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The Wind Rose: An essential tool in wind energy
The wind rose is a cartographic tool used for navigation since ancient times. It has become a crucial instrument for wind energy generation, allowing us to understand wind directions, frequency, speed, power, and other factors vital to the location and efficiency of wind turbines. By maximizing wind energy capture, we can optimize wind energy production. This article explores the importance of roses and their types for wind farm design. In addition, the link to the database of wind magnitudes and directions used to plot the types of wind roses is provided.
What is a wind rose?
The wind rose is a polar diagram that defines wind magnitude, frequency, power, and energy for different directions. It analyzes the origin of the wind and its characteristics. Typically, the wind rose is divided into 12 sectors, each spanning 30°, 16 sectors, each spanning 22.5° or for greater precision in 24 sectors, each covering 15°.
Wind magnitude and direction data
The simulation data can be downloaded from the following repository: https://data.mendeley.com/preview/zrr487ry6x
It is important to note that wind direction measurements are taken with geographical north as the reference and in a clockwise direction.
Types of wind roses
The wind energy sector employs the following types of wind roses, which have been calculated at a height of 50 meters:
a) Frequency rose
The polar diagram shows the frequency of wind magnitudes for each range of wind directions.
b) Speed rose
The polar diagram shows the average wind speeds (m/s) for each wind direction range.
c) Power rose
The polar diagram shows the average power per square meter (W/m²) for each wind direction range. The power data is directly proportional to the cube of the wind speed in the 
direction, with 
representing the air density.
d) Energy rose
The polar diagram shows the energy per square meter (kWh/m²) for each wind direction range. The energy for each direction is given by the wind turbine power j in the direction and the time for each time stamp of one hour.
Which type of wind rose is used in the design of a wind farm?
All types of wind roses provide us with specific information, but the type that is most relevant to optimizing the design of a wind farm is the so-called “energy rose.” This provides us with the directions that concentrate the most annual energy, i.e., the directions from which the wind blows for the most hours per year and with the most power.
Reference
[1] Cucó Pardillos, S. (2017). Manual de energía eólica. Desarrollo de proyectos e instalaciones. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/77752.
[2] R. Byrne, N.J. Hewitt, P. Griffiths, P. MacArtain, “Observed site obstacle impacts on the energy performance of a large scale urban wind turbine using an electrical energy rose”, Energy for Sustainable Development: The Journal of the International Energy Initiative, Volume 43, 2018, Pages 23-37, ISSN 0973-0826. https://doi.org/10.1016/j.esd.2017.12.002.
