In many developing countries the exponentially growing electricity demand can be covered by using locally available, sustainable low-enthalpy geothermal resources (80-150 C). Such low-enthalpy sources can make electricity generation more independent from oil imports or from the over-dependence on hydropower. Until now, this huge energy resource has only been used by some developed countries like the USA, Iceland and New Zealand. The reason why low-enthalpy geothermal resources are not used for electricity generation is that there is still a misconception that low-enthalpy thermal fluids are fit only for direct application. The advancement of drilling technology, development of efficient heat exchangers and deployment of high sensitive binary fluids contribute to the useful application of this energy resource on a much wider scale.
This book focuses on all aspects of low enthalpy geothermal thermal fluids. It will be an important source book for all scientists working on geothermal energy development. Specifically those involved in research in developing countries rich in such thermal resources, and for agencies involved in bilateral and international cooperation.
Preface by Angela Merkel foreword 1 Introduction 2 World electricity demand and source mix forecasts 2.1 World overview 2.2 Regional electricity markets and forecasts until 2030 2.3 Regional electricity source mix and forecasts until 2030 3 Worldwide potential of low-enthalpy geothermal resources 3.1 World geothermal resources 3.2 Types of geothermal systems 3.3 Available low- and high-enthalpy geothermal resources 3.4 Actual use and developments of low- and high-enthalpy geothermal resources for power generation 3.5 Overcoming barriers to geothermal Energy 4 Low-enthalpy resources as solution for power generation and global warming mitigation 4.1 Overview 4.2 Benefits through emission reduction 4.3 Benefits of domestic geothermal resources versus fossil fuel imports 4.4 Benefits of geothermal versus hydroelectric power generation 4.5 Rural geothermal electrification using low-enthalpy geothermal resources 5 Geological, geochemical and geophysical characteristics of geothermal fields 5.1 Geological and tectonic characteristics 5.2 Geothermal systems associated with active volcanism and tectonics 5.3 Geothermal systems associated with continental collision zones 5.4 Geothermal systems within the continental rift systems associated with active volcanism 5.5 Geothermal systems associated with continental rifts 6 Geochemical methods for geothermal exploration 6.1 Geochemical techniques 6.2 Classification of geothermal waters 6.3 Chemical constituents in geothermal waters 6.4 Dissolved constituents in thermal waters 7 Geophysical methods for geothermal resources exploration 7.1 Geophysical techniques 7.1 Heat flow measurements 7.2 Electrical resistivity methods 7.3 Magnetotelluric survey 7.4 Geophysical well logging 8 Power generation techniques 8.1 Overview 8.2 Criteria for the selection of working fluid 8.3 Heat exchangers 8.4 Kalina cycle 9 Economics of power plants using low-enthalpy resources 9.1 Drilling for low-enthalpy geothermal reservoirs 9.2 Drilling cost 9.3 Drilling costs versus depth 9.4 Well productivity versus reservoir temperature 9.5 Power production vs well head temperature and flow rate 9.6 High-enthalpy versus low-enthalpy power plants 10 Small low-enthalpy geothermal projects for rural electrification 10.1 Definition of small geothermal power plants 10.2 Characterization of resources and cost reduction 10.3 Energy need for rural sector 10.4 Markets for small power plants 10.5 Advantages of small power plants 10.6 Cost of small power plants 10.7 Examples of small power plants References
Dornadula Chandraskharam (1948, India) is the Head of the Centre of Studies in Resources Engineering, Indian Institute of Technology Bombay. He has been working in the fields of volcanology, groundwater pollution, and geothermics for the past 25 years. Prof. Chandrasekharam conducted research on low enthalpy geothermal resources in India and is currently the Chairman of M/s GeoSyndicate Power Private Ltd., the only geothermal company in India. He is one of the executive members of the International Society of Groundwater for Sustainable Development (ISGSD). Jochen Bundschuh (1960, Germany) is working in geothermics, subsurface- and surface hydrology and integrated water resources management, and connected disciplines. In 2001 he was appointed to the Integrated Expert Program of CIM (GTZ/BA), Frankfurt, Germany and works within the framework of the German governmental cooperation as adviser in mission to Costa Rica at the Instituto Costarricense de Electricidad (ICE). In 2005, he was appointed as affiliate professor of the Royal Institute of Technology, Stockholm, Sweden. He is elected Vice-President of the International Society of Groundwater for Sustainable Development.
The forte of the book is the part dealing with modern methodology and techniques of exploring the geothermal resources, and beneficially converting the heat energy of geothermal waters into electricity. It offers solutions for generation of power that would ensure that no greenhouse gases are formed. In other words, tapping the energy of hot-springs on a large-scale implies effective contribution to the lessening of global warming. In: CURRENT SCIENCE, VOL. 95, NO. 12. DECEMBER 2008 "! case studies described in this book clearly demonstrate how low-enthalpy geothermal resources can be utilized for improving the socio-economic status of rural areas in developing countries." "This book is intended not only for graduate and research students as a primary dictionary, but also should prove useful for professional geologists and engineers, as well as professionals involved in energy planning and greenhouse gas mitigation." in: ENERGY SOURCES, Part A, 31:98, 2009