Navigating the Lifecycle of Offshore Wind: A Roadmap to Project Success

The global shift to renewable energy has put offshore wind at the centre of the green revolution. However, transforming a stretch of open sea into a fully operational, high-voltage energy hub is one of the most complex engineering challenges in modern industry.

At Precedent Consultants, we focus on reducing risks during this process. By understanding the complex relationships in the project lifecycle, we aim to help our Clients not just build but build for long-term success, efficiency, and safety. Figure 1 provides an overview of the main civil engineering activities during a typical offshore wind farm project. Each stage of this process requires consideration of the information available at that time, the information needed, and an understanding of which risks should not be transferred to later stages.

Figure 1: Typical structural, ground and cable engineering activities associated with each phase of a civil engineering project ©Precedentconsultants

Feasibility (10% Accuracy)

Achieving success in offshore wind starts well before the first pile goes into the seabed. During the Feasibility or Conceptual Design phases, we can assist to address the critical "What If" questions that determine a project's viability.

• Site Selection: We help review and guide an analysis of metocean data, wind potential, and seabed conditions to make sure the project is both environmentally sound and technically feasible. 

• Integrated Ground Modelling: We suggest how combined geophysical and geotechnical data early on can create a detailed "map" of the subsurface.

• This detailed map coupled with the geotechnical data is vital for selecting the optimum foundation type which can include the monopile, jacket with pin-piles, jacket with suction caissons or gravity based solution (GBS) in shallow water depths.

• For deeper water depths, floating structures are adopted, the connectivity to the seabed again depends on project and site requirements.

• At the end of the conceptual design, financial decisions are usually made to based on the outcome. It is here as the risks present need to be understood by decision makers. Having an experienced team in offshore wind contributing to the design process, can aid in ensuring that all parties are aware of the inherent risks in the project, therefore ensuring informed financial decisions are made.

Front-End Engineering or FEED (60% Accuracy)

During each phase of design there are iterative loops from updated ground models leading to a better understanding of the structural behaviour of turbines. Within these early project phases, funding is limited, therefore the best use of resources is needed to ensure the project has a good chance of success. Reliance here is heavily on ensuring appropriately trained engineering personnel are supporting the Client team as these stages are critical to project success.

In preparation for this FEED stage, additional metocean and supporting site investigations are undertaken. These are used to progress the foundation designs completed during the concept phase and further improve an understanding of project cost. Here, the aim is to ensure that only minimal risks are passed to latter stages of the design. Therefore, the studies and site data obtained, need to address the unknowns identified during the conceptual stage. Within our experience, there have been times in which Clients have be misled, which has increased their cost of spending later on. At Precedent Consultants, our aim is to ensure that this is not the case.

Detailed Design (For Construction)

As the project enters the Detailed Design phase, the focus is on fine-tuning the designs completed and decisions taken at the previous stages. During the detailed stage, all wind farm components are considered and more fully optimised. This ranges from the cable designs, including onshore, land-fall solution, export and inter-array, the design of the substations, both foundations and topsides, and wind turbine generators, in terms of foundation designs and turbine loading. Typically, much of the required data would be available at this stage, and the main focus is on exhausting the use of available data to ensure all risks are minimised. This process is therefore very involved and the lengthiest of all the stages.

Certification is one of the main goals of this stage. The preparatory work done in the earlier stages is used to prepare a case to the Certification Authority to obtain the approval that the design has met the required industry standard and can move to the next phase.

Fabrication & Installation 

The Fabrication and Installation phases are where experience truly meets the ocean. However, inherent within this process is the true test of the overall design. Can the designs be accurately fabricated, installed and operate as intended?

There is a lot of work associated with the fabrication, but as there is usually a deadline within which the WTG’s need to be installed, there is a critical path that needs to be followed to ensure all components are completed, transported to site, marshalled, and installed.

The installation of the WTG foundations components is among the main construction risks. At Precedent Consultants we have experience in mitigating this aspect of the works for several foundation options and have done so for varying foundation options.

Cables are still prone to much risks in the offshore wind industry. These are as a result of a number of items with one of the main issues being burial at the required depths. There is scope here for doing more integration of the geological, geophysical and geotechnical data with the Installation Contractors and Designers, to reduce these risks going forward. Precedent Consultants can support with these studies, bring our experience to your project.

Operations, Maintenance & Decommissioning 

An offshore wind farm is a dynamic asset. Once it becomes operational, the focus shifts to Asset Management and Life Extension.

• Continuous Monitoring: This requires the usage and placement of the correct digital tools and sensor data to track structural health and enhance power output.

• Sustainable Decommissioning: There is limited data in the industry on decommissioning, with only one major wind farm, Vindeby, decommissioned in recent years. Due to the overdesign done in early wind farm projects, much of the recent work involves life extension as projects meet their 25-year lifespan. This process requires additional structural analysis and consideration of the in-place state of the structures. Adequate maintenance frequencies of offshore wind farms can lead to much longer operational lifespans.

The Precedent Advantage 

Offshore wind projects typically take 7 to 11 years from idea to operation. Throughout this lengthy process, Precedent Consultants can serve as your Technical Advisor. We are not experts in all engineering disciplines, but via our network can assist in several areas. Our multidisciplinary approach combines technical discipline experience from geological, geotechnical engineering, and risk assessment to ensure your project is both financially viable and strong.

Whether you're in the initial feasibility phases or optimising an operational asset, our experts are here to assist. Visit www.precedentconsultants.com to learn more about our services or to schedule a call to discuss your project needs.