Tuesday, June 12, 2007

>geothermal


belajar nulis inggris. msh belepotan. blm diedit.tlg kasi tau klo da yg salah


GEOTHERMAL: AN ALTERNATIVE ENERGY
FOR THE BETTER FUTURE

Introduction
Indonesia’s archipelago is located among some plates tectonic. It caused many of volcanoes appear along there, that is called the ring of fire. Due to its location, Indonesia has the biggest potential geothermal resource in the world. It is approximately 40% world resource or 20,000 MW which spread out along Sumatra, Java, Bali, Nusa Tenggara, Halmahera, and Sulawesi islands. Almost half (8,000 MW) of this potential energy is located in Java and Bali, the most populous islands with the highest demand of electricity. Nevertheless, only 4% of Indonesia’s geothermal resource have been using. Research activities for geothermal resource begun on early 1900s by the Dutch colonialism. However, the first geothermal exploration activities was done in 1974 in Kamojang, West Java, and eight years later commersial power plant had done.

The Importance of Geothermal
The existence of geothermal is associated with volcanism activity. It can be understanding that, commonly, geothermal field has located on volcanic area. According to Armstead (1983) that geothermal is the energy which come from the depth of earth that can be hot steam, fluid, or mix both of them and it can be extracted to the top of earth to economical activity. There are three basic categories of geothermal resources: hydrothermal, geopressured, and hot dry rock (Blair, et. al., 1982). Hydrothermal is fluid that accumulated to magmatic with the result that hot fluid. Geopressured is the geothermal energy that comes from the earth pressure. It gives gradient temperature by different depth. Whereas, hot dry rock is geothermal energy that caused by impermeable rocks that have been heated. However, from the three of them, only hydrothermal source can be used economically.
Geotermal field can be identified by seeing the phenomena on the its surface. It can be fumarole, water hot pool, hot spring, geyser, steaming ground, etc. However, that are not enough for geologists. They need some evidence to proof the potential resource. Due to their responsible about it, they observe five components of geothermal field: heat source, fluid, fracture, reservoir, and cap rock. Heat source comes from the magma activities in the depth of earth. It is the power to produce hot fluid. Fluid comes from, mostly, the meteoric water. The water flow until some of the dept which contact with magma and change it to be hot water and steam. To flow until the earth depth, water needs a way to reach it. It is called fracture. In order to the water accumulation not to spread out anywhere, impermeable rocks needed to catch it. The rocks likes that is called reservoir. And the last component is cap rock. It function as a trap on the top of reservoir in order to keep the fluid stay flowing.
What is geothermal for? It can be used to many of human needs. Geothermal energy can be utilized as directly and indirectly. In directly utilization, such as domestic services, like the Maoris activities, in New Zealand. A man catch his trout in a cool river and drop it into a nearby pool of boiling water to cook it. A few yards away his wife administering a geothermal bath to the baby, while his daughter is doing the household laundry in a hot spring and the vegetables are cooking over a fumarole. In addition, hot water has many of minerals that very usefull to cure some of the skin disesases. Moreover, woman usually used it to their beauty treatment by swimming in the hot water pool. It can make them have more good skin because of the regeneration of their cells. Farmer also use geothermal for their products. Natural hot waters are used to heat greenhouses in which vegetables, fruits, mushrooms, and flowers. Due to many advantages of geothermal, it may invite tourists to come to the geothermal field. So, many of economic activities may be occurred.
Moreover, in indirectly utilization, geothermal energy is used to generate power plant to produce electricity. This is the most important things to do because the increasing of electricity needs day by day. Nowdays, the energy crisis faced in all of the world because the decreasing of petroleoum and gas resources. Enviromental issue push up many countries did many researches to find another alternative energy. One of them is geothermal energy. In many researches, it has proved that geothermal is clean energy. It is almost no pollution caused by the utilization as electric power plant. Futhermore, geothermal is recycle energy. Steam or hot water, which produced by geothermal wells, used to turn the turbine and after that the water, which to be cooler than before, reinjected to the wells. Then the water flowing to the depth of earth and warming up again by the hot source.
Geothermal in Yogyakarta
There is very less geothermal phenomena in Yogyakarta. We can see it in the Parangtritis beach as small hot water pool. Eventhough Mt. Merapi is very active volcano, but based on geology research, it known that bad reservoir in the stratigraphic subsurface. Due to the capacity of the hot water pool is very low, there is no power plant built.

The Future of Geothermal Energy
According to Kyoto’s Protocol Clean Development Mechanism every country expected to make greenhouse gas reduction program. The Government of Indonesia has had little success in promoting development of energy resource over the past several years. Indonesia utilizes 525 MW of geothermal energy from 787 MW of installed geothermal capacity. As a result, Indonesia saves the equivalent of some 6,300 barrels/day of oil. According the Directorate General of Oil and Gas, Indonesia produced 37.6 million tons of geothermal steam in 2000, which translates into 4,696 GwH of electricity (www.indonext.com/report/report433.html).
Eventhough Indonesia has a lot of geothermal resource, however, utilization of geothermal potential has very slowly and facing difficult challenges. Ministry of Energy and Mineral Resources statistics indicate that renewable energy utilization (hydropower, geothermal and biomass) account for only 3.4% of total potential reserves. This is caused by government’s policies. The government does not give concern seriously to expand geothermal exploration. It caused geothermal energy can not be exported like petroleoum, natural gas, or coal. On the other hand, geothermal is indigenous energy. That means it can be used only in around area that geothermal field had been located.
The abundance of geothermal energy in Indonesia makes it an important natural resource for future energy development. Until the 1997 economic crisis, the regulations enacted by the Government of Indonesia successfully promoted the rapid exploration and development of geothermal energy. Recently, the government has policy to increase petroleoum fuel prices, it may stimulates further utilization of alternative and renewable energy to make our environmental more friendly and cleaner. Moreover, developing geothermal utilization needs a legal basis. Therefore, the government issued geothermal law on 2001. It provides guidliness for geothermal investment and brings a new hoping for better future.

Conclusion
Indonesia has a lot of geothermal resource. Indirectly utilization for electricity, however, is still less. Future geothermal energy development will be dependent on action both of government and investor. Geothermal can be an alternative energy which friendly and reneweable to built better enviromental.

References
· Armstead, H. C. H., 1983, GEOTHERMAL ENERGY: Its past, present and future contributions to the energy needs of man, E. & F. N. Spon Ltd., London.
· Blair, P. D., Cassel, T. A. V., and Edelstein, R. H., 1982, GEOTHERMAL ENERGY: INVESTMENT DECISIONS & COMMERCIAL DEVELOPMENT, John Willey and Sons, Toronto.
· www.indonext.com/report/report433.html (download at March 29, 2006, 04.06 p.m)

1 comment:

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