carbon Neutral Energy Solutions Laboratory (CNES). The students were part of the nearly 300 student volunteers participating in Georgia Tech Beautification Day and visited CNES to clean the building’s rooftop solar array made of photovoltaic (PV) panels. The CNES building entered operation in 2011 and its panels have accumulated grime over the years, impacting their efficiency.

Simmons explained the importance of this project, emphasizing how cleaning the panels restores their efficiency and contributes to ongoing research. "We've used this project to better understand PV efficiency in an urban environment and have instrumented the newly cleaned arrays to continue monitoring. An initial study last year suggested efficiency could increase by 10-20% just from a thorough cleaning. This project is both a handy research tool, an educational conduit, and a means of campus engagement related to sustainability," he shared.

Safety was paramount, and proactive communication between the research, health and safety, and infrastructure and sustainability teams ensured a successful event. Equipped with hard hats, eye protection, and high-visibility safety vests, the students scrubbed the panels with sponges and bristle brushes. The hands-on experience was both educational and rewarding.

After cleaning, Simmons led the group to the inverter room, where the DC electricity generated by the panels is converted into AC so that it can be consumed within the building or exported to the campus grid. He explained that excess solar power can also be stored in the newly installed 150-kWh Stryten battery system or used to charge campus vehicles through the newly installed EV chargers in the building’s parking lot. He demonstrated how magnetic monitoring devices measure the electricity produced by the arrays, allowing for a comparison of the efficiency of panels that were just cleaned, to those that were cleaned last year, and those that have never been cleaned in the 13 years since their installation.

Through initiatives like this, Georgia Tech continues to lead in research and education, inspiring the next generation of innovators and problem-solvers.

This article was written with the assistance of Microsoft Copilot (Apr. 9, 2025) and edited by Georgia Tech EPIcenter's Gilbert X. Gonzalez and Rich Simmons.

In July 2024, the Strategic Energy Institute (SEI), in partnership with the Georgia Tech Research Institute (GTRI), launched the Energy and National Security Initiative through a campuswide workshop. The event attracted over 100 participants from units across Georgia Tech and GTRI. John Tien, SEI distinguished external fellow, professor of the practice, and former deputy secretary for the Department of Homeland Security, along with Tom Fanning, former CEO at Southern Company, kicked off the workshop with a discussion on the role of energy in national security and the opportunities for Georgia Tech to align its research with this critical topic. 

The event concluded with the announcement of two rounds of seed funding, offering up to $500,000 annually for three years. The first round, announced in September 2024, provided planning grants to six teams to support their initiatives in the fall.  

Recipients of the second phase of seed funding have now been announced. This phase will provide research support in the spring, with an option for additional funding through the 2025-26 academic year. 

“This seed funding initiative by SEI and GTRI is a significant step toward advancing national security through innovative energy solutions. We believe this support will empower the funded teams to explore critical intersections between energy infrastructure and security, fostering groundbreaking advancements for a safer energy future,” said Christine Conwell, SEI’s interim executive director.  

Seven interdisciplinary projects by team members from Georgia Tech and GTRI have been selected for the second phase, also known as Category B (Table 1). 

“The seed grant initiative is supporting energy and national security collaboration among researchers from multiple units across the Georgia Tech campus,” said William H. Robinson, interim chief technology officer and deputy director for Research in GTRI’s Information and Cyber Sciences Directorate. “We are very pleased to see the teamwork of these faculty members as they address important issues facing our nation.”

A follow-up workshop will be held this summer to bring together the awardees of the seed grant program. Additionally, a lunch and learn seminar series is planned in the fall to showcase the research progress of the seed grant program. For updates, visit the Strategic Energy Institute event webpage.

When the International Maritime Organization enacted a mandatory cap on the sulfur content of marine fuels in 2020, with an eye toward reducing harmful environmental and health impacts, it left shipping companies with three main options.

