As the global push for a hydrogen economy accelerates, researchers are urging policy-makers to address new knowledge and fill in some profound data gaps, with recent studies revealing the considerable global warming potential of a fuel that many fossils see as their industry’s best hope for a second life.
The global hydrogen juggernaut has been picking up steam for a few years now, with strong advocates around the world and at least two different colour schemes meant to distinguish between gradations of environmentally friendly or high-emitting, fossil-dependent product. “Between November 2019 and March 2020, market analysts increased the list of planned global investments from 3.2 GW to 8.2 GW of [green hydrogen-generating] electrolysers by 2030,” the European Commission writes in a 2020 strategy roadmap.
By July, 2022, reported Columbia University’s Center on Global Energy Policy, more than 30 countries had joined the EU in publishing formal hydrogen strategies.
That such hydrogen roadmaps should increasingly figure prominently in national climate plans is hardly surprising. When hydrogen is run through a fuel cell to produce electricity, its only byproduct is water. The universe’s smallest element embodies far more energy for a given weight than lithium batteries can store, and it takes far less time to refill a hydrogen tank than to recharge a battery. Those factors have helped position hydrogen as a promising source of energy for hard-to-decarbonize sectors like aviation, shipping, and long-haul trucking.
Already used at scale in chemical (primarily ammonia) manufacturing, oil refining, and iron and steel making, to the tune of roughly 90 million tonnes per year globally, hydrogen is projected to rapidly become a central pillar in the energy transition. The International Energy Agency’s Net Zero by 2050 report has its use quintupling to 528 megatonnes per year by 2050.
Illustrating the widespread political conviction that the transition to hydrogen will be a significant generator of wealth and jobs, Canada’s Hydrogen Strategy declares that with a global market projected to “reach over $11 trillion by 2050,” a rapid shift “can spark early economic recovery, lead to a $50-billion domestic hydrogen sector, and generate more than 350,000 high-paying jobs from coast to coast.”
Letting Politics Get Ahead of the Science
The prodigious promise of hydrogen is sure to loom large when German Chancellor Olaf Scholz and Prime Minister Justin Trudeau meet in Canada August 22-23. The Trudeau government has been looking for a path to help Germany in its urgent quest to wean itself off Russian natural gas, with both leaders signalling that any buildout of liquefied natural gas (LNG) terminals will have to include a promise to convert those terminals to “hydrogen hubs” as soon as possible.
But many of the hydrogen strategies that different jurisdictions have produced are long on hype, but short on details. The problems begin with a lack of rigorous data on hydrogen supply and demand, the Center on Global Energy Policy reported in April. Both the dollars to be made and the emission reductions to be achieved will depend on getting those numbers right.
There’ve been persistent concerns that “blue” hydrogen—which involves deriving the end product from fossil gas, then capturing and storing the resulting emissions—produces more climate pollution than just burning the gas outright once the related methane emissions are factored in.
But even if the production process is clean and green, there is “very little data on hydrogen leakage along the existing value chain, and that which does exist comes from theoretical assessments, simulation, or extrapolation rather than measures from operations,” the Center warns in an early July analysis. The available numbers suggest that annual hydrogen leakage could increase from 2.4 million tonnes in 2020 to between 15.3 and 29.6 megatonnes in 2050, depending on technical improvements and the degree of government regulation.
The Center projects green hydrogen production, transportation, and storage, road transport vehicles, electricity generation, and synthetic fuel production contributing 77% of global hydrogen leakage, at a cost of up to US$59 billion per year in lost product.
How Hydrogen Can Warm the Atmosphere
But economic losses are by no means the only concern with hydrogen leakage. While hydrogen molecules themselves do not trap heat, they exert an indirect warming effect when they’re released into the atmosphere, primarily because they tend to react with atmospheric hydroxyl, a substance that also reacts with methane. As more hydrogen leaks into the atmosphere, less hydroxyl will be available to neutralize the devastating short-term effects of methane, a greenhouse gas that is about 85 times more powerful a warming agent than carbon dioxide over a 20-year span.
Hydrogen is also part of the chemical chain reaction that leads to the formation of ground-level ozone, another potent climate pollutant.
And any leaked hydrogen that makes it into the stratosphere produces water vapour, itself a significant heat trapping agent.
All of which adds up to hydrogen having very considerable potential to warm the atmosphere. A UK government report in April found that over a 100-year time period, a tonne of hydrogen in the atmosphere will warm the Earth roughly 11 times more than a tonne of CO2 (with a fairly wide margin for error), making its impact about twice as bad as previously understood.
Over a 20-year span, Bloomberg writes, hydrogen has 33 times the global warming potential of an equivalent amount of CO2.
There’s one more wrinkle to the still unfolding saga of how leaked hydrogen might make the climate crisis worse. The latest soil science indicates that some 80% of leaked hydrogen is absorbed by hydrogen-eating bacteria in soils, but the authors of the UK report warn that “a lack of detailed understanding of the [hydrogen soil] sink is a major source of uncertainty in calculations of hydrogen change and its impact on climate.”
Princeton University’s Carbon Mitigation Initiative (CMI) grapples with this problem in its 2020 annual report, noting that “the large-scale use of hydrogen as energy carrier may increase the H2 atmospheric concentration” from its current level of 530 parts per billion, “and the environmental implications are not yet clear.”
