当涂市档案局举办新农村建设档案工.pptVIP

ENERGY RENEWABLE ENERGY- Inexhaustible source of energy. Ex-solar, Hydro, Wind, Tidal Geothermal NON-RENEWABLE ENERGY-Exhaustible with time. Ex- Fossil fuels, Nuclear fuels. SOLAR ENERGY Earth Receives 1018kwh of solar energy every year The surface of the earth receives about 1014 kW from sun Obstacles in harnessing solar energy It is not constantly available on earth Thus some form of storage is needed to sustain solar energy through the night and during rainy season Solar energy is diffused. SOLAR WATER HEATING Flat plate collector Parabolic or concentrating collector Flat plate collector The absorber plate is metallic. It is usually coated black to absorb more heat energy. Tubes, passages or channels integral with the collector carry water or other working fluid. Insulation should be provided at the back and at the sides to minimize the heat losses. Usually glass wool is used as insulation material. Parabolic or concentrating collector The reflector will have a parabolic shape so that the sun rays striking the profile will be reflected on its focal point. If a tube carrying a fluid is kept along the focal line, the fluid will be heated to a very high temperature. Low temperature system This system uses a flat plate collector, which can heat water up to about 800C only. Water is circulated through the flat plate collector. Heat exchanger is used to vaporize a low boiling fluid (butane) and the butane vapor will run the turbine High temperature system A receiver is mounted on the tower which is 100 to 500m high reflecting mirrors are known as heliostat. The heliostat are arranged in such a way that they direct the solar energy on the receiver throughout the day. The receiver is designed and positioned in such a way to intercept, absorb and transfer maximum heat to working fluid. The temperature achieved is 15000C to 17000C ADVANTAGES Renewable source of energy Pollution free After the capital cost, the cost of power generation is quite low