A hybrid transmission network in pelagic islands with submarine cables and all-electric vessel based energy transmission routes

Abstract

Isolated microgrid is a conventional power supply mode for inhabited pelagic islands, but limited land resources restrict the capacity of renewable energy units, resulting in overreliance on diesel turbines or gas turbines, which consumes a large amount of fossil fuels and produces substantial emissions. Establishing effective connections among pelagic islands can optimize the use of land/energy resources in uninhabited islands. However, a transmission network composed solely of submarine cables is not feasible or economical. This paper proposes an energy transmission route that uses all-electric vessels (AEVs) to transport battery energy storage (BES) between islands. The battery swapping mode is employed and part of the cable network is replaced by AEV routes to transmit the renewable energy and lower the overall cost. First, the transmission modes composed of AEVs and batteries are modeled to analyze energy transmission efficiency and cost-effectiveness. Then, a hybrid transmission planning model is established using scenario clustering method, and the additional costs under extreme weather scenarios are also considered. The model is optimized with the chaotic gravitational search algorithm, and the feasibility and effectiveness of the proposed method are verified through actual cases and sensitivity analysis.