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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 52 (1968)

Issue: 3. (March)

First Page: 564

Last Page: 564

Title: Worldwide Development of Geothermal Industry: ABSTRACT

Author(s): James R. McNitt

Article Type: Meeting abstract

Abstract:

The total installed capacity of geothermal generating plants in the world today is approximately 630 megawatts (MW), distributed among the following five countries: Italy 340; New Zealand, 190; USA, 50; USSR, 30; and Japan, 20. Approximately half of this present capacity has been installed during the last 10 yr and the success of these installations is stimulating worldwide interest in geothermal energy. Exploration projects are now underway in Mexico, El Salvador, Chile, Turkey, Kenya, China (Taiwan), and the Philippines.

Although approximately 30 thermal areas have been drilled in the western United States during the past 10 yr, only two are undergoing active development. The Geysers field in northern California accounts for all the geothermal power production in the United States, and the Salton Sea field in southern California is being developed for the extraction of sodium and calcium chlorides from geothermal brines.

The principal incentives for development of geothermal power are: (a) lack of more conventional sources in the market area, and (b) competitive economic position of geothermal power even where other sources are available. Geothermal sources generate low-cost, base-load power even at capacities under 100 MW, making them particularly advantageous in market areas where power demands are still low. Low steam pressures make it necessary to use small generating units, i.e., on the order of 25-50 MW, but total capacities of several hundred megawatts can be expected from a single steam field.

All the thermal areas now under investigation share a common regional geologic setting: the areas are located in orogenic zones, where late Tertiary or Quaternary volcanism has taken place. Tectonically the regions are characterized by vertical movements, both uplift and subsidence, which have taken place on normal faults. The geometry of fault-block movement appears to be an important factor in controlling the location of shallow igneous intrusions which are believed to be the source of heat for the high-temperature thermal systems now being exploited for power generation.

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Copyright 1997 American Association of Petroleum Geologists