Offshore wind farm assets require regular inspections. Studies and industry experience have highlighted the importance of selecting the appropriate inspection and maintenance (I&M) plan, as it directly impacts the reliability of the components and the associated maintenance cost. If inspections are carried out too frequently, the associated risks will be low and reliability will be high, but the cost will also be high. On the contrary, if no or very few inspections are carried out, unexpected failures of the structures could occur. This paper presents a risk-based inspection (RBI) framework for offshore wind farms, building on existing knowledge from other industries including nuclear, oil & gas, chemical and aerospace. This approach considers the probability, the consequences and the cost of the operational or maintenance activity via a criticality analysis that allows optimal selection and prioritisation of I&M activities. A case study is presented where this framework is implemented on the transition pieces (TPs) of the wind turbines, by investigating information received from design, operation and inspection reports as well as monitoring equipment. Guidelines are also proposed on how to utilise novel monitoring and visual inspection techniques to further improve the implementation of RBI. The results of this paper suggest a less frequent I&M strategy, which could reduce the associated TP inspection costs by up to £0.7 million/MW installed and increase the safety of personnel. The study will be of interest to offshore wind farm developers, operators and maintenance providers, to better prioritise I&M activities and increase the operating revenue of their assets.

This paper presents a methodology for the reliability and power flow assessments of island/off grid power networks for situations of scarce data and information. This could be a useful tool to help decision makers replacing fossil fuel with renewable energy sources for the off grid/ Island power networks. The aim of the paper is to present and apply a general methodology, informing the decision making towards sustainable island communities. Ushant Island, a small French island, is considered as a case study. The assessment of the current power network status and the reliability analysis reliability are presented. The grid performance parameters are further compared for conventional diesel generator operation and renewable energy generation scenarios to emphasis the advantages of replacing the ordinary diesel units with renewable energy sources in terms of system reliability and network future structure plan. It provides recommendations for the system structure.

Floating offshore wind is an emerging technology that holds considerable potential to utilise areas deeper than 60 m for sustainable energy generation. As the floating offshore wind turbine industry continues to develop and grow, the capabilities of established port facilities need to be assessed as to their ability to support the expanding construction and installation requirements. This article assesses current infrastructure requirements and projected changes to port facilities that may be required to support the floating offshore wind industry. Understanding the infrastructure needs will help to identify the port-related requirements. Floating offshore wind turbines can be installed further out to sea and in deeper waters than traditional fixed offshore wind arrays, meaning they can take advantage of stronger winds and additional sea locations. Separate ports are required for substructure construction and fit-out of the turbines and maintenance. Large areas are required, about twice the plan area of the structure, for the laydown of mooring equipment, inter array cables, turbine blades and nacelles. The capabilities of established port facilities to support floating wind farms can be assessed by evaluation of size of substructures, height of wind turbine with regards to the cranes for fitting of blades, distance to offshore site and offshore installation vessel characteristics. Spar, barge, TLP and semisubmersible types have been deployed as demonstration units. Pre commercial units have been installed off the coasts of Portugal and the east coast of Scotland. This article reviews and defines the port and shipyard requirements for floating offshore wind turbines. It will support decision-makers to guide port infrastructure investments and project developers in their site selections. There up to 15 port functions that need to be considered, for construction, assembly and support of offshore activities. These could be fulfilled by one or a combination of different ports.

Control and Instrumentation (C&I) systems provide the framework for monitoring critical data streams and implementing control functions during the operation of a wave energy converter. However, cost and power constraints of wave energy converters present a challenge in designing a C&I architecture that is appropriate for the application. This study describes the design of a C&I system for an integrated wave energy array. A specification is first developed by defining operational requirements and design principles, measurement and control priorities are then identified, incorporating a failure mode and effects analysis. Available instrumentation options in the industry are reviewed and C&I topologies are presented. A distributed control system is proposed for the Albatern WaveNET Array, allowing for the implementation of control and protection strategies and condition monitoring. Improved C&I allows for the reduction of unplanned maintenance, maximising device availability for energy production.