The DOWEC project aims at implementation of large wind turbines in large scale offshore farms. A baseline wind farm has been determined consisting out of 80 wind turbines of 6 MW each and is located 43 km off the Dutch coast. The following access systems for O&M crew have been investigated in the paper: rubber boat, offshore access system and helicopter. For these access systems the operational limits, expressed as maximum mean wind speed and significant wave height, have been established. On basis of the NEXT database the statistics of the corresponding weather windows have been determined. These statistics together with the failure statistics and the regular maintenance demand of the wind turbines and other farm components determine the availability of an offshore wind farm at the specific site. Estimates of the availability of the offshore wind farm have been realised with a sophisticated Monte Carlo simulation model of the operations within the wind farm. The simulations show that in order to maintain a farm availability of above 90% use should be made of access systems with an accessibility of at least 82%; this rules out simple options as rubber boat.
|Title of host publication||MAREC 2002, International Conference on Marine Renewable Energy|
|Place of Publication||Newcastle upon Tyne|
|Publication status||Published - 2002|