Modelling logistics strategies for the installation of offshore wind farms

Abstract

The construction of an offshore wind project is a complex process that involves many uncertainties and technical risks. Challenges include installation schedule delays and cost overruns caused by harsh weather conditions, as well as supply chain restrictions and constraints regarding port infrastructure and a shortage of specialised installation vessels. These uncertainties may impact the achievement of the global offshore wind installed capacity target of over 1,100GW by 2050. Therefore, optimising offshore logistics and installation methods is critical to strengthen the risk identification process at the planning and pre-construction phases of future offshore wind projects, including fixed-bottom and floating wind technologies.

The stages and processes involved in the project lifecycle of an offshore wind farm are well-documented, ranging from the initial project planning and permitting through to the decommissioning (or repowering) phases. Models and simulation tools for long-term logistical planning have been developed, yet great uncertainty remains in the logistics requirements for the transport and installation operations of large-scale offshore wind projects, particularly for floating offshore wind technologies. Most of the tools have focused on operations and maintenance (O&M) and operating cost (OPEX) estimation, with limited research addressing the performance of installation vessels and the likely impact of logistics strategies on project installation time and costs.

This research contributes to the knowledge by exploring the current installation methods and logistical approaches for the installation of monopiles and semi-submersible floating structures –the most common offshore wind turbine foundations to date. After analysing current and future trends in offshore wind industry development, a novel construction model was developed using an advanced forecasting and discrete-event simulation support tool. The construction model was validated through: i) real system data validation; ii) benchmarking; and iii) industrial case studies.

The model represents key offshore wind farm T&I processes, predicts campaign installation times, and assess the impact of installation methods and operational weather conditions on offshore installation duration. Validation results indicate that the construction simulation model closely aligns with existing T&I procedures and accurately represents different strategies for ports, vessels, and offshore logistics operations.

Research findings suggest that large-scale floating wind projects in the UK's North Sea waters are more sensitive to the distance between the marshalling port and the wind farm site than monopile-based projects, highlighting the need for significant capital investment in port infrastructure to meet offshore wind ambitions of large deployment by 2050. Moreover, the study underscores the importance of precise input data and assumptions in reducing uncertainty in offshore wind logistics models. Inadequate or inconsistent input information may lead to inaccurate risk assessments related to weather downtime, installation timing, and vessel cost estimation.

Ultimately, this research highlights the necessity of enhanced industry collaboration and data-sharing initiatives to refine offshore wind T&I strategies.