They could burn low-sulfur fossil fuels, like marine gas oil, or install cleaning systems to remove sulfur from the exhaust gas produced by burning heavy fuel oil. Biofuels with lower sulfur content offer another alternative, though their limited availability makes them a less feasible option.

While installing exhaust gas cleaning systems, known as scrubbers, is the most feasible and cost-effective option, there has been a great deal of uncertainty among firms, policymakers, and scientists as to how “green” these scrubbers are.

Through a novel lifecycle assessment, researchers from MIT, Georgia Tech, and elsewhere have now found that burning heavy fuel oil with scrubbers in the open ocean can match or surpass using low-sulfur fuels, when a wide variety of environmental factors is considered.

The scientists combined data on the production and operation of scrubbers and fuels with emissions measurements taken onboard an oceangoing cargo ship.

They found that, when the entire supply chain is considered, burning heavy fuel oil with scrubbers was the least harmful option in terms of nearly all 10 environmental impact factors they studied, such as greenhouse gas emissions, terrestrial acidification, and ozone formation.

“In our collaboration with Oldendorff Carriers to broadly explore reducing the environmental impact of shipping, this study of scrubbers turned out to be an unexpectedly deep and important transitional issue,” says Neil Gershenfeld, an MIT professor, director of the Center for Bits and Atoms (CBA), and senior author of the study.

“Claims about environmental hazards and policies to mitigate them should be backed by science. You need to see the data, be objective, and design studies that take into account the full picture to be able to compare different options from an apples-to-apples perspective,” adds lead author Patricia Stathatou, an assistant professor at Georgia Tech's School of Chemical and Biomolecular Engineering, who began this study as a postdoc in the CBA.

Stathatou is joined on the paper by Michael Triantafyllou and others at the National Technical University of Athens in Greece and the maritime shipping firm Oldendorff Carriers. The research appears today in Environmental Science and Technology.

Slashing sulfur emissions

Heavy fuel oil, traditionally burned by bulk carriers that make up about 30 percent of the global maritime fleet, usually has a sulfur content around 2 to 3 percent. This is far higher than the International Maritime Organization’s 2020 cap of 0.5 percent in most areas of the ocean and 0.1 percent in areas near population centers or environmentally sensitive regions.

Sulfur oxide emissions contribute to air pollution and acid rain, and can damage the human respiratory system.

In 2018, fewer than 1,000 vessels employed scrubbers. After the cap went into place, higher prices of low-sulfur fossil fuels and limited availability of alternative fuels led many firms to install scrubbers so they could keep burning heavy fuel oil.

Today, more than 5,800 vessels utilize scrubbers, the majority of which are wet, open-loop scrubbers.

“Scrubbers are a very mature technology. They have traditionally been used for decades in land-based applications like power plants to remove pollutants,” Stathatou says.

A wet, open-loop marine scrubber is a huge, metal, vertical tank installed in a ship’s exhaust stack, above the engines. Inside, seawater drawn from the ocean is sprayed through a series of nozzles downward to wash the hot exhaust gases as they exit the engines.

The seawater interacts with sulfur dioxide in the exhaust, converting it to sulfates — water-soluble, environmentally benign compounds that naturally occur in seawater. The washwater is released back into the ocean, while the cleaned exhaust escapes to the atmosphere with little to no sulfur dioxide emissions.

But the acidic washwater can contain other combustion byproducts like heavy metals, so scientists wondered if scrubbers were comparable, from a holistic environmental point of view, to burning low-sulfur fuels.

Several studies explored toxicity of washwater and fuel system pollution, but none painted a full picture.

The researchers set out to fill that scientific gap.

A “well-to-wake” analysis

The team conducted a lifecycle assessment using a global environmental database on production and transport of fossil fuels, such as heavy fuel oil, marine gas oil, and very-low sulfur fuel oil. Considering the entire lifecycle of each fuel is key, since producing low-sulfur fuel requires extra processing steps in the refinery, causing additional emissions of greenhouse gases and particulate matter.

“If we just look at everything that happens before the fuel is bunkered onboard the vessel, heavy fuel oil is significantly more low-impact, environmentally, than low-sulfur fuels,” she says.

