Weather conditions

The most important weather parameter in the coastal observatory and test bed is wind, as this is directionally linked to generating energy from off-shore wind turbines.

First of all, an analysis of average wind conditions was conducted at a height of 10m, based on the outputs of the CFSR model (Climate Forecast System Reanalysis). This model is based on the global meteorological model GFS (Global Forecast System) by adding the assimilation of instrumental data from multiple sources (weather stations, buoys, remote sensing, etc.).

The second analysis done was aimed at assessing wind conditions at a height of 100m, given that this is the probable height of the next generation of off-shore wind turbines. This study was done with the reanalysis data from the Era-Interim model at the nearest grid point to the test bed.

The main characteristics of the models used are shown in the next table, and the positions of the grid points analysed (P7-CFSR and P7-ERA-INTERIM) are shown in the graph.

 

  CFSR ERA-Interim
Data supplier NOAA/ National Weather Service ECMWF
Data analysis period 01/01/1980 - 31/12/2009 (30 years) 01/01/1979 - 31/03/2003 (24 years)
Time resolution hourly Every 6 hours
Spatial resolution 2.5⁰ 0.75⁰
Height from mean sea levelr 10 metres 100 metres
Parameters Date: yyyy-mm-dd HH:MM (UTC time)
VWIND: Velocity (m/s) at 10 m
DWIND: Mean direction (dextrorotation from north)
Wind_Speed_100m
Wind_Direction_100m dextrorotation from north)
Position study node (P7-CFSR) 15.25⁰W, 27.75⁰N (P7-ERA-INTERIM) 15.00⁰W, 28.30⁰N

Point P7-CFSR is slightly to the south and east of the position of the test bed, although it can be considered as representative of the area of the coastal observatory and the test bed. Below is the mean and extreme behaviour of the wind at this point.

Point P7-ERA-INTERIM is significantly to the north and east of the position of the test bed, so the extent to which it represents the test bed should be taken with caution.

For further information, there is the Wind Map of Spain drawn up by the IDAE (Institute for Energy Diversification and Saving), where information is available on different aspects of wind resources. Equivalent hours in a given area can be determined from the wind energy per unit of area and the power curve of a given wind turbine.

RWind resources and number of equivalent hours.

 

The Canary Island Institute of Technology (ITC) on the other hand, also has an on-line tool that shows wind resources of the Canary Islands. This tool allows you to consult the wind rose on a grid of points covering the entire Canary Islands, including the PLOCAN test bed area. Furthermore, it allows you to calculate the annual energy generated by a wind turbine from a power curve provided by the user.

Meso Inc. This model obtains winds in a grid with a 100m spatial resolution with a digital model of the terrain of 90m provided by the SRTM (Shuttle Radar Topography Mission) and it simulates the representative atmospheric conditions of a 15 year period.

RWind resources calculated at a point within the test bed area.