Geothermal energy taps into the natural heat stored beneath the Earths surface. This heat comes from radioactive decay deep inside the planet and from leftover warmth from when the Earth formed billions of years ago. In the United States, this resource powers homes, generates electricity, and supports industries in ways that traditional fuels cannot match. You might picture it as a steady, underground boiler that never runs out of fuel.
People use geothermal energy for heating and cooling homes through systems called ground-source heat pumps. These pumps pull constant temperatures from just a few feet underground, which stay around 50 to 60 degrees Fahrenheit year-round, even when surface weather swings wildly. For residential heating, a loop of pipes buried in the yard circulates fluid that absorbs ground heat in winter and dumps excess home heat into the soil in summer. This setup cuts electricity use by 25% to 50% compared to standard air conditioners or furnaces. Businesses and apartment buildings also rely on these systems for efficient climate control.
Power generation takes geothermal to another level by drilling miles deep into hot rock reservoirs. Steam or hot water from these depths spins turbines to create electricity. The Geysers in California stands as the largest complex of this kind, operating since the 1960s and supplying enough power for over 700,000 homes today. In Nevada, the 240-megawatt McGinness Hills plant churns out clean electricity around the clock. These facilities provide baseload power, meaning they run continuously unlike solar or wind that depend on weather.
Geothermal stands out for its low impact on the air. Power plants emit almost no greenhouse gases during operation, slashing carbon output by up to 90% over coal plants. Heat pumps avoid burning fossil fuels entirely, which cuts local pollution and improves air quality in cities. Over a year, a typical home system prevents about 5.5 tons of carbon dioxide from escaping, roughly equal to taking one car off the road. Water use stays minimal too, since closed-loop systems recycle fluids.
Upfront costs pose the biggest challenge, with residential heat pumps running $20,000 to $40,000 installed, depending on yard size and local labor. Large power projects demand even more, often $4 million to $6 million per megawatt due to deep drilling risks. Federal tax credits cover 30% of costs through 2032, which helps, but payback takes five to ten years for homes. Still, lifetime savings hit 40% to 70% on energy bills, and systems last 20 to 50 years with little maintenance.
Several projects highlight geothermal’s growth. Fervo Energy drills next-generation wells in Utah, aiming for 400 megawatts by 2028 using horizontal drilling borrowed from oil fields. In Oregon, the Cascade Geothermal Power Project eyes new reservoirs near existing plants. Nevada leads with over 20 plants online, while New York tests enhanced systems that fracture hot dry rock to create steam. These efforts added 136 megawatts of capacity in 2024 alone.
Exploration revealed promising finds last year. In 2025, teams identified a massive reservoir under the Salton Sea in California, potentially holding enough heat for gigawatts of power. Alaska saw new hot spots near Mount Spurr capable of fueling remote communities. Texas uncovered blind geothermal zones with no surface signs, thanks to advanced seismic mapping.
Zanskar Geothermal shows how artificial intelligence changes the hunt for heat. The company uses machine learning to sift through seismic data and predict hidden reservoirs faster than old methods. After proving its tech, Zanskar raised $115 million in Series C funding to scale operations. This approach cuts drilling guesswork and opens areas once passed over.
Geothermal capacity in the U.S. reached 3.7 gigawatts by late 2025, enough for three million homes, with more in the pipeline. Heat pumps now warm over two million residences, proving reliability across climates. As costs drop and technology sharpens, this quiet energy source gains traction nationwide.
