Optimisation of the Resen Wave Energy Converter: weakly nonlinear potential flow theory analysis and optimization of the performance of the RESEN wave energy buoy in both the frequency and time domains

Wave energy converters are one of the most innovative renewable energy devices that have as main target the exploitement of the energy content of the ocean waves, to then generate non-fossil usefull electrical energy. The Resen Waves Smart Power Buoy is a promising device in the field of wave energy conversion. Developed by Resen Waves, this buoy is a point absorber that serves multiple purposes, making it a versatile solution for various applications, like: 1.??providing sustainable electricity to remote offshore locations, including small cities and devices located within the ocean. By harnessing the power of waves, it offers a renewable energy source that can help reduce reliance on traditional grid systems. 2.??providing real time data from remote locations, usually from measurement instruments. 3.??Reduce the costs of real time measurements in offshore locations. Traditionally measurement devices, due to their remote offshore locations, are run by battery. The problem of the batteries is that they need to be changed periodically and this operation requires specialised personnel and specific vessels to reach the locations, which will increase dramatically the cost of these measurements and the required time to be collected (while often it’s essential to collect them in real time, like when earthquakes and tsunamis are monitored). Moreover, adverse weather conditions in the ocean can further complicate the battery replacement process. To address these challenges, the Resen Waves Power Buoy incorporates an innovative solution. It powers a battery pack located on the seabed through the mooring line, enabling it to supply power to various instruments and machinery in the open sea. Furthermore, the buoy can log data from connected instruments via a fibre optic connection in the mooring lines. This data is then transmitted to shore using satellite, 3G, or 4G connections, ensuring seamless and uninterrupted data communication. The study has as objective several goals that has been fulfilled during the analysis: 1.??Conduct an in-depth investigation into the design, performance and efficiency of different float configurations for the existing power buoy model developed by Resen waves in the previous years. 2.??Explore the implementation of a new component within the buoy: a battery pack positioned on the float back instead of the current placement inside the drum and shaft assembly. 3.??A time domain simulation will be performed to confirm the obtained results mentioned in the first two points, also in the time domain. To facilitate this investigation, a multi-faceted approach will be adopted, utilizing existing literature, available data on the device, and numerical models (mostly written in MATLAB). Through extensive frequency domain and time domain analyses, significant findings have emerged, holding promise for enhancing the performance of this device and contributing to the advancement of wave energy converters and renewable energy technologies.