Techno-economic assessment of waste heat recovery for green hydrogen production: a simulation study

The demand for hydrogen as a green energy carrier is increasing as energy sources shift towards sustainable solutions. Alkaline electrolysers offer a clean method to produce hydrogen, though their limited efficiency results in significant energy loss. This study explores the potential to enhance electrolyser efficiency through waste heat recovery. It examines the technical and economic aspects of using excess heat from an alkaline electrolyser, powered by surplus renewable energy, as a feed-in source for district heating. Utilising a simulation framework for renewable power plants, the study integrates a validated electrolyser model. The analysis focuses on the impact of heat utilisation and heat sales on system efficiency, economic viability, and hydrogen pricing. Findings show improved efficiency with heat supply, especially for smaller electrolyser configurations. Heat sales lead to a slight reduction in hydrogen costs and the study demonstrates their viability for smaller electrolysers. Additionally, it highlights the need for an advanced cooling strategy for larger systems. Overall, the results underscore the potential of integrating electrolysis with district heating, offering valuable insights for future renewable-powered energy systems.