Wind Farm Definition, Purpose, and Locations Explained
A wind farm is a power station which houses multiple wind turbines that are used for large-scale wind energy capture and electricity generation. This article discusses wind farm definition, purpose and locations.
-Wind Farm Definition: 7 Ways to Define Wind Farms
Wind Farm Definition: 7 Ways to Define Wind Farms
A wind farm is an array of tens or hundreds of wind turbines which are used simultaneously to generate power [3].
Other terms used to refer to wind farms include wind power plant, wind station, wind power station, and wind park. The following alternative wind farm definition, portrays the ‘farm’ as a power station;
A wind farm is a power plant that is equipped with facilities to capture and convert wind energy and generate power, in a manner that ensures energy conservation and efficiency.
The purpose of wind farms is to generate electricity in large-scale, from wind energy. In the wind farm definition below, this is highlighted;
Wind farm is a power station that comprises of multiple wind turbines which work in collaboration for the purpose of electricity generation from wind energy.
Some of the equipment in wind power plants are mentioned in the alternative wind farm definition below;
A wind farm is a power plant that is equipped with wind turbines, power inverters, deep cycle batteries, electric generators and transmission systems to capture and convert wind energy to electricity.
The main locations of wind farms can be used to characterize them. This is shown in the following wind farm definition;
A wind farm is a power-generation site that may be located onshore of offshore, and is used for wind energy capture and conversion [6].
Another alternative wind farm definition may highlight the role of these facilities in harnessing renewable energy, based on integration between wind farms and other systems;
A wind farm is a renewable energy facility that unifies the operations of multiple wind turbines, and can be integrated with solar panels and wave power converters; in offshore and onshore locations.
Lastly, the wind farm definition can be outlined to include average power capacity of wind farms;
A wind farm is a power station that depends on wind energy to generate electricity, and may range in power capacity from approximately 1,000 MW to 8,000 MW.
Purpose of Wind Farms
The purpose of wind farms is to generate electricity, by capturing and converting wind energy.
As the statement above implies, electricity generation in a wind farm is only possible after wind has been captured and converted. These functions must also be performed in unison across all wind turbines in the farm.
The three aspects of the purpose of wind farms are discussed individually below;
1). Wind Energy Capture (as part of the Purpose of Wind Farms)
The blades of wind turbines are the main components responsible for wind capture, in a wind farm.
Other parts of the turbine may play supportive roles. However, it is the turbine blades that are equipped with an airfoil design that interacts with air currents and traps or ‘captures’ them [6].
The capture of wind energy by the blades of a turbine occurs when air currents collide with the turbine blades, and cause them to rotate.
Factors that determine the effectiveness and scale of wind capture include the size and geometry of turbine blades, and the height of the turbine.
With regards to height; the tower of a wind turbine must be high enough to position the nacelle and blades in the line of air currents. The average height of wind turbines in the United States is about 80 meters [5].
The location of a wind farm also affects wind capture effectiveness.
Generally, it is recommendable to install wind turbines in remote areas where there are few obstructions to air current flow. This includes rural, off-grid areas, and offshore sites.
After wind energy has been captured, it can then be converted to generate electricity.
2). Wind Conversion
Wind conversion is an aspect of the overall purpose of wind farms.
It is also a very important aspect, because it is impossible to generate electricity from wind energy without conversion.
With regards to energy conversion, wind farms can be considered similar to other power systems like hydroelectric plants. The principle behind this type of energy conversion is the use of energy to drive or operate a prime mover.
There are two main stages of energy conversion that occur in wind farms. The first of these is conversion of kinetic energy to mechanical energy.
When wind is captured by the blades of a wind turbine, it occurs in the form of kinetic energy [7]. This kinetic energy causes the blades of the turbine to rotate, transferring the rotary motion to a rotor, which is connected to a main shaft.
Rotation of the shaft implies that kinetic energy has been converted to mechanical energy.
The next stage of conversion involves transforming mechanical energy to electricity. This occurs when the rotating shaft activates an electric generator.
‘Activation’ of the electric generator is based on electromagnetism [2]; whereby electric currents are caused to flow through a rotating conductor under the influence of a magnetic field.
The power which is generated may then be transmitted to the point(s) of use.
In conversion, electricity generation, and transmission, efforts are necessary to achieve sustainability by minimizing energy losses. Also, in very large wind farms, a turbine generator may be used for power generation.
