Advanced geothermal: Techniques
Fractured rock, sealed loops and superhot volcanic water
What this tab covers The methods used to capture this energy: how each works, and how they compare on efficiency, cost, life-cycle emissions, maturity and scale.Enhanced geothermal is entering commercial service and closed loops have first grid power; supercritical and co-production approaches remain at research and pilot stage.
Comparison
| Method | Efficiency | Cost | Life-cycle emissions | Maturity | Scale |
|---|---|---|---|---|---|
| Enhanced geothermal systems (fractured hot rock)56713 | Over 10 MW per production well at Cape Station | Overnight capital cost (NREL ATB 2025): near-field EGS USD 5,405-12,150/kW, deep EGS USD 9,868-16,795/kW | No EGS-specific figure; geothermal life-cycle median 38 g CO2e/kWh | early commercial | Project Red (Nevada) since 2023; Cape Station (Utah) first 33 MW block online 2026, about 100 MW phase I, 400 MW more due 2028 |
| Closed-loop / advanced geothermal23415 | About 12.8% electric to thermal at Geretsried (design, calculated) | Baseline estimate USD 498,000-785,000/kWe (Malek et al. 2022); optimistic studies reach 7-8.3 US cents/kWh | No study found | pilot | Eavor Geretsried, Germany: two 4.5-5 km wells with 12 laterals; first grid power December 2025 |
| Deep / supercritical geothermal414 | Higher than conventional plants | No published figure found | No study found | research | No commercial plant |
| Co-production from oil and gas wells116 | Low end of the binary range | No published LCOE | No study found | pilot | US DOE oilfield test (Wyoming): a 180 kW (design) unit produced 1,918 MWh, online 97% of the time |
Enhanced systems have made the fastest progress: Fervo cut drilling time by 70% and tripled power per well. Their capital costs are still above those of conventional flash plants; the IEA calls next-generation costs relatively high today but expects them to fall by 80% by 2035, to around USD 50/MWh. Closed loops avoid fracturing and water loss but are limited by slow heat conduction.
How each method works
Enhanced geothermal systems (fractured hot rock)Wells are drilled into hot, low-permeability rock, often horizontally with oil-industry methods. High-pressure water opens fractures and is circulated from injection to production wells, collecting heat for a power plant.56713
Closed-loop / advanced geothermalFluid circulates in a sealed loop of wells and long horizontal laterals, never touching the rock; heat conducts through the rock and well wall into the fluid.23415
Deep / supercritical geothermalDrilling deeper or into volcanic zones reaches superhot rock (above about 373 °C) and supercritical water, which carries far more energy per kilogram.414
Co-production from oil and gas wellsHot water already produced with oil and gas is run through a small binary unit instead of being reinjected as waste.116
Sources
- Efficiency of geothermal power plants: A worldwide review (Zarrouk and Moon, Geothermics 51, 142-153) Elsevier, 2014
- Eavor reports first electricity generation at pioneering geothermal project in Geretsried, Germany ThinkGeoEnergy, 2025
- Innovative geothermal project powers up in Bavaria Energy Institute, New Energy World, 2025
- Technical barriers for deep closed-loop geothermal (McClure; reviews Malek et al. 2022, Beckers and Johnston 2022 and others) arXiv, 2023
- Fervo announces technical and commercial breakthroughs at Cape Station geothermal site ThinkGeoEnergy, 2024
- Annual Technology Baseline 2025: Geothermal National Laboratory of the Rockies (formerly NREL), 2025
- Fervo Energy achieves first power at flagship Utah geothermal project Power Engineering, 2026
- Climate Change 2014: Mitigation, Annex III Technology-specific cost and performance parameters, Table A.III.2 IPCC AR5 Working Group III, 2014
- The Future of Geothermal Energy IEA, 2024
- Techno-economic analysis of Advanced Geothermal Systems (AGS) (Malek, Adams, Rossi, Schiegg and Saar, Renewable Energy 186, 927-943) Elsevier, 2022
- Systems for Electrical Power from Coproduced and Low Temperature Geothermal Resources (Reinhardt, Johnson and Popovich, 36th Stanford Geothermal Workshop) US DOE, 2011