Energy-efficient towing of floating offshore wind turbines : challenges and perspectives on platform drag reduction

Abstract

Floating offshore wind turbines (FOWTs) are essential for expanding renewable energy capacity into deep-water regions. However, the deployment of semi-submersible FOWTs faces significant operational and financial hurdles, primarily driven by the high costs and logistical complexity of towing these structures to site. This perspective paper critiques current transportation processes, noting that existing offshore guidelines typically fail to account for the hydrodynamic drag generated by the unique bluff-body geometries of these hulls. The substantial pressure drag inherent in these structures leads to excessive fuel consumption and elevated carbon emissions during long-distance transit. Consequently, potential drag-reduction strategies must be explored to address these hydrodynamic inefficiencies. Among various technologies, fairings attached to the FOWT structure emerge as a promising solution, with potential drag reductions of around 40%. However, extensive research is required to ensure these designs do not compromise system stability, while also providing a net carbon emission reduction that justifies their production for large-scale deployment. Ultimately, integrating effective drag-reduction technologies is a vital step towards improving both the economic viability and the environmental footprint of the FOWT industry, ensuring its long-term sustainability in the global energy transition.