The green hydrogen movement                                                                                                                                                                                                                                                                                                                                                                                                                                                              

Green hydrogen is one of the most talked about topics in renewable energy right now - particularly as discussions intensify around the energy market and the UK’s energy security; many stating that it’s investment in renewable energy that holds the solution to much of our energy-related issues. But what exactly is green hydrogen; how is it different to blue or grey hydrogen, and why is it important?

Past challenges around hydrogen use in industry

It’s only in recent years that the interest in and uses of hydrogen have really begun to take hold - hydrogen production previously considered to be particularly expensive and, the production of green hydrogen, even more so.

This means that the true potential of hydrogen in energy production and industry is still being realised, with sectors such as transportation and utilities still yet to be fully actualised - currently considered as ‘emerging markets’.

Alongside this, not only has hydrogen production been traditionally considered as ‘too expensive’ for mass use in industry but there have also been concerns and difficulties surrounding the storage and transportation of hydrogen due to its density and (light)weight.

However, investment & interest in hydrogen production and, particularly green hydrogen, has boomed in recent months thanks, in no small part, to the costs associated with fossil fuels; with many investors and industry leaders now seeing hydrogen as a cost effective, renewable alternative to now extremely expensive gas & oil.

What is green hydrogen?

Green hydrogen refers to hydrogen produced from splitting water through electrolysis - the by-product of this being hydrogen and oxygen, as opposed to blue or grey hydrogen which is produced when natural gas is split into hydrogen and CO2, using either Steam Methane Reforming or Autothermal Reforming.

NB: The difference between blue and grey hydrogen is how the CO2 is stored; ‘blue’ being stored, and ‘grey’ being released into the atmosphere.

A note on blue hydrogen

Blue hydrogen describes hydrogen produced via natural gas, but where the CO2 is captured and stored (CCS/CCUS). This is considered to be more environmentally friendly than grey hydrogen as the CO2 is stored away, rather than simply released into the atmosphere which would contribute to greenhouse emissions.

Why is green hydrogen important?

Green hydrogen is important because it is a way of producing hydrogen that does not negatively impact the environment - cutting out CO2 completely which is one of the main greenhouse gases - and instead producing oxygen.

Technically, there’s no reason, then, why green hydrogen can’t replace blue or grey hydrogen in industry and energy generation - as hydrogen can be used in fuel cells to generate electricity, power and heat, and fertiliser production.

The hydrogen is the same, it’s the way it’s produced that makes it clean!

And, as hydrogen production continues to increase and the uses of hydrogen in the energy sector and industry also increase, it’s green hydrogen that will pave the way to decarbonisation and achieving “zero emissions”.