Measurement Data

OpenWind used publicly available raw data to produce an estimate of wind conditions. The data is provided by the DWD (Deutscher WetterDienst), which has over 400 measurement stations with available data. OpenWind analyses use the measurement data from these sites.

This pages lists the data that is extracted from the DWD files and used in the analyses.

Location Latitude/Longitude°

All measurements and the TRY data are based on a geographic location and this value is listed in the dashboard/report.

This helps to locate sites of interest.

Years of data Y years

The amount of data available varies at each site. The more data, the more accurate the predictions for future wind conditions. A standard wind site assessment requires at least one year of data at a prospective site. Each site page (Aachen Example) lists how many years of data are available and how recently the data has been updated.

More years of data means a better prediction of wind conditions.

Wind speed measurementsVAVE m/s

The wind speed is measured at a measurement station at every DWD site. These time histories provide the basis for the energy calculations. The heights of the measurement stations vary according to site. Over the years these stations have had updates and sometimes the measurement height has changed. The change in measurement heights in integrated into all the calculations and noted in the site dashboard pages. The data is quality checked to remove all missing or bad data and the data quality noted for all sites.

The wind speed data is used to estimate the annual wind speed probability distribution function (PDF)

Example Wind Speed Measurement Annual Average - Site: 00003 AachenCalculated wind speed average based on standard tower heights.More

Wind direction °

The wind direction is also measured at each site. While this does not directly affect the wind energy production value, it is a useful metric for arrays of turbine that can be optimized to be facing the oncoming wind and avoid wind shadows. The data is presented in a standard wind rose for each site.

Example Wind Direction Plot - Site: 00003 Aachen, Prevailing Wind: A preliminary analysis of the wind direction are provided along with the prevailing wind direction.More