3). Electricity Generation (as part of the Purpose of Wind Farms)
Electricity generation is the final aspect of the basic operation on a wind farm.
It occurs after energy conversion from kinetic to mechanical form, and can be described as the second stage of the wind energy conversion process.
Locations of Wind Farms
The two main locations of wind farms are offshore and onshore. These locations are selected and valued based on the availability and accessibility of wind.
Each of the main wind farm locations is discussed below;
1). Offshore Wind Farms (as one of the Locations of Wind Farms)
Offshore wind farms are wind farms located in water bodies at sea [1].
These wind farms are common in coastal areas with abundant supply of air currents.
Often, the air currents also produce waves, such that the wind farm is integrated with wave power converters.
The advantage of offshore as a location for wind turbines is its remoteness. Because there are few manmade structures at sea, air currents have little obstruction in their flow path. They are therefore able to be captured by wind turbines.
Electricity that is generated on offshore wind farms is often transmitted to the grid using undersea cables.
2). Onshore Wind Farms (as one of the Locations of Wind Farms)
Onshore wind farms are located in terrestrial areas, or on land.
These wind farms are very common, and constitute a major proportion of the total number of existing wind farms.
Selection of appropriate site for onshore wind farms is based on the availability of wind, and the absence of obstructions to air flow.
Suitable onshore sites include hilly areas, plains, and rural regions. Altitude is an important factor affecting the amount of available wind onshore.
Conclusion
A wind farm is a power station located onshore or offshore, which comprises of multiple wind turbines and is used to capture and convert wind energy.
The purpose of wind farms includes;
1. Wind Energy Capture
2. Wind Conversion
3. Electricity Generation
The two main locations of wind farms are;
1. Offshore Wind Farms
2. Onshore Wind Farms
References
1). Abramic, A.; Mendoza, A. G.; Haroun, A G. (2021). “Introducing offshore wind energy in the sea space: Canary Islands case study developed under Maritime Spatial Planning principles.” Renewable and Sustainable Energy Reviews 145(4):111119. Available at: https://doi.org/10.1016/j.rser.2021.111119. (Accessed 5 September 2022).
2). David, A. P. (2017). “ELECTRO-MAGNETIC INDUCTION: FREE ELECTRICITY GENERATOR.” 2ND INTERNATIONAL RESEARCH CONFERENCE” Addressing the Challenges of Globalization with ASEAN Perspectives”, Puerto Princesa, Palawan (Philippines). Available at: https://www.researchgate.net/publication/324030058_ELECTRO-MAGNETIC_INDUCTION_FREE_ELECTRICITY_GENERATOR. (Accessed 5 September 2022).
3). Dupont, E.; Koppelaar, R.; Jeanmart, H. (2017). “Global available wind energy with physical and energy return on investment constraints.” Applied Energy 209. Available at: https://doi.org/10.1016/j.apenergy.2017.09.085. (Accessed 5 September 2022).
4). Hevia-Koch, P.; Jacobsen, H. K. (2019). “Comparing offshore and onshore wind development considering acceptance costs.” Energy Policy 125:9-19. Available at: https://doi.org/10.1016/j.enpol.2018.10.019. (Accessed 5 September 2022).
5). Holt, E.; Wang, J. (2012). “Trends in Wind Speed at Wind Turbine Height of 80 m over the Contiguous United States Using the North American Regional Reanalysis (NARR).” Journal of Applied Meteorology and Climatology 51(12):2188-2202. Available at: https://doi.org/10.1175/JAMC-D-11-0205.1. (Accessed 5 September 2022).
6). Mamadaminov, U. (2013). “Review of Airfoil Structure for Wind Turbine Blades.” Available at: https://www.researchgate.net/publication/271829785_Review_of_Airfoil_Structure_for_Wind_Turbine_Blades. (Accessed 5 September 2022).
7). Memon, Z. A.; Sahito, A. A.; Leghari, Z. H.; Shaikh, P. H. (2016). “Output Voltage Characteristics of Wind Energy System Considering Wind Speed and Number of Blades.” Available at: https://www.researchgate.net/publication/312021618_Output_Voltage_Characteristics_of_Wind_Energy_System_Considering_Wind_Speed_and_Number_of_Blades. (Accessed 5 September 2022).
