In this episode, host Kristin Hayes talks with Nadia Gkritza, a professor at Purdue University. Gkritza is leading a team that’s independently evaluating a new product developed by Holcim, a global building materials and concrete company, and Magment, a German startup that is developing wireless charging infrastructure for electric vehicles. The team envisions a world where electric vehicles can recharge by simply driving over magnetized concrete, eliminating the need for separate charging stations and potentially reducing the need for larger batteries to combat range anxiety. Gkritza discusses the development, implementation, and benefits of the magnetized concrete technology; the next steps for the project; the collaboration involved; and the importance of funding electric vehicle charging infrastructure.
Listen to the Podcast
- The mechanics behind magnetized concrete: “This particular technology involves slabs made with magnetizable concrete instead of just the plain concrete that we all know. There’s an embedded coil, and we circulate a high-frequency current, and we generate a magnetic field. That field is then picked up by a compatible coil on an electric vehicle—so that vehicle’s retrofitted with a coil and converts it back to electricity and that can power the motor directly or charge the battery … The goal is to bring the charge to the vehicles, rather than the vehicle stopping at charging stations.” (3:44)
- Magnetized concrete can reduce electric vehicle costs: “This specific technology we’re looking at can reduce the size of the battery, and that will immediately reduce the cost, which is very important—both for private and also commercial vehicles. But specifically for commercial vehicles, smaller batteries will help them carry more cargo—so, that means more revenue. And if we end up building this electrified roadway infrastructure that is shared among all vehicle classes, that would really benefit electrified long-haul trucking and will bring additional benefits in terms of economic development, quality reductions, and so forth.” (10:34)
- Magnetized concrete is feasible and beneficial: “We already have initial results on the financial feasibility of this technology that I know a lot of people have been asking about. Our results indicate that, long term, the investment is feasible both for public and private owners and operators—direct benefits to both. But also indirect benefits to the broader economy and society; communities benefiting by reduced pollution; improved quality of life; and economic development, especially for rural and underserved areas.” (19:18)
Top of the Stack
- “Could Roads Recharge Electric Cars? The Technology May Be Close.” by Kerry Hannon
- “Indiana DOT, Purdue developing wireless EV charging for highways” by Katie Pyzyk
- “Pavement That Wirelessly Charges EVs Will Be Tested in Indiana” by Hazel Southwell
The Full Transcript
Kristin Hayes: Hello, and welcome to Resources Radio, a weekly podcast from Resources for the Future. I'm your host, Kristin Hayes. My guest today is Nadia Gkritza, professor of civil engineering and agriculture and biological engineering at Purdue University. Dr. Gkritza specializes in transportation and infrastructure systems and leads Purdue's Sustainable Transportation Systems Research Group, which is a multidisciplinary collaborative dedicated to assessing the direct and indirect impacts of proposed transportation solutions and emerging technologies.
It's one of those emerging technologies that's the subject of our conversation today. Dr. Gkritza is leading a team that is independently evaluating a new product developed by Holcim, a global building materials and concrete company, and Magment, a German startup that is developing wireless charging infrastructure for electric vehicles (EVs). So, in partnership, Holcim and Magment are envisioning a world where EVs can recharge by simply driving over magnetized concrete, eliminating the need for separate charging stations and potentially reducing the need for larger batteries in order to combat range anxiety. To me, this sounds like the coolest thing ever—I'll be the first to admit that. But fortunately, we have Dr. Gkritza; she and her team are the ones who are actually investigating if and how this can work in the real world, so I'm really looking forward to hearing more about this. Please stay with us.
Hi, Nadia and welcome to Resources Radio. Thank you so much for joining me.
Nadia Gkritza: Hi, Kristin. Thank you for having me.
Kristin Hayes: Of course. As I mentioned, you're a professor of engineering. I think we've had a few engineers on Resources Radio, but it is something a little bit different for us. Can you just say a little bit about what drew you to the field of engineering and how you became interested in transportation technologies in particular?
Nadia Gkritza: Sure. I have been told by my parents that I picked up engineering when I was probably six or seven years old, but I never thought of becoming a professor until after I received my PhD. I chose transportation engineering as my concentration area in my fourth year of undergraduate studies. I did my degree at the National Technical University of Athens in Greece, and that's a five-year degree program, and there's several specialization areas. I really like transportation because of its interdisciplinary nature. You can work on planning, operations, management of different transportation modes and systems. And you also need to think of the users—the people, their preferences—which really intrigues me.
