http://www.merinews.com/catFull.jsp?articleID=137435Puga...

http://www.merinews.com/catFull.jsp?articleID=137435

Puga geothermal plant can help in energy crisis

CJ: Aamir Ali , 8 hours ago Views:97 Comments:0
GEOTHERMAL IN Greek language means Earth and Heat. Geothermal energy is the heat produced inside earth. The Earth is composed of a number of layers known as the inner core, outer core, mantle and crust. Temperatures in the Earth’s core can reach over 4,500°C and in the mantle it varies from 4,000°C to 1,100°C. In the Earth’s crust the temperature increases with depth.

Under Earth’s crust, there is a layer of hot and molten rock called magma. Heat is continually produced there, mostly from the decay of naturally radioactive materials such as uranium and potassium. When magma comes close to the surface it heats ground water trapped in porous rock or water running along fractured rock surfaces and faults creating hydrothermal resources.

These naturally occurring hydrothermal resources are called geothermal reservoirs. The energy from these geothermal reservoirs can be used to generate electricity, by using steam, heat or hot water to provide the force that can spin the turbine generators to produce electricity. The used geothermal water is then returned down through an injection well into the reservoir to be reheated and in order to sustain the reservoir. There are three designs for geothermal power plants. In the first design, the steam goes directly through the turbine. In a second design, very hot water is converted to steam, which is used to drive the turbine. In the third and most commonly adopted design, called binary system, the hot water is passed through a heat exchanger, where it is used to heat another liquid, like isobutane.

The boiling point of isobutane is lower than water, so it easily gets converted into steam, to run the turbine. The choice design is determined by the geothermal resource. Usually hot water resources are more abundant than pure steam, so there is more potential in the binary design. The world’s geothermal energy production in 1990, was 5,033 megawatts and in 2000, it was 7,994 megawatts.

The estimated potential for geothermal energy in India is about 10,000 mw. In India, exploration and study of geothermal fields started in 1970. Around 350 potential geothermal locations have been identified in India by the Geological Survey of India (GSI). In March 2008, Puga valley in Ladakh has been selected for tapping the geo-thermal energy for power generation by the Union ministry of new and renewable energy. Puga valley is known for high temperature geothermal systems. The systems have been existing for the last 65 million years. The geothermal activity is concentrated in 3 sq km area of the 15 km long Puga valley. The Puga valley is famous for its hot water springs. Every year hundreds of visitors come to this valley for a bath in these springs as this is known to help people suffering from rheumatic and skin diseases.

The state government has been encouraging participation of private sector in many sectors, including geothermal energy, by allowing access to the data collected on geothermal resources and even to undertake investigations/assessment studies for geo-thermal energy and submission of detailed project reports for exploitation of this renewal resource.

It is, however, ironical that reportedly no one approached the Union ministry or the state government for financial support during the last three years for harnessing geothermal energy. Geothermal plants have almost no negative impact on the environment as these plants do not burn fuel to generate electricity. Geothermal energy is a clean and environmentally sustainable natural resource, which can generate electricity from the intense heat present inside the earth and can play an increasing role in meeting the world’s needs for clean energy. Private entrepreneurs should come forward to harness this clean and environmentally sustainable, natural and renewal geothermal resource, as a solution to the world energy crisis.