In order to meet the increasing demand for energy from renewable sources, the UK is being encouraged towards offshore array deployments and marine energy parks. The pressure to perform efficient, timely and cost effective marine operations consequently increases. Central to success is the accessibility of the site by suitable installation vessels and associated with this is the availability of appropriate weather windows, subsequently, via careful planning, the reduction of downtime and its associated cost.
There are a number of methods in existence which analyse the likelihood of accessible conditions occurring; however few methods sufficiently address complete, complex installation operations and vessel selection. Furthermore there exists a shortage of cost effective, appropriate installation vessels, particularly when seeking those capable of working in severe tidal currents. Efficient utilisation of available resource is therefore essential.
This work discusses two, complementary, solutions to these problems. Firstly a software package that has been specifically engineered for the analysis and optimisation of marine energy installations, Mermaid (Marine Economic Risk Management Aid). The second is a fit-for-purpose vessel designed specifically to perform optimally during installation, maintenance and decommissioning of marine energy devices – the HiFlo-4 Installation Vessel (HF4). Herein Mermaid is applied to a case study tidal energy array installation, demonstrating the methods which may be used to optimise the process, ultimately achieving a reduction in capital expenditure. Throughout this analysis traditional offshore construction vessels are considered alongside the HF4. This process demonstrates the importance of performing a thorough weather risk analysis, and of selecting the most suitable tools and methods for the task at hand.