Dynamic hydrogen blending mechanism for offshore islanded energy systems based on renewable hydrogen storage

Offshore oil and gas platforms operating in islanded mode rely heavily on gas turbines and therefore face persistent decarbonization challenges. This study develops a wind–PV–hydrogen integrated energy system that couples renewable generation, PEM electrolysis, hydrogen storage, a fuel cell, and a hydrogen-blended gas turbine. A storage-dependent rule-based energy management strategy is proposed to coordinate renewable-electricity delivery, surplus-to-hydrogen conversion, fuel-cell support, and gas-turbine fuel substitution. An 8784-h simulation based on 2024 meteorological data delivers 26.273% renewable electricity while maintaining zero hourly loss of power supply under the assumption of continuous natural-gas backup. Annual operational CO 2 emissions decrease by 11,087.84 t, or 26.273%, relative to the natural-gas-only baseline. Hydrogen blending is pulse-like: 36 events exceed 1 vol% for at least 2 h, with a mean duration of 48.11 h and a maximum duration of 148 h. The annual time-average and maximum blending ratios are 0.912 and 20 vol%, respectively. A perfect-foresight offline benchmark subject to the same physical constraints improves annual CO 2 reduction by only 0.092 percentage points. Engineering screening further quantifies water-treatment demand, electrolyzer cycling and degradation scenarios, 350-bar storage mass and footprint, monthly variability, and offshore-cost sensitivities. The results demonstrate that renewable hydrogen acts mainly as a storage-constrained flexibility resource; they do not constitute power-quality validation, turbine certification, or investment-grade offshore design.