Enhanced energy sharing and management between cross-harbour zero-emission buildings based on a combination of electric ferries and deck-on electric vehicles with grid integrations

Abstract

The current challenge in zero-emission buildings lies in aligning renewable energy sources with energy consumption, which needs to be addressed. Excessive mismatch can affect the performance of zero-emission buildings and the stability of the electricity grid. Energy sharing emerges as a viable solution to optimise energy distribution effectively. In this study, based on a cross-harbour zero-energy system consisting of dual broad-scale harbour buildings, one electric vehicle ferry and 10 electric vehicles, we study the enhancement of the original energy sharing of the system and the impact on the system performance by exploring the vehicle-to-building interactions of the electric ferry and electric vehicles. Three scenarios were examined to compare energy performance: electric vehicles operating with and without vehicle-to-building functionality alongside all submarine cables and the inclusion of vehicle-to-building functions with the removal of an intermediate submarine cable. The energy-matching performance of the system is enhanced in scenarios where vehicle-to-building functionality has been incorporated. The enhancement results in a maximum percentage increase in NPVrel of 0.22% and a maximum value of 3.77 x 106 HKD. When electric ferries and cars became pivotal for energy sharing, the percentage of techno-economic enhancement increased. Communication time and available capacity of vehicles were two parameters limiting the enhancement of energy sharing. Results demonstrate the effectiveness of this study in realising the feasibility of cross-harbour zero-emission ferry terminals through hybrid ocean energy systems. Meanwhile, energy sharing is realised through submarine cables to make full use of renewable energy generation. Incorporating electric ferries and electric cars with vehicle-to-building functions can enhance energy sharing. Therefore, this study's contribution based on the scientific gap is summarised.