Kristin Hayes: Great. Yeah, that's a good way of characterizing all the things that it brings together. I can imagine that allows for a lot of intellectual interests for you to pursue those in lots of different ways. That sounds great.
So, we're here today to talk about the analysis that you and your team are doing on, as I mentioned, a joint Holcim-Magment magnetized concrete product. I hope I've characterized that correctly, but I would welcome just starting with an introductory conversation. Can you tell us just a little bit more about what the product is, what it's made of, and what it's designed to do?
Nadia Gkritza: Yeah, absolutely. So, a little bit of background: I started working on transportation electrification and technologies more than a decade ago, and I find it to be a fascinating area to work on, and this is a very promising technology to battle climate change. This particular technology involves slabs made with magnetizable concrete instead of just the plain concrete that we all know. There's an embedded coil, and we circulate a high-frequency current, and we generate a magnetic field. That field is then picked up by a compatible coil on an electric vehicle—so that vehicle's retrofitted with a coil and converts it back to electricity that can power the motor directly or charge the battery.
Kristin Hayes: How novel is this technology? Of course, as I mentioned at the beginning, this just sounds like the coolest, most futuristic thing ever to me, but of course, I imagine it's not. I imagine it's actually been evolving behind the scenes for some time. So, where does the technology stand in its development stage, or perhaps even in its use stage in other areas? Can you say a little bit more about that?
Nadia Gkritza: Yes. This specific technology, as you mentioned, can enable electric vehicles to charge as they drive over the pavement and can really help with range anxiety. The goal is to bring the charge to the vehicles, rather than the vehicle stopping at charging stations. This wireless power transport technology has been here for a while, and there are some standards in place for stationary wireless charging stations, let's say. But these in-motion dynamic solutions that we are investigating are currently under development, specifically for those high-speed, high-power applications like the ones we are starting for Indiana. But others—more lower-power, lower-speed vehicles; for example, electric buses at terminal stops, taxis, ride-hailing services, and intermodal facilities or parking facilities—those technologies exist now, and they're used.
Kristin Hayes: And what is the cost or challenge associated with that retrofitting process that you mentioned? I didn't realize that was part of this, as well. Is that a complicated effort? Is that a fairly straightforward effort?
Nadia Gkritza: It's pretty straightforward. There are products out there right now for vehicles, and that's something that the OEMs [original equipment manufacturers] have been looking at, so they are producing EVs with the retrofit and without, pretty much.
Kristin Hayes: How did you and your fellow researchers at Purdue actually get involved in studying this product and its potential applications? It sounds like you were brought into this coalition to really help ground this, so I'd be curious about how you originally got involved. And I'd love to hear more about what research you're undertaking at this point.
Nadia Gkritza: Sure. So our involvement with these in-road, in-pavement charging solutions began under an engineering research center funded by the National Science Foundation. The center is called ASPIRE, and it stands for Advancing Sustainability through Powered Infrastructure for Roadway Electrification—a mouthful, I would say. But ASPIRE is a partnership between several universities. Here in the United States, it's led by Utah State University, and the University of Auckland in New Zealand is our international partner. The center has a mission to advance sustainable, electrified, and equitable transportation. As part of the center, our goal is to develop these charging technologies for electric vehicles and ultimately accelerate the adoption of electric vehicles by eliminating the barriers that we talked about: charging access, range, and so forth.
Kristin Hayes: What are you testing these days? Are you actually a site for the construction of test beds? What are you looking at, in particular?
Nadia Gkritza: I lead one of the research trials in the center—it's called “adoption.” We look specifically at the technical and societal aspects that would impact market acceptance and adoption of electric vehicles, and specifically dynamic wireless charging. We are looking into community and user concerns about safety, cost, and so forth. But my colleagues, as you mentioned, at Purdue are doing quite a bit of testing and analysis and optimization to make sure the product would work.
A subsequent phase of this project would involve the construction of a quarter-mile-long test bed, which will test the concrete's capacity to charge a heavy duty vehicle so we're looking at trucks, 200 kilowatts and above. And that would be the first application at high power and on highway speeds.
Kristin Hayes: You've mentioned speed several times, which is something I hadn't really thought about. Are there particular challenges with charging at high speed compared to low speed? Does it change the volume of concrete needed? (You can tell I'm not an engineer.) But how does the need to go at highway speed change the product design?
Nadia Gkritza: It really affects the amount of power we need to transfer to the vehicle. And we are looking not only specifically to charge the batteries but also to give enough power so the vehicle can continue moving. In terms of constructability, we are looking both at understanding how that would work in concrete and also asphalt pavements.
