Optimal coupling of battery and green hydrogen storage for variable wind power: A real-world case study

The integration of variable wind power into electrical grids requires innovative storage solutions capable of addressing both short-term fluctuations and long-term energy imbalances. This study presents an empirical assessment of the optimal coupling between battery and green hydrogen storage using real-world data from a 140 MW wind farm. The analysis explicitly considers time-varying electricity demand to reflect realistic grid-connected operating conditions through a multi-layer simulation model. This study demonstrates that while batteries excel at short-term balancing with 90%–95% efficiency, and hydrogen enables seasonal energy shifting despite lower round trip efficiency (30%–45%), their hybrid configuration achieves superior performance. Results show that the hybrid system reduces curtailment to approximately 3%, increases renewable utilization to about 96.2%, and provides comprehensive flexibility across multiple time scales. Compared to a no-storage reference case, the hybrid configuration recovers approximately 136 GWh of renewable energy annually, corresponding to about 95 ktCO2 of avoided emissions. Economic analysis reveals distinct cost drivers: battery competitiveness hinges on capital cost reduction, while hydrogen economics depend primarily on electrolyzer efficiency and electricity prices. This paper provides a robust empirical validation of battery–hydrogen storage complementarity under variable demand, offering a replicable framework for regions targeting high renewable penetration and enhanced grid flexibility.