Creating hydrogen energy for Guam using seawater electrolysis

When Mechanical Engineer Fleur de Peralta visited her native Guam in 2021, a question began to form in her mind. How could she bring the engineering and energy expertise of her employer, Pacific Northwest National Laboratory (PNNL), to her home island?

"What I heard from people in Guam was the importance of energy independence from renewable sources," said de Peralta. Guam, a U.S. territory located in a string of Western Pacific islands known as Micronesia, currently meets its energy needs in the form of imported fossil fuels and intermittent renewable energy. Its goal is to generate 100% of its energy from renewable sources by 2045.

The answer to her question came in the form of a new funding opportunity from the Department of Energy's Reaching a New Energy Sciences Workforce (RENEW) program. RENEW was created specifically to provide research partnerships between the national laboratories and educational institutions that serve populations historically underrepresented in science, such as Pacific Islanders.

De Peralta's vision led to a successful proposal to investigate the science necessary to turn seawater into hydrogen using renewable electricity.

The abundant seawater surrounding Guam provides an enticing energy source: hydrogen. Through a process called electrolysis, energy from electricity splits water into hydrogen and oxygen. This generates a fuel that can also be stored and used when renewable electricity is not available.

"Being able to produce hydrogen from seawater would be a game changer for Guam," said John Limtiaco, an assistant professor of chemistry at the University of Guam (UOG) and the project lead. "UOG is a hub for students throughout Micronesia. We want to bring in students from outlying islands and get them excited about scientific research."

Limtiaco is partnering with researchers from PNNL, including Juan Lopez-Ruiz and Mal Soon Lee. Lopez-Ruiz has deep experience in electrochemistry. Lee creates computational models of chemical reactions, including electrochemical processes.

The RENEW funding enabled a small group of two UOG undergraduate civil engineering students and Limtiaco, their mentor, to spend the summer of 2023 at PNNL. During their stay in Richland, they are investigating the complexities of seawater electrolysis. Since seawater is more than just water—it includes salt, metals, and carbon-based molecules—the researchers must consider how each different component reacts with electricity. The team is focusing on how the carbon-containing molecules naturally found in seawater could deter the formation of potentially toxic chlorine gas while increasing hydrogen production.

"This is a perfect partnership opportunity for PNNL," said Karl Mueller, who leads the development of physical sciences research at PNNL. "Our teams have spent decades delving into electrochemistry, creating a rich knowledge base to help understand seawater electrolysis. This collaboration is a way to address a critically important scientific problem while training new scientists."

An electrochemical exchange

Electrochemistry has broad applications within a carbon-neutral future, but is rarely taught to undergraduate students. The 10-week research experience at PNNL has helped the UOG team kick off their electrochemical education. Understanding the reactions and electrochemical processes is a challenge that requires specific knowledge and equipment which is available at the national laboratories.

"It's been challenging to learn about the electrochemistry, since it's so new to me," said Merry Remetira, one of the UOG undergraduates currently at PNNL. "But it's been exciting to do experiments and see the science in action. We've gotten to see hydrogen bubbles coming off the electrode, which was really cool."

Currently, the team from UOG is focused on learning electrochemistry techniques to take back to Guam to study seawater electrolysis. The full experimental setup at PNNL is a perfect test ground for the UOG researchers. They can explore all types of electrochemistry measurements, run baseline testing, and determine the most effective measurements to perform for the rest of the project when they return to UOG. The team is using model solutions to create a set of standards to compare them against more complex systems and the new setups in Guam.

The process involves hands-on learning in the laboratory, coupled with computational work. The students are involved in a summer course to learn the coding language, Python, and are broadening their skill sets even further. "There's something exciting about being one of the first students on this project," said Anna Mallari, a UOG undergraduate. "We're bringing back new knowledge that can help the island."

Developing a renewable research hub

Limtiaco has sights on recruiting more students to join the project for the next two years of the three-year project. As the largest research university and scientific hub of the region, UOG draws students from across Micronesia.

The team sees this project as an initial step to a much larger program. "It starts with building our own expertise with help from PNNL," said Limtiaco. "Once we develop a research program, we can broaden it beyond this single project. We've already talked about future work with electrochemical waste conversion or finding ways to use the carbon dioxide dissolved in the ocean. The opportunities and collaborations with PNNL are just beginning."

As the three-year project progresses, the exchanges will continue. In addition to continuing the summer experiences at PNNL, the team already has plans for PNNL staff to visit the laboratory spaces in Guam in 2024. This trip will allow PNNL researchers to work directly with the experimental setups at UOG and learn from the university's seawater experts.

The project is about more than just research. The undergraduates who visit PNNL will share their knowledge with middle and high school students throughout Guam through demonstrations and other recruitment activities. They will become ambassadors for scientific research, encouraging younger students to consider the possibility of becoming scientists.

"A lot of students at UOG come from small islands," said de Peralta, "Seeing an Indigenous Chamorro scholar, like Dr. Limtiaco, leading this project shows Indigenous students a potential future for them in research. When we couple that with the connections from PNNL, we think this could have important effects on the next generation in Guam and the surrounding islands."

Provided by Pacific Northwest National Laboratory