The option of generating electricity without using fuel has undeniable appeal. According to the American Wind Energy Association, increasing this nation's capacity to produce electricity from wind energy by 20% before 2030 would result in a cumulative total reduction in greenhouse gases of 7,600 pounds of CO2. It would reduce water consumption by 4 trillion gallons. It would lower the price of natural gas by 12% and establish 30,000 direct manufacturing jobs. Lease payments to landowners would add over $600 million to struggling local economies, especially in rural communities, and bring in tax revenue over $1.5 billion annually by 2030. Perhaps best of all, wind power cannot be used up.
Wind is the fastest growing energy source in the world and one of the lowest priced renewable energy technologies today, at a cost of 4-6cents per killowatt hour. Leasing land to wind energy companies can bring in revenue for farmers and ranchers while still allowing them to use their land for agricultural purposes.
The generation of electricity from wind power takes place in several steps. It requires a rotor, usually consisting of 2-3 blades, mounted atop a tower; wiring; and "balance of power" components such as converters, inverters and batteries.
The wind pushes the rotor blades, converting kinetic energy to rotary motion. This spins a low-speed shaft, which turns a gear at the lower end. The gear in turn drives a smaller gear on a high-speed shaft that runs through a generator housing. If this is difficult to picture, take a look at the Department of Energy page, http://www.1.eere.energy.gov/windandhydro/wind_anima tion.html
A magnetic rotor on the high-speed shaft spins inside loops of copper wire that are wound around an iron core. This creates "electromagnetic induction" through the coils and generates an electric current. The current must be regulated for the strength of current desired (110 w in the US for household AC current). It is then fed into a grid or routed into a battery bank for later use.
All of this, of course, depends on having wind speed in the correct range, usually 10 - 30 mph. The reason for 100 ft towers is that the wind is stronger and less turbulent at that height from the ground. Wind turbine blades turn at a speed of 10-50 revolutions per minute, and are equipped with regulators that shut the system down during hazardous weather to avoid having them spin out of control.
Turbines will generally last for around 120,000 hours, or about 20-25 years. Since they have moving parts, they require maintenance and repair, at a cost of about 1 cent per killowatt hour produced, or 1-2% annually of the original cost of the turbine.
In the United States, General Electric is the leading producer of wind turbines and has established a global renewable energy headquarters in Schenectady, NY that established 650 new jobs. The potential of renewable energy to produce jobs and support a burgeoning economy well into the future cannot be ingnored.
References and further information:
http://www.1.eere.energy.gov/windandhydro/wind_anima tion.html
http://www.greenlivingtips.com