ECN brings access systems offshore wind turbines together in new overview
The report Offshore Wind Access 2017 brings together existing and under-development access systems for offshore wind Operation and Maintenance (O&M). For the first time, an overview of available access systems has been compiled to show the recent developments on offshore wind access and how they are related to O&M strategy selection.
What is offshore wind access?
Offshore wind farms are constantly moving further from shore in order to capture favourable wind conditions. However, challenges regarding their installation, operation and maintenance become more prominent. Especially, transfer of technicians to the wind turbines is the most important factor of weather downtime during maintenance activities, leading to high revenue losses due to loss of energy production. Accessibility (the percentage of time technicians can be safely transferred to offshore wind turbines) can drop to less than 80 percent during winter months in a typical North Sea location. This has driven research into new logistic concepts and innovative access systems.
Based on the point of access, three categories are identified:
- Access to the boat landing
- Access to the platform of the transition piece
- Access to the helideck on top of the nacelle.
Besides the conventional method of access to the boat landing through crew transfer vessels, motion compensated gangways on the deck of service operation vessels have entered the market during the last decade, moving the maintenance base offshore. The report shows the growth of this market in alignment with the needs for more efficient and safer transfer of technicians and cargo to offshore wind turbines.
How ECN can help you reduce costs of O&M?
Assessing the impact of various O&M strategies and access systems on the performance of offshore wind farms requires dedicated scenario modelling considering the interactions with other factors such as: component failures, metocean conditions, weather operating limits for vessels and equipment, availability of access systems, vessels, equipment and spare parts and technicians working shift patterns.
ECN's in-house developed tool ECN O&M Access provides the framework for offshore wind farm operators to optimise the O&M strategy depending on site-specifics and supports the decision making regarding the selection of the optimal access system. It allows vessel and access system designers and developers to investigate the impact of their designs/systems on the wind farm availability and maintenance costs. This way, the drivers for the required research on access systems can be identified as well as the cost reductions that can be achieved.
For more information about ECN services on offshore wind O&M strategy and modelling, for R&D cooperation on the subject of accessibility or for interest in joining the Offshore Maintenance Joint Industry Project (JIP) please contact Georgios Katsouris or Rens Savenije via our contact form.