Marine operations represent a significant proportion of costs involved in the installation, operation, maintenance and decommissioning phases of a floating wind farm. The floating-wind industry is reaching array-scale deployments, and it is very important to optimize the various marine operations involved in each of these phases. This paper analyses the various challenges in the path and opportunities for encountering them by the transfer of technical know-how from similar offshore sectors.

This study analyses two logistical strategies that could be considered for operation and maintenance of floating wind farms. The results show that the OPEX for the strategy with an offshore maintenance base (OMB) is 5 %–8 % lower than with a service operation vessel. When CAPEX and the net present value are taken into account, then the fixed costs associated with building the OMB have a significant impact on selecting a preferred strategy.

This paper presents the state-of-the-art technologies and development trends of wind turbine drivetrains – the energy conversion systems transferring the kinetic energy of the wind to electrical energy – in different stages of their life cycle: design, manufacturing, installation, operation, lifetime extension, decommissioning and recycling. The main aim of this article is to review the drivetrain technology development as well as to identify future challenges and research gaps.

The estimation of fatigue in offshore wind turbine is highly relevant, as it can help extend the lifetime of these assets. This article attempts to answer this issue by developing a methodology based on artificial intelligence and data collected by sensors installed in real-world turbines. Good results are obtained, and this methodology is further used to learn the value of eight different sensor setups and employed in a real-world wind farm with 48 wind turbines.

A novel inverse-problem-based methodology estimates drivetrain main-shaft torsional stiffness and displacement by using high-frequency SCADA (supervisory control and data acquisition) measurements without an aeroelastic design basis. It involves Tikhonov regularisation for regularising the measurement data and the collage method for system identification. The estimated quantities can be further used to identify the site-specific torsional loads and the damage-equivalent load of the main shaft.