Geothermal power generation worldwide

Abstract

This paper discusses the state of art in harnessing geothermal power for medium- and large-scale generation of electricity (and for space heating) worldwide. It reviews current, probable, possible and potential developments both in developed and developing countries in near future and long term. First, world energy consumption is reviewed. Then relative contribution of energy sources in the world in OECD countries with respect to renewables is discussed. The paper examines the salient technological aspects of geothermal power generation with geothermal energy in the United States and highlights heat flow, tectonic controls, types of geothermal systems, U.S. geothermal potential, geothermal energy in the United States, operation conditions for electricity generation, and environmental constraints. The central part of the paper goes on to review field experience with innovative geothermal plants considering geothermal power plant analysis and design (optimization in design of geothermal power plants, optimization of prime movers, heat cycle considerations, resource considerations), a review of experimental plants (proposed systems and tested systems), and innovative power plants in commercial operation (low enthalpy, moderate enthalpy, and high enthalpy resources) is discussed. The paper then examines R&D programs that are underway to significantly enhance the use of geothermal. Highlighted is typical research and development projects such as enhanced heat transfer in air-cooled condensers, materials research, instruments for real time monitoring of geothermal processes, plant optimization, removal of non-condensable gases from binary power plants, silica and metals extraction, and small-scale power plant field verification projects. Geothermal drilling R&D is also reviewed. The final part of the paper considers goals and objectives of improving geothermal power plants where potential impact of geothermal R & D is reviewed. Integration and connection of dispersed geothermal generation to the grid network is also discussed.