Kristin Hayes: Well, we've also referenced several times the barriers to EV adoption in the United States. I think they're promising signs—certainly, EVs are experiencing greater adoption already, but they are still, I would say, relatively high cost compared to internal combustion engine vehicles, and at the moment, there's a less-than-robust network of charging stations. Although again, it seems to be expanding rapidly, and we'll come back to that in a second.
But my understanding is that, in order for the ranges of several hundred miles (I'll refer to them as road trip ranges) that would allow an EV to be competitive with an internal combustion engine car, batteries have definitely gotten more efficient—but they've also gotten larger and more expensive. Is that right?
Nadia Gkritza: Yeah. So as you mentioned, as the United States specifically transitions to electrified transportation, there are still many challenges, like the ones you mentioned. We are aware that electric vehicles and the initial cost of owning them is really cost prohibitive for some user groups. So, affordability is one of the things we want to look at through ASPIRE and how we can make EVs available to everyone. And that's where we see more of a second used EV market on the rise now that would lower the cost and make that available for everyone.
Additionally, this specific technology we're looking at can reduce the size of the battery, and that will immediately reduce the cost, which is very important—both for private and also commercial vehicles. But specifically for commercial vehicles, smaller batteries will help them carry more cargo—so, that means more revenue. And if we end up building this electrified roadway infrastructure that is shared among all vehicle classes, that would really benefit electrified long-haul trucking and will bring additional benefits in terms of economic development, quality reductions, and so forth.
Kristin Hayes: That is very interesting. Thank you for talking through the specific impacts that it might have on the market, because it does seem like you've confirmed … If this network of magnetized concrete charging availability were robust enough, that means these vehicles could in fact have smaller batteries. And it sounds like the batteries … Or, again, my understanding is that the batteries really are—at least to date—one of the most expensive parts, so that reduction in batteries would reduce overall costs and potentially really change the market dynamics for EV adoption.
This is all sounding very rosy, but I imagine there are quite a few challenges in actually deploying the technology at scale. So, what would it take to have such a product really make inroads, pun intended, in the United States? Are there specific places that might be better suited to this than others? Do you see this as a substitute for charging stations, or is it a complement? I must admit I have a hard time envisioning the United States tearing up its roads and installing this everywhere, and yet we are at a moment where the United States is looking quite closely at infrastructure. So, I'd be curious to hear what you think about the likelihood and possibilities here?
Nadia Gkritza: Thank you for the question. Absolutely, we don't envision 100 percent of the roads being electrified, but we see the potential for wireless charging pavement technology as complementary to an expanding network of EV charging stations that we will see very soon here in the United States. We feel it would be useful in areas where charging stations are scarce (what we call charging deserts) in underserved communities, even helping support transit routes where initial charging at the depots and terminal stations might not be enough and there might need to be some charging in between the routes.
So, we want to optimize the network to make sure we don't invest in too many charging stations that are not utilized most of the time; but at the same time, we are also screening the network. That's one thing we do for the Indiana DOT— Department of Transportation—where we want to identify those charging deserts and advise the states where they should invest so these technologies are utilized.
Kristin Hayes: Yeah, that's a really interesting point, too, in the context of how much money is included in the Bipartisan Infrastructure Law and how much I feel the United States is about to invest in infrastructure. So, there does seem like there's a moment here where we have a lot of opportunity related to infrastructure development.
But I guess I wanted to ask in that context: Does the Bipartisan Infrastructure Law allow for any additional technology experimentation? Is it really focused on EV charging stations? And, I guess, do we run the risk of locking ourselves into one technology when it sounds like there are other options—more complementary options—that might become available? That's a lot of questions all bundled into one, but I am curious how you think about this moment in terms of the investments that the United States is getting ready to make.
Nadia Gkritza: Yeah. First of all, I think this is much-needed funding to accelerate the adoption of electric vehicles. We've seen that having infrastructure available will help drive adoption and make drivers confident about owning an EV. Especially now that we've seen EV sales grow by 85 percent during the last year, it's very important. There is some discretionary funding in the bill that we hope can support this type of demonstration project, and pilots that are very important so we can scale the technologies for widespread adoption.
As part of ASPIRE, our goal is to continue the implementation of those quarter-mile or half-mile test beds that ultimately can grow into longer, corridor-wide implementations of the technology. Besides the test bed I mentioned in Indiana that we are involved with, ASPIRE has seen growing interest in the technology from other states and partners.
