Assessing Offshore Wind System Integration: Comparative Analysis of Floating Photovoltaics, Oscillating Surge Wave Converters, and Battery Energy Storage Systems

Abstract: The high penetration of wind power is increasing the intermittency and power variability into the existing power grid. This is forcing industries to look for optimal configurations in order to improve their systems performance and minimize these effects from the power production method. Studies show that there are different ways of reducing the power variability and therefore stabilize the energy supply. Hybrid offshore energy systems based on the combination of two or more marine renewable energy sources can reduce the variability and costs associated with the installation and operation of the systems. Battery energy storage systems combined with wind power could also smoothen the fluctuation of the power supply and improve the utilization and overall energy efficiency. This master thesis was performed on behalf of RWE Renewables AB in Malmö, and conducted at the Department of Energy Sciences at Lund University, Faculty of Engineering. The purpose of this thesis was to examine the possibilities of system integration with one of RWE Renewables planned offshore wind farms, the Neptuni project. Extra focus was put on studying system integration of three different technologies, their power generation for the specific site, their economic feasibility and the potential reduction of power fluctuations with the hybrid systems respectively. The potential benefits and challenges of the three technologies were first studied in a literature review. Thereafter, a case study was executed to perform simulations and calculations of the technologies power generation and measure their and the respective hybrid systems potential revenues and mitigation of power fluctuations. Four different electricity spot price scenarios for the future are conducted enabling the calculation of the Net Present Value of each technology for each scenario. The findings indicate that one scenario of floating Photovoltaics (FPV) yields a positive Net Present Value over its lifetime, while the other scenarios yields a negative value, as well as the Oscillating Surge Wave Converter (OSWC) and Li-Ion Battery Energy Storage System (BESS), are not currently profitable investments. However, economic viability should not be the sole determinant for investment decisions, as these technologies offer valuable contributions such as experience and innovation. Additionally, integrating FPV and OSWC with an offshore wind farm results in reduced variability. Also, increased correlation with the system load with higher installed capacity, enhancing grid stability, is confirmed for all technologies examined. While the analyzed technologies may not be immediately viable for investment, their potential for future development, long-term cost stability, and enhanced energy security make investments in renewable energy strategic for the future. Starting with modest installed capacities and considering the broader benefits of renewable energy are advisable when making investment decisions.