European Wind Energy Association

Comparative Resource and Energy Yield Assessment Procedures (CREYAP) Exercise Part II

How close do resource assessors get to reality? 60 teams, from 56 organisations in 17 countries have taken part in the pre-workshop exercise. Attend the workshop to see how they did!

Many thanks to the following organisations that submitted results:

3E (Belgium); 3TIER (USA); ALTRAN (Spain); ATM-PRO (Belgium); AWS Truepower (USA); Barlovento Recursos Naturales (Spain); BBB Umwelttechnik (Germany); Casa dos Ventos (Brazil); CENER (Spain); China Wind Power Center / CEPRI (China); CIRCE (Spain); CRES (Greece); Deutsche WindGuard (Germany); Digital Engineering (UK); DTU Wind Energy (Denmark); EDF Renewable Energy (USA); Edison (Italy); EMD International (Denmark); ENALLAKTIKI ENERGIAKI (Greece); ENERPARK Inżynieria Wiatrowa (Poland); EREDA (Spain); ESB International (Ireland); Estia (Greece); Etha (Finland); European Weather Consult (Germany); Fichtner (Germany); Fujian Hydro Power (China); GAMESA (Spain); GDF SUEZ (France); IMPSA (Brazil); INOVA Energy (Brazil); International Wind Engineering (Greece); Istos Renewables (Greece); ITOCHU Techno-Solutions (Japan); Kjeller Vindteknikk (Norway); Lahmeyer (Germany); Mainstream (USA); Megajoule (Portugal); Meteodyn (France); Mott MacDonald (UK); MS Techno (China); NREL (USA); Natural Power (UK); North China Electric Power University (China); Prevailing (UK); REpower Systems (Germany); RES Ltd. (UK); RSE S.p.A. (Italy); SgurrEnergy (UK); The Wind Consultancy Service (UK); Tractebel Engineering (Belgium); Wind Energy Corporation (Japan); Wind Prospect (UK); WIND-consult (Germany); WindSim (Norway); Winwind (Finland)

A highlight of the workshop is the Comparative Resource and Energy Yield Assessment Procedures (CREYAP) Exercise Part II. Between February and May 2013 parties were invited to carry out a wind speed and energy yield prediction for a wind farm project with the aim to compare results of different industry standard models and approaches.

Participant’s results are now being independently compared and contrasted with one another, as well as against real wind farm performance data. The results and lessons for the industry to learn will be presented and debated in the concluding session of the workshop.

Exercise description

This exercise builds on the first CREYAP exercise performed for the 2011 EWEA Wind Resource Assessment Technology Workshop: 36 organisations analysed and reported, amongst other information, the measured wind climate and net energy yield for a 14 turbine wind farm. Inputs included site measured data, terrain and layout data, and a range of simplified assumptions that were to be applied. Participants’ results were independently collated and compared on a relative basis. Download the presentation of the results from the 2011 CREYAP Exercise Part I.

The CREYAP Exercise Part II builds on the previous exercise by providing a wider range of inputs, including roughness information, a choice of reference data, and a comprehensive site assessment measurement campaign designed to improve the spatial resolution of the site measured data. In addition to this, participants’ results will be independently analysed and compared with wind farm production data from the site analysed in this case study. To enable the comparison to be undertaken the long term estimate of actual performance of the wind farm has been derived from production data taken from early 2007 until the present day and normalised to an overall availability (turbine, grid, & balance of plant) of 96.8%.

It should be noted that all digital data supplied with this package are under licence and once used for the purposes of this study should be deleted and not used for any other purpose.

EWEA wishes to thank the parties that have made both comparison exercises possible:

• Renewable Energy Systems Ltd. for providing the data and preparing the data pack;
• DTU Wind Energy for the analysis and presentation of the results.

The deadline for submitting the results was 10 May 2013, but you may still download the data pack by completing the form below.

Meet these leading companies exhibiting at the workshop: