TY - BOOK AU - Boyle,Godfrey TI - Renewable energy / SN - 0199261784 PY - 2004/// CY - Oxford : PB - Oxford University Press, KW - ENERGIA SOLAR KW - ENERGIA FOTOVOLTAICA KW - BIOENERGIA KW - ENERGIA HIDROELECTRICA KW - ENERGIA EOLICA KW - ENERGIA MAREOMOTRIZ KW - ENERGIA GEOTERMICA KW - WAVE ENERGY KW - ENERGIA ALTERNATIVA KW - FUENTE DE ENERGIA NO CONVENCIONAL N1 - CONTENIDO CHAPTER I INTRODUCING RENEWABLE ENERGY 1.1 Introduction 2 Force, energy and power 3 Energy conservation:The First Law of Thermodynamics 4 Forms of energy 4 Conversion and efficiency 6 1.2 Present-day energy use 6 World energy supplies 6 Energy use in the UK 8 1.3 Fossil fuels and climate change 10 1.4 Renewable energy sources 11 Solar energy: Direct uses 11 Solar energy: Indirect uses 12 Non-solar renewables 13 1.5 Renewable energy in a sustainable future 14 References and further information 15 CHAPTER 2 SOLAR THERMAL ENERGY 2.1 Introduction 18 2.2 The rooftop solar water heater 19 The pumped solar water heater 19 The thermosyphon solar water heater 20 2.3 The nature and availability of solar radiation 21 The wavelengths of solar radiation 21 Direct and diffuse radiation 22 Availability of solar radiation 22 Tilt and orientation 24 2.4 The magic of glass 26 Transparency 26 Heat loss mechanisms 27 2.5 Low-temperature solar energy applications 30 Domestic water heating 31 Domestic space heating 32 Varieties of solar heating system 34 2.6 Active solar heating 36 History 36 Solar collectors 36 Robustness, mounting and orientation 37 Active solar space heating 38 Interseasonal storage and solar district heating 39 2.7 Passive solar heating 40 History 40 Direct gain buildings as solar collectors 41 Passive solar heating versus superinsulation 41 Window energy balance 41 General passive solar heating techniques 45 Conservatories, greenhouses and atria 47 Trombe walls 48 Avoiding overshading 48 2.8 Daylighting 49 2.9 Solar thermal engines and electricity generation 51 The first solar engine age 52 The new solar age 54 Power towers 54 Parabolic trough concentrator systems 55 Parabolic dish concentrator systems 56 Solar ponds 56 Ocean thermal energy conversion (OTEC) 57 Solar chimneys 57 2.10 Economics, potential and environmental impact 58 Domestic active solar water heating 58 Swimming pool water heating 60 Active solar space heating and district heating 60 Passive solar heating and daylighting 60 Solar thermal engines and electricity generation 61 Conclusions 62 References 63 CHAPTER 3 SOLAR PHOTOVOLTAICS 3.1 Introduction 66 3.2 introducing photovoltaics 66 A brief history of PV 66 3.3 PV in silicon: basic principles 68 Semiconductors and 'doping' 68 The p-n junction 71 The PV effect 71 Monocrystalline silicon cells 75 3.4 Crystalline PV: reducing costs and raising efficiency 76 Polycrystalline silicon 76 Silicon ribbons and sheets 77 Gallium arsenide 77 3.5 Thin film PV 78 Amorphous silicon 78 3.6 Other thin film PV Technologies 79 Other innovative PV technologies 80 Multi-junction PV cells 80 Concentrating PV systems 80 Silicon spheres 81 Photoelectrochemical cells 81 'Third generation' PV Cells 82 3.7 Electrical characteristics of silicon PV cells and modules 83 3.8 PV systems for remote power 84 3.9 Grid-connected PV systems 85 PV systems for homes 85 PV Systems for non-domestic buildings 89 Large, grid-connected PV power plant 90 Satellite solar power 91 3.10 Costs of energy from PV 92 Reducing the costs of power from PV 94 3.11 Environmental impact and safety 95 Environmental impact and safety of PV systems 95 Environmental impact and safety of PV production 95 Energy balance of Pv systems 96 3.12 PV integration, resources and future prospects 96 Integration 96 PV resources 98 The growing world photovoltaics market 98 Future prospects: national and international PV research, development and demonstration programmes 99 Realizing the global potential 100 References 101 Further information 103 CHAPTER 4 BIOENERGY 4.1 Introduction 106 4.2 Bioenergy past and present 108 From wood to coal 108 Present biomass contributions 108 4.3 Biomass as a fuel 109 What are fuels? 