FAQ Wind Power
FAQ Wind Power
What is wind energy?
Wind energy is the use of the wind as an energy source. A wind energy system transforms the kinetic (moving) energy of the wind into mechanical or electrical energy that can be harnessed for practical use.
Mechanical energy: Wind energy can be harnessed by sails for transportation (sailboats) and other purposes such as grinding grain and pumping water. In the United States, some six million mechanical windmills were in operation in the late 1880s until about 1935, helping homesteaders and farmers to settle the West. Mechanical wind energy is most commonly used today for pumping water in rural or remote locations.
Electrical energy: Harnessing the wind for electricity generation is the most widespread use of wind energy today. Wind turbines, activated by the wind, generate electricity for homes, businesses, and for sale to utilities. In the U.S., use of wind for electricity generation by utilities is limited but growing. In 2002, less than 1% of U.S. electricity supply came from wind power. Some European countries get a larger share of their electricity from the wind (Denmark gets 20% of its total electricity supply from wind power, Germany 5%).
? How does a wind turbine work?
Horizontal-axis wind turbines are most commonly used today. The wind blows through blades, which converts the wind’s energy into rotational shaft energy. The blades are mounted atop a high tower to a drive train, usually with a gearbox, that uses the rotational energy from the blades to spin magnets in the generator and convert that energy into electrical current. The shaft, drive train and generator are covered by a protective enclosure called a nacelle.
Electronic and electrical equipment including controls, electrical cables, ground support equipment, and interconnection equipment control the turbine, ensure maximum productivity, and transmit the electrical current. Today’s utility-scale turbines can be 100 meters (over 300 feet) high or more.
? Electricity: how is it measured?
Electricity production and consumption are most commonly measured in kilowatt-hours (kWh). A kilowatt-hour means one kilowatt (1,000 watts) of electricity produced or consumed for one hour. One 50-watt light bulb left on for 20 hours consumes one kilowatt-hour of electricity (50 watts x 20 hours = 1,000 watt-hours = 1 kilowatt-hour). The average American household consumes about 10,000 kWh annually.
? How much does a wind turbine generate?
The output of a wind turbine depends on the turbine’s size or power rating, and the wind’s speed through the rotor. Wind turbines being manufactured now have power ratings ranging from 250 watts (for battery charging) to 10-kW (which can generate about 15,000 kWh annually, more than enough to power a typical household) to 1.8 megawatts (MW) or more?enough to power some 500 households
? Why wind power?
Wind power is a growing source of electricity generation today. Worldwide, wind is the fastest-growing energy source — installed generating capacity increased by an average 32% annually from 1998 to 2002. Its use is expanding because modern technology has reduced the cost by more than 80% since the first commercial wind turbines were installed in California in the 1980s (many of those wind turbines still work today, and can be seen in Palm Springs and Tehachapi in Southern California, and in the Altamont Pass outside San Francisco).
In areas with an excellent wind resource, it can sometimes be more affordable to get new power by building a wind farm than by building a coal, natural gas, or other type of power plant. In addition, wind energy is a clean, safe, and renewable (inexhaustible) power source.
? More information?
The Most Frequently Asked Questions About Wind Energy, a publication of the American Wind Energy Association, is a free guide to more information about wind energy, including wind energy basics, costs, potential, wind energy and the economy, wind energy and the environment, statistics, and much more.
Originally published here.
yoni levy