Effect of Shared Anchor System for a Floating Offshore Wind Project on Reductions in CO2 Emissions

Abstract

Abstract The trend of the offshore wind industry is expected to shift from fixed towers in shallow water to floating platforms in deeper water due to factors such as wind resource consistency and local seafloor bathymetry. The floating offshore wind industry requires cost-effective anchor alternatives suitable to a range of mooring types, water depths, geological locations, and environmental conditions. One attractive and cost-effective anchor solution can be the shared anchor system, with multiple mooring lines attached to a single anchor. Previous preliminary studies indicate that the shared anchor system provides significant capital cost savings due to its multiline potential resulting in reductions in required anchor footprints and logistic efforts. While they provide valuable insights into anchor performance and its cost-saving effect, these studies did not address the environmental impact in view of greenhouse gas emissions. This spurs the current study to estimate the effect of the shared anchor systems on reductions in CO2 emission. Firstly, this paper compares envisioned shared anchor systems, such as a suction anchor, a deeply embedded ring anchor (DERA), and a skirt, from optimal design standpoints. Secondly, embodied carbon in steel-based anchor alternatives is computed using a carbon calculator tool based on standardized data and compared to each solution. Lastly, the study carries out a comparative study on how anchor transportation from the factory to the construction site affects CO2 emission. The findings from the study provide a platform to select the shared anchor system considering cost reductions and estimate the environmental effects, which is a key consideration to Green Construction. The results show that the DERA is a cost-effective and environmental-friendly alternative for the floating offshore wind project.