IRENA | Innovation trends in electrolysers for hydrogen production

Renewables-based hydrogen can be used as feedstock for the chemical sector and as fuel in fuel cells where the only by-product is water. It can also replace fossil sources in synthetic fuels, for example, when combined with captured carbon.

Additionally, hydrogen is abundant and can be obtained through the electrolysis of water, using renewable electricity, in the presence of electrocatalysts.

These factors make hydrogen very attractive as a green energy source – but only provided that its production, through electrolysers, is green too.

The new report tracks the evolution of patent filings over the last 15 years and highlights several trends, including:

• In 2016, the number of patent families for water electrolysis technologies surpassed the number of patents related to producing hydrogen from fossil sources (e.g. solid or liquid coal and oil-based hydrogen sources).
• In 2018, inventions for electrocatalysts based on cheaper minerals surpassed the number of inventions based on more traditional but expensive electrocatalysts (which use e.g. gold, silver, platinum or other noble metals), confirming the drive for cheaper alternatives. This trend is pronounced and demonstrated by a surge in Chinese national patent filings.
• Photo electrolysis is a strong newly emerging technology that can integrate electricity and hydrogen production in a single step, potentially lowering production costs. The report notes an above average number of international patent families in this area - some 50% of which are filed by universities.