In Fairbanks, four trainloads of coal arrive every day to power and heat the University of Alaska campus that's known for its cutting-edge research on integrating renewable energy technologies. Building a brand new coal-fired power plant in the 21st century was, to put it mildly, a controversial decision. But believe me when I tell you—we researched the heck out of it. Today on the show, I'll walk you through the backstory of how, when it came time to replace our campus power plant, we ticked through all our options and ended up with the newest coal plant in the country — and, some would argue, possibly the last.

Closing the Gap is hosted by Gwen Holdmann. Tony Williams is our producer and engineer. Jennifer Pemberton is our writer and editor. Music is from Blue Dot Sessions.

Norway is determined to move away from coal and other fossil fuels entirely, but the town of Longyearbyen in the Arctic outpost of Svalbard is literally built around coal and has identified strongly as a coal town for more than 100 years. This year, the last coal mine in Longyearbyen shut down — not because they ran out of coal, but because the country is deeply committed to trying something else, even if they haven't totally figured out what that something else is yet.

Closing the Gap is hosted by Gwen Holdmann. Tony Williams is our producer and engineer. Jennifer Pemberton is our writer and editor. Music is from Blue Dot Sessions.

On this podcast, we spend a lot of time talking about electricity — how to generate it, store it, and use less of it. But the truth is, the bigger share of our energy use often goes to heating and cooling — the invisible comfort systems that keep us alive in the places we choose to live.

Humans are unusual that way. Most species adapt to their environment. We do the opposite — we adapt the environment to suit us. It's how we survive in deserts and tundra, in glass towers and remote villages.

Today on the show, we're talking about passive cooling. We bring you three stories of designs that take advantage of natural temperature differences instead of using up a bunch of energy just to make something cold.

Closing the Gap is hosted by Gwen Holdmann. Tony Williams is our producer and engineer. Jennifer Pemberton is our writer and editor. Music is from Blue Dot Sessions.

Waste-to-energy systems kill two birds with one stone: they deal with garbage and produce power at the same time. Copenhill in Denmark has been called the coolest power plant in the world, and it's hard to argue with that. It's a place where you can ski down the roof, climb up the side, and then grab coffee under the smokestack — all while the building generates heat and energy for the city. At least one Alaskan community thinks Copenhagen might hold the answer for its energy and waste problems — and that's exactly where this episode takes us.

The multi-million dollar fighter jets that roar over the local tennis court where I coach the high school team is a daily reminder that Fairbanks is home to one of the most strategically important Air Force bases in the world. And now, Eielson Air Force Base is about to make history on a very different front — testing a first-of-its-kind nuclear microreactor.

Closing the Gap is hosted by Gwen Holdmann, edited by Jennifer Pemberton, and produced by Tony Williams.

Back in 2019, Congress directed the Department of Defense to find a site and pilot a small nuclear reactor to enhance energy resilience at military installations. That site is Eielson Air Force Base near Fairbanks, Alaska. Recently the Air Force named a developer for the reactor, so we're revisiting the story we told back in Episode 5. In future episodes you'll hear directly from the key people moving the project forward—both the technical lead for the Air Force and the senior commander guiding its integration on the ground. For now, we're sharing episode 5 with you as a refresher.

Water is 800 times denser than air and when large volumes start moving in a single direction with force and purpose, it becomes virtually unstoppable. And that force represents an opportunity to harness the power of water in a way that's different from conventional hydropower. Instead of relying on elevation and gravity, we can capture energy directly from the flow itself. Afterall, the tides are pulled by the moon, creating a rhythm that has been in motion since long before fossil fuels were even imaginable. It's not just renewable—it's perpetual. Today on the show -- tidal energy in many different forms.

Closing the Gap is hosted by Gwen Holdmann. Jennifer Pemberton is our editor. Liz Smith and Tony Williams produced this episode. Music is from Bluedot Sessions. Special thanks to David Lane at Neuralsurfer, who let us use his wonderful recording of Edgar Allen Poe's "A Descent Into The Maelstrom".

Hydropower comes in many forms, though most people still associate it with big dams. In the heyday of dam building, projects like Grand Coulee Dam and Boulder Dam in the American West were monumental efforts. But back then, we didn't fully understand how dams could disrupt ecosystems; now we do, and as a result, large dams have fallen out of favor in many places. And where the U.S. was once the leader in large scale hydropower, we're now removing more dams than we're building. Today, the biggest obstacles to constructing new hydroelectric projects in the U.S. aren't just environmental—they're economic and regulatory. But hydropower is a very site-specific technology—and there are plenty of ways to make it more environmentally friendly.

Closing the Gap is hosted by Gwen Holdmann and edited by Jennifer Pemberton. This episode was produced by Tony Williams. Music is from Blue Dot Sessions.