109 Biomass as a solar energy store 111 Conversion efficiencies 112 4.4 Bioenergy sources 113 Energy crops 113 Woody crops 114 Agricultural crops 116 4.5 Bioenergy sources 116 Wastes 116 Wood residues 116 Temperate crop wastes 117 Tropical crop wastes 119 Animal wastes 119 Municipal solid waste 120 Landfill gas 120 Commercial and industrial wastes 122 4.6 Combustion of solid biomass 123 Combustion of wood and crop residues 123 Charcoal 124 Combustion of municipal solid wastes 125 4.7 Production of gaseous fuels from biomass 127 Anaerobic digestion 127 Anaerobic digesters for MSW 130 Gasification 131 4.8 Production of liquid fuels from biomass 133 Pyrolysis to produce bio-oil 133 Synthesizing liquid fuels 134 Fermentation te produce ethanol 134 Vegetable oils to biodiesel 136 4.9 Environmental benefits and impacts 137 Atmospheric emissions 137 Land use 139 Energy balance 140 4.10 Economics 141 Energy Prices 141 Costing bioenergy 141 Electricity from wastes 142 Electricity from Energy crops 143 4.11 Future prospects 144 References 145 CHAPTER 5 HYDROELECTRICITY 5.1 Introduction 148 5.2 The Galloway hydros 148 Origins 148 The scheme 149 Power 150 The turbines 150 The salmon 151 Economics 152 5.3 Hydro:The resource 153 The world resource 153 World capacity and output 154 5.4 Stored energy and available power 155 Stored potential energy 155 Power, head and flow rate 156 5.5 A brief history of water-power 157 The prime mover 157 Nineteenth-century hydro technology 160 5.6 Types of hydroelectric plant 16 Low, medium and high heads 162 Estimating the power 164 5.7 The Francis turbine 164 Action of the turbine 164 Maximizing the efficiency 167 Limits to the Francis turbine 167 5.8 'Propellers' 168 5.9 Impulse turbines 169 Pelton wheels 169 Turgo and cross-flow turbines 171 5.10 Ranges of application 172 Specific speed 172 5.11 Small-scale hydroelectricity 173 World-wide developments 173 SSH in the UK 175 5.12 Environmental considerations 177 Hydrological effects 177 Dams and reservoirs 179 Social effects 181 Small-scale systems 182 Comparisons 182 5.13 Integration 183 Power stations as elements in a system 183 Pumped storage 184 5.14 Economics 186 Capital costs 186 Investing in hydroelectricity 188 5.15 Future prospects 190 Small-scale hydro (SSH) 191 References 192 CHAPTER 6 TIDAL POWER 6.1 Introduction 196 The nature of the resource 197 Basic physics 198 Power generation 203 6.2 Technical factors 204 6.3 Environmental factors 210 6.4 Integration 215 6.5 Economic factors 218 6.6 Tidal energy potential 223 United Kingdom 223 World 225 6.7 Tidal barrages: conclusions 228 6.8 Tidal streams 230 Practical projects in the UK 231 Tidal current projects and concepts around the world 234 6.9 Tidal current turbines: the next stage 237 6.10 Tidal current assessment 239 References 241 CHAPTER 7 WIND ENERGY 7.1 Introduction 244 7.2 The wind 245 Energy and power in the wind 248 7.3 Wind turbines 249 A brief history of wind energy 249 Wind turbine types 252 Horizontal axis wind turbines 253 Vertical axis wind turbines 255 7.4 Aerodynamics of wind turbines 256 Aerodynamic forces 256 Aerofoils 258 Relative wind velocity 259 Harnessing aerodynamic forces 261 Horizontal axis wind turbines 261 Vertical axis wind turbines 264 7.5 Power and energy from wind turbines 265 How much power does a wind turbine produce? 265 How much energy will wind turbines produce? 