A paper by researchers from the US universities Cornell and Stanford, published today in the journal Energy Science & Engineering, estimates that so-called ‘blue hydrogen’ could have a footprint 20% greater than natural gas. As such, huge public investment in the sector over the coming years “appears difficult to justify on climate grounds” it finds.
The government’s Hydrogen Strategy was rumoured for publication a fortnight ago, yet did not emerge amid reports of an increasingly fractious Cabinet dispute over the costs and practicalities of meeting net zero. It is expected to set out plans to invest more in blue hydrogen and associated carbon capture and storage infrastructure than ‘green’ hydrogen, produced from the renewably-powered electrolysis of water.
Professor Robert Howarth – whose background is in ecology and oceanography – and civil and environmental engineering professor Mark Jacobson’s figures are the first peer-reviewed attempt to assess blue hydrogen’s lifecycle greenhouse gas emissions, taking into account both CO2 and releases of unburned methane.
“Far from being low carbon, greenhouse gas emissions from the production of blue hydrogen are quite high, particularly due to the release of fugitive methane,” they say. Under their default assumptions, including a 3.5% methane leak rate, blue hydrogen comes out as about 9-12% lower than ‘grey’ hydrogen, made from natural gas but without capturing CO2. This is due to more methane being used to power the carbon capture process.
“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 paper states.
Its conclusion is blunt: the technology “provides no benefit. We suggest that blue hydrogen is best viewed as a distraction, something than may delay needed action to truly decarbonize the global energy economy, in the same way that has been described for shale gas as a bridge fuel and for carbon capture and storage in general.”
David Cebon, professor of mechanical engineering at the University of Cambridge, described the research as a “landmark”, shedding 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.”
Reliance on it could also continue to allow the oil-backed influence of states such as Russia and Saudi Arabia to linger, says another paper, published yesterday in the journal Energy Research & Social Science.
If the nascent hydrogen economy becomes truly global in scale, with the gas traded as a commodity rather than simply produced locally, it could simply replicate the security implications of reliance on oil, it finds, with the same competition over access to strategic resources and locations, such as the Strait of Hormuz and the Suez Canal. Pipelines would also be vulnerable to regional animosities, according to the study.
Benjamin Sovacool, professor of energy policy at the University of Sussex Business School and one of the authors, said: “In the current fossil-fuel led global economy, energy security is uneven across nations and presents important national and human security implications. Fossil energy resources are used as foreign policy instruments, to create military advantage, enable some countries to hold disproportionate influence in international affairs and stoke geopolitical tensions.
“It is envisaged that the move to a renewables-led global economy will see many of these issues dissipate as we move to energy production that can be localized, stored and used across multiple sectors. However the role of hydrogen complicates that narrative and allows for the potential for the energy tensions of the past to interfere with the present remain unless action is taken during the migration from one global energy system to the other.”
It expects a struggle to emerge between countries “strongly oriented toward green hydrogen” – including EU member states – and those hoping to benefit from the export of blue hydrogen, and derivatives such as ammonia.
Though industry lobby groups are lobbying for hydrogen to heat homes and fuel vehicles, critics have accused them of vested interests and said such uses would be wasteful when more appropriate technology, such as batteries and heat pumps, are available. It would be wiser to restrict hydrogen production for harder to decarbonise sectors, such as steel and cement, they say.
Hydrogen boilers would also continue to emit nitrogen oxides, a leading air pollution scientist warned last month.
But blue hydrogen advocates, keen not to see the value of their investments in fossil fuels dwindle, appear to have the ear of Whitehall. The Hydrogen Advisory Council is co-chaired by the former head of Shell in the UK (now in global charge of low-carbon fuels), with fellow oil and gas firms Equinor and BP also represented.
"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,” said Howarth, who warned that the paper he co-authored 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.”
Business interest in green hydrogen is rising, as evidenced by the recently-completed construction of what is claimed to be the world’s largest electrolyser factory in Sheffield, run by ITM Power. The firm is also building Europe’s largest polymer electrolyte membrane electrolyser system at a Shell oil refinery in Germany.
A government spokesperson said: “Low carbon hydrogen will be essential for meeting our legally binding commitment to eliminating the UK’s contribution to climate change by 2050, with more details to be set out in our forthcoming Hydrogen Strategy.
“Independent reports, including that from the Climate Change Committee, show that a combination of blue and green hydrogen is consistent with reaching net zero but alongside the strategy, we will consult on a new UK standard for low carbon hydrogen production to ensure the technologies we support make a real contribution to our goals.”