1. Wind Energy

2. started with simple, light devices by aerodynamic drag forces, then to heavy, material-intensive drag devices earliest known use of wind power is sail boat, then windmills earliest known design of the windmill is vertical-axis developed in Persia about 500-900 A.D. most scienic and successful applicants of windpower is the use of water pumping machines on island of Crete original heyday of wind in United States was between 1870 and 1930 thousands of farmers all around the country used wind to pump water started off as small electric wind turbines in rural areas around the 1920's larger machines were built around the 1940's interest in wind power decreased when effiecent methods were made, but then came back during energy crisis in the 1970's boost for wind developement was provided in early 1990's due to improvements in technology which led to an increase in turbine reliability and lower costs of production History of Wind Power

3. How Wind Power Works when sun heats up an area of land, the air around that land mass absorbs the heat once at a certain temperature, the hotter air begins to rise very quickly because a given volume of hot air is lighter than an equal volume of cooler air particles moving faster exert more pressure than slow-moving particles rotor blades- blades that are the sails of the system; act as barriers to the wind shaft- connected to the center of the rotor; when rotor spins, shaft also spins so the rotor transfers its mechanical rotational energy to the shaft which then enters electrical generator at the other end generator- uses properties of electromagnetic induction to produce electrical voltage if wind speed doubles, then the power output increases eight times wind speeds are divided into seven classes (class 1 is the lowest, class 7 is the highest) wind turbines operate over a limited range of wind speeds if the wind is too slow, then there won't be enough power for it to run but if there is too much wind, then it will shut off to avoid being damaged

4. modern turbines use aerodynamic principles to capture wind's energy more efficiently two primary forces in wind-turbine rotors are lifts and drags turbine blades shaped like air plane wings comes in many different designs; big or small most common style is the "horizontal axis design" this turbine has 2 or 3 blades that spin upwind of the tower that it sits on small wind turbines are used for providing power off the grid Turbine Aerodynamics

5. Information About Wind Energy one of cleanest, most sustanable ways to generate electricity doesn't produce toxic emissions and no heat trapping emissions that contribute to global warming fastest growing source of electricity in the world 2008-more than 27,000 megawatts new were installed worldwide form of solar energy caused by uneven heating of atmosphere by the sun, irregularities of earth's surface, and rotation of the earth wind flow/motion energy can be used to generate electricity