Geothermal Energy Flashcards
What are the general forms of geothermal energy systems?
Geothermal energy systems are classified by operating temperatures, such as high-temperature systems that generate electricity from steam and low-temperature resources for heating.
What is an Enhanced Geothermal System (EGS)?
Extracts heat from the earth using moderately high temperatures (above 80-100 degrees Celsius) even in non-volcanic areas.
How do low temperature geothermal resources differ from high temperature ones?
Between 50 to 80 degrees Celsius, are typically used for heating rather than electricity production
What makes shallow geothermal energy sustainable?
Most of the heat extracted is recharged through solar energy.
What is the purpose of ground heat exchangers in geothermal energy systems?
Transfer heat between the ground and the building, with various types like closed loops, vertical and horizontal loops, open loops, and thermo-active structures
What does the Thermal Response Test (TRT) measure?
TRT measures the ground’s thermal properties like conductivity and diffusivity, essential for designing geothermal systems
What is wrong with high temp areas?
Rare and EGSs are
expensive
What is the main design criterion for geothermal systems?
To prevent depletion of heat in closed loops and prevent thermal breakthrough in open loops systems
What factors need to be considered in the design of thermo-active structures?
- Thermal properties of materials
- soil strength
- stiffness, foundation
- displacements
- ground movements
What is the main application of shallow geothermal energy?
Shallow geothermal energy is primarily used for heating and cooling buildings through ground-source heat pumps.
What does the Geothermal City concept entail?
Integrates geothermal heating and cooling systems into residential and commercial buildings, infrastructure, and as storage for intermittent energy sources.
Why is volumetric heat capacity important in geothermal energy?
Volumetric heat capacity determines how much energy a volume of material can store and release
What properties are needed in GE?
- Specific heat capacity
- Thermal conductivity
- Permeability
What are the available methods for borehole heat exchangers
MCS MIS 2500 (UK)
What is the main design criterion for thermo-active structures?
- Stresses in the structural elements
- Strength of adjacent soil