But scientists already know that “complex interactions between biotic and abiotic processes govern” the uptake of atmospheric hydrogen by soil bacteria, CMI writes. And “soil moisture plays the main role, as it affects the rate at which H2 is consumed by bacteria (the bacteria metabolism) and the rate at which H2 becomes available for bacteria (H2 diffusion through the soil).”
Reviewing research dating back to 2006, CMI warns that “at very low levels of soil moisture, bacterial metabolism is inhibited because of water stress,” while “at high values of soil moisture, the soil H2 uptake is limited by the reduced diffusivity of H2 through the moist soil.”
Those findings may not sit well with overall climate projections that many wet places will become increasingly wet, while arid regions grow ever drier.
Fossil Hype Trumps Scientific Substance
But the story of hydrogen and its explosive growth is not just a matter of data gaps and (steadily shrinking) scientific uncertainty. It’s also about the canny machinations of a fossil sector scrambling to get traction as the global energy system shifts to renewables.
The cascading hype around the hydrogen economy is reflected in the growth of the CEO-led International Hydrogen Council, which has seen its membership skyrocket from 13 in 2017, to 81 in 2020, to 131 today. The Council recently declared that “hydrogen solutions are here: mature, safe, and ready to be deployed at scale. The time for industry, governments, and investors to tap into the potential of hydrogen is now.”
It may be no coincidence that that unconditional optimism comes from a group whose steering committee includes colossal fossils Shell, Sinopec, TotalÉnergies, Saudi Aramco, and BP, with companies like Chevron, Indian Oil, Malaysian state fossil Petronas, and Canada’s Enbridge stepping up as supporting members. For some critical observers, those connections and influences make hydrogen hype a path to salvaging stranded oil and gas infrastructure—by “repurposing” those installations to carry hydrogen, even if the process is really limited to blending low proportions of hydrogen into existing fossil gas pipelines and shading them “green”.
It may also speak to the fossil industry’s clear-eyed recognition that its only path to survival lies through decarbonization, and they hydrogen may be their ticket to that path.
“Maintaining the illusion that their gas transmission and distribution infrastructure can be used to produce, transport, and sell hydrogen is existentially important to these people,” writes chemical engineer and process development expert Paul Martin, a co-founder of the Hydrogen Science Coalition, in a recent LinkedIn post. “Without that illusion, it becomes clear to the market that their assets are actually liabilities with an abandonment cost. You can therefore bet good money that they will do everything they can to maintain that illusion, even if what is required is a considerable stretching of the limits of credulity.”
Martin points to the ongoing dialogue between Canada and Germany over fast-tracking “LNG terminals-turned-hydrogen hub” infrastructure as Exhibit A for such mental gymnastics, citing the temperature at which each substance liquefies as one of the many profound differences between the gases. “What’s the likelihood that the equipment optimized for the liquefaction of methane at -161°C can be reused for the optimal liquefaction of hydrogen at -249°C?” he asks. “Pretty poor, to say the least!”
Arno Beux, chief commercial officer at Flyxus, which operates an LNG terminal in Belgium, agreed in a recent interview with Bloomberg that the conversion of an LNG terminal to process liquid hydrogen is “a technical challenge,” with “an economically viable business model… far from imminent.”
Liquid hydrogen is not the only option on the table, Bloomberg explains. Ammonia, which liquefies at -33°C, could be used as a carrier, and Beux said an LNG terminal could be “tweaked” to handle the product at just 15% of the cost of a new facility. But converting ammonia to hydrogen “is also extremely energy intensive, meaning companies have to find vast amounts of clean power to ensure the process is zero-emission.”
The net result, writes Bloomberg, is that “most of the planned LNG terminals in Germany are proposing a third option in the interim: importing a fuel known as synthetic LNG,” made by combining hydrogen with carbon dioxide, itself an extremely energy-intensive process. “There are currently no plants doing this on a commercial scale.”
Getting the Details Right
Synthetic LNG could well be the answer Big Oil is looking for, however: chemically identical to fossil methane, it requires no new infrastructure for storage and transport. Its production also requires vast amounts of CO2, which fossils generate in abundance.
But again, commercial-scale production is not yet in view, so cash-strapped policy-makers continue their push to repurpose existing gas infrastructure. “Repurposing may provide an opportunity for a cost-effective energy transition in combination with (relatively limited) newly built hydrogen dedicated infrastructure,” states the European Commission’s 2020 Hydrogen Strategy.
As part of a “supportive and enabling” framework for hydrogen development, the Commission advises policy-makers to design market rules that “enable” the deployment of hydrogen and remove barriers to “efficient hydrogen infrastructure development (e.g. via repurposing).”
But Columbia’s Center on Global Energy Policy advises against that degree of deregulation without a more complete picture of existing hydrogen systems—including the hydrogen soil sink.
“A lack of understanding of the current hydrogen system and the significance of leakage prevents the development of realistic solutions and appropriate regulations,” the Centre warns. “To understand and rigorously estimate the scale of hydrogen leakage, new regulations and policies should emphasize hydrogen leakage detection.”
Since “the real leakage risk will likely be new processes such as green hydrogen production, fuel cell vehicles, and dedicated hydrogen deliveries,” the Center adds, rigorous monitoring at all stages of development is imperative, and regulations and policies will need to be in place to ensure that monitoring happens.