Sustainable Energy
2nd Edition
ISBN: 9781337551663
Author: DUNLAP, Richard A.
Publisher: Cengage,
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A large commercial wind turbine has a blade span of 100 m and tower (4 m diameter uniform) height of 150 m high (hub height above the ground). If the combined turbine-generator efficiency of 40%, wind speed of 15 km/h and the air density 1.2 kg/m3 (disregard frictional effects on the mast) determine the following:a) Electrical power generated by the turbine (in MW).b) Total horizontal force (kN) exerted by the wind on the supporting mast of the turbine and the distance (m) of this resultant force from the ground. Assume uniform tower diameter throughout the height.c) What will be the electrical power generated (in MW) when the wind speed is 30 km/h
Two sites are being considered for wind power generation. In the first site, the wind blows steadily at 7 m/s for 3000 hours per year, whereas in the second site the wind blows at 10 m/s for 2000 hours per year. Assuming the wind velocity is negligible at other times for simplicity, determine which is a better site for wind power generation. Hint: Note that the mass flow rate of air is proportional to wind velocity.[take the density of air to be ρ = 1.25 kg/m3]
1. On a particular day, the wind speed is 2 m/s at a height of 10 m. Estimate the wind speed at heights of 100 m and 300 m if the power law exponent on the velocity profile is 0.15 (level ground, little cover). Repeat the estimates for an exponent of 0.4 (urban area). 2. The wind speed over an urban area is 10 m/s at a height of 10 m. Estimate the wind speed at a height of 30 m.
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