# Advanced geothermal: Techniques

Fractured rock, sealed loops and superhot volcanic water

Source page: https://www.materialinsights.org/energy/e_adv_geo/techniques/

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)**^[5](https://www.thinkgeoenergy.com/fervo-announces-technical-and-commercial-breakthroughs-at-cape-station-geothermal-site/)^[6](https://atb.nlr.gov/electricity/2025/geothermal)^[7](https://www.power-eng.com/renewables/geothermal/fervo-energy-achieves-first-power-at-flagship-utah-geothermal-project/)^[13](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7) | 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 geothermal**^[2](https://www.thinkgeoenergy.com/?p=67393)^[3](https://knowledge.energyinst.org/new-energy-world/article?id=140011)^[4](https://arxiv.org/pdf/2303.12689)^[15](https://doi.org/10.1016/j.renene.2022.01.012) | 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 geothermal**^[4](https://arxiv.org/pdf/2303.12689)^[14](https://iea.blob.core.windows.net/assets/b5b73936-ee21-4e38-843b-8ba7430fbe92/TheFutureofGeothermal.pdf) | Higher than conventional plants | No published figure found | No study found | research | No commercial plant |
| **Co-production from oil and gas wells**^[1](https://doi.org/10.1016/j.geothermics.2013.11.001)^[16](https://www.energy.gov/sites/prod/files/2014/02/f7/systems_for_electrical_power_from_coproduced_and_low_final.pdf) | 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.^[5](https://www.thinkgeoenergy.com/fervo-announces-technical-and-commercial-breakthroughs-at-cape-station-geothermal-site/)^[6](https://atb.nlr.gov/electricity/2025/geothermal)^[7](https://www.power-eng.com/renewables/geothermal/fervo-energy-achieves-first-power-at-flagship-utah-geothermal-project/)^[13](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7)
**Closed-loop / advanced geothermal**

Fluid 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.^[2](https://www.thinkgeoenergy.com/?p=67393)^[3](https://knowledge.energyinst.org/new-energy-world/article?id=140011)^[4](https://arxiv.org/pdf/2303.12689)^[15](https://doi.org/10.1016/j.renene.2022.01.012)
**Deep / supercritical geothermal**

Drilling deeper or into volcanic zones reaches superhot rock (above about 373 °C) and supercritical water, which carries far more energy per kilogram.^[4](https://arxiv.org/pdf/2303.12689)^[14](https://iea.blob.core.windows.net/assets/b5b73936-ee21-4e38-843b-8ba7430fbe92/TheFutureofGeothermal.pdf)
**Co-production from oil and gas wells**

Hot water already produced with oil and gas is run through a small binary unit instead of being reinjected as waste.^[1](https://doi.org/10.1016/j.geothermics.2013.11.001)^[16](https://www.energy.gov/sites/prod/files/2014/02/f7/systems_for_electrical_power_from_coproduced_and_low_final.pdf)

#### Sources

1. [Efficiency of geothermal power plants: A worldwide review (Zarrouk and Moon, Geothermics 51, 142-153)](https://doi.org/10.1016/j.geothermics.2013.11.001) Elsevier, 2014
2. [Eavor reports first electricity generation at pioneering geothermal project in Geretsried, Germany](https://www.thinkgeoenergy.com/?p=67393) ThinkGeoEnergy, 2025
3. [Innovative geothermal project powers up in Bavaria](https://knowledge.energyinst.org/new-energy-world/article?id=140011) Energy Institute, New Energy World, 2025
4. [Technical barriers for deep closed-loop geothermal (McClure; reviews Malek et al. 2022, Beckers and Johnston 2022 and others)](https://arxiv.org/pdf/2303.12689) arXiv, 2023
5. [Fervo announces technical and commercial breakthroughs at Cape Station geothermal site](https://www.thinkgeoenergy.com/fervo-announces-technical-and-commercial-breakthroughs-at-cape-station-geothermal-site/) ThinkGeoEnergy, 2024
6. [Annual Technology Baseline 2025: Geothermal](https://atb.nlr.gov/electricity/2025/geothermal) National Laboratory of the Rockies (formerly NREL), 2025
7. [Fervo Energy achieves first power at flagship Utah geothermal project](https://www.power-eng.com/renewables/geothermal/fervo-energy-achieves-first-power-at-flagship-utah-geothermal-project/) Power Engineering, 2026
8. [Climate Change 2014: Mitigation, Annex III Technology-specific cost and performance parameters, Table A.III.2](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7) IPCC AR5 Working Group III, 2014
9. [The Future of Geothermal Energy](https://iea.blob.core.windows.net/assets/b5b73936-ee21-4e38-843b-8ba7430fbe92/TheFutureofGeothermal.pdf) IEA, 2024
10. [Techno-economic analysis of Advanced Geothermal Systems (AGS) (Malek, Adams, Rossi, Schiegg and Saar, Renewable Energy 186, 927-943)](https://doi.org/10.1016/j.renene.2022.01.012) Elsevier, 2022
11. [Systems for Electrical Power from Coproduced and Low Temperature Geothermal Resources (Reinhardt, Johnson and Popovich, 36th Stanford Geothermal Workshop)](https://www.energy.gov/sites/prod/files/2014/02/f7/systems_for_electrical_power_from_coproduced_and_low_final.pdf) US DOE, 2011

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_adv_geo/index.md)
- [Overview](https://www.materialinsights.org/energy/e_adv_geo/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_adv_geo/correlation/index.md)
- [Efficiency](https://www.materialinsights.org/energy/e_adv_geo/efficiency/index.md)
- [Resources and labour](https://www.materialinsights.org/energy/e_adv_geo/resources/index.md)
- [Impact on the biosphere](https://www.materialinsights.org/energy/e_adv_geo/biosphere/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_adv_geo/links/index.md)