The researchers also collaborated with a scrubber manufacturer to obtain detailed information on all materials, production processes, and transportation steps involved in marine scrubber fabrication and installation.

“If you consider that the scrubber has a lifetime of about 20 years, the environmental impacts of producing the scrubber over its lifetime are negligible compared to producing heavy fuel oil,” she adds.

For the final piece, Stathatou spent a week onboard a bulk carrier vessel in China to measure emissions and gather seawater and washwater samples. The ship burned heavy fuel oil with a scrubber and low-sulfur fuels under similar ocean conditions and engine settings.

Collecting these onboard data was the most challenging part of the study.

“All the safety gear, combined with the heat and the noise from the engines on a moving ship, was very overwhelming,” she says.

Their results showed that scrubbers reduce sulfur dioxide emissions by 97 percent, putting heavy fuel oil on par with low-sulfur fuels according to that measure. The researchers saw similar trends for emissions of other pollutants like carbon monoxide and nitrous oxide.

In addition, they tested washwater samples for more than 60 chemical parameters, including nitrogen, phosphorus, polycyclic aromatic hydrocarbons, and 23 metals.

The concentrations of chemicals regulated by the IMO were far below the organization’s requirements. For unregulated chemicals, the researchers compared the concentrations to the strictest limits for industrial effluents from the U.S. Environmental Protection Agency and European Union.

Most chemical concentrations were at least an order of magnitude below these requirements.

In addition, since washwater is diluted thousands of times as it is dispersed by a moving vessel, the concentrations of such chemicals would be even lower in the open ocean.

These findings suggest that the use of scrubbers with heavy fuel oil can be considered as equal to or more environmentally friendly than low-sulfur fuels across many of the impact categories the researchers studied.

“This study demonstrates the scientific complexity of the waste stream of scrubbers. Having finally conducted a multiyear, comprehensive, and peer-reviewed study, commonly held fears and assumptions are now put to rest,” says Scott Bergeron, managing director at Oldendorff Carriers and co-author of the study.

“This first-of-its-kind study on a well-to-wake basis provides very valuable input to ongoing discussion at the IMO,” adds Thomas Klenum, executive vice president of innovation and regulatory affairs at the Liberian Registry, emphasizing the need “for regulatory decisions to be made based on scientific studies providing factual data and conclusions.”

Ultimately, this study shows the importance of incorporating lifecycle assessments into future environmental impact reduction policies, Stathatou says.

“There is all this discussion about switching to alternative fuels in the future, but how green are these fuels? We must do our due diligence to compare them equally with existing solutions to see the costs and benefits,” she adds.

This study was supported, in part, by Oldendorff Carriers.

- Written by Adam Zewe, MIT News Office

A pair of Georgia Tech School of Electrical and Computer Engineering (ECE) students were awarded a 2024-25 IEEE Power and Energy Society (PES) Scholarship.

Fourth-year electrical engineering major Susannah Gordon and third-year electrical engineering major Radhika Sharma became the latest ECE students to win the selective award, joining Denitsa Dimitrova who won it last year.

The PES Scholarship Plus Initiative provides scholarships and real-world experience to undergraduates majoring in electrical engineering, who are high achievers with strong GPAs, distinctive extracurricular involvement, and are committed to pursuing careers in power and energy engineering.

Gordon and Sharma were two of just 84 winners from around North America.

On top of the PES Scholarship, Gordon won the John W. Estey Outstanding Scholar Award, which goes to the top PES student in each of the organization’s seven regions. She was chosen as the winner for Region 3.

Gordon’s academic path follows the Electric Energy Systems and Robotics curriculum threads. She has been interested in renewable energy and power engineering since her first year when she joined the Gaming for Electric Power Grids Vertically Integrated Project.

She’s conducted research with ECE associate professor Daniel Molzahn, focusing on generating a synthetic distribution system model for the State of Georgia based on public available information.

