Written by: Luca Grispiani
Wind Speed Distribution
Following the assessment of the site location for the wind park, next is the definition of the Wind Speed Distribution in the East 2 Marine area, in order to assess the wind energy yield available in a typical year.
A three-parameter Weibull Distribution is implemented. In literature, it is common practice to adopt a maximum likelihood analytical method starting from hourly wind data, aiming to define the Weibull Parameters. Nevertheless, in this feasibility study, the Weibull Parameters have been defined a priori.
The equation that represents the Weibull Distribution is presented below, where u (above underlined) is the Annual Mean Wind Speed, A is the scale parameter and k corresponds to the shape parameter.
Specifically referring to the Marine Area East 2, the Scale Parameter is fixed to 125% of the mean annual wind speed, while the Shape Parameter is obtained from a Physical Environmental Analysis conducted by Statoil Company in the marine area of Buchan Deep (Statoil, 2014), few miles away from East 2.
Accordingly, Weibull Parameters are defined as:
Table: Weibull Parameters
| Wind Mean Speed u | Scale Parameter A | Shape Parameter k |
| m/s | m/s | [ ] |
| 10,7 | 13,375 | 2,235 |
Therefore, the Annual Wind Speed Distribution and the Cumulative Density distribution are represented in the following charts:
Figure: Annual Wind speed Distribution and Cumulative Density Distribution
Once the Probability Density of the Wind Speed Distribution is defined for a range of wind speeds from 0 m/s to 50 m/s, it possible to assess the wind power available in a typical year related to a specific wind turbine characteristic.
References
Analysis of Wind Power Potential by the Three-Parameter Weibull Distribution to install a wind turbine, K. Sukkiramathi1 and C.V. Seshaiah, Energy Exploration & Exploitation,2020, Vol. 38(1) 158–174, DOI: 10.1177/0144598719871628
Hywind Buchan Deep Meteocean Design Basis RE2014-002
Wind Energy Engineering, Trevor M. Letcher, 2017, Elsevier, ISBN: 978-0-12-809451-8