Glassley William E. Geothermal Energy: Renewable Energy and the Environment

CRC Press / Taylor & Francis Group, 2010. 285 p. ISBN: 978-1-4200-7570-0 (Hardback)Historically, cost effective, reliable, sustainable, and environmentally friendly, use of geothermal energy has been limited to areas where obvious surface features pointed to the presence of a shallow local heat source, such as hot springs and volcanoes. However, recent technological advances have dramatically expanded the range and size of viable resources, especially for applications such as modular power generation, home heating, and other applications that can use heat directly. These recent developments have greatly expanded opportunities for utilizing geothermal energy. Reflecting current interest in alternative energy, Geothermal Energy: Renewable Energy and the Environment explores where geothermal energy comes from and how to find it, how it can be accessed, successful applications, and improvements for future uses.The author reviews the background, theory, power generation, applications, strengths, weaknesses, and practical techniques for implementing geothermal energy projects. He stresses the links between acquisition and consumption and the environment. Packed with real world case studies and practical implementation steps, the book covers geosciences principles, exploration concepts and methods, drilling operations and techniques, equipment needs, and economic and environmental topics. Each chapter includes an annotated list of key sources that provide useful information beyond that contained in the text.The minor environmental impacts caused by geothermal energy gives it the potential to play an important role in the transition from fossil fuels to more sustainable fuels. Successful deployment, however, requires that the resource be matched to the application being developed. Rigorously covering all aspects of geothermal energy, this book provides up-to-date scientific information that can be used to discern applications and regions best suited for geothermal energy.The Global Energy Landscape
The Historical Role of Fuel
The Impact of Population Growth and per Capita Energy Use
Fuel Emissions and Environmental Considerations
Geothermal Energy as a Renewable Energy Source
No Fuel, Few Emissions
Geothermal Energy Is a Flexible Energy Resource
Electrical Demand and the Characteristics of Geothermal Energy
Generating Electrical Power for the Grid
Generating Electrical Power for Local Use
How This Book Is OrganizedSources of Geothermal Heat: Earth as a Heat Engine
Origin of Earth’s Heat
Heat from Formation of the Core
Heat from Radioactive Decay of Long-Lived Isotopes
Transfer of Heat in the Earth
Radiation
Conduction
Convection
Plate Tectonics and the Distribution of Geothermal Resources
Availability and Utilization of Geothermal Energy
Synopsis
Case Studies
Spreading Centers
Subduction Zones
Hot SpotsThermodynamics and Geothermal Systems
The First Law of Thermodynamics: The Equivalence of Heat and Work and the Conservation of Energy
Conservation of Energy Internal Energy
PV Work
Enthalpy
The Second Law of Thermodynamics: The Inevitable Increase of Entropy
Efficiency
Carnot Cycle
Heat Capacity
Entropy
Gibbs Function and Gibbs Energy (ΔG)
The Standard State
Thermodynamic Efficiency
Case Study: The Thermodynamic Properties of Water and
Rock-Water InteractionSubsurface Fluid Flow: The Hydrology of Geothermal Systems
A General Model for Subsurface Fluid Flow
Matrix Porosity and Permeability
Definition of Matrix Permeability
The Kozeny–Carman Equation
Hydraulic Conductivity
Fracture Porosity and Permeability
Fracture Permeability
Fracture Transmissivity
Effect of Depth on Porosity and Permeability
Hydrologic Properties of Real Geothermal Systems
Case Study: Long Valley CalderaChemistry of Geothermal Fluids
Why the Geochemistry of Geothermal Fluids Matters
Water as a Chemical Agent
Components and Chemical Systems
Chemical Potentials, μ, and Gibbs Energy
Activity, a
Saturation and The Law of Mass Action
Equilibrium Constants
Activity Coefficients, γ
Affinity
Ion Exchange
Kinetics of Geothermal Reactions
Gases in Geothermal Fluids
