When I was thinking about the concept of wind energy, the question of how the wind is actually converted into electricity came into my mind. So, I took some time to research the energy conversion process of wind turbines to learn how they work internally.
How is wind energy converted to electricity? The blades on a wind turbine automatically spin when they come in contact with the wind. The kinetic energy that is taken from the wind’s movement then travels through the turbine to the inside of its generator. Finally, that energy moves through more of the turbine’s internal components where it is converted into usable electricity.
When wind turbines come to mind, most people have no idea how many components actually work together inside them to generate electricity. Although they look like very simple structures from the outside, there are multiple parts that have important functions that are vital to the conversion of energy.
The Working Components of a Wind Turbine
There are four main parts of a wind turbine that have various smaller components within them. The rotor consists of the blades, hub, spinner, and pitch system. These are the parts that spin the blades that are visible on the outside of the turbine and collect energy from the wind. You might recognize that the blades look like wings or airplane propellers. Ultimately, the main function of the rotor is to generate the wind’s torque and gain momentum off of it.
The next component of a wind turbine is the nacelle. This is the piece that actually converts the wind into electrical power. The wind will enter from the hub and travel into the main shaft within the rotor until it reaches the gearbox.
The wind’s energy is then transferred into the shaft of the turbine and through to the generator. The generator is connected directly to the converter in the back of the turbine, which transforms the energy into electricity. The nacelle also includes a brake function for stopping motion in case of emergency or unfit weather conditions.
All pieces within the nacelle sit on top of something called the bedplate, which is a flat tray-like component that has the ability to rotate the nacelle as needed.
The largest component of a wind turbine is its tower. This is the long vertical piece that holds up the entire structure and keeps the rotor in the path of the wind. Wind turbine towers can be built in different shapes with various materials.
Most towers are either tubular with a solid cylindrical shape, lattice with an intertwining steel base, or a combination of both. No matter what the tower is made of, it will not affect the function of the wind turbine.
The final component is located at the very bottom of each wind turbine and is called the foundation. The foundation is the base on the ground directly below the tower that holds the entire structure upright. Just like the tower, a foundation can come in multiple shapes and sizes.
The different types of foundations include tripods, monopiles, jackets, and floating structures like semi-submersible and spar body foundations.
A Wind Turbine’s Degrees of Freedom and and Power Efficiency
Degrees of freedom are a variety of different states of movement a system can be in at any time depending on variable factors. For a wind turbine, there are three main degrees of freedom called azimuth, yaw, and pitch.
Azimuth is the rotation of the rotor from the wind. This is achieved when the rotor is turned to face the wind’s direction and the blades begin to rotate. Yaw, on the other hand, refers to the actual rotation of the nacelle around the vertical axis of the tower.
This happens when the bedplate moves the rotor from side to side depending on where the wind’s energy can be received from. Finally, the pitch is the rotation of the blades around the horizontal axis due to pitch control action.
Additionally, certain components of the wind turbine have their own degrees of freedom. The tower has three of its own: lateral, longitudinal, and torsion. The blades, on the other hand, have four: flapwise, edgewise, torsion, and to rotate in pitch.
Working wind turbines will always be spinning and reacting to consistent wind speeds. However, they could stand still if there is not enough wind or if the speeds are too high. The brake system that is built into the nacelle piece is designed to automatically stop the rotor from spinning when there is too much wind for it to handle.
This process prevents a lot of damage that could be done to the turbine’s structure if the speed of the blades got out of control. Additionally, wind turbines could be intentionally stopped and turned off if there is scheduled maintenance that needs to be done in order to make sure all parts are working properly.
The overall efficiency of the wind turbine, or how often it is actively converting energy, can be up to 80 percent of the time.
How The Parts of a Wind Turbine Work Together to Convert Energy
All of the individual components that are placed inside of the wind turbine work together in a system to create electricity. The wind’s energy is essentially passed through the structure by each working part and is turned into usable electric energy when the process is complete.
The process of energy conversion begins with the anemometer. This is a small metal piece that usually sits on top of the nacelle and rotates with the wind just like the rotor. When the anemometer moves with the wind, it is measuring its speed and direction in order to transmit the information to the inner components of the wind turbine.
When the nacelle receives this information, it is rotated to face the direction where the wind is blowing to intake the energy. The energy that is taken from the wind is called kinetic energy, which comes from motion. This kinetic energy is taken into the turbine and is replaced with mechanical energy as a result of the blades spinning around.
The rotor piece that holds the spinning blades is connected to the main shaft, which turns inside of the generator. The rotor is magnetic and spins inside loops of copper wire that are found inside the generator. The electrons that are given off during this process turn the mechanical energy into electrical energy, also known as electricity.
There is a piece called the step-up transformer located inside the nacelle that then increases the volts of electricity by almost five times.
The newly created electricity then travels down cables that are inside the tower from the nacelle and continues to run through a network of underground cables. The energy from all wind turbines in this area are then transported to a substation, where the electrical output increases in voltage again.
The transmission line that is connected to this substation is also connected to the region’s electrical grids on the other side. Finally, the electricity is distributed to nearby homes and businesses to be put to use.
How The Wind Energy Conversion Process is Environmentally Friendly
Wind energy conversion is much more environmentally friendly than alternate methods of creating electricity. Fossil fuel power plants, for example, require the burning of oils and gases in order to create energy.
These toxic fumes are then released into the environment and can be harmful to people and animals in the area over long periods of time. Since wind turbines are powered by natural energy directly from the earth, there are no chemicals given off from the process of creating electricity in this way.
Even though wind turbines look like a few spinning blades attached to the top of a tower, there is an entire network of pieces and components inside of them. From the blades to the underground cables, there is a more complex process involved in the conversion of wind energy than meets the eye.
How Much Power Can Wind Energy Really Produce?
The amount of power generated by wind energy depends on the size and capacity of each individual wind turbine that is calculated in a unit of measurement called kilowatts. Turbines on a smaller scale can provide power to a single family home, whereas larger turbines can supply energy to thousands of homes and businesses every year.
What Kinds of Things Can Wind Energy Be Used For?
Wind energy can be used for virtually anything that normal electricity is usually used for. The electricity that is generated by wind produces the same results as alternate methods of energy conversion, it just comes from a better and more natural source. Wind energy can supply electrical power to wide networks of buildings and facilities and can even power an entire region.
At What Speed do the Blades Turn on a Wind Turbine?
Depending on the amounts of wind that are blowing directly toward the wind turbine, the blades have the ability to move at a speed of up to 20 rotations per minute. The speed of the rotor will be determined inside of the wind turbine based on the speed of the wind that is detected by the anemometer on top of the nacelle.
If you’re serious about learning more about wind energy, I recommend the Wind Energy Handbook on Amazon. This book is great for both students and professionals, and it holds invaluable information on the subject of wind power.