On campus, she is involved in ECE Ambassadors, Ramblin’ Reck Club, and Tau Beta Pi.

Upon graduating in May, she will join Kimley-Horn full time as an electrical analyst and hopes to pursue of a master’s degree in electrical engineering part-time at Georgia Tech.

Sharma has been involved in a number of campus organizations, including the Energy Club at Georgia Tech since her first semester at Georgia Tech, where she plans Energy Chats and networking events, along with helping to organize the Southeastern Energy Conference every year.

She’s also on the officer board of Women in ECE (WECE) and is a peer instructor at the Interdisciplinary Design Commons (also known as the Hive Makerspace).

Outside of Georgia Tech she’s completed two internships in power systems. One in power delivery at Florida Power & Light and another in substation design at Burns & McDonnell.

Her main research interest is in scaling the electric power grid. She also conducts research in power reliability with renewable energy sources.

Sharma plans to use the scholarship to finish the fourth year of her degree and use the PES resources that come with it to learn more about the different fields of power systems.

Applications for the 2025 cycle PES Scholarship are open and close on April 30.

The 2025 Southeastern Energy Conference, Georgia Tech’s annual student-led energy and sustainability conference, took place from Feb. 28 to March 1, 2025. Organized by the Energy Club at Georgia Tech, the conference welcomed over 100 attendees, including industry leaders, policymakers, researchers, and students, fostering dynamic discussions on the future of energy. The theme for this year’s conference, "Going Global: Energy’s Place on the World Stage," highlighted the international nature of energy challenges and solutions, emphasizing collaboration across borders.

The event kicked off with a keynote address from Hon. John Tien, who provided thought-provoking insights into the evolving energy landscape. Following the keynote, the first panel of the day, "The Ukraine Energy War: Lessons in Energy Security," featured expert analysis from Anna Mikulsa of the IDA Science and Technology Policy Institute and Gabriel Collins of Rice University’s Baker Institute. The session was moderated by Georgia Tech student Grant Espy. This was followed by a discussion on the role of nuclear energy globally, where Seth Grae, president and CEO of Lightbridge Corporation, and CJ Fong, vice president of Regulatory Affairs at Blue Energy, shared their perspectives, moderated by Anna Schafer, a student at Georgia Tech.

Throughout the day, attendees had the opportunity to engage with representatives from 10 local and regional energy companies through the Industry Showcase. Companies such as GE Vernova, Georgia Power, Kimley-Horn, and the Georgia Cleantech Innovation Hub were present, providing valuable networking and career development opportunities for students and professionals alike. The day concluded with an engaging panel on "The Potential of Clean Hydrogen," featuring insights from industry leaders including Comas Haynes of Georgia Tech's Strategic Energy Institute, Hayley Ryan of ExxonMobil, Luis Alcoser of Chevron Technology Ventures, and Scott McWhorter of the Southeast Hydrogen Energy Alliance, moderated by Eli Acree, a student at Georgia Tech.

The second day of the conference opened with a keynote speech from Tim Lieuwen, executive vice president for Research at Georgia Tech, who laid out what a carbon-neutral future could truly look like in energy. The "Cybersecurity for Energy Systems" panel brought together Seymour E. Goodman of Georgia Tech, Jake Braun of the University of Chicago, Juan Villarreal of Villarreal Energy, and Forrest Shriver of Sentinel Devices to discuss the challenges and solutions in securing energy infrastructure. Following that, the "Applications of Solar Microgrids" panel moderated by John Blankenhorn, a Ph.D. candidate at Georgia Tech, featured expert perspectives from Letian Dou of Purdue University, Ben Ollis of Oak Ridge National Laboratory, and Raymond Hill of Emory University’s Goizueta Business School.

One of the standout moments of the conference was the Student Symposium, where seven student researchers had the opportunity to present their work, competing for $500 in prize money. Projects explored topics ranging from photocatalysts to heat-driven desalination to thermal batteries for buildings.

