Flexible operation strategy of an integrated renewable multi-generation system for electricity, hydrogen, ammonia, and heating

Abstract

Sustainable development and efficient integration of different resources are imperative for future energy systems. To solve the uneven temporal–spatial distribution of renewables, green hydrogen and ammonia can be used as short- and long-term energy storage mediums, respectively. The synergistic effect of introducing these two media into an integrated renewable multi-generation system was examined in this study. The system provided a constant 10 MW electrical baseload and green ammonia when excess hydrogen was available to satisfy the electricity needs for 24 h. The effects of energy storage capacity and baseload electricity were considered. The performance of the system and strategy was thermodynamically investigated, and its generality and feasibility were dynamically evaluated based on the hourly weather data of 10 cities in China in 2020. The analysis revealed that the maximum overall energy and exergy efficiencies were 50% and 73.1%, respectively. The maximum energy efficiency in each subsystem varied from 33.7% to 73.8%, whereas the maximum exergy efficiency changed from 43.5% to 60.9%. In the baseline condition, the total energy outputs of solar, wind, and backup power subsystems were 33.3, 48.5, and 16.4 GWh, respectively. The hydrogen and ammonia yields were 994.5 and 7,201 t·y−1, respectively. The higher hydrogen and ammonia yields of Shenyang, Shanghai, Kunming, and Harbin demonstrate great potential for the development of this system.