Posters

Abstract

Operations and maintenance makes up one fifth of the total cost of an offshore wind project. Optimising accessibility to offshore sites offers great opportunities to reduce costs for offshore wind. Optimisation is possible through accurate forecasting models that can successfully support crew dispatch decisions. Inaccurate forecasting models can lead to loss of revenue in two ways. Firstly, an overestimating forecast results in lost opportunity to carry out maintenance at the offshore location. An underestimating forecast could result in an unsuccessful crew transfer and money wasted on vessel hire. It also poses a large risk to the crew safety if conditions are treacherous. This study uses real operational data to assess the relationship between metocean forecasts and the real time decisions made for an offshore wind farm. It focuses on data where the significant wave height is around the access limit for a crew transfer vessel, as this is where the biggest opportunity for cost reduction lies. The operational data includes an on-site wave radar and information provided by the marine coordinator, which contains two marginal days. Utilising this operational data, the errors for the metocean forecast were analysed and discussed. Previous studies have benchmarked various forecast models using different error metrics but in this work the errors can be translated into the practical use of a forecast at an on-site location and the importance of forecasting for offshore accessibility on marginal days.