I can name a few; for example, Utah State University receives funding from the state to implement high-power, stationary, wireless charging technology for heavy-duty vehicles in the Utah Inland Port. In Florida, the Central Florida Expressway plans to invest in the construction of a one-mile test bed and in-motion wireless charging technology west of Orlando. So, for your listeners who are going to visit Disney World anytime soon, they might start seeing the construction. And that's what we want to provide—this roadmap for the rollout of this technology nationwide.
Kristin Hayes: Very interesting. I would love to head to Disneyland and also check that out. That makes me curious, too:are there places in other parts of the world where this technology is already in more robust testing stages?
Nadia Gkritza: There have been a lot of efforts in both Asia and Europe. A lot of pilot studies, especially in Europe, looking at this technology, but mostly at an experimental stage. But we've seen—for example, Magment is a German company; Electron is another member of ASPIRE that has different pilots in Europe, Israel, the United Kingdom, and so forth. And we've seen efforts in Asia, Korea, and other places. So, definitely there's an interest, and we all want to learn from each other's pilots and move this technology forward.
Kristin Hayes: It sounds like ASPIRE is a really interesting combination of not only … well, I guess I'd characterize it as a public-private partnership, if that's fair. But certainly there are government entities that are looking at your research results, there are obviously academics such as yourself, there are industries who are feeding in information. I feel like I'm feeding you the answer here, but: How would you characterize the importance of those public-private partnerships in this kind of research?
Nadia Gkritza: ASPIRE provides this innovation ecosystem in which we engage with the broader stakeholder community. And you named the key players—the government, utilities, obviously those who develop the technology. So, we have a wide industrial innovation board that participates in this wide range of activities with the research partner projects, public-private partnership pilots, and that's something that you will see announced in Florida.
But we are also exploring those business models. What would be the role of the public sector? The private sector? Who drives what? Who operates what? Who maintains the facilities? There are some very interesting questions there, and once we bring all these stakeholders together, we'll see the transformation that we are looking for—both in the automotive-transportation and electric-grid industries.
Kristin Hayes: Right. That makes a lot of sense. And you mentioned early on that ASPIRE (the group that you work with) is looking across all of these different factors that will make this successful. So, it's really not just about getting the product right, but it's about consumer acceptance and, as you point out, the management or administrative ecosystem in which all of these pieces are happening. So, what should our listeners be on the lookout for, then, in terms of either your research results in particular? You mentioned that there are going to be longer and longer test beds, but are there other next steps that folks can be keeping an eye out for?
Nadia Gkritza: We already have initial results on the financial feasibility of this technology that I know a lot of people have been asking about. Our results indicate that, long term, the investment is feasible both for public and private owners and operators—direct benefits to both. But also indirect benefits to the broader economy and society; communities benefiting by reduced pollution; improved quality of life; and economic development, especially for rural and underserved areas. We will also have some preliminary results to show of the testing we are conducting right now on Purdue this spring and with the construction of the test bed the following summer. Our partners in Utah and Florida, I mentioned, also follow similar timelines, so we should be able to share more results soon.
Kristin Hayes: Oh, fantastic. Well, we might have to get you back for a repeat visit, then. It certainly would be interesting to know how everything's evolving. But this has been great; I really appreciate you taking the time to share a little bit more about these developments, put them in context with what's happening in the United States with the infrastructure bill, and share something new that sounds quite promising for our listeners to think about. So, thank you very much.
Nadia Gkritza: Thank you very much.
Kristin Hayes: Let's close with our regular feature, Top of the Stack. I wanted to ask you, Nadia, if there's anything you'd want to recommend—and I always caveat for our guests that it can certainly be content on the topic that we're talking about. I imagine there's a lot of interesting stuff out there about emerging technologies in the transportation space. But of course, it can also be anything else that's on the top of your stack that you might want to recommend. So I'll turn it over to you.
Nadia Gkritza: Thank you. And I would hate to disappoint your listeners, but right now, at this time of year, at the top of my stack I have a PhD dissertation and a couple of research papers that I need to review, so my students can graduate in May. But I definitely hope I'll catch up with reading books and more fun things over the summer, and I will certainly be tuning in to hear book recommendations from your guests.
Kristin Hayes: Great. I'm sure that PhD student will pass his or her dissertation with flying colors. And maybe we'll look for that, too, someday. Well, thank you again, and I hope you enjoy the rest of your day, and we'll look forward to hearing more about how this technology is evolving.
Nadia Gkritza: Sounds good. Thank you so much.
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