University of Tennessee EF 152 A 2. The Wind O Nator. Team A 2 7. Richard Ammons, Rachel Dunlap, Kayla Hughes, and Uchung Whang 12/2/2009

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1 1 University of Tennessee EF 152 A 2 The Wind O Nator Team A 2 7 Richard Ammons, Rachel Dunlap, Kayla Hughes, and Uchung Whang 12/2/2009

2 2 Abstract The main objective was to create a generator that was able to light a 3V LED light bulb utilizing wind energy. We used a rotational propeller-like device to convert the wind into usable energy, and with the magnetic generator, we were able to light the light bulb even though the efficiency of our wind-powered generator was calculated to be around 5%. Introduction Recently, wind energy has been a hot topic for environmentalists, politicians, scientists, engineers, and all of the inhabitants of the world alike. With enough energy to wipe out cities, flood nations, and carry plagues to vast reaches of the world, but also with enough energy to harmlessly allow families to enjoy a wonderful outing of kite flying, wind yields great power, and we were tasked to harness this great power. With only a 40 dollar budget (out of our own pockets), we were to utilize it to light a tiny LED light bulb. Simple! Although not as easy as we thought, through our evaluations of the project we can conclude with a number of if only possibilities to control even a small portion of this great power could be able to produce enough energy to light up the whole world. Background When we talk about wind energy, we are really referring to the release of energy caused by the movement of air. The heating of the atmosphere by the sun, the irregularities of the Earth s surface, and the rotation of the Earth all contribute to creating wind. Therefore, the environment plays an important role in effecting the wind ( People have known about the destructive power of wind for thousands of years, and they have been utilizing to power their day-to-day working lives and livelihoods. The usage of lift created by the wind helped sailors sail to the ends of the world on their sailboats, which later helped create windmills that helped farmers grind grain and pump water ( The exercise of trying to make well use of this force of nature doesn t just end at these primitive thoughts, but in the past thirty years, people are continually maximizing the electrical output capacities obtained from the wind. The concept of wind energy can be better grasped by looking

3 3 at the numbers in the following example provided by the American Wind Energy Association: The output of a wind turbine depends on the turbine's size and the wind's speed through the rotor. Wind turbines being manufactured now have power ratings ranging from 250 watts to 5 megawatts (MW). The average U.S. household consumes about 10,000 kwh of electricity each year.for example, a 10-kW wind turbine can generate about 10,000 kwh annually at a site with wind speeds averaging 12 miles per hour, or about enough to power a typical household. A 5-MW turbine can produce more than 15 million kwh in a year--enough to power more than 1, 400 households. Design and Process The conversion of wind energy into usable electricity for small generators like the ones we used in class involves the spinning of magnets and then the electricity caught from the magnetic wiring around the housing of the spinning magnets. For the process of our design, we can separate our wind turbine into 4 different parts. First, we needed a type of device to catch the wind usually a rotating turbine either in the horizontal or vertical axis. The wind turbine along the horizontal axis seemed the most logical because of the all of the blades constantly spinning with the oncoming wind, while the vertical turbines can only accept wind one blade at a time. Second, we needed a magnetic generator with a large enough magnet and a long enough string of coated magnetic wire to extract as much electricity as possible without causing hindrance to the spinning of the wind blades, and third, we needed an object to connect the first two items that will cause the magnets to spin along with the wind turbine. Fourth and finally, we needed a structure to hold everything in place as the wind is being collected and the power being generated.

4 4 The figure to left shows the basic aerodynamic principles of the wind turning the turbine ( Device Description Our concept was simple. First we made the generator using 600 ft of 30 gauge magnetic copper wire around a cardboard box-shaped housing that had two open ends on each side. We inserted four 1x2x5 cm ceramic magnets inside the opening, stuck an 8 cm nail through the center of the housing, and tied the ceramic magnets to the nail. The generator looks like the picture below.

5 5 Then, for the wind catching device, we obtained the fan blades from a box fan and stuck an 8cm nail through the center of it. We, then, connected the generator and the fan blades via hammering the 8 cm nails into a wooden dowel. Our main problem lied in the structure of the system that supported the newly made turbine. We used a vertical piece of plywood to support the fan, in which we inserted a PVC pipe to support the wooden dowel, and a horizontal piece of plywood as the base of the system to nail in part of a 2 x4 wooden piece that supported the generator. During our first attempt, we were able to light the light bulb, and later, we added some cool designs. Below is the finished product without the designs.

6 6 Analysis Equations: ρ = kg/m 3 V = 7.5 m/s Area = m 2 Power = 0.5(ρ)AV 3 η= efficiency = P generated = 2.7Volts P wind = (.5)(1.225kg/m 3 )(0.203m 2 )(7.5m/s) 3 = 52.4Volts η= efficiency = (2.7V/52.4V )(100)= 5.16% Since we used cardboard and PVC pipe to minimize friction due to rubbing, the horizontal force from the wind pushing our horizontal system should have caused a plethora of energy loss. The forces from friction were the nail spinning against the wire and the cardboard, the magnets against the cardboard, and the dowel on the PVC pipe. In order to reduce a good portion of the friction, we could have used a ball bearing system, which would have allowed a smoother rotation, but that was way out of our budget. We calculated our efficiency to be around only five percent, and this just proves that there is so much potential in what wind energy has to offer. If we were to minimize all of our energy loss, we could have lit up the whole classroom by using a single fan (on a high setting).

7 7 Bill of Materials Blade $ 3.00 Dowel $ 2.86 Ductape free Light bulb free Magnets $ 6.00 Nails free PVC pipe free Wire $ 6.00 Wood $ 1.53 Total $ Conclusion In the end, although not as efficient as we would have liked, we were able to make our generator pump out 2.6 volts, which was more than enough to light our 3 volts light bulb. With just 5% efficiency, wind energy proves to be far more powerful than we expected. By taking more measures in calculating the aerodynamics and mechanics of the generator, I think we could have been able to utilize more energy from the wind. Whether the conversion to wind energy can slow down global warming and spare the planet a couple of extra natural resources and years of life or whether wind energy is just so abundant that it is just too ignorant of us as inhabitants of this world to overlook, the proper steps are being taken by scientists and engineers everywhere to completely grasp this concept that is already at our fingertips. With our little light bulb we can conclude that the conversion of wind energy into electricity will not only light up our cities, streets, and homes but also the future.

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