1. You will read the following texts about geothermal energy. Choose the most important facts from each one.
2. Write the summary of the texts.
ARGENTINA
Sources of high-temperature geothermal heat exist in western Argentina, along the Andes range. Moderate to low-temperature thermal fields have been identified in other parts of the country. A 670 kW binary-cycle pilot plant has been in operation at Copahue (in the west-central province of Neuquen) since 1988. Direct use is made of hot water from the Domuyo geothermal field (located to the north of Copahue) in space heating and bathing in the Villa Aguas Calientes tourist complex. However, the amount involved is extremely small. There is a project for using the Copahue geothermal resource for space heating in the nearby village of Caviahue.
AUSTRALIA
Australia's best resources of conventional geothermal energy are located in the Great Artesian Basin region of central Australia where there are many bores! which discharge water at high enough temperatures (above 80 °C) to operate a heat engine. Although these resources are not appropriate for large-scale electricity generation, they can be used to generate electricity for remote homesteads2 and communities in this area. Examples include a district heating system at Portland (Victoria), a geothermal well providing hot water for paper manufacture at Traralgon (Victoria), power production (20 kWe binary cycle) from hot water aquifers3at Mulka station (South Australia), and a binary plant (150 kWe) at Birdsville (Queensland).
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D. Geothermal Energy in Different Countries of the World 127
Geothermal energy is also available from 'hot dry rocks' (HDR) buried several kilometres below the earth's surface. Recent studies of the prospects for HDR in Australia have established that a very significant resource exists, particularly in eastern Australia. Moreover, the economics of energy extraction based on HDR in Australia appear to be favorable, owing to a very advantageous combination of geological factors: high rate of heat generation in the crust4, low-conductivity sedimentary rocks which retain the heat, and horizontally oriented HDR reservoirs which provide the cheapest drilling access. Given the scale of the engineering required, the technology is likely to be most appropriate for grid-connected applications.
GREECE
Geothermal exploration undertaken since 1970 has located numerous fields, both high-enthalpy' and low-enthalpy. Development activities during the last five years have concentrated on low-enthalpy fields in Thrace, Macedonia and central Greece. There is now a considerable area of geothermally-heated greenhouses in operation. A 2 MWe pilot power plant was built in 1986 at Milos in the Cyclades, but complaints2from local residents caused it to be shut down in 1988. Environmental problems continue to inhibit3 the exploitation of Greece's high-temperature geothermal resources.
1 - скважина; 2 — фермы; 3 - водоносный слой; 4 — земная кора
COSTARICA
The Central American volcanic belt (пояс) passes through Costa Rica, evidenced by numerous volcanoes and a number of geothermal fields. In March 1994, a 55 MWe geothermal power station was brought into service at a site close to the Miravalles volcano, in the north-west of the republic. In January 1995, the 5 MWe Boca de Pozo plant came into operation at the same field. The construction of Miravalles II, with a projected capacity of 55 MWe, is under way; completion was scheduled for end-2004.
EL SALVADOR
As does Costa Rica, El Salvador lies on the Central American volcanic belt. Geothermal exploration began in 1954 and the first of its geothermal power plants came on line in 1975 at Ahuachapan (30 MWe), in the west of the republic near the border with Guatemala. Further units were added in 1976 (30 MWe) and 1980 (35 MWe), bringing total generating capacity at Ahuachapan up to 95 MWe. The Berlin geothermal field in the eastern part of the republic was explored from the 1960's onwards, eventually leading to the installation of two 5 MWe back-pressure plants in 1992. At first only one plant was run at a time but the drilling of additional wells now enables the two units to be run simultaneously.
1 - теплосодержание, теплоемкость; 2 — жалобы; 3 — тормозить
ICELAND
Geothermal energy has been utilized on a commercial scale since 1930. Currently the resource is mainly used for space heating, with electricity generation being of fairly small significance (reflecting Iceland's wealth of hydroelectric resources).
Two conventional geothermal power plants are in operation - Krafla, 30 MWe and Namafjall, 3 MWe. In addition, pioneering development work on the cogeneration of heat (district heating) and electricity has been undertaken. At present two cogeneration plants are in operation: Svartsengi (16.4 MWe), where both single flash and binary turbines are in use, and Nesjavellir (60 MWe), where it is expected that production of electricity will begin during 1998.
