Blue hydrogen has “no role in a carbon-free future” – and is actually up to 20% worse for the planet than burning gas or coal to produce heat, according to what is claimed as a landmark academic study.

In the week that the United Nations declared “code red for humanity” over the climate emergency, researchers from Cornell and Stanford universities in the US branded the blue variety of hydrogen beloved of the fossil fuel sector as a “distraction” that could divert focus away from genuinely green technologies.

Blue H2, produced using natural gas with carbon capture and storage (CCS), is a key plank of the energy transition strategies of a number of major nations and global fossil fuel players, billed as an essential short-term answer to decarbonising economies without the need to wait for green hydrogen from renewable-powered electrolysis to achieve sufficient scale and cost reductions.

But the Cornell and Stanford researchers claim a first-of-a-kind peer-reviewed study of blue hydrogen’s lifecycle greenhouse gases footprint debunks any notion that it represents an emissions-free, or even low-emissions option, citing the large amounts of natural gas needed to fuel the process itself and the escape of “fugitive methane” from wells and other equipment along the supply chain.

The academics in a study published on Thursday in Energy Science and Engineering put the CO2 emissions profile of blue H2 as barely superior to the grey hydrogen made using unabated gas that it is supposed to supplant.

And “while carbon dioxide emissions are lower, fugitive methane emissions for blue hydrogen are higher than for grey hydrogen because of an increased use of natural gas to power the carbon capture.

“Perhaps surprisingly, the greenhouse gas footprint of blue hydrogen is more than 20% greater than burning natural gas or coal for heat and some 60% greater than burning diesel oil for heat.”

The study’s authors add: “Our analysis assumes that captured carbon dioxide can be stored indefinitely, an optimistic and unproven assumption. Even if true though, the use of blue hydrogen appears difficult to justify on climate grounds.

“There really is no role for blue hydrogen in a carbon-free future. We suggest that blue hydrogen is best viewed as a distraction, something that may delay needed action to truly decarbonise the global energy economy.”

'Bets on blue'

Robert Howarth, co-author of the study and professor of ecology and environmental biology at Cornell University, said: "Politicians around the world, from the UK and Canada to Australia and Japan, are placing expensive bets on blue hydrogen as a leading solution in the energy transition.

“Our research is the first in a peer-reviewed journal to lay out the significant lifecycle emissions intensity of blue hydrogen. This is a warning signal to governments that the only 'clean' hydrogen they should invest public funds in is truly net-zero, green hydrogen made from wind and solar energy."

The UK government is prominent among those aiming to put blue hydrogen – which it often bills as ‘low carbon’ – at the core of its energy transition agenda, with flagship CCS projects planned for northern England with the enthusiastic participation of oil & gas majors such as BP and Shell.

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With the British government poised to announce a national hydrogen strategy, David Cebon, professor of mechanical engineering at the University of Cambridge said: “This landmark paper sheds light on the key unknown in the UK’s hydrogen debate: the greenhouse gas footprint of blue hydrogen. The calculation method is rigorous, the assumptions are all solid and the results are stark.

“Blue hydrogen cannot be considered ‘low-carbon’ or a ‘clean’ solution. In fact, this paper shows that producing blue hydrogen is significantly worse than burning fossil fuels for heat, such as gas or coal, in the first place.”

Cebon added: “Politicians must take notice of this important finding before considering investment in blue hydrogen under the premise that it supports our climate goals. The only hydrogen we can consider truly emissions-free, is that made from renewable energy such as green hydrogen.”

Blue v green debate

The Cornell/Stanford study adds fuel to a debate that has raged for several years in the energy sector over the respective roles of blue and green hydrogen in the energy transition, one extensively charted by Recharge.

That has seen a broad split between those in the fossil fuel industry that champion the former – leading to accusations that they are seeking to prolong the role in the energy mix of one of their core products, gas – and those from the power sector who align with the view of a top executive from renewables giant Enel that any other form of H2 than green “will be a trick”.

While widely seen as a good option in sectors such as chemicals and heavy industries, there is also scepticism over hydrogen’s suitability to decarbonise some parts of the economy at all.

Prominent clean energy analyst and commentator Michael Liebreich recently told Recharge that oil & gas players “have an interest” in talking up hydrogen’s role in areas such as cars and domestic heating, despite more efficient and cheaper electric solutions being available.