Economic Superiority of PIP Slip Joint Compared to Conventional Tubular Joints

Abstract

This paper examines the costs associated with installing PIP (Pile-in-Pile) slip joints compared to traditional tubular joints, focusing on investment, installation processes, and long-term benefits. Previous studies have indicated that the structural performance of PIP slip joints is superior to that of traditional joints. By utilizing the frictional interfaces between conventional structural steel components and the simplest installation methods, PIP slip joints maximize structural integrity and ease of maintenance. As a result, they can lead to lower lifecycle costs, provided they are installed correctly. Quantitatively, the PIP slip joint achieved the highest internal rate of return (IRR) at 43.42%, the lowest Levelized Cost of Energy (LCOE) at 0.013589 EUR/kWh, and the shortest payback period at 2.92 years—outperforming grouted and bolted flange joints across all key financial metrics. The analysis also addresses logistical challenges and workforce requirements, highlighting that significant economic benefits can be realized when implemented appropriately. Furthermore, the PIP slip joint promotes sustainability goals by minimizing material usage, which ultimately leads to reduced carbon emissions through more efficient fabrication and installation, as well as enabling faster deployment. A comprehensive financial assessment of these joint systems in offshore wind monopiles reveals that PIP slip joints are the most cost-effective and financially advantageous option, outperforming key metrics like IRR, LCOE, and payback period due to lower initial investments and operational costs. As PIP slip joints yield a higher net present value (NPV), a shorter payback period, and a lower LCOE, they can enhance profitability and reduce financial risk, and are suitable for streamlined implementation. While grouted and bolted flange joints exhibit similar financial performance, PIP slip joints’ minimal expenditure and consistent superiority make them the optimal choice for sustainable and economically viable offshore wind projects.

Keywords

• PIP slip joints
• lifecycle cost analysis
• net present value
• structural integrity
• Levelized Cost of Energy
• economic feasibility