1. Wind Power It’ll Blow You Away

2. History of Wind Power Sailboats and other sailing stuff: 5,500 years ago Sinhalese uses monsoon winds to heat steel smelting furnaces up to 1200 o C in 300 B.C. Wind turbines used in Persia in 200 B.C. and Rome in 250 A.D. First practical windmills built in Afghanistan in 7 th c. A.D. First windmill for electricity: Scotland 1887 By 1900 there were about 2500 windmills in Denmark that supplied a combined 30 MW 1927: Jacobs brothers open a factory in MN that specializes in making windmills for out-of-the way areas such as Africa and Antarctica First MW-sized windmill (right): Vermont 1941 1970s: NASA leads research in wind power, comes up with 4 new major types of wind power design 2008: Rock Port, Missouri, is first U.S. city to receive 100% of its energy from the wind

3. Wind Energy (causes) The uneven heating of the sun on the Earth and the high specific heat of water results in an atmospheric convection current. Most wind energy is found at high altitudes (stratosphere) where wind speeds average ~ 100 mph. Remember, hot air rises, cool air sinks, etc.

4. Potential The estimated total amount of wind energy available is 72TW. Earth currently uses about 15TW of power from ALL sources. However, a number of limiting factors prevent this idealized # from ever being realized.

5. Calculation of Wind Power The WPD (wind power density) is calculated as the – Elevation about ground level/period of time – It is essentially the force of the wind at any given location. – It uses the worldwide trend that the higher one is, the faster the wind speed will be at that particular location. – F=ma (wind velocity and mass are taken into account)

6. Capacity Factor Wind speed is NOT constant Multiplying the supposed yield from a certain generator by the number of hrs in a year is not a true reading of annual power output. The ratio of actual, measured productivity to this theoretical maximum is the capacity factor. If the capacity factor is 25% for a 1MW turbine, then annual yield is – 1MW*(.25)*24*365=2190MW per year

7. Non-Dispatchable Power Wind power comes in sporadic bursts, so all available power must be taken out whenever it can. Something like hydropower would have to be a constant supply ready to back up the wind power system.

8. HAWTA FUNCTIONALITY/BENEFITS The most recognizable wind turbine is the Horizontal Axis Wind Turbine (HAWT) A main rotor shaft and electrical generator are placed at the top of the tower Small turbines use wind vanes to point them in the right direction, whereas larger turbines use a wind sensor and a servo motor. Most wind turbines are upwind of the tower. This is because turbulence from the tower would hinder the efficiency of a downwind machine. HAWTs have variable blade pitch, which allows for optimum efficiency HAWTs can be built higher to take advantage of wind shear and improve efficiency HAWT blades always move perpendicularly, so there are no reciprocating actions However, transporting turbine parts can be costly because of their large size; transportation costs may comprise up to 20% of equipment costs HAWTs also require a yaw control mechanism to turn blades toward the wind

10. VAWT Functionality/Benefits Vertical Axis Wind Turbines (VAWTs) are oriented vertically so that no yaw is needed Same basic premise as HAWTs, but oriented differently “Eggbeater” (Bottom right) turbines spin around their axes, not through their axes “Gyromills” (Bottom center) have straight, not curved, blades Aren’t as high as HAWTs, so shipping and installation is easier Lower wind startup speeds than HAWTs, but weaker winds used More difficult to change parts in a VAWT

11. Windbelt Invented by Shawn Frayne (winner of 2007 breakthrough award in PM), the device uses aero elastic flutter to vibrate a piece of material. Two magnets attached at its ends pass through metal coils, generating electricity. – http://www.youtube.com/watch?v=paxI4y_WmZI http://www.youtube.com/watch?v=paxI4y_WmZI

12. “Greenness” Wind power consumes no fuel and gives off no negative emissions EPBT of about 9 months Danger to birds and bats (about 1 bird per turbine per year) Although wind farms take up large tracts of land, up to 99% of the land may be used for other things simultaneously (such as agriculture) Energy Return on Investment (EROI) is about 5 to 35 for most windmills, depending on size Leaking lubricating oil may contaminate nearby drinking water Analysis of seabed geology, marine mammals, and birds finds little detrimental effects to offshore turbines Falling ice, brake failures, and improper construction can lead to small numbers of deaths

13. T-SHIRTS GE LOGO? Other designs? Colors? Sizes? Companies?