Offshore wind power generation is one of the most promising technology to deliver significant amounts of clean energy to meet the World's growing energy needs. However shallow water depth space limitations and conflict of usage with other sea stakeholders caps the electricity generation potential. Delivering offshore wind's full potential means to access deeper and more remote locations where only floating foundation technologies are eligible. Current floating technology types comprise barges, spar buoys, semi-submersible and tension-leg platforms. Many concepts are present and some have been tested offshore. However, none of them can reach a significantly low LCOE price range to allow them to compete against traditional bottom-fixed wind farms and onshore photovoltaics. Reduction of overall LCOE means a global effort to reduce CAPEX, based on 4 pillars: more efficient serial fabrication methods, optimized installation procedures and reaching most wind resource abundant areas with economies of scale based on the size of the wind turbines. But none of the above can reach the CAPEX target if not supported by a floater design optimized for future market conditions. Saipem has developed and patented a novel offshore wind floater design that is based on 3 main basic principles: decoupling of the floater movement from wave motions, cost-efficient pendular ballast system for angular motion stability and large pipe truss structure design, compatible with serial fabrication. The main characteristics of the floater will be presented and compared to state-of-the-art existing solutions. Sensitivity studies will be shown as to compare the floater's performance versus increase in wind turbine size.
This paper will describe the main innovation steps that led to Saipem's floating wind concept. After reviewing the pros and cons of existing floater concepts, the specifications of an ideal design will be explained. The main steps of the following innovation path will then be explained from a hydrodynamic, then structural point of view. Finally, comparison of the resulting pendular floater concept with existing floater concepts will be performed, with a projection onto the coming commercial floating wind farms.
The floating foundations of offshore wind platforms are mainly derived from the Oil & Gas industry experience. These are mainly barges, spar buoys, tension-leg platforms and semi-submersible platforms.