1. WIND POWER PORTER WESSON

2. WIND GENERATORS -A wind generator (wind turbine) works by capturing kinetic wind energy and converting it to electrical energy. -Wind turbines are used for different purposes based mainly on their size  Large turbines in “wind farms” produce electricity for cities.  Smaller turbines contribute energy to a community and sell extra energy back to the energy supplier.  Small-scale turbines are used to charge batteries.

3. How it all works  For a conventional horizontal-axis turbine:  Three wing-shaped blades are positioned facing horizontal to wind.  The blades create lift and spin.  Blades spin a rotor connected to a low-speed shaft.  Low speed shaft rotates between 30 and 60 rpm.  Gear box connects low-speed shaft to high- speed shaft.  High speed shaft rotates between 1000 and 1800 rpm.  High-speed shaft spins the generator.

4. Advantages & Disadvantages  Advantages:  Energy produced is:  Clean  Domestic  Sustainable  One of the cheapest renewable energy sources.  Isn’t a large disruption to the terrestrial environment.  Can be land, ocean or air based.  70-85% efficient.  Disadvantages:  Requires higher initial investments then non- renewable energy sources and is sometimes not cost effective.  Places that need energy don’t have good wind.  Auditory and visual concerns.  Potential hazard to avian environment  Terrestrial turbines only generate about 30% of their capacity factor. Off-shore is higher.

5. Disadvantages continued: Fairly self-explanatory…

6. Restricting factors:  Only spin at wind speeds higher than roughly 8mph.  Shut down at wind speeds greater than roughly 55mph due to the compromising of structure strength.  Generates peak power between the range of 25-55 mph.  Highest and most consistent wind speeds are generated at high altitudes.  Highest density air is found at low altitudes.

7. Wind Power Classification:

9. Other kinds of wind turbines: Vertical axis turbines

10. Different designs:

11. Wind Power Development:

13. Other developments:

14. The math behind it all:  The energy produced by a traditional horizontal axis turbine is given by the equation  Kinetic energy per unit time (E k /s) = ½ pAv 3  p = air density in Kg/m 3  A = turbine blades “sweep area” given by using the formula for area of a circle.  v = velocity of wind. Found by subtracting the velocity of the wind after passing through the turbine by the initial velocity of the wind. Given in m/s.  This equation is for the potential amount of power the turbine can generate. Since it is impossible for a turbine to perform at 100% efficiency, this equation only gives a theoretical answer.

15. PUT IT TO WORK!!!  1) How much power does a wind turbine with a blade length of 35 meters (which is typical industrial turbine size) snag from the windy wind moving at an initial velocity of 18 m s -1 with a constant density of 1.4 kg m -3 ? The velocity of the air immediately after passing through the turbine sweep area is 13 m s -1.

16. PUT IT TO WORK AGAIN!!!  2) DUH!! Wind turbines aren’t 100% efficient! Estimating that the efficiency of this turbine is 75%, calculate the electrical power created by the generator.

17. YOU BETTER HAVE DONE IT RIGHT!!!  1) 1.3 X 10 4 kW  2) 1.0 X 10 4 kW

18. WORKS CITED:  http://energy.gov/eere/wind/how-do-wind-turbines-work http://energy.gov/eere/wind/how-do-wind-turbines-work  http://environment.nationalgeographic.com/environment/global- warming/wind-power-interactive/ http://environment.nationalgeographic.com/environment/global- warming/wind-power-interactive/  http://www.alternative-energy-news.info/technology/wind- power/wind-turbines/ http://www.alternative-energy-news.info/technology/wind- power/wind-turbines/  http://www.reddit.com/r/worldnews/comments/1byje4/ontario_is_p utting_an_end_to_coalburning_power/ http://www.reddit.com/r/worldnews/comments/1byje4/ontario_is_p utting_an_end_to_coalburning_power/  http://www.smartplanet.com/blog/thinking-tech/wind-powers- future-may-soar-with-flying-wind-turbine/ http://www.smartplanet.com/blog/thinking-tech/wind-powers- future-may-soar-with-flying-wind-turbine/  http://www.globalwindday.org/faqs/how-efficient-are-wind- turbines/ http://www.globalwindday.org/faqs/how-efficient-are-wind- turbines/