6. Glossary

Hydrogène noir ou gris ; black or gray hydrogen

Hydrogen produced by burning coal, gas and oil. In 2021, 95% of the world's grey or black hydrogen will be produced from fossil fuels, mainly for use in refineries and cement works, which obviously does not meet today's decarbonized requirements.

Hydrogène bleu foncé; deep blue hydrogen

Hydrogen produced by burning coal, gas and oil with slightly less harmful production in terms of greenhouse gas emissions when the CO ₂ can be captured and stored.

Green hydrogen

Hydrogen produced exclusively with renewable energies (solar, wind, hydroelectric, biomass, nuclear, etc.). Today, it represents one of the hopes for achieving the zero-carbon objective by 2050, i.e. doing without...