Introduction to Offshore Wind Turbine Designs

Offshore wind turbines are a rapidly developing technology. As its name implies, they are wind turbines that operate in the ocean to generate electricity. Offshore wind technology generates more power than conventional wind turbines due to the higher wind speeds in the ocean. However, this technology requires more complex technologies - for example the mooring system - to be incorporated in its design, as well as computational calculations. In this article, I will be talking about the considerations for a physical design of offshore wind turbines rather than theoretical computational calculations, which is a prediction tool used for calculating power generation and efficiency.

One source of complexity for offshore wind turbines is the multitude of components needed. A conventional wind turbine would only require a tower, shaft, blades, and internal circuits to convert the kinetic energy into electrical energy. On the other hand, offshore wind turbines contain certain components that greatly differentiates and complicates the design for offshore wind turbines: the mooring system and the floating platform.

The floating platform is what keeps the turbine afloat and a lot of considerations need to be taken into account when designing the floating platform: it needs to have great stability, it needs to be able to handle the load of the thousand-tonne wind turbine, and it needs to be able to withstand harsh waves and storms. Various types of designs for the floating platform exist, such as the semi-submersible, the barge, the spar, and the tension leg (TLP). In terms of practicality, the TLP has the most stability, however many real-life wind turbines also utilise semi-submersible platforms. These two platform types have the most potential in integrating a hybrid energy system where a single turbine unit can harness both wind and wave energy.

The mooring system includes large chains that connect the turbine unit to the seabed, ensuring that the turbine unit stays in place. However, for the TLP platform, the mooring system is essential in maintaining tension and ensuring that the platform is semi-submerged for maximum stability. On paper, it may seem like a simple component, however, this mooring system needs to be connected from a turbine unit all the way down to 60-100m to the seabed.

These are only some of the design choices that researchers and engineers have to consider. There are other considerations, such as the adhesives used and the amount of rotors on a single unit. The number of rotors determines the number of rotating units in a single turbine, and theoretically, you can have up to 50 rotors on a single unit. Moreover, there have been considerations of using fibre-reinforced polymer instead of conventional steel to avoid corrosion due to high exposure to water.

Overall, despite the complexity of offshore wind turbines, it still serves as a contender to leading the clean energy industry. It is much more efficient than conventional wind turbines, and many researchers around the world are currently developing the most optimal designs for offshore wind turbines.

Reference:

Hu C. (n.d.). The 1st Asia Pacific Conference on Offshore Wind Technology (APCOW2024).

https://www.apcow2024.org/