Effects of Renewable Energy Unstable Source to Hydrogen Production: Safety Considerations

Hydrogen is considered a promising energy carrier for a sustainable future when it is produced by utilizing renewable energy. Nowadays, less than 4% of hydrogen production is based on electrolysis processes. Each component of a hydrogen energy system needs to be optimized to increase the operation time and system efficiency. Only in this way hydrogen produced by electrolysis processes can be competitive with the conventional fossil energy sources. As conventional electrolysers are designed for operation at fixed process conditions, the implementation of fluctuating and highly intermittent renewable energy is challenging. Alkaline water electrolysis is a key technology for large-scale hydrogen production powered by renewable energy. At low power availability, conventional alkaline water electrolysers show a limited part-load range due to an increased gas impurity. Explosive mixtures of hydrogen and oxygen must be prevented; thus, a safety shutdown is performed when reaching specific gas contamination. The University of Pisa is setting up a dedicated laboratory, including a 40-kW commercial alkaline electrolyser: the focus of the study is to analyze the safety of the electrolyser, together with its performance and the real energy efficiency, analyzing its operational data collected under different operating conditions affected by the unstable energy supply.