The final panel of the event, "Scaled Sustainable Development," moderated by Conference Chair Sam Woolsey, a student at Georgia Tech, featured Jonathan Elkind of Columbia University’s Center on Global Energy Policy, Miguel Granier of the Cox Cleantech Accelerator, and Hon. Jobeth Lillian Coleby-Davis, Minister of Energy & Transport for the Government of the Bahamas.

Faculty Advisor Dan Molzahn also praised the conference, stating, "I've been incredibly impressed by the student organizers in pulling together such a remarkable and well-executed event. Given all the change occurring in the world today around energy, the students' foresight to focus on this topic by bringing in a broad range of experts was a huge benefit to the Georgia Tech community."

Reflecting on the success of the event, Sam Woolsey shared, "I was honored to serve as Energy Club's 2025 Conference Chair and to see the conference so positively received. It was a pleasure to see the ways this year's conference encouraged Georgia Tech engineers to get out of their comfort zone and discuss the policy and international affairs of energy."

The 11th annual Southeastern Energy Conference set a high standard for future student-led initiatives in energy and sustainability at Georgia Tech, fostering meaningful discussions and connections that will continue shaping the field. With a diverse lineup of experts, engaging panels, and invaluable networking opportunities, this event demonstrated Georgia Tech’s leadership in fostering innovative discussions on global energy challenges. The Energy Club extends its heartfelt thanks to all speakers, panelists, industry representatives, and attendees for making this conference a success. Stay tuned for future events and continued conversations on the evolving energy landscape!

Written by: Energy Conference Committee Members:  Braden Queen, Eli Acree, Sam Woolsey, Anna Schafer, Grant Espy, John Blankenhorn

Successful test results of a new machine learning (ML) technique developed at Georgia Tech could help communities prepare for extreme weather and coastal flooding. The approach could also be applied to other models that predict how natural systems impact society. 

Ph.D. student Phillip Si and Assistant Professor Peng Chen developed Latent-EnSF, a technique that improves how ML models assimilate data to make predictions.

In experiments predicting medium-range weather forecasting and shallow water wave propagation, Latent-EnSF demonstrated higher accuracy, faster convergence, and greater efficiency than existing methods for sparse data assimilation.

“We are currently involved in an NSF-funded project aimed at providing real-time information on extreme flooding events in Pinellas County, Florida,” said Si, who studies computational science and engineering (CSE). 

“We're actively working on integrating Latent-EnSF into the system, which will facilitate accurate and synchronized modeling of natural disasters. This initiative aims to enhance community preparedness and safety measures in response to flooding risks.” 

Latent-EnSF outperformed three comparable models in assimilation speed, accuracy, and efficiency in shallow water wave propagation experiments. These tests show models can make better and faster predictions of coastal flood waves, tides, and tsunamis. 

In experiments on medium-range weather forecasting, Latent-EnSF surpassed the same three control models in accuracy, convergence, and time. Additionally, this test demonstrated Latent-EnSF's scalability compared to other methods.

These promising results support using ML models to simulate climate, weather, and other complex systems.

Traditionally, such studies require employment of large, energy-intensive supercomputers. However, advances like Latent-EnSF are making smaller, more efficient ML models feasible for these purposes.

The Georgia Tech team mentioned this comparison in its paper. It takes hours for the European Center for Medium-Range Weather Forecasts computer to run its simulations. Conversely, the ML model FourCastNet calculated the same forecast in seconds.

“Resolution, complexity, and data-diversity will continue to increase into the future,” said Chen, an assistant professor in the School of CSE. 

“To keep pace with this trend, we believe that ML models and ML-based data assimilation methods will become indispensable for studying large-scale complex systems.”

Data assimilation is the process by which models continuously ingest new, real-world data to update predictions. This data is often sparse, meaning it is limited, incomplete, or unevenly distributed over time. 

Latent-EnSF builds on the Ensemble Filter Scores (EnSF) model developed by Florida State University and Oak Ridge National Laboratory researchers. 

