top of page

Advanced geothermal could take continuous clean power beyond volcanic regions

Advanced geothermal could take continuous clean power beyond volcanic regions
Advanced geothermal could take continuous clean power beyond volcanic regions | Photo: Toby Elliott

Published on 2 August 2026 at 05:31 GMT

By Editorial Team SDG7

 


Advanced geothermal energy is moving from a resource tied mainly to volcanic regions towards a technology that could be developed across much wider areas. The shift is being driven by deeper drilling, directional wells, improved subsurface imaging and reservoir engineering adapted from the oil and gas industry. If these methods become commercially reliable, geothermal plants could provide electricity and heat around the clock in places that lack naturally accessible hot water or steam.



The opportunity is significant because conventional geothermal power depends on an unusual combination of heat, permeable rock and naturally occurring fluids close enough to the surface to be reached economically. Those conditions are concentrated in countries and regions with favourable geology. Advanced systems attempt to overcome at least part of that constraint by engineering access to hot rock rather than waiting for a naturally productive hydrothermal reservoir.


 

Engineering a reservoir instead of finding one

The best-known approach is the enhanced geothermal system, or EGS. Wells are drilled into hot, relatively impermeable rock, and fluid is injected to open or reactivate small fractures. Water can then circulate through the heated rock and return to the surface, where its heat is used to generate electricity or supply direct heating. The fluid is normally reinjected, creating a managed circulation system rather than relying entirely on a naturally flowing geothermal field.



A second family of designs, often described as closed-loop geothermal, aims to circulate fluid through sealed underground pipes without creating a permeable reservoir. Some concepts use long horizontal or multilateral wells to increase contact with hot rock. Closed-loop systems may reduce dependence on naturally occurring water and avoid reservoir stimulation, although they can require more drilling and must transfer enough heat through the well structure to compete economically.



These technologies do not make geology irrelevant. Temperature still rises at different rates from one location to another, and drilling deeper raises cost and technical difficulty. However, the International Energy Agency concluded in its 2024 geothermal assessment that next-generation technologies could greatly expand the geographical reach of the resource. It estimated that, with continued technological improvement and lower project costs, geothermal could meet up to 15 per cent of global electricity-demand growth to 2050. This is a scenario based on successful innovation and deployment, not a forecast of guaranteed expansion.


 

Oil and gas expertise moves into geothermal

The transfer of oil and gas drilling expertise is central to this development. Directional drilling, high-temperature well construction, hydraulic stimulation, fibre-optic monitoring and detailed modelling of underground formations were refined through decades of hydrocarbon production. Many of the same service companies, engineers and supply chains can be used for geothermal projects, offering a possible transition route for workers and industrial regions affected by changes in fossil-fuel demand.



The United States Department of Energy has highlighted drilling and well construction as major cost barriers for EGS. Its Utah FORGE research site has tested techniques intended to improve drilling speed, stimulation and monitoring in hard crystalline rock. The International Energy Agency reported in January 2026 that drilling rates at the site had risen substantially between the first wells and later demonstrations, illustrating how shared knowledge and repeated field testing can reduce time and cost.



Private developers are also applying horizontal drilling and multi-stage stimulation methods associated with shale production. These projects have strengthened confidence that engineered reservoirs can circulate commercially useful volumes of hot water. Yet successful demonstrations do not automatically establish that the model will be affordable in every geology or electricity market. Exploration risk, well failure, financing costs and the need for specialised equipment remain substantial.


 

Continuous power has a different value

Unlike wind and solar generation, continuous low-carbon power from geothermal does not depend on daily weather conditions. Plants can operate at high capacity factors and can, in some configurations, adjust output to help balance electricity systems with growing shares of variable renewable energy. Geothermal heat can also serve district heating, greenhouses and some industrial processes, sometimes using temperatures below those required for electricity generation.



This reliability gives geothermal a potential value beyond the number of megawatt-hours produced. Electricity systems increasingly need clean sources that can operate during long periods of low wind or limited sunlight. However, geothermal should not be described as impact-free. Its climate performance, land footprint and resource use depend on drilling depth, plant design, construction materials, cooling technology and the source of electricity used during development.


 

Seismic activity requires more than reassurance

Induced seismic activity is one of the most sensitive concerns surrounding EGS. Injecting fluid changes pressure along existing fractures and can trigger small earthquakes. Most monitored events are minor, but past geothermal projects in Basel, Switzerland, and Pohang, South Korea, demonstrated that larger events can damage public confidence and, in some circumstances, cause material harm.



The United States Geological Survey states that stimulation requires site-specific seismic-hazard assessment and an induced-seismicity mitigation plan. Responsible development therefore depends on mapping faults before drilling, establishing background seismicity, operating dense monitoring networks and adjusting or stopping injection when agreed thresholds are reached. Transparent communication and clear liability arrangements are equally important, particularly where communities have little influence over project decisions.



Closed-loop systems may avoid stimulation-related seismicity because they do not require the same creation of an underground fracture network. They still involve deep drilling and must be assessed for well integrity, subsurface uncertainty and construction impacts. No single design removes every risk.


 

Water use varies sharply by design and location

Local water use is another potential constraint. EGS projects require water during drilling and reservoir stimulation, while operational systems may need replacement water if part of the circulating fluid is lost into surrounding rock. Power plants using evaporative cooling can add further demand, which may be significant in dry regions where geothermal resources and water scarcity overlap.



Air-cooled plants can reduce operational water consumption, although they may cost more and lose efficiency during hot weather. Closed-loop designs can limit contact between working fluid and the surrounding formation, but construction still requires water and other materials. Project assessments should therefore report expected withdrawals, consumption, fluid losses and cooling requirements rather than treating geothermal water use as a single universal figure.


 

Commercial promise depends on public safeguards

Advanced geothermal remains more expensive and less mature than established wind and solar technologies in many markets. The United States Department of Energy has set a goal of reducing EGS costs to approximately US$45 per megawatt-hour by 2035, a target that depends on major improvements in drilling, well performance and project repetition.


Early plants may require public support, long-term power contracts or risk-sharing mechanisms because a large share of spending occurs before the underground resource is fully proven.



Policy design will determine whether support builds durable public value. Competitive procurement can reward reliable low-carbon electricity, while geological data-sharing can reduce duplicated exploration. Strong permitting should address water, seismic monitoring, land access and decommissioning without creating unnecessary delays. Communities should receive understandable information before operations begin and should have access to monitoring results throughout a project’s life.



The issue connects most directly to SDG 7 (affordable and clean energy) because advanced geothermal could broaden access to dependable renewable electricity and heat. The connection is conditional: power will not be affordable or socially sustainable if high development risks are transferred to the public while private developers retain the benefits.



The technology is therefore neither a universal solution nor a niche limited permanently to volcanic landscapes. Its strongest case lies in combining deep drilling innovation, disciplined environmental management and transparent local agreements. If costs fall and safeguards prove effective, the heat beneath ordinary landscapes could become an important part of a diversified low-carbon energy system.



Further information:


• International Energy Agency, Its 2024 special report assesses global geothermal potential, next-generation technologies, costs and links with oil and gas expertise.


• United States Department of Energy, Office of Geothermal, Its official EGS resources explain the technology, well-construction barriers and federal research programmes.


• Utah FORGE, This US research observatory conducts field-scale testing of drilling, stimulation, monitoring and reservoir-management techniques.


• United States Geological Survey, Its induced-earthquake research explains the seismic risks associated with fluid injection and the need for hazard assessment and mitigation.


• National Renewable Energy Laboratory, Its geothermal research and technical publications examine resource assessment, drilling, grid value and environmental performance.

 


bottom of page