ENERGY. Renewable Energy and the Environment. William E. Glassley. CRC Press Taylor & Francis Group. Boca Raton London New York

Transcription

1 GEOTHERMAL ENERGY Renewable Energy and the Environment William E. Glassley CRC Press Taylor & Francis Group Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business

2 Contents Series Editor's Preface... xi Preface... xv Acknowledgments... xvii Series Editor... xix Author... xxi Chapter 1 Introduction... 1 The Global Energy Landscape... 1 The Historical Role of Fuel... 1 The Impact of Population Growth and per Capita Energy Use... 2 Fuel Emissions and Environmental Considerations... 3 Geothermal Energy as a Renewable Energy Source... 4 No Fuel, Few Emissions... 4 Geothermal Energy Is a Flexible Energy Resource... 5 Electrical Demand and the Characteristics of Geothermal Energy... 7 Generating Electrical Power for the Grid... 7 Generating Electrical Power for Local Use... 8 How This Book Is Organized... 8 Synopsis... 8 References... 9 Further Information Sources... 9 Chapter 2 Sources 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 Spots References Further Information Chapter 3 Thermodynamics and Geothermal Systems The First Law of Thermodynamics: The Equivalence of Heat and Work and the Conservation of Energy Conservation of Energy... 31

3 vi Contents 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 (AG) The Standard State Thermodynamic Efficiency Case Study: The Thermodynamic Properties of Water and Rock Water Interaction Synopsis References Further Information Chapter 4 Subsurface 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 an Porosity and Permeability Hydrologic Properties of Real Geothermal Systems Case Study: Long Valley Caldera Synopsis References Further Information Chapter 5 Chemistry of Geothermal Fluids Why the Geochemistry of Geothermal Fluids Matters Water as a Chemical Agent Components and Chemical Systems Chemical Potentials, 1.1., and Gibbs Energy Activity, a Saturation and The Law of Mass Action Equilibrium Constants Activity Coefficients, y 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... 84

4 Contents vii Case Study: The Silica System Synopsis References Chapter 6 Exploring 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, Nevada Synposis References Further Information Chapter 7 Resource 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 Resource Synopsis References Further Information Chapter 8 Drilling 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

5 viii Contents Confining Pressure and Rock Strength Temperature and Drilling Fluid Stability Casing and Grouting Packers Lost Circulation Directional Drilling Case Study: Kakkonda, Japan Synopsis References Further Information Chapter 9 Generating 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 Reinjection Synopsis References Further Information Chapter 10 Low 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 Insolation Soil Characteristics Thermal Conductivity and Heat Capacity of Soils Design Considerations for Closed-Loop Systems Heating and Cooling Loads Calculating Loop Length Case Study: Weaverville Synopsis References Further Information Chapter 11 Direct Use of Geothermal Resources Assessing the Magnitude of the Direct Use Reservoir The Nature of Thermal Energy Transfer

6 Contents ix 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 System Synopsis References Further Information Chapter 12 Use 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 Use Synopsis References Additional Information Chapter 13 Use 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

7 x Contents Refining the Resource Assessment through Exploration Drilling Production Wells and Feasibility Study Synopsis References Chapter 14 The 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 Synopsis References Further Information Index Index of Locations