Electricity-hydrogen coupled energy storage bilevel optimization for offshore wind-powered zero‑carbon port microgrids considering multiple uncertainties

Zero‑carbon port microgrids (ZCPMGs) are essential energy hubs for maritime transportation, ensuring secure energy supplies and supporting low-carbon development. ZCPMGs typically rely on offshore wind power generation, complemented by energy storage systems, to operate in off-grid island mode. Previous ZCPMGs focused on electricity supply, and the rising hydrogen demand from shipboard microgrids (SMGs) makes electricity–hydrogen integration indispensable, placing greater demands on the configuration of electricity–hydrogen coupled energy storage systems (EHCESs). Furthermore, uncertainties associated with offshore wind power, ship load, and electricity prices significantly complicate the optimization of EHCES configurations. To address these challenges, a bilevel optimization model is proposed, with the upper layer focusing on the EHCES configuration and the lower layer on the daily operation of the ZCPMG. Specifically, an energy management optimization model is proposed for the SMG to identify load demands under various operating scenarios, accompanied by refined EHCES modeling. The model will be analyzed using stochastic programming to address renewable energy variability and information gap decision theory to manage extreme uncertainties in ship loads and energy prices. A case study based on an ZCPMG in northern Europe is conducted, and the results indicate that EHCES investments are economically viable under both opportunity and deterministic scenarios, although less under robust conditions. Among the uncertainties, energy price fluctuations exert the most significant influence on economic feasibility. Conversely, hydrogen prices and power-to‑hydrogen efficiency have minimal impacts, whereas electricity prices have a more substantial effect on the viability of EHCES configurations.