Colours of Hydrogen

Blue hydrogen’s discredited contribution to the net zero transition makes green hydrogen the only viable option.

With the UK Government’s recent publishing of a hydrogen strategy outlining an ambition for 5 GW of low carbon hydrogen production capacity by 2030, interest and enthusiasm for hydrogen is quickly gaining traction. The UK hydrogen strategy estimates that the hydrogen economy will deliver a 41 million tonne saving of carbon dioxide equivalent (CO2e) between 2023-2032.

Both the Committee on Climate Change and National Grid’s Future Energy Scenarios modelling recognises the major role that the hydrogen economy will play in a 2050 net zero future. However, electrification is predicted to dwarf hydrogen and other low carbon technologies with four times as much emissions reduction from electrification compared to hydrogen.

Utilising hydrogen to decarbonise space heating and cooking in domestic homes is unsubstantiated where electrification of appliances and low carbon heating technologies present a more efficient and immediate response to the climate emergency. There are clearer opportunities for hydrogen to help decarbonise industries where electrification is not possible, including aviation, steel making, cement production, and large-scale heating.

Misleading ambitions

Hydrogen is classified as green (electrolysis of water), brown (gasification of coal), grey (steam methane reforming), and blue (steam methane reforming with CO2 capture), with grey hydrogen currently the most common. One of the by-products of brown and grey hydrogen is carbon dioxide, hence the carbon capture utilisation and storage (CCUS) element of blue hydrogen, which claims to reduce the negative climate impacts of hydrogen production.

It’s estimated that a quarter of the net global warming that’s occurred in recent decades is due to methane. Research published in August by academics from Cornell and Stanford universities concluded that the fugitive methane emissions from blue hydrogen are higher than grey hydrogen production and total CO2e emissions for blue hydrogen are only 9-12% lower than grey. Furthermore, the research calculates that blue hydrogen could produce over 20% more greenhouse gases than burning natural gas or coal for heat and 60% more than burning diesel oil for heat.

Due to the Government’s proposed endorsement of blue hydrogen, the chair of the UK Hydrogen and Fuel Cell Association, Chris Jackson, recently stepped down, highlighting that the UK will fail to meet its decarbonisation goals if it continues with its dependence on fossil fuels.

The UK hydrogen strategy outlines a “twin track” approach for producing large quantities of green and blue hydrogen, yet the map of known proposed facilities illustrates around 115 MW of green hydrogen production and 900 MW of blue hydrogen production.

Future is green

It’s no surprise that green hydrogen is currently significantly more expensive than blue hydrogen, making it difficult to compete with blue hydrogen and the counterfactual of natural gas. However, similar to other low carbon generators, the cost of green hydrogen is expected to reduce over the next 10 years.

Activities have taken place internationally to phase hydrogen into energy systems, with natural gas and hydrogen blending in its early stages of development and seen as a promising option for increasing hydrogen use. In the UK, live trials of up to 20% blended hydrogen and natural gas have been successful, but health and safety concerns of wider deployment still remain.

Forecasting future trends in the energy industry is notoriously challenging, but if hydrogen can be produced via electrolysis of water powered by renewables, then the industries employing this approach can achieve widespread decarbonisation of their activities. Conversely, if blue hydrogen with CCUS prevails then the UK’s decarbonisation efforts will continue to stall.


What opportunities will endure for the green hydrogen industry and will it receive the support it needs to scale appropriately?