Advanced wind resource assessments in offshore, nearshore and coastal environments

Infrastructure Access Report Infrastructure: NTNU Full-Scale Wind Measurement Station

User-Project: AWRA-ONCE. Advanced wind resource assessments in offshore, nearshore and coastal environments.

This report describes improvements in coastal and offshore wind resource assessment methods. A model of the vertical profile of horizontal wind speeds is required in order to estimate wind resources at the rotor heights of proposed turbines. The specific goals were to (i) identify the best existing data sources and methods to incorporate atmospheric stability into vertical wind profile models and (ii) make recommendations for future offshore wind prospecting campaigns in order to adequately represent the effects of atmospheric stability. The coastal wind speed data and related support obtained from NTNU allowed us to validate atmospheric stability corrections at a coastal site with a long marine fetch in several wind sectors. This allowed us to test the applicability of methodologies developed at offshore sites. The bulk correction method using sea surface roughness and temperatures performed well for the overseas fetch sector. The diabatic profile improved the vertical wind profile prediction in comparison to the neutral profile suggesting that the wind flow regime is predominantly influenced by the marine boundary layer. The air methods also showed potential to calculate the stability, although a difficulty arose from the use of the 25m temperature readings which appeared to cause errors. Possible impacts include improved wind resource and energy yield estimates for offshore wind farm sites