We cover the basics of geothermal energy before diving in to the more extreme versions of the technology in the next few episodes. And where better to kick off an episode on geothermal than with a mini-tour of Iceland — a country that has arguably made better use of geothermal than anywhere else on earth? In this episode, we'll visit three sites in the southwest near the capital of Reykjavik before winding up in my own backyard in Alaska.

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.