Grey hydrogen
Hydrogen is extracted from fossil gas releasing CO2 emissions into the air
CO2
Hydrogen
Blue hydrogen
Hydrogen is extracted from fossil gas before CO2 emissions are trapped and stored permanently underground
Hydrogen
Fossil gas
Underground
storage
CO2
Green hydrogen
Hydrogen is extracted from water using renewable electricity and releasing oxygen into the air
Renewable
electricity
O2
Hydrogen
Water
Grey hydrogen
Green hydrogen
Blue hydrogen
Hydrogen is extracted from fossil gas releasing CO2 emissions into the air
Hydrogen is extracted from water using renewable electricity and releasing oxygen into the air
Hydrogen is extracted from fossil gas before CO2 emissions are trapped and stored permanently underground
CO2
O2
Renewable
electricity
Hydrogen
Hydrogen
Hydrogen
Fossil gas
Underground
storage
Water
CO2