From the Editor: The hype about hydrogen [Gas in Transition]
The global energy transition/evolution/revolution – call it what you will – may have something approaching its first “silver bullet” in hydrogen – give it whatever color you fancy – but there are a few inconvenient truths about the magic, low-carbon energy “carrier” that may tarnish its image.
Around the world, energy and climate policy makers are settling on hydrogen as the fuel to get us to a lower carbon, 1.5°C future. Hydrogen strategies are everywhere – 14 national strategies have been released in the past couple of years, and another 22 are in various stages of development, according to the International Energy Agency (IEA).
Hydrogen backbones are springing up in Europe and North America to facilitate hydrogen trade, and carbon capture and storage (CCS) hubs, critical to the production of blue and turquoise hydrogen from natural gas, are being advanced in Canada, the US, the North Sea and elsewhere.
And the EU – the biggest hydrogen cheerleader of them all – is counting on H2 in all its forms to provide a safety net as it cuts its natural gas ties with Russia.
The global hydrogen generation market, estimated at about $129bn in 2020, is expected to approach $220bn by 2030, and by 2050, hydrogen could account for 12% of global energy use, prompting the International Renewable Energy Agency (IRENA) to dub it the “missing link to a climate-safe energy future.”
But is it?
In 2020, the IEA says, about 70 MW of electrolysis capacity (to produce green hydrogen) was added worldwide, doubling the previous year’s record, while two facilities producing blue hydrogen became operational, increasing production capacity by about 15%. Both achievements, in the midst of Covid-19 restrictions, were remarkable, the IEA said, and proved the resilience of hydrogen technologies.
But the progress of adding new production capacity, the IEA adds, is falling well short of what is needed under its Net Zero by 2050 scenario. “Moreover, low-carbon hydrogen demand for new applications remains low, limited to road transport only. Therefore, more efforts are needed in demand creation and in reducing emissions associated with hydrogen production.”
And it is in that last statement from the IEA where we find the kernels of doubt surrounding hydrogen’s worth as a “silver bullet” or its value as the “missing link”.
On the demand question, Anne-Sophie Corbeau from the Center on Global Energy Policy at Columbia University weighed in recently with a commentary on the lack of standardisation in data related to hydrogen demand.
The problem, she wrote in an April 11 blog post, is that nobody knows exactly how much hydrogen is consumed in the world each day because nobody uses a standard definition of exactly which demand is being measured: pure hydrogen demand, mostly from the oil refining and ammonia production sectors, hydrogen demand, which includes pure hydrogen demand but adds in hydrogen that is mixed with other gases and used to produce steel or methanol, or total hydrogen, which includes pure hydrogen but also other hydrogen used by industry without prior separation from other gases, beyond that which is used for steel and methanol.
The other side of that data conundrum has to do with how hydrogen is measured. Cost estimates use kilograms; trade statistics largely rely on metric tons, similar to LNG trade; and production statistics offer energy units, such as exajoules or kilowatt-hours.
As hydrogen grows in importance, Corbeau suggests data gathering be standardised around energy units rather than on weight measures, a move which would build on an existing trend away from units that are clearly linked to fossil fuels. Both the IEA and global major BP have moved in this direction, she notes, and adopting one standard would ensure everyone is speaking the same language.
The second part of the IEA’s statement, relating to reducing the emissions associated with hydrogen production, is a little more sinister: hydrogen production, as we all know, generates a wide spectrum of CO2 emission outcomes, ranging from very little if renewable electricity is used to electrolyse water to extreme, if steam methane reforming is used to produce grey hydrogen from natural gas without CCS.
But the consumption of hydrogen carries its own emissions cost: a recent study released by the UK’s department of business, energy and industrial strategy (BEIS) has found that hydrogen itself is twice as powerful a greenhouse gas as previously thought because it reacts with other greenhouse gases in the atmosphere to increase their global warming potential (GWP).
Hydrogen-induced changes in methane and ozone in the lower atmosphere (the troposphere) are well-known, the study says; its impacts in the stratosphere (just above the troposphere), however, are only now becoming understood – and it’s not a good look.
The 100-year GWP (GWP100) for hydrogen, for years considered to be about 5.8 (for context, the GWP for CO2 is estimated at 1, whether at the 100-year horizon or the 20-year horizon), is actually somewhere between 6 and 16, with 11 considered the average – 100% higher than previously published calculations.
More importantly, especially in the context of the race to net zero by 2050, the 20-year GWP for hydrogen is now considered to be 33, with an uncertainty range of 20 to 44.
And because the hydrogen molecule is much smaller than the methane molecule or the CO2 molecule, it will leak from existing infrastructure much more easily, especially if that infrastructure is made of iron rather than polyethylene or copper.
In that regard, the study authors note, our efforts to get to net zero by increasingly relying on H2 may actually be undone by our increased reliance on H2 as a fuel to get to net zero.
“Any leakage of H2 will result in an indirect global warming, offsetting greenhouse gas emission reductions made as a result of a switch from fossil fuel to H2.”
Words to ponder, indeed, as we make our way down that bumpy road to a lower-carbon Utopia.