Wind Turbine
or
(WECS:Wind Energy Conversion System)
Site Selection Considerations
The power available in the wind increases rapidly with the speed, hence energy conversion machines should be located in areas where winds are strong and persistent.
Some of the main considerations are mentioned below:
1. High annual average wind speed:
To understand this let us try various approaches to estimate this aspect:
Calculation Of Wind Power
Calculate the power of the wind hitting your wind turbine generator
There are many complicated calculations and equations involved in understanding and constructing wind turbine generators however the layman need not worry about most of these and should instead ensure they remember the following vital information:
1) The power output of a wind generator is proportional to the area swept by the rotor - i.e. double the swept area and the power output will also double.
2) The power output of a wind generator is proportional to the cube of the wind speed - i.e. double the wind speed and the power output will increase by a factor of eight (2 x 2 x 2)!
The Power of Wind
1) The power output of a wind generator is proportional to the area swept by the rotor - i.e. double the swept area and the power output will also double.
2) The power output of a wind generator is proportional to the cube of the wind speed - i.e. double the wind speed and the power output will increase by a factor of eight (2 x 2 x 2)!
The Power of Wind
Wind is made up of moving air molecules which have mass - though not a lot. Any moving object with mass carries kinetic energy in an amount which is given by the equation:
Kinetic Energy = 0.5 x Mass x Velocity2
where the mass is measured in kg, the velocity in m/s, and the energy is given in joules.
Air has a known density (around 1.23 kg/m3 at sea level), so the mass of air hitting our wind turbine (which sweeps a known area) each second is given by the following equation:
Mass/sec (kg/s) = Velocity (m/s) x Area (m2) x Density (kg/m3)
And therefore, the power (i.e. energy per second) in the wind hitting a wind turbine with a certain swept area is given by simply inserting the mass per second calculation into the standard kinetic energy equation given above resulting in the following vital equation:
Power = 0.5 x Swept Area x Air Density x Velocity3
where Power is given in Watts (i.e. joules/second), the Swept area in square metres, the Air density in kilograms per cubic metre, and the Velocity in metres per second.
Read World Wind Power Calculation
The world's largest wind turbine generator has a rotor blade diameter of 126 metres and so the rotors sweep an area of π x (diameter/2)2 = 12470 m2! As this is an offshore wind turbine, we know it is situated at sea-level and so we know the air density is 1.23 kg/m3. The turbine is rated at 5MW in 30mph (14m/s) winds, and so putting in the known values we get:
Wind Power = 0.5 x 12,470 x 1.23 x (14 x 14 x 14)
...which gives us a wind power of around 21,000,000 Watts. (Yes, 21MW)
Remember, Anemometer data is normally based on wind speed measurements from a height of 10m.
Strategy for siting generally comprises of
(i) Survey of historical wind data.
(ii) Contour map of terrain and wind are consulted.
(iii) Potential sites are visited.
(iv) Best sites are instrumented for approximately one year.
(v) Choose optimal data.
2. Availability of anemometer data:
The principle object is to measure the wind speed which basically determines the WECS output power, but there are many practical difficulties with instrumentation and measurement methods. E.g. the anemometer height above the ground, accuracy, linearity, location on the support tower, shadowing and inaccurate readings therefrom, icing, inertia of rotor, whether it is measuring the horizontal or vertical velocity component, temperature effects.
Anemometer data should be available over some time for each proposed spot before a siting decision is made.
3. Altitude of the proposed site.
It affects the air density and thus the power in the wind, and hence the useful WECS electrical output.
Also, as is well known, the winds tend to have higher velocities above ground.
4. Terrain and its aerodynamics
5. Local Ecology
Birds life specially effected by the wind turbine so chose that place where bird life is less as land also favor for wind turbine.
Birds life specially effected by the wind turbine so chose that place where bird life is less as land also favor for wind turbine.
6. Distance to Roads or Railways
Less distance from roads because easily provide Electricity there. Depend on the air calculation but its necessary.
Less distance from roads because easily provide Electricity there. Depend on the air calculation but its necessary.
7. Nearness of sites to local center/users.
For easily provide electricity to the near users.
For easily provide electricity to the near users.
8. Nature of ground.
Nature of ground should be not agriculture land. A damaged area of land or by air calculation if fit to place wind turbine than that place is better.
Nature of ground should be not agriculture land. A damaged area of land or by air calculation if fit to place wind turbine than that place is better.
9. Favorable Land Cost.
10. Other Conditions.
Other is Water turbine also provide good product of electricity.
Other is Water turbine also provide good product of electricity.
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