Wind Energy Resource and Technologies

Transcription

1 Wind Energy Resource and Technologies Dr. Ram Chandra DBT s Energy Bioscience Overseas Fellow Centre for Rural Development and Technology Indian Institute of Technology Delhi Hauz Khas, New Delhi

2 58.3 GW Renewable Energy Scenario (16% share) Wind 33.0 GW (58.8%) Small hydro 4.2 GW (7.2%) Solar PV 13.0 GW (22.3%) Biomass 8.0 GW (13.7%) Waste to energy 0.13 (0.2%) 2

3 Wind Energy Wind possesses energy by virtue of its motion. Wind speed increases with height. The measurement of wind speed is done at a standard height of 10 m. The wind speed at surface is nearly % lower than that at standard height. At a height of 60 m wind speed may be % higher due to reduction in the drag effect of the earth s surface.

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5 FPM- 107 Three factors determine the power output from a wind energy converter: 1) Wind speed 2) Cross sectional area of wind swept rotor 3) Overall conversion efficiency of the rotor, transmission system and generator or pump

6 Horizontal Axis Wind Turbine

7 Verticle Axis Wind Turbine 7

8 The Energy Extracting Stream-tube of a Wind Turbine

9 Continued The power in wind can be computed by using the concept of kinetics. Wind mill works on the principles of converting kinetic energy of the wind into mechanical energy. Power = Work done/time (J/sec = Watt) Kinetic Energy = ½ (mv 2 ) 1 The amount of air passing in unit time, through an area, A with a velocity = AV Then, m = ρav.2 (ρ air = kg/m 3 )

10 Continued Thus, K. E. = ½ (ρav 3 ).3 Then, Power Available in wind, P a = ½ [ρ(π/4)d 2 V 3 )...4 P a = 1/8[ρπD 2 V 3 ]...4a The fraction of the free flow wind power that can be extracted by the rotor is called POWER COEFFICIENT. Power Coefficient = [Power of Wind Rotor/Power Available in the Wind)

11 Continued The maximum theoretical coefficient is equal to 16/27 or For the best practical rotor, the power coefficient is about The factor is known as the BITZ LIMIT (after the name of the engineer who first derived this relationship)

12 WIND FARM 132KV/33KV 33KV/690V GRID Line feeder Wind generator

13 WIND DATA Surface wind data on a national or regional basis is usually presented in the form of: 1: Isovents: are contours of average wind velocity (m/s or km/h). The average period varies widely but monthly, quarterly, and yearly averages are common. 2: Isodynes: are contours of constant wind power (W/m 2 of area perpendicular to the wind flow).

14 Wind Survey: Typical wind measurements at potential sites for wind machines usually requires the following: (1)Instrumentation: 3 cup anemometer and wind direction sensors, height of instruments, 10 m for preliminary data, m for long time data. (2) Data Recording System: Strip chart, magnetic tape. (3) Type of Data: Wind speed and hourly direction. (4) Data Reporting: Wind frequency curves daily, weekly, monthly, energy estimation are basic wind data.

15 Annual hours or duration of various wind speed associated with design of wind mill. 1.Cut in speed: The speed below which the wind mill does not work. 2. Design Speed: The speed for which rotor is designed. 3. Furling Speed: The speed at which the rotor is turned away from facing the wind or stopped otherwise, with a view to protect the wind mill. 4. Rated Velocity: At which the plant output is maximum.

16 YAW CONTROL The area of the wind streams swept by the wind turbine is maximum, when blade face into the wind. This is achieved by control arrangement, in which when the wind direction changes, a motor rotates the turbine slowly about the vertical (or yaw) axis so as to face the blades into the wind.

17 Cut-in speed (V in ) Rated speed (V full ) Cut-out speed (V out )

18 Advantages of Wind Power 1. The wind is free and with modern technology it can be captured efficiently. 2. Once the wind turbine is built the energy it produces does not cause green house gases or other pollutants. 3. Although wind turbines can be very tall each takes up only a small plot of land. This means that the land below can still be used. This is especially the case in agricultural areas as farming can still continue. 4. Many people find wind farms an interesting feature of the landscape. 5. Remote areas that are not connected to the electricity power grid can use wind turbines to produce their own supply. 6. Wind turbines have a role to play in both the developed and third world. 7. Wind turbines are available in a range of sizes which means a vast range of people and businesses can use them. Single households to small towns and villages can make good use of range of wind turbines available today. 18

19 Disadvantages of Wind Power 1. The strength of the wind is not constant and it varies from zero to storm force. This means that wind turbines do not produce the same amount of electricity all the time. There will be times when they produce no electricity at all. 2. Many people feel that the countryside should be left untouched, without these large structures being built. The landscape should left in its natural form for everyone to enjoy. 3. Wind turbines are noisy. Each one can generate the same level of noise as a family car travelling at 70 mph. 4. Many people see large wind turbines as unsightly structures and not pleasant or interesting to look at. They disfigure the countryside and are generally ugly. 5. When wind turbines are being manufactured some pollution is produced. Therefore wind power does produce some pollution. 19

20 Thank You