Cars, Concrete, and Changes to the Grid

In this episode, our hosts discuss: 

• Carbon-Negative Concrete – Learn about the BUILD'EM project, which aims to replace traditional cement with a low-carbon alternative made from lignin and other innovative materials. This new concrete not only reduces emissions but also promises to be cost-competitive and environmentally friendly. Discover how these new pavers could significantly lower the carbon footprint of concrete and contribute to a more sustainable built environment. 
• EV Charging Infrastructure – With electric vehicle sales surging, NREL researchers are focused on expanding the national charging network to ensure convenient, reliable access for all drivers. We’ll discuss the tools and models, like the EVI-X Modeling Suite and TEMPO, that are guiding the deployment of charging stations and the importance of equitable infrastructure. 

Plus, understand the need for a modernized grid to accommodate the growing use of renewable energy sources. We’re developing medium-voltage converters that could replace traditional transformers. These new devices aim to enhance grid flexibility, reduce costs, and support the integration of solar and wind energy into the power system. 

This episode was hosted by Kerrin Jeromin and Taylor Mankle, written and produced by Allison Montroy and Kaitlyn Stottler, and edited by James Wilcox, Joe DelNero, and Brittany Falch. Graphics are by Brittnee Gayet. Our title music is written and performed by Ted Vaca and episode music by Chuck Kurnik, Jim Riley, and Mark Sanseverino of Drift BC. Transforming Energy: The NREL Podcast is created by the U.S. Department of Energy’s National Renewable Energy Laboratory in Golden, Colorado. We express our gratitude and acknowledge that the land we are on is the traditional and ancestral homelands of the Arapaho, Cheyenne, and Ute peoples. Email us at podcast@nrel.gov. Follow NREL on X, Instagram, LinkedIn, YouTube, Threads, and Facebook.

Transcript

[intro music, fades]  

Taylor: Welcome to Transforming Energy: The NREL Podcast, brought to you by the U.S. Department of Energy’s National Renewable Energy Laboratory. We’re highlighting the latest in clean energy research and innovations happening at the lab. It’s Wednesday, August 21. I’m Taylor Mankle.  

Kerrin: And I’m Kerrin Jeromin.  

Taylor: We’ve got a really interesting set of stories to get through today, Kerrin. From how we drive, to what we drive on, and how we power what we drive, this episode is packed and will really connect to those of you driving while listening!  

Kerrin: Yeah, and we’re talking about EV research, carbon-negative concrete, and improving our nation’s grid and renewable energy-based power system. Let’s get rolling!  

[music]  

Taylor: You know Kerrin, with our beautiful campus here in Golden, Colorado, there’s so much to look around at that its not often we’re looking down.  

Kerrin: True except for the summertime when we’re watching for any stray rattlesnakes. Those kind of frequent campus.  

Taylor: Necessary point. 

Kerrin: Yeah, but you’re right. We’re not looking down often but turns out we should be! Because there’s research right underneath our feet. There are two brick pavers on our campus – right outside this office, actually – that are very different than all the other pavers out there.  

Taylor: These two dark-colored pavers are part of a research project to unearth a carbon-negative alternative to traditional concrete. And when we say pavers think those concrete blocks that can make up pathways, roads, sidewalks, etc. But before we get into more details, I’ve got a fun fact for you to get mixing on this story if you will.  

Kerrin: Ooh yeah let’s mix it up. A fun fact about cement? Let’s have it!  

Taylor: So, cement and concrete are like flour and bread.  

Kerrin: Not where I thought this was going, Taylor. Where are you going with this? 

Taylor: Right, but it’s an important distinction. Cement is like flour. You can do things with it as is. But if you add water and yeast to the flour, you can make bread. In this case, you add water and aggregate, which is like crushed rocks, to the cement, you get concrete.  

Kerrin: Oh okay, I see where you’re goin with this. This is a great analogy. So cement is an ingredient in concrete but yet, still its own thing. 

Taylor: Right! Now, getting back to the NREL research and our new pavers that we mentioned. Creating cement is a notoriously energy intensive process – and it creates a lot of carbon emissions.  

Kerrin: Right. The process requires heating billions of tons of materials to a whopping--get this--2,642 degrees Fahrenheit, which is generally achieved using coal or natural gas. Not only are there emissions associated with these high temperatures, but the chemical reaction used to make cement generates carbon dioxide (CO2) as a byproduct. And our new pavers are part of a project to see if we can make an alternative to cement without all that.  

Taylor: And not just without all the emissions, but to actually be carbon negative. And we need it because the cement production industry is responsible for approximately 7% of the world’s greenhouse gas production.  

