
TOKYO -- Though Japan continues to lead the world in hydrogen-related technology, its edge is narrowing as new patent filings by the country's companies and research institutions slow while Chinese players forge ahead with government backing.
Hydrogen is considered the ultimate clean fuel since it emits no carbon dioxide when burned. Tokyo-based research company Astamuse, in which Nikkei has a stake, has compiled a ranking of countries, scored in terms of the competitiveness of their hydrogen technologies between 2011 and 2020, based on the number of times their patents were cited in similar patent applications, expiration dates and other data. The 2020 figures were based on preliminary data.