Concrete Floaters: A Promising Solution for Floating Wind Energy

Abstract The competitiveness of floating concepts in floating wind projects has been a subject of extensive study by TotalEnergies during the last three years, with a comparative analysis of 100 different concepts revealing several key insights about the concrete concepts. Firstly, while concrete floaters are significantly heavier than their steel counterparts – by a factor of 4 to 6 – this weight disadvantage is offset by the cost benefits. Steel fabrication is 4 to 6 times more expensive than concrete fabrication, and the ability to locally fabricate concrete floaters further reduces transportation costs, making them a cost-effective option. Secondly, the efficiency of concrete construction methodologies plays a crucial role in cost reduction. Techniques such as caisson slipforming and limited prestressing operations minimize the need for extensive equipment and labour, thereby decreasing overall costs. These efficient construction philosophies are essential for the economic viability of concrete floaters. However, the load-out operation presents a significant challenge due to the heavy nature of concrete floaters. The current scarcity of semi-submersible barges capable of performing this operation is a bottleneck. Nonetheless, ongoing developments in barge technology are promising and should be closely monitored to mitigate this issue. Ultimately, the affordability of concrete floaters varies with the project's geography, making them a solid addition to a range of solutions rather than a one-size-fits-all answer. In conclusion, despite the challenges associated with their weight and load-out operations, concrete floaters present a competitive and cost-effective alternative to steel floaters in floating wind projects, particularly when efficient construction methodologies and local fabrication are employed.