Gas Partitioning between Liquid and Vapor
Fluid Flow and Mixing in Natural Systems
Simulating Reactive Transport Case Study: The Silica SystemExploring for Geothermal Systems
Field Geology and Surface Manifestations
Volcanoes: Active and Dormant
Faulting and Associated Rock Alteration
Surface Deposits
Geochemistry as an Exploration Tool
Fluid Composition and Geothermometry
Isotopes
Geophysics as an Exploration Tool
Aeromagnetic Surveys
Resistivity and Magnetotelluric Surveys
Gravity Surveys
Seismicity and Reflection Seismology
Temperature Measurements
Remote Sensing as an Exploration Tool: A Promising New Technique
Multispectral Studies
Case Study: Fallon, NevadaResource Assessments
Assessing a Geothermal Resource
Resource Base and Reserves
Uncertainty
Establishing the Reservoir Volume
Establishing the Reservoir Heat Content
The Significance of Heat Capacity
Efficiency of Heat Extraction
Case Study: Establishing the United States Geothermal ResourceDrilling
Background
Drilling for Ground Source Heat Pump and Direct Use Applications
Drilling Equipment and Technology
Drilling Fluid and Circulation
Properties of Drilling Fluids
Well Completion
Environmental Issues
Drilling for Geothermal Fluids for Power Generation
Drilling Rigs Confining Pressure and Rock Strength
Temperature and Drilling Fluid Stability
Casing and Grouting
Packers
Lost Circulation
Directional Drilling
Case Study: Kakkonda, JapanGenerating Power Using Geothermal Resources
The History of Geothermal Power Production
General Features of Geothermal Power Generation Facilities
Dry Steam Resources
Hydrothermal Systems
Flashing
Steam Quality
Dual-Flash Systems
The End State: Condensers and Cooling Towers
Binary Generation Facilities: The Organic Rankine Cycle
Case Study: The Geysers
Geology
Power Generation History
Emissions
Sustainability and ReinjectionLow Temperature Geothermal Resources: Ground Source Heat Pumps
Basic Heat Pump Principles
Thermodynamics of Heat Pumps
Coefficient of Performance (COP) and Energy Efficiency Ratio (EER)
Near-Surface Thermal Reservoir
Solar Isolation
Soil Characteristics
Thermal Conductivity and Heat Capacity of Soils
Design Considerations for Closed-Loop Systems
Heating and Cooling Loads
Calculating Loop Length
Case Study: WeavervilleDirect Use of Geothermal Resources
Assessing the Magnitude of the Direct Use Reservoir
The Nature of Thermal Energy Transfer
Heat Transfer by Conduction
Heat Transfer by Convection
Heat Transfer by Radiation
Heat Transfer by Evaporation
Establishing the Feasibility of a Direct Use Application
District Heating
Evaluation and Operation
Managing Return Temperature
Piping and Heat Loss
Materials Compatibility and Fluid Chemistry
Aquaculture
Drying
Case Study: Canby Cascaded SystemUse of Geothermal Resources: Environmental Considerations
Emissions
Carbon Dioxide
Hydrogen Sulfide
Mercury
Solute Load and Resource Recovery
Seismicity
Mechanics of Seismic Events
Shear Stress, Normal Stress, and Frictional Strength
Pore Water
Seismic Activity Associated with Geothermal Projects
Seismicity Associated with Injection of Cool Water
Rupture Area and Magnitude
Seismicity Associated with Fluid Extraction
Seismicity Associated with High-Pressure Injection of Fluid to
Enhance Reservoir Permeability
Ground Subsidence
Water Use
Land UseUse of Geothermal Resources: Economic Considerations
Economics of Geothermal Power
Capacity Factors
Levelized Costs
Economics of R&D Investment in Geothermal Energy
Technology Evolution and S-Curves
Projected Energy Costs
Developing a Geothermal Project
Rights to Develop a Resource and Permitting
Initial Resource Assessments Refining the Resource Assessment through Exploration Drilling
Production Wells and Feasibility StudyThe Geothermal Energy Future: Possibilities and Issues
Geopressured Resources
Magnitude of the Resource
Why Geopressured Reservoirs Form
Challenges to Development
Fluid Chemistry
Reinjection
Enhanced Geothermal Systems (EGS)
Magnitude of the Resource
Technological Requirements
EGS Efforts to Date
Drilling and Downhole Equipment
Drilling Fluids
High-Temperature Downhole Equipment
Reservoir Engineering
Reservoir Management for Sustainability