A key phase in the development of a wind farm is monitoring the wind speeds and wind directions at the site. This data is used at many different stages of the project, from determining what type and size of wind turbine would be the best choice, to deciding whether the site is economically viable.

Wind Prospect is not tied to a specific wind turbine manufacturer so we can choose the turbine best suited to extract the most energy from the wind at that site. We install a wind monitoring mast on site for a period of approximately two years. This ensures that we record a reliable data set over at least one calendar year. This data is then compared to long-term wind data acquired from the Met Office in order to predict average wind speeds for the site over the next 20 years.

Wind Monitoring Masts

The most common way of measuring wind speed on site is to use a wind monitoring mast. These masts are usually between 40m and 80m high. They are mounted with wind speed measuring equipment (anemometers) and wind direction measuring equipment (wind vanes) at various heights. It is not uncommon to have six or seven anemometers at different heights. These are all electronic, and they relay their data automatically every day to Wind Prospect offices. Once received the data is checked to ensure that the monitoring equipment is working properly.

The only time we need to go on site is if repairs or maintenance to the equipment is needed that can not be undertaken by the landowner or, if the monitoring period is complete and its time for the mast to be removed. The monitoring equipment is powered by a solar module so no electricity connection is needed.

Data Analysis

Once we have collected 6 months of wind data we will do an initial analysis using computer modelling techniques. The modeling takes into account the contours and characteristics of the surrounding land, including any obstacles such as buildings, forests and turbulence effects produced by other turbines and the turbines themselves. From this analysis, a long-term wind speed is predicted for the site, along with monthly averages during the year. The prediction is used to select the most appropriate types of wind turbine to install at the site. From the analysis, we also optimize the position of the turbines in order to provide the highest possible energy yield.

Guy-wires support the mast, and 4 booms on either side, 135° apart where measurements are taken

Example of meteorological mast in Chatham-Kent

This is a typical wind rose showing the speed and direction of the wind on a proposed site