This post is part of a series on the Ralph O’Connor Sustainable Energy Institute (ROSEI) website that will feature Q&A’s with our affiliated researchers. Next up is Susanna Thon, an associate professor in the Department of Electrical and Computer Engineering (ECE) who also serves on ROSEI’s leadership council.

How did you first get involved with or learn about sustainability?

Susanna Thon

ST: Early on in my life I feel like there were various causes that caught my attention, and sustainability was one of those. I think when I was in first or second grade we had an assignment to come up with an invention, and I thought of a “universal recycling system” that could recycle every kind of material that a second grader could think of. Starting in college, though, what I really became passionate about was science and math. As I began pursuing my PhD in physics, it became really important to me for my work to have some kind of application that would provide some good for the world. Renewable energy seemed like an obvious fit because it represented a challenging and important problem that a physicist could contribute to solving. So, I would say my passion for sustainability didn’t really take off until I made a practical choice that it would be a good field where my skills could have a big impact.

Why are you passionate about sustainability/renewable energy?

ST: Through my research and the communities I have connected with as a result, I, along with many other people, have come to view the climate crisis as the existential problem of our times. What I mean by that is that it connects to everything. It isn’t just about the environment; solving the climate crisis is intimately connected to raising standards of living around the world. The people who are being hardest hit by issues related to climate change are those who are already in the most desperate situations. If we actually care about improving conditions across the world and eliminating suffering, we have to start by addressing climate problems. The way I see it is that human beings are being very irresponsible and demonstrating our disdain for future generations if we don’t use our resources to solve these pressing issues now.

How does your commitment to sustainability play out in your everyday life?

ST: I have dabbled in vegetarianism throughout my life, and while I am not a full vegetarian, I make it a point to limit my meat intake because meat production is a huge contributor to climate change, as well as being a sustainability and land-use issue. I’m also in the process of driving my old car into the ground rather than buying a new more fuel-efficient one, both because this makes sense from a sustainability life-cycle perspective and because I’m lazy.

Tell us about your research, and what aspects currently or in the future tie into sustainable energy efforts?

ST: My background is in optical physics, and my research focuses on engineering light to generate energy. My group is interested in building high-efficiency and low-cost solar cells by taking advantage of the interesting physical effects that are found in materials structured on the nanoscale. Another way to convert light into energy is through photocatalysis where light is used to directly catalyze chemical reactions. Our current methods for catalyzing the chemical reactions that are used to produce all of the world’s useful materials are very energy intensive, so it would be great to instead use free, clean energy in the form of light for this.

Another area I have become interested in is connecting light energy to the energy storage problem. A basic problem with using sunlight as an energy source is the sun, obviously, doesn’t shine all the time. It is really important to think about ways to store the energy that comes from the sun for when you need it. Through ROSEI and the LITES initiative, my group has connected with battery experts to build technology that generates energy from sunlight but also stores it, all in a single device. This new technology could have a huge impact on industries like transportation. For example, electric vehicles are charged using energy from the grid, which is fine if the energy from the grid is clean, but wouldn’t it be better to just charge your car by leaving it in the sun and not have to worry about plugging it into to a potentially dirty energy source?

Is there an article, book or podcast that people can check out to help better understand the area you work in or your specific work?

ST: Here’s a good, brief article that summarizes the promise and challenges of next-generation solar technology:

For my specific work, here are some articles:

What advice or suggestions do you have for students who want to pursue careers in sustainable energy?

ST: This is advice that I probably need to do a better job of following: If you are going to do any sort of technical work in the field of energy it is important to learn about the policy side of things because it will help you communicate with your non-technical audience much better. It’s important to broaden your horizons and make sure you understand the context of where your research fits in the world. It will help you explain your work to people not in your field, which is a crucial skill.

How has the creation of ROSEI affected sustainable energy efforts at Hopkins?

ST: ROSEI has been great in terms of forging new connections between people working on aspects of the same problem or slightly different problems, but helping discover where synergies really exist. It has enabled me to collaborate with Sara Thoi on photobatteries, but it has also connected us to experts at APL like Jeff Maranchi who have a lot of expertise and equipment to scale up some of these systems, which is what you need to do to take your invention out of the lab and into the world.

I have also met people from all over Hopkins working in different areas of energy because of ROSEI, and I have seen how the institute has stimulated interest in sustainable energy on campus. I’ve heard from researchers from different departments who had never really thought about sustainable energy being something their work applies to who now want to get involved because there is this new institute that is nucleating this work. This is really exciting because we need all of this diverse expertise to solve the climate crisis, and ROSEI is one way to catalyze those interactions at Hopkins.