A Hybrid Power Generation Platform Combining Floating Wind Turbine and Oscillating Water Column Wave Energy Converters

Abstract

Abstract Recent years have seen rapid development in offshore wind technology. Particularly, floating offshore wind turbines possess great potential in deep water coastal places around the world, though they are now still in the demonstration phase. At the same time, the unused wave energy is also abundant at the sites of offshore wind farms, especially those in deep sea regions. Collecting wave energy in offshore wind farms might benefit both total energy production and reduce maintenance cost. Therefore, integrating offshore wind turbine with wave energy conversion devices could be a good idea to achieve higher efficiency and lower cost. In this paper, we report a combined wind and wave energy power generation concept called WindOWC, which constits of a 5MW wind turbine and three oscillating-water-column (OWC) wave energy converters (WECs). The wind turbine is mounted on a semi-submersible floating platform, which is similar to OC4-semibsubmersible, and the OWCs are located in its three offset columns. In this design, the wind turbine and WECs share the same supporting platform and the power transmission system, thus is expected to reduce the cost of energy. Also, it is possible the OWCs may improve the platform dynamic performance by providing positive damping through controlling the air turbine rotational speed. In this work, we describe the geometry properties of the proposed WindOWC concept and conduct preliminary hydrodynamic analysis using potential flow theory. The ANSYS AQWA is used to obtain the system dynamic responses in frequency and time domain, respectively. The OWC dynamics and expected positive damping from them will be investigated in the future.