Geothermal Heat Pump Opportunities, Sun Nerds Convene at NREL, and Kestrel Flies Beyond the Lab

In this Halloween-inspired episode, our hosts explore recent highlights in NREL’s research, including: 

• A look into the potential of geothermal heat pumps (GHPs). NREL’s 19 new case studies provide real-world GHP examples across various U.S. climate zones, with installations at the NREL Alaska Campus, Seattle Public Schools, and more.  
• A gathering of “Sun Nerds” at the NREL Pyrheliometer Comparisons (NPC) event, during which scientists from around the world had the chance to calibrate solar measurement tools, ensuring accuracy for solar energy and climate research. 
• How researchers throughout the U.S. can utilize NREL’s Kestrel Supercomputer for their projects. Students from across the country used Kestrel's computing power to advance clean energy projects, including modeling solar wind effects on energy grids, developing hydrogen-based engines, and optimizing vehicle designs. 

Learn more about these cutting-edge clean energy innovations shaping the future! 

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, October 30th. I’m Taylor Mankle.

Kerrin: And I’m Kerrin Jeromin. Taylor, it is All Hallow’s Eve … Eve, Eve. Do you have a Halloween costume? 

Taylor: Oh, I am notorious for last minute costumes. I’ve got a couple items at home that always come into consideration. How about yourself?

Kerrin: Yeah, no I’m in the same boat. I’ve got a box of costumes, and every year, the day of Halloween, I go, “okay, what am I going to be today?” So that’s probably how I’ll role this year as well.

Taylor: Love it, love it! I’m just excited for the trick-or-treaters this year. I’ve moved to a neighborhood where apparently, it’s really good trick-or-treating, so I’m really excited for that this year.

Kerrin: You better be handing out the full-sized candy bar.

Taylor: We’ll see about that. Maybe next year. But I’ve actually got a little bit of Halloween spirit to kick us off! 

Kerrin: Ooh, I love it! Let’s go! 

[spooky Halloween music]

Taylor: 

Round about the cauldron go;   

In the poison’d entrails throw.   

Toad, that under cold stone    

Days and nights hast thirty one   

Swelter’d venom sleeping got,   

Boil thou first i’ the charmed pot.   

Double, double toil and trouble; 

Fire burn and cauldron bubble.

[echoing]

Kerrin: Ooh, it’s so spooky. Macbeth—very, very classy. 

Taylor: Well, yes and it’s not just because of spooky season. I’m also excited to share a story about the cauldron … of the earth! [echoing] I’m talking about geothermal energy - boiling and bubbling up from the earth. 

Kerrin: A very exciting technology that while we most often think of it heating things up, can also help cool things down—geothermal that is. Geothermal heat pump systems take advantage of subsurface temperatures, which are typically warmer than the air in the winter and cooler than the air in the summer—regardless of the overall climate in a particular region.  

Taylor: Right, geothermal heat pumps— or GHPs— leverage the constant temperatures to heat and cool buildings more efficiently than traditional systems and can be used for single buildings or as networks for multiple buildings.  

Kerrin: GHPs could be really beneficial for many homeowners or businesses, but it can be hard to know where to begin if you’re interested in installing this kind of system.  

Taylor: So, to address this gap, NREL, on behalf of the Department of Energy, put together 19 case studies to help people better understand GHP systems, installations, and benefits. The studies detail GHP installations in climate zones across the United States, with varying system types, sizes, and end uses.  

Kerrin: Providing real-life examples of GHP systems in different parts of the country through these case studies will make it much easier for everyone to understand how a system might work for them. And these case studies are pretty cool … or maybe they’re pretty hot. Depends on how you look at it.

Taylor: They really are! While none of these systems are funded by the Department of Energy, they provide valuable insights into the uses of GHPs. 

Kerrin: some of the different sites featured in the case studies that use geothermal heat pumps include: the College of Southern Idaho, the Dallas-Fort Worth Bridge, Colorado Mesa University, Greensburg City Hall in Greensburg, Kansas, Montana State University, Seattle Public Schools, and NREL’s own Alaska Campus. 

Taylor: A very diverse group of locations! And the Alaska Campus is actually an active research project. Our researchers wanted to know if geothermal heat pumps can be used in the harshest of conditions—with winter temperatures that regularly dip to negative 40 degrees, and ground temperatures just barely above freezing, it really is the epitome of harsh.

Kerrin:  Absolutely. The system was installed in 2013 and the system has delivered 20,000-30,000 kilowatt-hours of heat annually, eliminating 700 gallons of fuel oil per year and significantly reducing carbon emissions.  

Taylor: Wow! Sounds like there’s nothing spooky about geothermal heat pump systems. 

Kerrin: Much more of a treat than a trick, would you say? 

Taylor: Geothermal heat pump-kin systems?

Kerrin: [Laughing] Okay, let’s just stop here. I think we’ve overstayed our Halloween welcome.

Taylor: Agreed.

[Halloween, spooky music]

Kerrin: Alright, shifting from beneath the earth to above the earth for this story. We’re talking solar energy – specifically, something that a lot of people might wonder about-- How do we know how much energy we’re going to get from a solar array?  

