How Wind Energy is Converted to Electricity Using a Wind Turbine
Ever wonder how wind energy is converted to electricity using a wind turbine? The process is not as complex as you might think. There are variables with wind energy that are not common to other processes associated with creating electricity.
Wind is variable and is caused when the sun heats the earth's atmosphere. The surface of our planet is not flat and uniform. There are oceans and mountains and huge valleys that affect how freely wind flows.
The flat surface of the oceans allows more even heating by the sun and that heated air flows onshore naturally. This creates wind patterns and the earth's uneven terrain disperses the solar energy from the sun in wind. This can be a gentle breeze off the ocean or a gale whipping through the plains. Wind is energy in motion and a wind turbine is used to harvest that energy.
How a Wind Turbine Works
The blades on a modern wind turbine resemble helicopter propellers as they are long and thin. In operation, a wind turbine is almost a direct opposite of a fan. Where a fan uses electricity to blow air that cools you off on a hot day, a wind turbine pulls in wind to make electricity.
The force of the wind causes the blades of a wind turbine to turn. This spins a shaft attached to the blade assembly and the shaft powers a generator that creates electricity.
To understand how wind energy is converted to electricity using a wind turbine you should know the basic of how a turbine works. A horizontal turbine has a blade or rotor that spins and a drive train that includes a generator and a gearbox. This turbine is supported by a tower and attached to cables and controls to connect the equipment and transmit the electricity produced.
A wind farm is a collection of towers that are placed into a group pattern to form a single power plant to generate large amount of electricity from wind power. The electricity is then routed through the grid of a local utility company and then distributed as electrical power to the customers on that grid. For the customers, the electricity works just the same as any power from a conventional power grid.
How much wind energy is converted to electricity using a wind turbine depends on the size and strength of the turbine. Wind turbines are assigned power ratings. A high rated wind tower can be as high as twenty stories and product enough power for a small town.
On a machine of this size, the blades are extremely large and may have a tip to tip span the size of a football field. This is a huge wind turbine that can provide power to as many as 1400 homes.
More commonly seen are utility scale turbines that stand approximately thirty feet tall on their towers. The propellers have a span of about twenty feet. This turbine can produce anywhere from 50 to 750 kilowatts of energy. One turbine of this size can provide full power for a small business or for an all-electric home.
On a smaller scale, wind energy is converted to electricity using a wind turbine that creates less than 50 kilowatts of power. These smaller wind towers are often used to power most of the systems in a single family home, to pump water from wells or for irrigation and for satellites dishes used by telecommunications companies.
Where the Wind Blows
The variable nature of wind energy can be a problem when locating wind farms. The land must be cleared as obstructions such as tall trees and buildings change the direction of the wind and can cause turbulence. Turbulent air is not easily captured and converted to electricity. The best wind energy is from steady winds that are blowing in straight directions.
Thus, most wind farms are located based on studies of wind patterns in the country. Areas of the most reliable winds are rated from 1-7 where one is a location where winds are light and wind energy unreliable. Wind turbines are best located in geographical areas rated 3 or higher on the scale.
Advantages and Disadvantages
Wind is a free and renewable resource. Wind energy is converted to electricity using a wind turbine without producing damage to the environment. However, the technology is expensive and the initial cost of a wind turbine or a wind farm can be quite high. Most of the cost is the machinery itself but about 20% of the investment is spent to prepare the land and install the wind turbine.
There is no radiation hazard, no chemical pollutants or waste runoff associated with wind energy converted to electricity using a wind turbine. No greenhouse gases are produced and a wind farm is not surrounded by smog as you might see where a fossil fuel power plant is located. Wind energy can be used to offset the pollution of automobiles and manufacturing.
Environmental concerns about wind energy are focused on the noise of the turbines and possible damage to bird species that might fly into the blades. These problems have been addressed in new turbine designs. Noise levels have been greatly reduced and slower propellers are easily seen and avoided by birds.
The other concern is the use of large areas of land for wind farm development. Until recently it was assumed that this land could serve no other purpose other than providing a base for wind towers. That has been proven false as livestock can be pastured in a wind farm and agriculture can be continued on the same land where wind turbines are installed.
Summary
A rather simple mechanical system is how wind energy is converted to electricity using a wind turbine. The basic process has been used for many years but recent technological advances have improved wind turbines. The result of many studies now allows us to build wind farms in areas where wind energy is most plentiful and to design towers to suit differing needs for electrical power.
The main concerns about wind turbines have been use of land and noise. New designs have reduced noise levels to a quiet hum and we now know that land surrounding wind towers can be used for pasture or agriculture without negative consequences.
