WIND ENERGY THE NEW ALTERNATIVE By James Washechek

WIND ENERGY: THE NEW ALTERNATIVE By James Washechek Department of Chemical Engineering, The University of Texas at Austin

DESCRIPTION OF WIND TURBINES Converts wind kinetic energy into electrical power Numerous industrial turbine designs, for example horizontal and vertical axis wind turbines Clean energy alternative, with little to no environmental impact Affects environmental aesthetic integrity, some migratory bird patterns, and downwind velocity.

HISTORY OF WIND POWERED TURBINES 200 B. C. – Wind powered machines utilized by Persians. 1888 – Charles F. Brush developed first energy producing windmill in Cleveland, Ohio. 1980 s - First modern wind turbines were constructed. Past 20 years – Newer, better designed wind turbines have been developed.

FUTURE WIND ENERGY CAPACITY Increasing exponentially 3 to 5 times larger energy capacity over next 6 years 20% of electrical energy supplied by wind energy by 2030 World Wind Energy Capacity Approximation (Wiki, 2008)

TURBINE POWER Directly proportional to density of air, area of rotor blades, and cube of velocity Efficiency of internal parts affects maximum power available Limited to 59% maximum efficiency where, P = power (W) α = design efficiency factor ρ = density of air (kg/m³) r = radius of wind turbine (m) v = velocity of wind (m/s)

COMPARISONS TO OTHER ENERGY SOURCES Environmentally friendly Large resource supply Cheap operating costs, 1 cent/k. W·hr Wind vs. Wind – $55. 80/MWh Coal – $53. 10/MWh Natural Gas – $52. 50/MWh Coal Natural Gas

HORIZONTAL AXIS WIND TURBINE (HAWT) Horizontal Axis Wind Turbine Design Most common industrial design today Wind sensors to rotate tower in yaw direction Many found in West Texas where wind velocities are high

HAWT ADVANTAGES AND DISADVANTAGES Advantages Variable wind pitch to optimize amount of wind absorbed. Able to increase height of tower to harness higher wind velocities at higher altitudes. Already the major design for industrial wind power generation. Disadvantages Inefficient close to ground level due to turbulence Must be large scale making expensive construction costs Must be comprised of strong materials (carbon fiber and steel) to deal with high winds

VERTICAL AXIS WIND TURBINE (VAWT) Gearbox and generator at base of vertical rotor shaft. Utilizes wind flow in all directions (360°). Constructed on buildings to avoid ground level turbulence. Vertical Axis Wind Turbine Design

VAWT ADVANTAGES AND DISADVANTAGES Advantages Cheaper due to less height needed for effective operation. No motor is needed to turn rotor blades. Routine maintenance easy due to components being situated under vertical rotor shaft Little chance of structural failure Disadvantages Create only half the amount of energy of a comparable HAWT Cannot harness higher winds at higher altitudes due to smaller height. Complete deconstruction for maintenance.

CONCLUSIONS Horizontal axis wind turbine the preferred design for future industrial use. Future efforts in wind energy technology. Combination of wind energy with current energy infrastructure. Airborne Wind Generator

REFERENCES Hansen, Martin O. L. Aerodynamics of Wind Turbines, 2 nd Ed. Publications Ltd, January 2008. Earthscan Hau, Erich and H. von Renouard. Wind Turbines: Fundamentals, Technologies, Application, Economics, 2 nd Ed. Springer, 1, 2005. October Mc. Cabe, W. L. and J. C. Smith. Unit Operations of Chemical Engineering, 7 th Ed. Mc. Graw-Hill, New York. Ragheb, M. “Theory of Wind Machines, Betz Equation. ” 16 Nov. 2008 <https: //netfiles. uiuc. edu/mragheb/www/NPRE%20498 WP%20 Wind%20 Power%20 Systems/Theory%20 of%20 Wind%20 Machin es%20 Betz%20 Equation. . pdf>. "Wind Power. " Wikipedia: The Free Encyclopedia. 10 Nov. 2008 <http: //en. wikipedia. org/wiki/Wind_power>. "Wind Turbine. " Wikipedia: The Free Encyclopedia. 17 Nov. 2008 <http: //en. wikipedia. org/wiki/Wind_turbine>.