Taylor: It’s a great question. If, for instance, you’re in the market for solar panels for your roof, and you’re researching the different options, you may notice the efficiency that they claim. How do you know you can trust that number? 

Kerrin: Exactly. A lot of questions to be answered! And who could’ve guessed that NREL plays a major role in providing the measurement that creates the standard?

Taylor: Of course. In September, groups of scientists and engineers from around the world gathered at NREL’s Golden, Colorado, campus for the 24th NREL Pyrheliometer Comparisons, or NPC. NREL keeps its reference instruments calibrated directly to the World Radiometric Reference and World Infrared Standard Group. Since 1996, NPC has been a gathering place for people from across the globe to calibrate their reference instruments to the world standard.

Kerrin: As researchers strive to get more and more precise measurements, they also need to ensure that the measurements used are compliant with international standards. And this is something that has guided NREL’s mission since the very beginning ... 

Taylor: NPC, which is affectionately called the “sun nerds convention,” serves as a World Meteorological Organization regional comparison for maintaining traceability– meaning the ability to trace your measurement back to a standard source that is common to everyone. It’s how we all know that our measurements of efficiency are the same and accurate.

Kerrin: Right, so NPC allows researchers from around the world to take their instruments back to their organizations and continue doing the important work of solar resource assessment, climate change studies, and atmospheric research with the assurance that their measurements are aligned with the world standard. 

[music]

Taylor: I always like covering stories that show how NREL’s work gets out of the lab, like our last story about NPC. And this is another one all about opening up NREL’s immense research capability to folks outside of the lab!

Kerrin: —Which we love! Immense capability is like an understatement here. We’re talking about Kestrel, the third-generation supercomputer hosted at NREL. Kestrel can reach 44 petaflops of computing power focused on renewable energy and energy efficiency research. And for context, a petaflop, which is just kind of a funny word in itself, is a million-billion calculations per second.

Taylor: I can barely wrap my mind around that concept. But that massive computing power was put in the hands of students from across the country in 2024. 

Kerrin: What an opportunity. Students from Iowa State University—

Taylor: —Go Cyclones! Gotta give some love to my alma mater when I get the chance.

Kerrin: These Iowa State students used Kestrel to study the effect of solar wind and other space weather phenomena on solar energy infrastructure. Using the supercomputer's advanced processing capabilities, the team tested new scalable algorithms to provide robust and accurate methods to model solar wind, with the goal of understanding the effects it may have on the stability and efficiency of solar power plants, all to improve power grid reliability and resilience. 

Taylor: Another group from the University of Minnesota used computational fluid dynamic codes on Kestrel to design novel engines that use hydrogen for combustion. The project leveraged an Exascale Computing Project code to perform a first-of-its-kind, high-fidelity three-dimensional simulations of explosive hydrogen reactions to investigate how hydrogen combustion can be used for future hypersonic propulsion systems, advancing fuel technologies research to reduce fossil fuels.

Kerrin: I mean, talk about mindblowing! I can’t even wrap my head around what they are doing. That is incredible! Okay, and then there were the students from Stanford University who used Kestrel's advanced artificial intelligence, or AI, and machine learning capabilities in a manufacturing research project to apply AI models to model realistic car shapes. The project goal was to set new standards for vehicle design and optimization, aiming to improve fuel efficiency and reduce carbon emissions. Very cool!

Taylor: These are just a few of the impressive projects students worked on with Kestrel’s help. Providing students with access to Kestrel not only advances current research but also shapes the future of clean energy technologies by equipping students with advanced skills to lead in the field of energy innovation and research.   

Kerrin: Exactly. Tackling complex energy challenges requires powerful computational resources, along with support to ensure the productive use of these resources. It’s so cool to see NREL sharing national lab resources with students shaping the future of clean energy! Isn’t it? 

Taylor: Absolutely! And if you are a student interested in getting involved with Kestrel, you can apply for time now! The applications are open until November 30th and decisions will be made by January 2025. You can find out more on our website, nrel.gov by searching Kestrel. That’s k-e-s-t-r-e-l. 

[music]

Taylor: Another one in the books, Kerrin!  

Kerrin: Ah yes, another one in the books! A little spooky this time, but also quite educational. It’s really a nice Halloween episode we hope for you.    

Taylor: Most definitely. 

Kerrin: Alright, well before we go, do you have any more Shakespeare to close us out? 

Taylor: To be or not to be ... done with this episode. I guess we shall say goodbye and wish everyone a safe and happy Halloween!

Kerrin: No legacy is so rich as honesty, and that listeners, is the truth. We thank you for listening to another episode of Transforming Energy: The NREL podcast. If you like the show, be sure to leave us a review on your favorite podcast player or send us an email at podcast@nrel.gov. We’ll be back in two weeks with more news from the lab. 

[music]

Taylor: This episode was adapted from NREL news articles from October 2024 written by Kelly MacGregor, Emily Mousel and Marsha Sanchez. 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.