266 Estimating wind speed characteristics of a site 268 7.6 Environmental impact 270 Environmental benefits of electricity generation by wind energy 270 Environmental impacts of wind turbines 270 Electromagnetic interference 273 Wind turbines and military aviation 274 Visual impact 274 Public attitudes to wind power 275 Wind turbines and birds 276 Additional environmental factors 277 Planning and wind energy 277 7.7 Economics 278 Calculating the costs of wind energy 278 7.8 Commercial development and wind energy potential 280 Wind energy developments world-wide 280 Small-scale wind turbines 283 Local community and co-operatively-owned wind turbines 283 Wind energy and buildings 284 Wind energy potential 285 7.9 Offshore wind energy 286 Offshore wind energy in the UK 288 References 292 Further Reading 295 Internet Sources 296 CHAPTER 8 WAVE ENERGY 8.1 Introduction 298 Recent history 298 8.2 Introductory case studies 299 8.3 Physical principles of wave energy 303 Typical sea state 303 Variations in the wave power at any location 307 Wave direction 308 What happens beneath the surface? 308 Moving into shallow water 309 Refraction 310 8.4 Wave energy resources 310 8.5 Wave energy technology 312 Fixed devices 314 Floating devices 317 Tethered devices 322 Wave energy research and development activity around the world 324 8.6 Economics 332 8.7 Environmental impact 334 8.8 Integration 334 Wave energy for isolated communities 334 Wave energy for large electricity grids 336 8.9 Future prospects 337 References 337 CHAPTER 9 GEOTHERMAL ENERGY 9.1 Geothermal energy an overview 342 The mining of geothermal heat 342 The source of heat 344 Historical perspective 346 9.2 The physics of geothermal resources 350 Primary ingredients 350 Volcano-related heat sources and fluids 353 The heat source in sedimentary basins 355 Geothermal waters 357 Why are there hot dry rocks? 358 9.3 Technologies for geothermal resource exploitation 359 Resources in high-enthalpy steam fields 359 Dry steam power plant 360 Single flash steam power plant 361 Binary cycle power plant 362 Double flash power plant 362 Future developments 363 Resources for direct use geothermal energy 363 Ground source heat pumps 364 Hot dry rock technology 368 9.4 Environmental implications 373 9.5 Economics and world potential 375 9.6 Geothermal potential in the United Kingdom 378 Sedimentary basin aquifers 378 Hot dry rocks 379 References 381 Further reading 381 The world wide web 381 Conference proceedings 382 Background material 382 CHAPTER 10 INTEGRATION 10.1 Introduction 384 10.2 The existing UK energy system 385 Energy flows 385 Distribution 386 10.3 How much renewable energy is available? 388 10.4 Are renewable-energy supplies available where we want them? 391 The present electricity grid 392 Wave, wind and tidal power 393 10.5 Are renewable-energy supplies available when we want them? 394 Renewables as heat suppliers 395 Integrating renewable electricity 396 10.6 Some system solutions 404 Grid strengthening 404 Demand management 405 PV, micro-CHP and emergency generators 405 Hydrogen - the fuel of the future? 406 10.7 Balancing economic options 410 Renewables and conservation 410 Balancing economic and environmental considerations 411 Renewable energy and planning permission 413 10.8 Promoting renewables 414 Supporting research and development 414 Targets 415 Legislation and building regulations 415 Financial incentives 415 Future EU policies 419 10.9 Energy scenarios: Danish examples 420 10.10 Global scenarios 422 International Energy Agency projections 422 10.11 Conclusions 429 References 430 Further information 432 Appendix 433 A1 Investing in renewable energy 433 A2 Units 437 ACKNOWLEDGEMENTS 439 INDEX 443 ER -