HR Wallingford – Marine Operations

HR Wallingford – Marine Operations

It’s all in the planning

By using an event simulation system, offshore wind developers can create the optimum strategy for marine operations

Developing offshore windfarms in the UK comes with considerable risk even after a project has been granted consent. To win in the competitive CFD auctions, developers have to look holistically at the lifetime costs and performance of their assets to identify opportunities to drive down the Levelised Cost of Energy (LCoE). Optimising the planning and execution of windfarm construction projects is therefore critical to their success.

As part of the planning and design process it is necessary to consider the impact of, and the interactions between, all the component parts of the windfarm construction process. These components include the complex installation sequences, the onshore port facilities, the vessels to be used and the metocean conditions.

Examining this process in detail enables the selection of the most cost-effective operational strategies and avoids loss of revenue.  An event simulation system brings all these components together, allowing the optimal strategy to be developed for both short- and long-term planning of marine operations.

During the construction phase and throughout the lifetime of the windfarm for maintenance purposes, ensuring safe and efficient operations is a priority. This can be assisted by a decision support tool, based on an event simulation system, which examines the operation in question with the selected facilities and forecast metocean conditions to advise on the time windows available.

PortOps is an event simulation model which was originally developed by HR Wallingford for the LNG industry. With an extensive track record spanning over a decade of successful application on LNG projects, it now provides an innovative tool for the optimisation of windfarm construction. It can be used to enhance the planning and execution of complex installation sequences with multiple interfaces and dependencies and also to support the undertaking of those installation sequences as a decision support tool.

This event simulation model helps to ensure safe and efficient marine operations protecting offshore personnel and vessel assets by accounting for windfarm service vessel thresholds of operation in harbours and open seas and the operability of vessels such as jack-up barges, which are susceptible to currents and mobile beds.

Tailor-made event and cost simulation
Michael Case, Renewable Energy Lead at HR Wallingford explained: “PortOps has been developed as a ‘shell’. This means individual installation components, such as vessel arrivals, cargo handling and the allocation of resources (pilots, tugs, berths, equipment and labour) can all be represented as sub-modules. This allows us to develop a tailor-made, bespoke implementation for each project to accurately represent the specific operations involved. It can also be used as a real-time decision-making tool during turbine installation.”

The operation is simulated, incorporating historical or forecast marine weather conditions and their influence on the operation, allowing windows of uptime to be accurately represented for each discrete operation.

As windfarms move further offshore and operate in increasingly challenging wave and wind conditions, minimising the installation, operating and maintenance costs is a critical success factor. The use of event simulation systems can improve vessel accessibility and reduce the need to suspend costly vessel operations, for example, minimising downtime and unnecessary operational costs. PortOps can also incorporate economic evaluation routines to enable the entire operation to be assessed based on realistic cost assumptions.

Port selection and design
Linking a port and terminal operations simulation system with port selection and design from the outset is one of the most effective ways of optimising the planning of marine operations. HR Wallingford links PortOps to port selection, port design validation (including physical model testing) and port operations advisory services. The marine consultancy has ten state of the art navigation simulators which can be used to plan and optimise detailed port operations and vessel movements.

Planning for decommissioning
There remains considerable uncertainty around the future decommissioning costs of large-scale offshore wind projects. In fact, as part of its ongoing research plan, HR Wallingford will be looking at the possibilities for pile removal and seeking insight into appropriate and effective methods to minimise both the cost and environmental impacts associated with the decommissioning of offshore piled structures. An event simulation system such as PortOps can be used to build a realistic model of a decommissioning project, helping to reduce uncertainty and associated risk.

In summary
Improved planning and enhanced operational decision-making are fundamental to driving down the cost of production of offshore wind energy. The use of an event simulation system from the earliest stages of a development project, through operation, maintenance and decommissioning can provide an innovative tool to support this drive.

HR Wallingford