Background: A significant effort has been underway to put renewable energy sources at the heart of the current energy model. Hydrogen produced via water electrolysis has been identified as one of the most promising means to help achieve this goal, especially by enabling energy storage in a sustainable and non-polluting way. In recent years, this situation has triggered novel developments in water electrolysis technologies and patenting of new inventions.
Objective: The aim of this work is to review the state-of-the-art in hydrogen production from water electrolysis using a patent search and analysis. The paper also reviews, in brief, some relevant patents on water electrolysis technologies.
Method: The patent search was carried out on the European Espacenet database. The research method was based on the use of keywords and subsequent content analysis. Patent data was discussed and analyzed in terms of production technology, year of publication, geographical area of the holder and applicant type.
Results: A total of 103 patent documents were identified, most of them (75%) reporting developments on conventional water electrolysis technologies. Patents on emergent technologies were mostly granted after 2005. Global research effort was mainly supported by academia both in Europe and the US. Industry played an important role in Japan.
Conclusion: Patent data suggests that water electrolysis technologies are either in their early stages of growth (High Steam Temperature Electrolysis, High Pressure Electrolysis) or in a phase of growth/maturity (Alkaline Electrolysis, Solid Polymer Electrolysis) with novel developments still needed and more patents foreseen in the future.