  Kerrin: Wow. So, these new pavers were created with low-cost chemicals and lignin—which comes from pulp and paper or biofuel production waste. The result is something that acts like an epoxy resin, but it doesn’t actually use an epoxy resin.  

Taylor: Now let’s pause real quick to talk about epoxy resin. Why do we want to create something that mimics epoxy resin? Well, Epoxy resins are stronger than concrete—but they’re also more carbon-intensive and expensive than cement. So, the researchers wanted to create a low-carbon alternative that was also cheaper. And that’s why they turned to lignin.  

Kerrin: And because lignin comes from trees, the carbon dioxide is captured from the air in the form of biomass. Even better is that this project captures and uses this biomass, which is normally burned as a low-value fuel, and the material can be created at much lower temperatures without emitting carbon dioxide.  

Taylor: The NREL team, cleverly calling the project BUILD’EM (you know that’s an acronym—read the story to learn more), determined a combination of chemicals that could not only achieve the same strength of traditional concrete but substantially exceed it. The team also conducted some additional analysis to determine that, even with the additional processing required, BUILD'EM produced 50% to 80% lower emissions and even is approaching a cost-competitive price point to traditional cement-based concrete.  

Kerrin: You know,I learn something new on this podcast every episode! And now I really need to pay attention to what I’m walking on—I’m going to go find these pavers on campus now.  

Taylor: And soon they’ll be easier to find. The team is planning on installing 1 metric ton of material all over the NREL campus as a demonstration, further expanding NREL’s role as a living laboratory full of active science projects. 

[music]  

Kerrin: Alright, Taylor, I know you’re all about fun stats. So, did you know, in 2023, roughly 1.6 million light-duty electric vehicles—think pickup trucks, SUVs, small cars—were sold in the United States.  

Talyor: That’s huge! 

Kerrin: Yeah, isn’t it? Which is a huge increase from the just 600,000 sold only two years earlier. 

Taylor: EVs are everywhere, which means charging has to keep pace. A national network of private and public charging ports offering convenient, reliable, and affordable charging options are basically a requirement to secure long-term buy-in from drivers.  

Kerrin: Absolutely! Myself included, right? I’m like, where can I charge this thing if I get one. You want to know you can charge up while you’re on the go. And NREL researchers have been working on how we build up the network to build up confidence.  

Taylor: In NREL’s 2030 National Charging Network study, researchers found the need for a mix of publicly accessible charging stations along highways and near homes and workplaces, and private charging ports at single-family homes, apartments, and offices.  

Kerrin: So, we need people to see that the infrastructure is there in order to get them on board with buying an electric vehicle.  

Taylor: OK, but how does that happen? 

Kerrin: Great question, right? Well, amid growing concern about climate change, researchers at NREL developed cutting-edge tools and are producing groundbreaking research to study zero-emission vehicles and related infrastructure, including their integration into the energy system.  

Taylor: Two of NREL’s resources include the E-V-I-X Modeling Suite of Electric Vehicle Charging Infrastructure Analysis Tools to help guide deployment of charging infrastructure and the Transportation Energy & Mobility Pathway Options, or TEMPO, model that explores pathways for achieving long-term climate goals. 

Kerrin: Boy! Need a break after that one? That was a lot of acronyms jammed into this episode.  

Taylor: And with transportation accounting for the US’ largest share of greenhouse gas emissions with more than 90% of the energy supplied by petroleum, these tools are desperately needed.  

Kerrin: Absolutely. Getting more EVs on the road means eventually there will be fewer internal combustion engines—like most cars on the road today--which mean less emissions. But we also need to think about how we do that equitably.  

Taylor: No doubt. We have the need to build infrastructure to charge EVs. But where do we build those stations – and how do we make sure they can be used by everyone? The Electric Vehicle Infrastructure for Equity model, or E-V-I-Equity, is built for just that.  

Kerrin: The EVI-Equity model was created in response to an implicit bias when it comes to where to build charging stations. We have tended to skip low-income and rural areas. The use of EVI-Equity guides more equitable and just EV adoption and infrastructure deployment. 

Taylor: So now we know how and where, but we’re still wondering how much it’ll cost us to build an EV charging station. Don’t worry, NREL has a tool for that: the Locally Optimized Charging Assessment Tool and Estimator, or E-V-I-LOCATE.  

Kerrin: Okay. One more acronym in there for you. The E-V-I-LOCATE is an online tool, currently available for federal agencies but will be made available to the public later this year. This tool can help accelerate the deployment of charging stations.  

Taylor: The tool estimates the cost of installing charging stations, which varies depending on several factors such as how far away the location is from a transformer and where the charging station is installed.  

