In the Build Back Better bill, there are billions of dollars that would support a key but relatively unused renewable energy source: geothermal energy. The bill could make the energy source a major contributor to President Joe Biden’s ambitious climate goals, according to supporters. But that’s only if the broader debate over the package doesn’t derail it. POLITICO’s Jonathan Custodio explains.   Nirmal Mulaikal is a POLITICO audio host-producer.  Jonathan Custodio is a fellow for POLITICO.  Carlos Prieto is an audio producer for POLITICO.  Raghu Manavalan is a senior editor for POLITICO audio. Jenny Ament is the interim executive producer of POLITICO’s audio department. Learn more about your ad choices. Visit megaphone.fm/adchoices