Advanced logistics planning for offshore wind farm operation and maintenance activities

Abstract

Offshore wind turbine technology is moving forward as a cleaner alternative to the fossil fuelled power production. However, there are a number of challenges in offshore; wind turbines are subject to different loads that are not often experienced onshore and more importantly challenging wind and wave conditions limit the operability of the vessels needed to access offshore wind farms. As the power generation capacity improves constantly, advanced planning of Operation and Maintenance (O&M)activities, which supports the developers in achieving reduced downtime, optimised availability and maximised revenue, has gained vital importance. In this context, the focus of this research is the investigation of the most cost-effective approach to allocate O&M resources which may include helicopter, crew transfer vessels, offshore access vessels, and jack-up vessels. This target is achieved through the implementation of a time domain Monte-Carlo simulation approach which includes analysis of environmental conditions (wind speed, wave height, and wave period), operational analysis of transportation systems, investigation of failures (type and frequency), and simulation of repairs. The developed methodology highlights how the O&M fleets can be operated in a cost-effective manner in order to support associated day-to-day O&M activities and sustain continuous power production

Improved Methodology of Weather Window Prediction for Offshore Operations Based on Probabilities of Operation Failure

“…Typically, the accessibility of offshore wind farm depends on choice of access/installation vessels and their respective weather limits. Dalgic et al suggests different weather limits for crew transfer (CTV) and jack-up vessels-1.5 m and 25 m/s for the former and 2.8 m significant wave height and 36 m/s wind speed limits for the latter [13]. O Conor et al [22] presents a more detailed overview of state-of-the art access vessels and their wave height limits-significant wave height limits range from 1.5 to 3 m depending on the type of vessel used.…”

“…A major contributor, among others, to these costs are related heavy lift and transportation vessel charter expenditures. Dalgic et al [13] suggests that costs associated with transportation systems can amount to 73% of total O & M costs for an offshore wind farm. Furthermore, it can be estimated from Fingersh et al [14] that transportation system costs can add up to 50% of the total installation expenditures.…”

Strategic Maintenance Scheduling of an Offshore Wind Farm in a Deregulated Power System

“…In addition, a sensitivity analysis is carried out that deduces that the electricity price is one of the major parameters affecting the outcomes. Moreover, [24,25] mention that there is also a need for improving the way the condition monitoring features are being currently exploited as the transportation costs and scheduling of the transport mediums include the majority of the costs [26]. Furthermore, the study in [27] performs a sensitivity analysis in order to find out the most important parameters affecting O&M. It concludes that repair duration and labor working shift length are two of the most significant variables influencing the cost; maintenance resource availability and components' failure rates are the other two impacting availability.…”

An Approach for Evaluating the Influence of Accessibility on Offshore Wind Power Generation

“…In [12], an optimal model for offshore maintenance scheduling and vessels routing is proposed, in which multiple wind farms, multiple vessels, multiple periods and multiple Operation & Maintenance (O&M) bases are taken into account. Dalgic et al [13] used a time domain Monte-Carlo simulation approach to achieve the most cost-effective approach to allocate O&M resources as transport vehicles. They also analyzed the environmental conditions such as wind speed, wave height, and wave period.…”