Kerrin: Well, it sounds like we’re ready to build, right? 

Taylor: It certainly seems like we have what it takes with the help of NREL’s EV tools and models.  

[music]  

Kerrin: Alright Taylor this is going to be weird, but our final story is about a facelift.  

Taylor: Oh. So you’re saying I need some work done... just kidding, I think the facelift you’re talking about is probably a little larger.  

Kerrin: That’s right; this is a facelift for our nation’s grid.  

Taylor: Now that could use some work for sure. To electrify everything from vehicles to heating systems to stovetops, the U.S. grid must expand by about 57% and get more flexible, too. Solar and wind energy are the renewables most likely to dominate a future clean energy grid. But they are found primarily in remote areas, far from the hubs that need their power.  

Kerrin: And that is the problem. Today’s transmission system simply is not designed to ingest all that remote power. Bursts of power on, say, a bright, sunny day in the desert could cause grid faults—little blips that can propagate and cause outages—or overload power lines.  

Taylor: But don’t worry, NREL researchers are on the job, with some help from partners at Florida State University and Ohio State University. Over the last four years, this team has built a testbed to study and hone a new kind of grid technology. 

Kerrin: One that could help grid operators better regulate how and where electricity flows. The device, called a back-to-back, medium-voltage converter, could do that with a fraction of the weight and cost of the transformer technology it could replace. Today, transformers—not the action-movie-car kind but you know, the on-your-power-line-pole-outside kind—they convert medium voltage electricity into both higher and lower voltage.    

Taylor: Higher means it can zoom across high-speed power lines and lower so it can safely enter out homes. Transformers also can be open and closed to move power from a damaged line or to turn it off completely.    

Kerrin: And while that’s good, NREL and partners think we can do better by swapping the transformers to medium-voltage converters. A converter could help utilities safely control how and where electricity moves through local grids.  

Taylor: Plus, many of today’s rooftop solar panels must first convert their energy to low voltages and then to a medium voltage. With medium-voltage converters, that energy can skip an unnecessary hurdle. It’s medium all the way through!  

Kerrin: In summary, medium-voltage converters could help utilities safely control how and where electricity moves through local grids. And that could help make a future clean energy grid both resilient and reliable—giving the grid a much-needed refresh. Not you, Taylor.

Taylor: Yeah, not me. 

Kerrin: It all makes sense now, really.  

Taylor: Absolutely. But we can’t just start taking down transformers. We have to make sure it actually works. So, the team painstakingly constructed a replica of the kind of power system that could benefit from their medium-voltage converters and ran tests with a 10-kilovolt silicon-carbide-based power converter. Now for some context, 10 kilovolts is equal to 10 thousand volts, which is equal to the electric fence they tried to use to keep the T-rex in at Jurassic Park. 

Kerrin: When you put it in that context, I’m going to understand anything you say. You know kilovolts otherwise, those terms really get me, they really do. And apparently it worked! The team could then see how well their system-controlled electricity flow and whether they needed to make any changes.   

Taylor: So cool. And they aren’t done yet. This research took place in the Energy Systems Integration Facility here at NREL. But the team hopes to reach even higher voltages in an entirely new facility dedicated to medium-voltage power electronics.  

Kerrin: So, you’re saying the T-rex might actually stay inside this time? That would good. 

Taylor: We would hope. 

Kerrin: It’s going to be exciting stuff to watch with this team.  

[music]  

Taylor: Cars, concrete, and changes to the grid. NREL’s work is touching it all!  

Kerrin: I know. I feel like this week’s episode really embodies NREL’s mission and our podcast name: Transforming Energy. All these stories showcased our nations’ transforming energy landscape.  

Taylor: Definitely. Listeners thanks so much for tuning in. If you like the show, be sure to leave us a review on Apple Podcasts, drop us a comment on Spotify, or send us an email at podcast@nrel.gov.  

Kerrin: We can’t wait to hear from you! Thanks, and we’ll be back in two weeks with more news from the lab.  

[music]  

Taylor: This episode was adapted from NREL news articles from July 2024 written by Caitlin McDermott-Murphy and Wayne Hicks. Our theme music is written and performed by Ted Vaca and episode music by Chuck Kurnik, Jim Riley, and Mark Sanseverino, of Drift B-C. This podcast is produced by NREL’s Communications Office and recorded at the National Renewable Energy Laboratory in Colorado. We express our gratitude and acknowledge that the land we are on is the traditional and ancestral homelands of the Arapaho, Cheyenne, and Ute peoples. We recognize and pay respect to the Indigenous peoples from our past, present, and future, and are grateful to those who have been and continue to be stewards of this land.