Wind power or wind energy is the process that uses the renewable energy of wind to generate electricity. Human beings have used wind energy to generate power for many years now, from sails of a ship to floating wind turbines. All wind power generation occurs in a similar way: using the wind to turn a blade that is converted into a more useful process like moving a boat or generating electricity.
Where does wind come from?
Wind is the movement of air from high pressure areas to lower pressure areas. Earth’s changing temperatures affect air pressure, and higher temperatures cause higher pressure air. This is because higher temperatures make air molecules move faster and spread out, causing higher air pressure. The opposite is true, as air gets colder, the molecules move slower and the air pressure goes down. Since Earth’s warming and cooling is a naturally occurring process, wind and the energy we get from it is a renewable energy source.
History of wind energy
Humans have used wind energy for many centuries. Initially, wind energy was utilized to propel boats across bodies of water. Over time, we got better at capturing wind power and developed wind pumps and windmills to move water for farming and irrigation. Humans also developed windmills to capture wind energy and use it for other tasks like wood cutting in wind power sawmills. Today, with more reliable grid energy, the main use of wind energy conversion systems are to create a renewable source of power and send it to the local grid to power homes, businesses, and transportation.
How do we make electricity from wind energy
Wind turbines convert the kinetic energy from wind power into electrical energy. They do this by using the wind’s kinetic energy to turn their blades. The blades are attached to a driveshaft and spin the conductor coil in a generator. The generator uses the principle of electromagnetic induction to convert the mechanical energy into electrical energy (electricity). The electricity is then transmitted to the local grid via transmission lines.
Parts of Wind Turbines
Wind turbines have 4 main parts: Foundation, Tower, Nacelle, and Rotor. All 4 parts have a specific task in helping us convert renewable wind power into electricity. There are different types of each part depending on the application and installation, including onshore, offshore, fixed, and floating.
Wind turbine foundation
The foundation of a wind turbine is what supports the turbine and keeps it stable. Stability is important because any foundation movement will reduce the wind turbine’s efficiency. There are different foundations for different types of wind turbines: Onshore foundations, offshore fixed foundations, and offshore floating foundations.
Wind turbine tower
The tower of a wind turbine is a critical part as it connects the foundation to the electrical generating top of the turbine. The towers need to be strong enough to support the nacelle and rotor hundreds of meters in the air, and also sturdy enough to not be blown around by the wind that powers the turbine. The towers also hold the cables that connect the generator to transmission lines.
Wind turbine rotor
The rotor is the most recognizable part of a wind turbine. The modern wind turbines have a rotor diameter of hundreds of meters to help capture as much renewable wind energy per rotation. The rotors are manufactured to specifications based on the wind speed at the wind farm.
Wind turbine nacelle
The nacelle of a wind turbine is where the wind energy gets converted to electricity. The nacelle is connected to the rotor by a shaft. The rotor gives the shaft rotational energy, which is used to turn a coil in a generator that makes electricity. The nacelle also holds a gearbox that increases the rotational energy of the shaft to more effectively produce electricity.
Types of wind power
Wind blows all around us, so in theory we can harvest its power anywhere in the world. Of course, there are many factors that determine if it makes sense to have a wind farm in a location. The primary reason is that wind needs to be strong enough to move the large wind turbines and consistent enough to continuously produce electricity. There are two main types of wind power that meet these criteria: Onshore Wind and Offshore Wind.
Onshore wind
Onshore wind power is electricity generated by wind on land. These wind farms are typically found in lower population density areas, as the wind turbines are very large and can be quite loud. Onshore wind energy is one of the least expensive forms of energy since they have relatively low installation and maintenance costs.
Offshore wind
Offshore wind is a source of renewable energy powered by the wind gusts in the ocean. The offshore wind power is used to generate electricity in a wind farm made up of many wind turbines. The electricity is then sent via underwater electrical transmission lines to the shore where it is hooked up to the existing onshore electrical grid.
Benefits of wind energy
There is no doubt the world needs more sources of clean, renewable energy to power humanity. Compared to other sources of energy, like fossil fuels, wind power is one of the most useful forms of energy for many reasons:
Renewable: The wind will never stop blowing! Just like Earth will keep heating and cooling with every sunrise and sunset, the air pressures will change and wind will continue to blow.
Cost-Effective: Wind is free, so the only costs are building and maintenance costs. Once a wind farm produces electricity to pay for the installation costs, then it has paid for itself and will provide power at no further cost.
No Pollution: Wind energy does not involve combustion, or burning something to make power.
Negatives of wind power
As with any energy source, there are some downsides associated with using them. It is important to recognize and understand the positives and negatives of each source, and be able to effectively manage solutions to mitigate the negative effects. The majority of the negative impact of wind energy comes from the impact on the public and impact on the environment.
Public impact of wind energy
Just because wind farms do not pollute or radiate smells like power plants that doesn’t mean they are out of sight and out of mind to the general public. Wind turbines are very tall and not visually appealing, especially since they require significant space between them and they stand very tall. Also, the turbines are very loud as the large blades cut through air similar to a car driving on the highway.
Since wind farms are sometimes installed in populated areas, locals should take precautionary measures and maintain a safe distance in case of accidents such as a turbine breaking or falling apart. Also, it is important to keep aircrafts away from the turbines and not risk any collisions that may result in an accident. Similarly, in the ocean, offshore wind turbines can present obstacles for boats and other vessels. Environmental impact of wind energy
Environmental impact of wind energy
Although wind energy is a great renewable energy source and not a direct pollutant, it does have some negative impacts on the environment.
Land use: Onshore wind turbines take up a lot of space given their large diameter, and need to be adequately spaced out to avoid hitting each other. As a result, they span large distances to maximize wind capture and may require altering the local land for installation. For instance, approximately forty to seventy acres of land may be needed between 2 MW (MegaWatt) turbines.
Water use: Offshore wind turbines are in water, and have their own unique environmental impacts. They may disrupt local waterways and other bodies of water, and the downstream impacts may not be fully known.
Birds: Since wind turbines are in locations of high winds, they also are in the path of birds and other flying animals like bats. Unfortunately, there are many incidents where birds are killed by the rotors. To reduce bird and bat fatalities engineers and conservationists have begun analyzing the design of turbines. For example, research has shown that some turbine colors attract insects and therefore lure more predators. In an effort to protect and deter birds and bats some wind farms have begun painting their turbines with UV reflective paint.
Wildlife: Wind turbines may affect the local ecosystem where they are installed. Both onshore and offshore installation can lead to adverse environmental damages, harming wildlife and degrading habitats.