Enhanced geothermal systems

Definition

Enhanced geothermal systems (EGS) are engineered reservoirs that extract geothermal energy from hot, dry rock formations, which are typically not suitable for conventional geothermal energy extraction. By injecting water into these hot rock formations to create fractures, EGS can significantly improve heat flow and enable the extraction of geothermal energy, even in areas with low natural permeability. This technology expands the potential for harnessing geothermal energy beyond traditional geothermal resources.

5 Must Know Facts For Your Next Test

1. EGS can be developed in areas without natural geothermal resources, making it a viable option for increasing renewable energy sources.
2. By utilizing hydraulic fracturing techniques, EGS enhances the permeability of rock formations, allowing water to circulate and transfer heat more effectively.
3. The success of an EGS project depends on the geological characteristics of the site, including temperature, rock type, and fracture systems.
4. Monitoring and managing the environmental impacts of EGS is crucial to ensure sustainable operations and prevent induced seismicity.
5. EGS technology is still in the development phase, but it holds significant promise for contributing to the global transition to renewable energy.

Review Questions

• How do enhanced geothermal systems improve heat extraction compared to conventional geothermal systems?
  • Enhanced geothermal systems improve heat extraction by artificially creating fractures in hot, dry rock formations, which enhances the permeability and allows water to circulate more effectively. In conventional geothermal systems, energy is usually extracted from naturally occurring hot water or steam reservoirs. By engineering these reservoirs through techniques such as hydraulic fracturing, EGS can access geothermal energy in regions that would otherwise be unsuitable for conventional methods.
• What geological factors are critical for the successful implementation of enhanced geothermal systems?
  • The successful implementation of enhanced geothermal systems relies on several geological factors, including the temperature of the rock formations, the type of rock present, and existing fracture systems that can be utilized or enhanced. Ideal sites have high temperatures at manageable depths and sufficient fracture networks to facilitate fluid movement. Understanding these geological characteristics is essential for designing effective EGS projects and ensuring their economic viability.
• Evaluate the potential environmental impacts of enhanced geothermal systems and suggest ways to mitigate these effects.
  • Enhanced geothermal systems can have potential environmental impacts, such as induced seismicity due to hydraulic fracturing and water usage concerns. To mitigate these effects, comprehensive site assessments should be conducted to evaluate geological stability before initiating projects. Additionally, monitoring programs can be established to track seismic activity and water quality. Implementing best practices in fluid management and using environmentally friendly additives can also reduce risks associated with hydraulic fracturing processes.

Related terms

Geothermal gradient: The rate at which temperature increases with depth in the Earth's crust, typically measured in degrees Celsius per kilometer.

Hydraulic fracturing: A technique used to create fractures in underground rock formations by injecting high-pressure fluid, which is essential for enhancing geothermal systems.

Heat flow: The transfer of thermal energy from the Earth's interior to the surface, measured in watts per square meter, playing a crucial role in assessing geothermal potential.