How do you produce green hydrogen?
Hydrogen is not a new energy source. According to the International Energy Agency (IEA), the global demand for hydrogen, has grown threefold since 1975 and is continuing to rise.
To produce hydrogen requires a source of energy, and to date, the majority of hydrogen has been produced from hydrocarbons or 'fossil fuels'. Around 6% of natural gas and 2% of coal is currently being used for hydrogen production.
The hydrogen is generated using 'steam methane reforming' (SMR), but these processes release carbon dioxide into the atmosphere, adding to greenhouse gas emissions - and is referred to as 'Grey Hydrogen'.
The IEA estimates that the production of hydrogen accounts for around 830 million tonnes of carbon dioxide per year, which is the equivalent to the total CO2 emissions of the UK and Indonesia combined.
'Blue hydrogen' is when the carbon dioxide generated by steam reforming is captured and stored underground. If we are to scale our use of hydrogen as an energy source, whilst simultaneously cutting greenhouse gas emissions, we need to be producing 'Green Hydrogen' - at scale.
Green hydrogen uses an electrolyzer - technology that passes an electric current through water to split the molecules into hydrogen and oxygen atoms.
Hydrogen produced from electrolysis can be stored and transported and converted back into electricity using fuel cell technology to power cars and heavy goods vehicles (HGVs) - producing only water as a by-product.
If the electricity to power the electrolyzer comes from renewable energy sources (solar or wind) this is considered a super low carbon hydrogen fuel.
The challenge is that just 1% of all hydrogen fuel is currently generated using renewable technology and the amount of energy required to produce Green Hydrogen at scale is huge – making expansion in the renewable energy infrastructure critical.
