This blog post is by Sabrina Krupenko, a fall 2023 research translation intern with Sustainable Carolina.
Our local universities serve as innovation incubators, spearheading the sustainable energy transition as the world searches for a solution to climate change. At the University of North Carolina at Chapel Hill, one innovation hub strives to maximize the way we can harvest solar energy.
The Center for Hybrid Approaches in Solar Energy to Liquid Fuels (CHASE) Solar Hub is a multi-university, Department of Energy-funded, innovation research center focused on using solar energy to create liquid solar fuels. CHASE is one of two current Fuels from Sunlight Hubs in the entire nation, with the other one being located on the West Coast.
I had the opportunity to interview two important people in the CHASE Solar Hub: Prof. Jillian Dempsey, Deputy Director of CHASE, and Dr. Dan Kurtz, Technical Communications and Intellectual Property Manager. As the technical communications manager, Kurtz handles the internal communications of the center. Kurtz helps the Center report back to the Department of Energy (DOE) on research progress and handles external communications, which involves talking to new outlets and curious journalists like me. Dempsey is the Deputy Director of the CHASE Solar Hub and is a principal investigator within the research center. As a principal investigator, she helps lead research projects, which include guiding a team of undergraduate, graduate, and postdoctoral researchers. Dempsey helps design the experiments, interpret the results, and disseminate the results. As Deputy Director, she works with the Director (Prof. Gerald Meyer), and Managing Director (Dr. Caley Allen) to run the Center.
After sitting down with these two members of CHASE, it’s safe to say the solar hub’s importance cannot be understated as a leading innovator in solar fuels research, and the work they do to train scientists in sustainable energy will serve many future generations to come.
Fundamental Science with an Ambitious Mission
The CHASE Solar Hub has an ambitious mission: refining and studying the elementary chemical reactions involved with taking solar energy and converting it directly to a carbon-based, liquid fuel for use in future solar energy technologies.
“Solar energy is a huge energy source with untapped potential,” said Dempsey. “We have mature technologies that allow us to take solar photons to electricity [solar panels], but storing electricity is challenging. We as a society really rely on liquid fuels – gasoline, diesel, oil. Liquid fuels have a big role in our society because they’re really important for the transportation sector. CHASE’s big challenge is to say, can we use sunlight to create liquid fuel molecules?”
CHASE’s objective is to answer yes to that question and innovate the ways in which we use solar energy. Dempsey elaborates on the basic science behind the experiment CHASE is currently refining:
“There are reactions that are uphill and downhill,” said Dempsey. “Combusting fuels to drive our cars is one of those [downhill] reactions. We can do the opposite, take water and CO2 and take it back to gasoline and to O2, [but] we have to put energy in. We do that backward reaction. We put the energy back in and remake the fuel. Essentially what you do is you make a fuel from sunlight, solar fuels.”
Scientists at CHASE Solar Hub have successfully created an integrated system that does just that. They constructed a hybrid photoelectrode, which contains semiconductors that absorb sunlight and molecular catalysts that will make the fuel. The molecular catalysts drive the reactivity of CO2.
Dempsey explains that the catalysts make the fuel and semiconductors absorb the light. When you’re able to get them to work together, you can create an integrated system.
An Integrated System in Action
Among CHASE’s myriad of success stories is the successful demonstration of one of these systems. The system Dempsey goes on to describe uses a silicon light absorber and a cobalt-based molecular catalyst. The system, created in collaboration with the University of Pennsylvania and Yale University, can make liquid methanol with 8% efficiency. The CHASE team has also made further advances that aren’t yet published.
Progress like this motivates Dempsey and her researchers to continue working on understanding systems better and further improving efficiency. Ultimately, CHASE’s goal is to create an integrated system with as close to 100% efficiency as possible!
Beyond their principal research, the CHASE Solar Hub takes pride in the infrastructure and knowledge exchange they’ve cultivated at UNC-Chapel Hill and its partner universities. Dan Kurtz is especially fond of the innovation center’s capacity for integrated knowledge exchange.
“There’s a lot of expertise in different areas,” said Kurtz. “Say we had 10-15% of the Center that worked on silicon before CHASE started. The number of people working on things outside their comfort zone in the beginning and learning new things is huge now. The new science that these labs are learning is something that can’t be done outside of a hub like this.”
Kurtz emphasized the importance and uniqueness of inter-site visits, where graduate students can visit facilities at another university to learn skills that they couldn’t learn at their home institutions. For example, students from Yale can come to UNC-Chapel Hill to learn a method and then go back to their home university and diffuse new knowledge.
“Our impact is multifold: The research advances what we’re making, leading to progress toward our mission,” said Dempsey. “The second major impact has been the infrastructure that CHASE has built: the Solar Fuels Product Analysis lab, the Molecular Synthesis Lab and the Spectroscopy Lab. We also have staff representation that works through the Chapel Hill Analytical and Nanofabrication Laboratory. There is an immeasurable impact of scientists being trained in this field of sustainable energy.”
This research was supported as part of the Center for Hybrid Approaches in Solar Energy to Liquid Fuels (CHASE), an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science.
This video provides an in-depth summary of CHASE’s objectives, infrastructure and collaborators.
About Dan Kurtz and Jillian Dempsey
Dan Kurtz, Ph.D., serves as the CHASE lead for intellectual property, identifying technologies for patent protection and managing CHASE scientific and technical communications. He also manages CHASE scientific conferences and outreach programs. He earned a B.S. in chemistry from Oakland University and a Ph.D. in inorganic chemistry from the University of North Carolina at Chapel Hill.
Jillian Dempsey, Ph.D., is the Bowman and Gordon Gray Distinguished Term Professor and director of undergraduate studies in the UNC Department of Chemistry. She earned a B.S. at the Massachusetts Institute of Technology and a Ph.D. from the California Institute of Technology.