Expert Reports on Wind

You will receive an expert report on wind during the preparatory phase of your wind power project with the necessary information with regard to the wind climate and the possible yields of wind energy plants in a particular location. Our expert reports also comply with the continuous and further development of the standards set by the Advisory Board for Wind Resource of the German Wind Energy Association (BWE e.V.).

A WAsP computer analysis is usually used to create a model of the wind stream. The calculation method has been developed by the Danish Risø Research Institute and has served since 1981 – with continuous updates – for the calculation of yields from wind energy projects.

Our calculations are based on data from measurements going back as far as 10 years and coming from 24 self-owned wind-measuring stations in Saxony, Thuringia, Brandenburg, Bavaria, Saarland, and in other European countries, as well as data from the German weather services. In addition we also have access to data on yields from numerous existing wind energy plants. We use this data in order to check our calculations and to verify our earlier calculation results retrospectively.

Our expert reports on wind usually include the following services:

  • A compulsory inspection of the location

  • Assessment (recording and assessing the roughness and obstacles, digitalization of the terrain)

  • Detailed description of the site, including an elevation relief of the environment of the location

  • Controlling calculations based on the yield data of existing wind energy plants and – if available – the results of wind-measuring at the site

  • Detailed description of the wind conditions at the site, including distribution into directions, and the altitude profile of the available wind speed

  • Calculation of the annual yield for specific types of wind energy converters, and if applicable the calculation of wake losses in farms

  • Assessment of the uncertainty of the annual energy calculation

  • Optional: Assessment of the average turbulence intensity

Expert reports on wind – Verification

Our quality management system contains a permanent comparison of the predicted energy yields of projects we have evaluated to the real WEC's yields earned after realisation. Many operators have supported us by providing operational data of their wind farms. In some cases, positions or types of WECs differ from the status assumed for the prediction; this could be considered when the respective information was available. For some projects, we have to suppose that operational characteristics of the WECs considerably differ from the ones applied for the prediction.

About 10 years after begin of the study, we have reported about the results of our statistical evaluation during the 11th German wind energy conference DEWEK 2012. A description of the study can be downloaded in the extract from the conference proceedings.

Apart from a critical review of terms like ‘hit’, the study shows that the quality of the calculations has increased over the years. Additionally, the important role of the data base for the quality of the results was confirmed.

Verification of our calculations is continued. Results are permanently used by us to check and to improve our calculation methods. You can support our verification by providing operational data of your project to us – we handle this information confidential and let you know about results.

Expert reports on wind – Estimate of the average turbulence intensity

(currently no translation available)