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  2. 2. PRESENTATION OVERVIEW Introduction Energy sources Limits of present renewable technologies Cross wind kite power Constructional details Operating principles Limitations Advantages Comparison with other renewable resources Summary References
  3. 3. INTRODUCTION Energy Kites, a revolutionary technique of power generation. Conventional source of energy causes pollution. Renewable energy is very low in cost. It does not have much negative impact on the environment. Airborne wind energy replaces the traditional structure of wind turbine by Kites tethered to ground.
  4. 4. ENERGY SOURCES Conventional energy sources: Coal, petroleum and natural gas, fuel woods, hydropower, nuclear energy. Non-conventional energy sources: Solar energy, wind energy, tidal energy, geothermal energy, biomass, biogas, energy from urban waste
  5. 5. LIMITS OF PRESENT RENEWABLE TECHNOLOGIES High production costs Large occupation of land The electricity generation capacity is still not large enough. Unreliable Low-efficiency levels
  6. 6. CROSSWIND KITE POWER Traditional wind turbine is replaced by Energy Kite, a wind turbine with a rotor supported in the air. Avoids the expense of tower construction. The Kite tethered to ground, flies in a crosswind direction. After achieving certain altitude this Kite obtains a circular trajectory. The power generated by energy Kite is transmitted to ground simultaneously.
  7. 7. CONSTRUCTIONALDETAILS Three main components: Kite Tether Ground Station
  8. 8. Kite: The main component of the power generation system. Material used must be light as well as strong to sustain various types of forces acting on it. Consists of small turbines that generate power by using the velocity of wind. Increase in number of rotors increases power output.
  9. 9. Tether: Acts as a link for Kite to ground contact. Used to transmit energy generated by energy Kite to the ground station. Made of thick Aluminium wires surrounded by a high strength composite fibre covering. When tether length exceeds a limit, it may lead to minor instability of the system. To overcome this and to get efficient power generation at short tethering distance, multiple Kites are used.
  10. 10. Ground station: Holds the tether. Used as a resting place for the energy Kite, when not in flight. Occupies less ground space. The ground station strength decides the length up to which the Kite can be tethered.
  11. 11. OPERATING PRINCIPLE Power generated by the energy kite can be given by, where, A- area of the kite wing CL- lift coefficient CD- drag coefficient VW- velocity of wind A ratio of lift coefficient to that of drag coefficient is the drag ratio. Initially the Kite is taken to a considerable height by the on board rotors attached to the Kite, which are powered by electricity from the ground station. When it reaches at suitable altitude, the Kite gets into its circular trajectory.
  12. 12. After this stage the same rotor generates energy when Kite gets into circular motion. Tether length plays an important role in setting diameter of rotation of the Kite. The total power Pwind that a flying wing extracts from this wind field is given by where, Fa- total aerodynamic force that the wing experiences - angle between the direction of this force and the wind
  13. 13. LIMITATIONS The non aerodynamic forces acting on the kite reduces the total usable power that can be harvested to a great extent. Kites come down when there is insufficient wind. Bad weather such as could temporarily suspend use of the machines. A prohibited airspace zone is required. During bad whether conditions, kite must be brought back down to the ground and covered.
  14. 14. ADVANTAGES Minimal effort in terms of a) generator structure. b)cost c)land occupation. Operates at significantly higher altitudes above the ground where stronger and more constant winds can be found and thus higher amounts of energy is generated.
  15. 15. COMPARISON WITH OTHER RENEWABLE RESOURCES Power generation of energy Kite is 150 times more than photovoltaic cell with much less land requirement. Power output of conventional wind turbines has increased at a cost of increase in rotor diameter as well as high cost to build such a huge structure. The mass of only 39 tons of Energy Kite generate 30 MW with wing area of 845msq. This equals to power output of four largest wind turbines in the world each with a rated power output of 7.5MW
  16. 16. Each Blade has a weight of 65 tons and a rotor diameter of 126 meter. Hence total weight of twelve blade of these four turbines goes to 780 tons. Including the weight of the tower total weight goes up to 12,400 tons.
  17. 17. SUMMARY Use of Energy Kites opens a new world of opportunities in the field of wind power generation by making complete use of air at high altitude too. If such technology is implemented on a large scale, the use of power plants that burn out conventional resources could be decreased to a great extent, thereby decreasing air pollution. Use of this clean energy will decrease the rate of global warming significantly.
  18. 18. REFERENCES on-renewable.html conventional-and-nonconventional-sources-explained/292 non-conventional-sources-of-energy.html vantages.aspx disadvantages-of-renewable-energy.php
  19. 19. THANK YOU