Introduction Geothermal Energy is heat (thermal) derived from earth (geo) Contained in rock and fluid in the earths crust Source of geothermal energy is radioactive decay
Geothermal energy Geothermal power is generated wherever water comes in contact with hot rocks below the earth’s surface. The rocks give off heat that makes the water hot enough to turn in to steam. Power companies can drill wells and pump the hot water or steam to the surface, where it can be used to generate energy. in areas where no underground water or steam exists naturally, engineers can pump water into the ground to be heated by hot rocks. Bolivia, Iceland, New Zealand, and the united states have developed geothermal power plants.
Types and Application of Geothermal Energy1.Direct use Involves using the heat in water directly Temperature: 38 C-149 C e.g. heating of buildings, industrial processes, greenhouses , aquaculture and resource
Types and Application ofGeothermal Energy2. Ground-source heat pumps use the earth or groundwater as a heat source in winter and sink in summer Temperatures: 4˚C to 38˚C Heat pump transfers heat from the soil to the house in winter and from the house to the soil in summer
Types and Application ofGeothermal Energy3.Power generation geothermal power plant taps the natural supplies of heat energy that have accumulated inside the earth.
Schematic energy of Geo-Thermal energy power plant
Indian Scenario Puga Valley (J&K) Godavari Basin Manikara (Himachal Pradesh) Bakreshwar (West Bengal) Tuwa (Gujarat) Jalgaon (Maharashtra)
Demerits of Geothermal Energy Heated water may give out after a while- hotspot moves or aquifer pressure drops. Geo thermal hot spots are sparsely distributed. Geothermal energy is quite low grade because the temperature of steam is only between 150 to 200 c(at 100 psi). salts in water can corrode equipment, shorten lifespan. Limited to geographic areas where geothermal heating naturally occurs.
Merits of Geothermal Energy Power source during construction Renewable as long as water is heated naturally Much lower greenhouse gas emissions than fossil fuels Meet the needs of electricity demand in limited area An experimental unit as a pilot plant for a larger size installation .