What is wind energy ?
What is Wind energy ?
Wind energy or wind power refers to the process of generating electricity using the wind. Generally, two terms are used regarding the harvesting the wind capacity, such as windmill and wind farm. The term windmill was used in the past for grinding grains, pump water from low elevation to higher elevation, mostly for irrigation and agricultural proposes. Today the term wind farm is used to generate electricity as described below:
Wind farm is a collection of wind turbines which are used to capture the wind’s kinetic energy and to convert it to mechanical energy with the help of big blades (fans) . Then this mechanical energy is sequentially converted to electrical energy by using converters. Finally, electricity is connected to the electricity network or used on the site.
Normally, a large number of wind turbines are built close together, which is referred to as a wind project or wind farm. A wind farm functions as a single power plant and sends electricity to the grid. Globally the wind energy is classified in three categories as follows:
Large scale: wind turbines that range in size from 100 kilowatts to several megawatts, where the electricity is supplied to the power grid and distributed to the end consumers by electric companies or power system operators.
Small scale: small wind turbines under 100 kilowatts that are used to direct power to a house, farm or small business, which are not connected to the electricity grid. In general, the wind turbines are installed either onshore (on land) or offshore (on sea). Typically, the onshore wind turbines have smaller production capacity in comparison with offshore turbines. The offshore wind turbines are installed on large bodies of water which are either fixed or floating, depending on feasibility.
Working mechanism of wind turbines:
When the wind blows towards a wind turbine, its blades capture the wind’s kinetic energy and rotate, turning it into mechanical energy. This rotation turns an internal shaft connected to a gearbox, which increases the speed of rotation by a factor of hundreds and finally it spins a generator that produces electricity.
Typically, the overall height of a wind turbine is around, or at least 80 meters (262 feet) from the ground level. Huge concrete foundations with tubular steel towers support a hub with three attached blades, which houses the shaft, gearbox, generator, and controls. Wind measurements are collected, which direct the turbine to rotate and face the strongest wind so that the blades capture the strong wind and produce maximum energy.
A typical modern turbine will start to generate electricity when wind’s speeds reach 9 to 15 kilometers per hour (kmph). Turbines will shut down if the wind is blowing too strong (approximately 88 kilometers an hour) to prevent equipment damage.
How wind energy gets to you
The wind turbines are collectively connected to the electricity grid. Afterwards, the electricity generated by the wind turbines travel long distance via different electrical distribution networks to reach the end users or consumers.
Smaller transmission lines, called distribution lines, collect electricity generated at the wind project and transport it to larger “network” transmission lines, where the electricity can travel across the long distances to the locations where it is required. Finally, smaller distribution lines deliver electricity directly to individuals, houses, communities, industries, etc.
WHAT ARE THE ENVIRONMENTAL BENEFITS OF WIND ENERGY?
Wind energy is abundantly, freely and readily available renewable energy source and capturing its power does not deplete our valuable natural resources. In fact, wind turbines can play a major role in producing clean and green energy, which ultimately reduce partially the effect of climate change. The Global Wind Energy Outlook projects that by 2030 wind energy will offset 2.5 billion tons per year of carbon dioxide. This is equivalent to taking 530 million cars off the road each year or avoiding the use of 4.6 billion barrels of oil globally. This would even offset emissions from 525 coal-fired power plants in one year.
The leading countries with maximum installed capacity are China, United States of America and Germany.
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