provides information on forces that create wind, types of turbines and some of the environmental problems associated with wind farms

1. Please take the time to check your audio connection by going to tools >> audio >> audio setup Welcome to our program on the environment. Live Earth Talk – Nov. 11 th ,2009

2. Live Earth Talk – Nov. 11 th , 2009

3. Wind and the controversies of Wind Power

5. The change in pressure measured across a given distance is called a " pressure gradient ". The pressure gradient results in a net force that is directed from high to low pressure and this force is called the " pressure gradient force ". Live Earth Talk – Nov. 11 th , 2009

6. The closer the isobars or height contours, the greater the PGF magnitude . Larger PGF result in stronger winds, so strong winds are associated with closely spaced contour lines . PGF points at a right angle to the local isobar or height contour line . It also points from high pressure to low pressure (or high heights to low heights) . Live Earth Talk – Nov. 11 th , 2009

11. Live Earth Talk – Nov. 11 th , 2009

12. An 'ideal' location for a wind turbine would have a near constant flow of non-turbulent wind throughout the year and would not suffer too many sudden powerful bursts of wind. Live Earth Talk – Nov. 11 th , 2009

13. Power produced by a turbine is a function of: Air density Cross sectional area Cube of the wind velocity Rough Estimate of Electricity Produced at a site: Annual Electricity = K V m 3 A t T K = 3.2 a factor depending on the turbine V m = mean wind speed m/s A t = area swept out by turbine T = Number of turbines Live Earth Talk – Nov. 11 th , 2009

14. An average wind speed value for a given location does not alone indicate the amount of energy a wind turbine could produce there. To assess the climatology of wind speeds at a particular location, a probability distribution function is often fit to the observed data. Different locations will have different wind speed distributions. Distribution of wind speed (red) and energy (blue) for all of 2002 at the Lee Ranch facility in Colorado. The histogram shows measured data, while the curve is the model distribution for the same average wind speed. Because so much power is generated by higher wind speed, much of the average power available comes in short bursts. The 2002 Lee Ranch sample is telling; half of the energy available arrived in just 15% of the operating time.

15. As a general rule, wind generators are practical where the average wind speed is 10 mph (16 km/h or 4.5 m/s) or greater.

16. Live Earth Talk – Nov. 11 th , 2009

17. http://www.evac.ou.edu

18. At the end of 2008 the worldwide capacity of all wind turbines was more than 121 gigawatts, which represents around 1.5% of all electricity use in the world. There is an inherent problem with wind power: It's not always there when you need it A key issue in the application of wind energy to replace substantial amounts of other electrical production is intermittency Live Earth Talk – Nov. 11 th , 2009

23. In addition to saving on carbon dioxide emissions, production of energy from wind turbines does not produce sulfur dioxide, mercury, particulates, or any other type of air pollution, as do conventional fossil fuel power sources. However, during manufacture of the wind turbine, steel, concrete, aluminum and other materials will have to be made and transported using energy-intensive processes, generally using fossil energy sources. Live Earth Talk – Nov. 11 th , 2009

24. An estimated 2.3 million people worldwide currently work either directly in renewables, or indirectly in supplier industries: solar thermal industry: at least 624,000 people wind power industry ~440,000 solar PV industry 170,000 biomass and biofuels sector more than 1 million small-scale hydropower 39,000 Geothermal 25,000 Wind industry jobs in the U.S. jumped to 85,000 in 2008 (70% increase from 2007), according to a report released from the American Wind Energy Association. The U.S. coal industry employs about 81,000 workers. (from a 2007 U.S. Department of Energy report but coal employment has remained steady in recent years though it's down by nearly 50% since 1986.)

31. Small wind systems British Wind Energy Association has put together a guide for home wind power: http://uk.oneworld.net/external/?url=http%3A%2F%2Fwww.bwea.com%2Fpdf%2Fbriefings%2Fsmallsystems.pdf http://www.awea.org/ http://www.nrel.gov/wind/ Other useful websites on wind power: Live Earth Talk – Nov. 11 th , 2009

32. Continue the discussion in Ning http://goapes.ning.com Live Earth Talk - Sept. 9, 2009

33. Presentation and Session Recording http://liveearthtalk.wikispaces.com Live Earth Talk – Nov. 11th, 2009