Page 10 - Geothermal Energy Renewable Energy and The Environment

Contents ix

Heat Transfer by Conduction ...............................................................................204
Heat Transfer by Convection ...............................................................................207
Heat Transfer by Radiation ..................................................................................208
Heat Transfer by Evaporation ..............................................................................209
Establishing the Feasibility of a Direct Use Application ......................................... 210
District Heating ........................................................................................................ 210
Evaluation and Operation .................................................................................... 210
Managing Return Temperature ........................................................................... 212
Piping and Heat Loss ........................................................................................... 213
Materials Compatibility and Fluid Chemistry .................................................... 213
Aquaculture .............................................................................................................. 214
Drying ...................................................................................................................... 216
Case Study: Canby Cascaded System ...................................................................... 217
Synopsis ....................................................................................................................222
References ................................................................................................................223
Further Information ..................................................................................................223

Chapter 12. Use of Geothermal Resources: Environmental Considerations ...............................225
Emissions .................................................................................................................225
Carbon Dioxide ...................................................................................................225
Hydrogen Sulfide .................................................................................................228
Mercury ...............................................................................................................229
Solute Load and Resource Recovery ........................................................................229
Seismicity ............................................................................................................ 231
Mechanics of Seismic Events .............................................................................. 231
Shear Stress, Normal Stress, and Frictional Strength .................................... 231
Pore Water.......................................................................................................232
Seismic Activity Associated with Geothermal Projects .....................................233
Seismicity Associated with Injection of Cool Water ......................................233
Rupture Area and Magnitude .........................................................................235
Seismicity Associated with Fluid Extraction ......................................................236
Seismicity Associated with High-Pressure Injection of Fluid to
Enhance Reservoir Permeability .........................................................................237
Ground Subsidence ...................................................................................................238
Water Use .................................................................................................................241
Land Use ..................................................................................................................242
Synopsis ....................................................................................................................244
References ................................................................................................................245
Additional Information .............................................................................................247

Chapter 13. Use of Geothermal Resources: Economic Considerations ....................................... 251

Economics of Geothermal Power ............................................................................. 251
Capacity Factors .................................................................................................. 251
Levelized Costs ...................................................................................................253
Economics of R&D Investment in Geothermal Energy...........................................255
Technology Evolution and S-Curves ...................................................................255
Projected Energy Costs .......................................................................................255
Developing a Geothermal Project ............................................................................257
Rights to Develop a Resource and Permitting .....................................................257
Initial Resource Assessments ..............................................................................258