Geothermal energy supplied nearly 7% of Iceland's electricity in 1996 and its utilization was as follows: electricity and CHP, 56%; direct use for space heating, 28%; industrial use, 6%; greenhouses, 4%; swimming pools, 3%; fish farming, 2% and snow-melting, 1%.
About 85% of households are supplied with geothermal heating, mostly via large district heating schemes such as that in Reykjavik, which serves about 150,000 people.
INDONESIA
The islands of Indonesia possess enormous geothermal resources: geological surveys have identified 217 geothermal prospects, including a
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total of 142 high-temperature reservoirs with an estimated resource potential of over 16,000 MWe. Of this potential, about 50% is in Java/Bali and 30% Sumatra. The first geothermal power plant to come into operation was a 2 MWe pilot plant' at Dieng (central Java), installed in 1981. A 30 MWe plant came on-line at Kamojang in west Java in 1983 and was augmented2by two units, each of 55 MWe, in 1988. In 1994 two 55 MWe units were installed at Salak and another of the same capacity at Dara-jat, both fields in Java. Total geothermal capacity at the end of 1996 stood at 308 MWe; the electricity generated in 1996 amounted to 2340 GWh, the fourth highest geothermal output in the world.
Four more 55 MWe units came on-line at Salak in 1997, three of them in a privately-developed project involving the US company Unocal and PT Nusamba Geothermal. Other projects for new geothermal capacity are reported to be on hold3, owing to the financial crisis that hit Indonesia towards the end of 1997.
1 — опытная станция; 2 — увеличена; 3 — отложены
ITALY
Italy is Europe's leading producer of geothermal electricity, with a 1996 share of about 90%. The world's first geothermal power plant was commissioned in 1904 at Larderello in Tuscany. Subsequent developments at this and other sites in the same region have brought gross geothermal capacity to 512 MWe (at end-1996), representing 1% of Italy's total electricity generating capacity.
Direct uses of geothermal heat had an aggregate installed capacity of just over 300 MWt at the end of 1996. In 1994, 57% of direct geothermal consumption related to baths and swimming pools, 19% to greenhouses, 16% to space heating, 7% to industrial process heat and 1 % to fish-farming. The low-medium temperature resources used for such purposes were all located north of Rome.
JAPAN
There is a long history of geothermal utilization, both direct and for power generation. The first commercial-scale geothermal power station came on-line at Matsukawa, in the north of the main island of
D. Geothermal Energy in Different Countries of the World 129
Honshu, in 1966. Following the oil crisis in the early 1970's, geothermal development was accelerated. Generating capacity rose to 280 MWe in 1990 and has since nearly doubled, to 530 MWe at the end of 1996. The existing plants are all located in the Tohoku region of northern Honshu and on the southern island of Kyushu. Planned development of geothermal power envisages 600 MWe by 2000 and 2800 MWe by 2010.
PHILIPPINES
The Philippines archipelago is exceptionally well-endowed'with geothermal resources. The first electricity-generating capacity came into operation in 1979 and by the end of 1984 geothermal capacity had reached 894 MWe. Further units were installed from 1993 onwards, bringing aggregate capacity to 1448 MWe by the end of 1996. The greater part of the capacity has been built on the islands of Luzon and Leyte. The output of geothermal electricity in 1996 represented about 18% of total generation in the Philippines. More capacity is under construction or planned, with 460 MWe expected to come on-line in 2001 and a further 240 MWe scheduled to be completed by 2005.
Geothermal heat is used directly in drying coconuts2 and other produce, and in fish-processing and salt production.
1 — хорошо обеспечены; 2 — плод кокосовой пальмы
RUSSIAN FEDERATION
Geothermal resources have been identified in various parts of the Federation but utilization is very largely confined to direct uses. The only electricity-generating facility is the 11 MWe Pauzhetskaya power plant in the far-eastern Kamchatka peninsula; this plant was built in 1966 and enlarged in 1980. An 80 MWe power plant is under construction at the Mutnovsky field in southern Kamchatka, with completion scheduled for 2000. Discharged waters from the Mutnovsky field will be piped 80 km to the town of Elizovo.
Geothermal-based district heating schemes were in operation in 1994 in six towns and eight large settlements in the Pre-Caucasus and Northern Caucasus regions. Much use is made of geothermal heat in
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greenhouses; minimal amounts of direct use are recorded in agricultural and industrial applications.