The techno-economic flexibility investigation and enhancement for the hybrid ocean-energy supported zero-energy building and seawater-transportation system

Toward net zero emissions by 2050, efficient renewable energy systems and various energy interactions are increasingly proposed to improve energy matching and flexibility capacities. The existing studies primarily focused on onshore solar and wind energy sources, which can interact with electric vehicles or static batteries to improve the economic performance by the energy flexibility control. However, the hybrid system of ocean energy interacting with buildings and electric boats is rarely discussed. This study proposes an innovative integrated energy flexibility control to improve the techno-economic performance of a hybrid wave energy converter (WEC) and floating photovoltaic panel (FPV) energy system supporting a coastal hotel building and eight electric boats. We propose five control strategies, guaranteeing the normal excursion function of the boats while supporting enough energy for the building. In addition, two new indicators are presented to investigate the peak-shaving (PSI) and valley-filling (VFI) capabilities. A weighted matching index (WMI) is provided to investigate the overall energy matching capability. Annual electricity fees and relative net present value (NPVrel) are introduced to analyse the economy. To analyse the environmental aspect, we use the annual operational equivalent CO2 emissions (CEa) to track the emissions of the hybrid system. We observe that strategy E, integrated with the non-dominated solutions from the other four strategies, shows a significant profitable economic performance The annual electricity fee is reduced by 12.22%, and the NPVrelis improved by around 16.62%. PSI and VFI can reach 98.01% and 17.05% for a 100 kW line.