EnSF’s strength is that it assimilates data with many features and unpredictable relationships between data points. However, integrating sparse data leads to lost information and knowledge gaps in the model. Also, such large models may stop learning entirely from small amounts of sparse data.

The Georgia Tech researchers employ two variational autoencoders (VAEs) in Latent-EnSF to help ML models integrate and use real-world data. The VAEs encode sparse data and predictive models together in the same space to assimilate data more accurately and efficiently.

Integrating models with new methods, like Latent-EnSF, accelerates data assimilation. Producing accurate predictions more quickly during real-world crises could save lives and property for communities.

[Related: University of South Florida Researchers Track Flooding in Coastal Communities During Hurricanes Helene and Milton]

To share Latent-EnSF to the broader research community, Chen and Si presented their paper at the SIAM Conference on Computational Science and Engineering (CSE25). The Society of Industrial and Applied Mathematics (SIAM) organized CSE25, held March 3-7 in Fort Worth, Texas.

Chen was one of ten School of CSE faculty members who presented research at CSE25, representing one-third of the School’s faculty body. Latent-EnSF was one of 15 papers by School of CSE authors and one of 23 Georgia Tech papers presented at the conference.

The pair will also present Latent-EnSF at the upcoming International Conference on Learning Representations (ICLR 2025). Occurring April 24-28 in Singapore, ICLR is one of the world’s most prestigious conferences dedicated to artificial intelligence research.

“We hope to bring attention to experts and domain scientists the exciting area of ML-based data assimilation by presenting our paper,” Chen said. “Our work offers a new solution to address some of the key shortcomings in the area for broader applications.”

Devesh Ranjan, the Eugene C. Gwaltney, Jr. School Chair of the George W. Woodruff School of Mechanical Engineering, has been named dean of the College of Engineering at the University of Wisconsin-Madison (UW).

Ranjan graduated from UW and has been at Georgia Tech since 2014. He was selected as dean by UW Provost Charles Isbell, a Georgia Tech graduate and former dean of the College of Computing.

Ranjan will lead the Woodruff School through the spring semester. He will join UW in June.

“Devesh is a visionary leader who has created numerous programs to strengthen the Woodruff School community,” said Raheem Beyah, dean of the College of Engineering and Southern Company Chair. “Georgia Tech is my alma mater, and I know there’s nothing like going home. Devesh’s deep commitment and determination will undoubtedly lead to his continued success as he returns to UW to innovate and lead the university’s college of engineering. I’m grateful for his commitment to Tech and the Woodruff School, as well as his valuable guidance and partnership.”

Read more on the COE Website

Students in Matthew Oliver’s economics of environment and international energy markets classes likely don’t have a clue about his unusual journey to the lectern: “I was bent on being a rock and roll musician from the time I was 16, and so I ended up dropping out of the University of Memphis after just three semesters,” says Oliver, an associate professor in the School of Economics at the Georgia Institute of Technology. “I was on tour for eight years — and I was starting to feel burned out.” 

At a crossroads, Oliver decided to end his musical career — a choice he credits with launching him into academia. “I was 28 and wondering what to do with my life, so I reenrolled in college and discovered economics.”  With a longtime love of the environment and growing concern for the climate, says Oliver, “I grew fascinated with solar power and other renewables and the new markets emerging around them.”  

Today, his work in energy and environmental economics has implications for policies shaping the energy transition, from subsidies for rooftop solar to the expansion of battery storage. 

“The current frontier of energy economics is electricity and renewables, and these are areas I am passionate about,” he says. 

PVs and amped up electric use 

One of Oliver’s core research thrusts is the solar rebound effect (SRE). This phenomenon involves a quirk of human behavior: When people install solar photovoltaic (PV) panels on the roofs of their homes, they often consume more electricity. “The introduction of solar energy does not perfectly displace grid-supplied energy, but instead reduces demand for grid-supplied energy on a less than one-for-one basis, because the household increases its total electricity consumption,” says Oliver. The bottom line: Solar PV systems may not lead to as much carbon emission reduction as anticipated.  

Read more on the EPIcenter Webpage