CTU welcomed Ph.D. candidate Sonia Martin from Stanford University, whose recent lecture at the Faculty of Electrical Engineering (FEE) focused on one of the central questions of sustainable mobility: how electric vehicles can be better integrated with the electricity grid. During her research stay, she also visited Škoda Auto, where questions of electromobility are playing out in practice. In this interview, she discusses vehicle-to-grid technology, the future of EV research, and why collaboration across disciplines, institutions, and industry matters. Sonia Martin closely cooperates with the CENT Centre, based at CIIRC.
On your profile on the Stanford website, it says that you work in the field of Mechanical Engineering. However, your research seems rather interdisciplinary. Could you explain your focus?
My Ph.D. research focuses on the integration of electric vehicles (EVs) and the electricity grid. It’s particularly interesting because these have historically been very separate fields. Transportation engineering and electrical engineering were quite separate, and now they are starting to merge because of the rise of EVs.
With that, there are a lot of challenges. Grid infrastructure needs to be able to meet the demand from EVs, and there are many other issues as well. One newer technology I focus on is called vehicle-to-grid charging. That’s when electric vehicles can not only charge from the grid, but also discharge energy back to it.
You introduced this topic thoroughly in your lecture at the FEE CTU. What was the key message?
Half of my talk focused on my Ph.D. research at Stanford, and the other half focused on research I did here at CTU in the Center for Energy, Networks & Transportation (CENT CIIRC), looking at EV charging stations owned by Škoda Auto at their manufacturing plant in Mladá Boleslav. We analyzed which of those charging stations could potentially be upgraded to support bidirectional, or vehicle-to-grid, charging. The core issue is that vehicle-to-grid is a promising technology, but it is still unclear how to adopt it, and data-driven approaches can help us understand that in real-world settings.
Could you explain a bit, why would an EV owner want to send electricity back to the grid?
That’s a good question. One big benefit is during a power outage. By discharging energy, the EVs can help support the grid. This can protect your home during a power outage, which maybe doesn’t happen as much here but happens frequently in the United States. Also, if you don’t need to drive anywhere, you might as well use the electricity stored in your car to power your refrigerator or other essentials.
The other reason relates to economic incentives. If the grid is strained at a certain time, electricity providers could offer money to EV owners to discharge some energy back to the grid. Then the car could charge again later. In that case, if your car is sitting in the garage anyway, you could earn money from it. Those mechanisms are not really in place yet, but that’s the idea.
But doesn’t sending electricity back and forth involve energy loss?
There is definitely energy loss, so you would only do this if you had either an economic incentive, a real benefit for the grid, or a power outage. The goal is that its value is greater than the energy you lose in the process.
Is this kind of stuff already in place somewhere, or is it still mostly a research problem?
It is happening on a very small scale. There are some locations in Europe where this is starting, and in the United States it’s also beginning very slowly, including with electric school buses as another use case. But we’re still talking about very small numbers of vehicles — in the tens, or fewer than a hundred.
Tell us, how you got into this field in the first place.
Going all the way back, I grew up very close to the ocean in California, with a climate where you can be outside all year. I think that made me interested in the environment and in understanding the world around me.
In high school, I was lucky to take what we called technical arts classes — things like wood shop, metal shop, and electronics. I really enjoyed that, together with math and science, and that made engineering feel like a natural path. Then in the last year of my bachelor’s degree, I took a course on power systems, or the electricity grid, which I found particularly interesting. It combined infrastructure, engineering, and the physical systems around us in a way that really clicked for me. That led me into the Ph.D., and then eventually into electric vehicles.
The future of electric mobility: from research to real-world adoption
Electric vehicles are a pretty sensitive political topic. What do you think is one of the biggest misunderstandings around EVs?
This isn’t exactly the focus of my research, but people often ask: if you charge an EV with electricity from coal, how can it really be better for the environment? And then there’s also concern about critical minerals and the materials needed to make the battery.
So I think one big misunderstanding is this idea that EVs can’t really be greener because battery production is so resource-intensive. But there’s a whole field called life cycle assessment, where people calculate emissions over the EV’s lifetime. Even though it takes energy and materials to make the battery, EVs still come out greener over the long run.
If EV adoption keeps growing, what should researchers and engineers be working on today to prepare for the future?
There are three things that come to mind. First, grid infrastructure is a huge issue, and I don’t think that will be solved immediately. On the large transmission scale, the question is whether there is enough electricity supply to meet demand. But also, on a smaller scale, the infrastructure around homes and neighborhoods (the distribution grid) was not designed for lots of EVs plugging in. Making sure the grid is ready for large-scale EV adoption is a major challenge.
Second, if we imagine a future with lots of EVs, then the electricity powering them also has to become cleaner. So there are big questions about renewable energy, storage, and how to phase out coal or natural gas. In other words: how do you make EVs truly low-emission over the long term?
And third, there’s the issue of controlling or aggregating EVs. If you imagine, for example, a fleet of self-driving electric vehicles, or just hundreds of cars and limited charging infrastructure, then the question becomes: how do you coordinate all of that? How do you decide which car charges when? How do you manage charging across a whole system? This is both a planning and control problem.
So this is also becoming a smart systems problem, correct?
Yes, exactly. We talk about “smart grid” and “connected mobility solutions”. EVs are not like gas cars just sitting in the garage. They are connected, they communicate, and there are aggregators that can understand things like state of charge or where a vehicle is going. There’s a much bigger connected system around mobility now, and I think mobility will look very different in the future.
Can this kind of research be done without industrial partners?
You can definitely do theoretical work without them, but I think it’s really important to collaborate with industry. During my Ph.D. I worked with Volkswagen, and here in Prague I’ve been working with Škoda, so it’s a very similar kind of collaboration.
It was really enlightening for me to understand what the goals of automakers actually are, because sometimes they were completely different from my research goals. You can do research in a silo, but if you ever want it to connect to practice, you need to understand what industry is trying to do and how your work might fit into that. And I think there is a sweet spot where your work could actually be useful to a company or become part of their plans in the future.
Author: Karolína Pštross, CTU
Photo: Rod Searcey, Stanford University
