Geothermal power generation : Global perspectives; U.S.A. and Iceland; technology, direct uses, plants, and drilling

• Published in: International journal of power & energy systems Vol. 27; no. 2; pp. 157 - 172
• Main Author: HAMMONS, T. J
• Format: Journal Article
• Language: English
• Published: Anaheim, CA International Association of Science and Technology for Development 2007; Calgary, AB ACTA Press; Zurich
• Subjects: Alternative energy sources; Applied sciences; Aquaculture; Biomass; Condensers; Developing countries; Development projects; Drilling; Electric power generation; Electric power plants; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Electricity; Electricity generation; Energy consumption; Energy policy; Energy resources; Energy shortages; Enhanced geothermal systems; Exact sciences and technology; Fossil fuels; Geothermal energy; Geothermal power; Geothermal resources; Greenhouse effect; Greenhouse gases; Heat; Heat flow; Heat transfer; Heating; High temperature; Industrial plant emissions; Industrialized nations; LDCs; Low temperature; Miscellaneous; Per capita; Power consumption; Power plants; R&D; Regulation and control; Renewable energy sources; Renewable resources; Research & development; Silica; Sustainable development; Technological change; Thermal power plants; United States; North America; America; State of the art; geothermal energy in U.S.A; Machining; Developing countries; Heat flow; High temperature; geothermal processes; improvement of geothermal plants; renewable energy; optimization of geothermal plants; Geothermal power; Flow control; geothermal drilling; Low temperature; Potential energy; world energy consumption; geothermal R&D programmes; geothermal energy in Iceland; Operating conditions; Medium power; Energy source; Renewable energy sources; Power consumption; Heating; Environment impact; Installed capacity; world energy resources; Production capacity; Electric power production; Heat transfer; Geothermal power plant
• ISSN: 1078-3466; 1710-2243; 1710-2243
• DOI: 10.2316/journal.203.2007.2.203-3463

This paper discusses the state of the 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 in both developed and developing countries in the near future and long term. The author first reviews world energy consumption and then discusses relative contribution of energy sources in the world in OECD countries, summarizes installed geothermal capacities for electricity generation, and examines direct use of geothermal energy worldwide together with the technical potential of renewable energy sources. The central part of the article examines geothermal energy in the United States, highlighting heat flow, tectonic controls, types of geothermal systems, United States geothermal potential, geothermal energy in the United States, operating conditions for electricity generation, and environmental constraints. Then the author considers Iceland's primary power consumption, production of electricity in Iceland, low-temperature geothermal resources, and high-temperature geothermal resources. The paper then examines the Geothermal Technologies Programme in the United States, reviewing the goals of geo-science and supporting technologies, exploration and drilling research, and energy systems research and testing; enhanced geothermal systems, and direct use of geothermal energy, considering district heating, agriculture, and aquaculture applications and future developments. Finally, improving geothermal power plants is discussed and typical R&D projects are reviewed. Highlighted are such research and development projects as enhanced heat transfer in air-cooled condensers, materials research, instruments for real time monitoring of geothermal processes, plant optimization, removal of noncondensable gases from binary power plants, and silica and metals extraction. The article also discusses geothermal drilling R&D aimed at reducing drilling costs by 25~50%. [PUBLICATION ABSTRACT]