What is Wind Energy?
Wind energy (or wind power) refers to the process of generating electricity using wind or naturally occurring air flow in the atmosphere of the earth. Modern wind turbines are used to extract kinetic energy from the wind and generate electricity.
There are three main types of wind energy:
a) Grid-scale wind: Wind turbines ranging from 100 kilowatt to several megawatts, where electricity is transmitted to the grid of power transmission lines and distributed to the end user by electrical institutions or power system operators.
b) Distributed or “small” wind: Single small wind turbines below 100 kilowatt, which are used directly to power a home, farm or small business and are not connected to the mains.
c) Far coastal wind: These are wind turbines that are usually located on the continental shelf and planted under water with their large bodies. These turbines are larger than land based turbines but provide more power.
How do wind turbines work?
When wind breezes pass into a wind turbine, the propeller blades hold the wind’s kinetic energy, direct it, and convert it into mechanical energy. This turn turns into an internal shaft connected to the gearbox, which increases the speed of the rotation by a factor of 100. This turns into a generator that generates electricity.
Steel pipe towers, which usually stand at least 80 meters (262 feet) in length, support the center with 3 interconnected propeller blades and a closed part that includes the shaft, gearbox, generator and controls. Wind measurements are collected to turn the turbine to steer and face the strongest wind and capture the energy of the angle or the tilt of the propellers and make the best use of it.
A typical modern turbine, known as the cutting speed, will start generating electricity when the wind speed reaches 6 to 9 miles per hour. If the wind blows too hard (roughly 55 miles per hour), the turbines will be disabled to prevent damage to the equipment. For a year, modern turbines can generate over 90 percent of usable electricity.
For example, if the wind in a turbine reaches a cutting speed of six to nine miles / hour, the turbine starts generating electricity. Electricity production increases as wind speeds increase.
Another common measure of wind power generation is called the capacity factor. This measures the amount of electricity a wind turbine generates in a given time (typically one year) based on its maximum potential.
For example, suppose the maximum theoretical output of two megawatts of wind turbines in a year is 17,520 megawatts-hours (twice 8,760 hours, the number of hours in a year). However, the turbine could only produce 7,884 megawatt hours throughout the year, because the wind was not always blowing hard enough to produce the maximum amount of electricity the turbine could produce. In this case, the turbine has a 45 percent (7.884 divided 17,520) capacity factor.
Remember, this does not mean that this turbine produces only 45 percent of electricity. Modern wind farms generally have more than 40 percent capacity factors,
Windmills and Wind Turbines
Sometimes people use the terms “pinwheel” and “wind turbine” interchangeably, but there are important differences. People have been using windmills for centuries to grind grain, pump water, and do other things. Windmills produce mechanical energy but not electricity. In contrast, modern wind turbines are highly developed machines with more than 8,000 parts that use the kinetic energy of the wind and convert it into electricity.
What is a wind farm?
Often, a large number of wind turbines, called a wind project or wind farm, are built close together. A wind farm functions as a single power plant and sends electricity to the grid.
How does wind energy reach you?
Turbines in a wind farm are connected so that the electricity they produce can switch from the wind farm to the power grid. When wind power is in the main power grid, electrical services or power operators send electricity to where people need it.
Smaller transmission lines, called distribution lines, collect the electricity generated in the wind project and carry it to larger “network” transmission lines where electricity can go where needed over long distances. Finally, smaller distribution lines transmit electricity directly to your city, home or business.