Economic Potential of Industrializing Floating Wind Turbine Foundations

The potential of offshore wind is enormous. It could meet Europes electric energy demand seven times over, and the United States energy demand four times over. However, much of the offshore potential is at water depths that can only be served by floating systems. In order to truly enable floating offshore wind, the cost of energy needs to reach the level of fixed-bottom offshore wind. At the present time, a number of suppliers are offering floating offshore wind foundations, but at cost levels that are prohibitive for large-scale application. The root cause of the high cost levels is that existing designs have emerged from the offshore oil and gas sector; they are manufactured using conventional, non-industrialized methods, weights are measured in thousands of tons and manufacturing times are measured in months. In contrast, the TetraSpar concept is based on the application of proven design and manufacturing technologies from the highly competitive wind industry. As a result, the weight is only a fraction of the weight of other floating wind turbine foundations, manufacturing takes place in factories using industrialized methods, and assembly and installation is measured in days or weeks, not months. The foundation and wind turbine can be installed in any port of a reasonable size using a standard, land-based crane, and the complete assembly can be towed to site and hooked up to the moorings and the electrical cable using standard tugs. This paper presents how these desirable economic traits of the TetraSpar design are achievable, and how the near future feasibility of offshore floating wind turbines may develop as a consequence of this radical change in cost levels.