Innovative Mooring Design to Raise Yield of Floating Wind Farms in Deep Water.

Presentation Description: There is a unique opportunity with floating offshore wind turbines (FOWTs) to increase the power density of the wind farms. Kent have explored the possibility of designing asymmetric moorings for FOWTs so the turbines move position depending on wind direction to minimise wake losses, maximising the power density of the farm. I.e. The turbines can passively change position, defined by the wind direction, seeking to minimise the interaction between upstream and downstream turbines by changing the effective spacing. To achieve this, Kent has adopted a gaussian wake model to understand how turbine wake effects decay towards the edges of the wake profile.

Kent has leant on their in-house expertise to perform MODOT (multi-objective design optimisation tool) driven mooring analyses for this study. The individual mooring lines are variable in terms of: stiffness, length and anchor position. The MODOT tool is then used to drive the system iterations towards the most optimum mooring solutions.

Currently, FOWT offset is a maximum of around 15% of water depth. So, this study is particularly relevant to deep and ultra-deep sites where deeper water allows for greater turbine offsets (and therefore more scope to reduce wake losses) using conventional mooring types such as catenary/semi-taut systems.