Effect of voltage elevation on cost and energy efficiency of power electronics in water electrolyzers

The interest in green hydrogen has been increasing in recent years for several applications, such as energy storage and different industrial sectors. The green hydrogen is produced from water electrolysis supplied by renewable electricity. The operation of industrial large-scale water electrolysis is characterized by a high DC current in the kiloampere range and a few hundred volts. Therefore, the rectifier unit plays an important role in converting AC current of the electricity grid into DC current supplied to the electrolyzer. The power electronic converters are also considered as one of the main cost components of the water electrolyzer system. The objective of this paper is to study whether the operation at a higher voltage than typical values (200 V- 300 V) can be beneficial both for the cost and energy efficiency of the power converters in water electrolyzer systems. In this study, three different rectifier topologies considered for an industrial-scale electrolyzer are analyzed and compared in terms of energy efficiency and cost. The simulation models of each topology are carried out in the Matlab/Simulink environment.

Automated summary

The interest in green hydrogen has been increasing in recent years for its applications in energy storage and various industrial sectors. This paper focuses on studying the operation at higher voltage than typical values to determine its potential benefits for cost reduction and energy efficiency in power converters for water electrolyzer systems. Three different rectifier topologies are analyzed and compared in terms of energy efficiency and cost using simulation models in Matlab/Simulink environment.