Reliable and Efficient High Power DC Distribution for Hydrogen Electrolysis

Hydrogen is a versatile fuel source, and electrolysis stands out as a promising method to produce hydrogen. Traditionally, the power distribution system for hydrogen electrolysis is designed for the individual electrolyzer modules with DC (direct current) power requirement in the range of 1 to 5 MW. The power supply to these modules is accomplished in three steps starting from high voltage to medium voltage and medium voltage to low voltage transformations. The last step involves the rectification process from AC power to DC power to electrolyzers. Supplying DC power to a gigawatt-scale hydrogen plant comprises of multiple power transformers, rectifier transformers and rectifiers in parallel leading to larger footprint, and higher capital and higher maintenance costs. Accordingly, this paper explores an alternative approach, where high-power DC distribution system, like those used in aluminum potlines, for hydrogen production. These are proven technologies used for long time in mining and metals industry. Operational experience of such a system highlights its reliability, efficiency, cost-effectiveness, and enhanced adaptability. This paper addresses the critical role of high-power DC distribution systems in realizing the full potential of hydrogen electrolysis for sustainable energy production.