Geothermal energy is renewable, reliable and powerful. So, why is most of it untapped? That’s what our listener, Anna in the UK, wants to know. Full disclosure, she’s a geologist and is thoroughly perplexed by the lack of uptake. Geothermal is renewable, reliable and abundant and yet, less than 1% of the world’s energy is generated from it. Host Graihagh Jackson hears about a team in Iceland who hope to "super-charge" geothermal power by drilling directly into volcanic magma. And she travels to Germany to visit Vulcan Energy, a company which is combining geothermal with extracting one of the world's most sought-after metals: Lithium. Plus, our reporter in Indonesia tells Graihagh about local opposition to some geothermal power plants. The programme was first broadcast in 2024. Got a question you’d like answered? Email: TheClimateQuestion@bbc.com or WhatsApp: +44 8000 321 721 Host: Graihagh Jackson Reporter in Indonesia: Johanes Hutabarat Producer: Osman Iqbal Sound Mix: James Beard and Tom Brignell Editor: Simon Watts