As the hydrogen economy grows, policy experts and scientists warn that aggressive regulation is critical to ensure that what is currently being promoted as a climate boon does not end up a carbon bomb.
The Biden administration is proposing a tax credit that would offer more than US$100 billion in investment support for clean hydrogen. That could be a step forward for emission reductions—but onlyifit funds projects that draw on clean power that is new, nearby, and unmistakably fossil-free, writes Leah C. Stokes, associate professor of environmental politics at the University of California, Santa Barbara, in an op-ed for the New York Times.
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Leaving out those guardrails will have huge climate consequences, warns Stokes. By one estimate, “lax rules could double the greenhouse gas pollution already created by today’s dirty grey hydrogen to more than 220 million tons of carbon emissions per year.”
“That’s like 26 new coal plants belching out pollution every year,” she adds. “And fossil fuel companies like BP and utilities like Constellation are already lobbying the government for the loose rules that could create a dirty hydrogen monster.”
The Inflation Reduction Act’s clean hydrogen tax credit is meant for hydrogen produced using zero- to low-carbon energy inputs, with “low” defined as less than four kilograms of carbon dioxide per kilogram of hydrogen produced. Green hydrogen, produced by energy sourced from wind and solar ,slips easily under this threshold, as might “blue” hydrogen, produced using natural gas, where the CO2 generated by the manufacturing process is properly captured and stored (CCS). (Though whether that process works as advertised is a whole other important story.)
“Grey” hydrogen—derived from fossil natural gas without CCS—generates between 10 and 12 kilos CO2 equivalent per kilo of hydrogen and would never fit the “clean” bill.
“Right now, almost all hydrogen produced in this country is grey,” Stokes says. But “if the Treasury Department sticks to the letter of the law as it writes the rules in the coming months, green hydrogen could flourish, helping to cut America’s—and the world’s—carbon pollution considerably,” writes Stokes.
Hydrogen Needs New, Nearby, Fossil-Free Power
That means all hydrogen projects that receive tax credits must draw on clean power that is genuinely new, and purpose-built. “If a hydrogen plant just pulls clean power from the grid, then it’s not creating additional power; it’s simply diverting power that could otherwise be used for running an electric vehicle or heating a home,” Stokes warns, a diversion that could “actually make the grid dirtier, since most utilities would respond to the increased demand by burning fossil fuels.”
The hydrogen project must also be located nearby a clean power source. “A company in Wyoming that uses coal to make hydrogen should not be able to dress itself up as green by buying a renewable energy credit from California, whose grid already has many clean energy sources,” she writes. The government can check that box by requiring that new, clean power be delivered to the same grid where the hydrogen plant draws its electricity.
Finally, companies must prove they’re producing the hydrogen “at the same time of day that the new clean energy is flowing into the grid, to ensure that it doesn’t end up using electricity from dirtier sources that are available at other times of day,” a transparency check known as “hourly matching.”
If this is “all too complicated to regulate,” officials should make one simple rule: “subsidize only new clean energy projects that create hydrogen onsite,” Stokes says.
Hydrogen Leaks Threaten Climate
But basic chemistry and the limits of technology could end up making hydrogen a worse climate bet than fossil fuels, regardless of the stringent policy measures Stokes recommends.
It has been understood for a while that the hydrogen economy could end up posing a climate threat due the tendency of a very small molecule to leak from the infrastructure meant to contain it, then react with atmospheric hydroxyl.
Known as “the detergent of the troposphere,” hydroxyl plays a critical role in breaking down climate-busting methane, writes SciTech Daily. But hydroxyl also likes to bind with hydrogen, which means that as more anthropogenic hydrogen is emitted into the atmosphere, less hydroxyl will be available to help keep methane under control.
Princeton University’s High Meadows Environmental Institute and the National Oceanic and Atmospheric Association recently published research that quantifies just how little hydrogen can be permitted to escape into the atmosphere.
Green hydrogen leakage will lead to an increase in atmospheric methane when emissions breach 9% of the total gas produced, said lead author and post-doctoral researcher Matteo Bertagni. For blue hydrogen, which uses methane as its energy input, the threshold is much lower, around 4.5%, because producers will have to factor in methane leakage as well as hydrogen losses.
“Managing leakage rates of hydrogen and methane will be critical,” Bertagni told SciTech Daily. “If you have just a small amount of methane leakage and a bit of hydrogen leakage, then the blue hydrogen that you produce really might not be much better than using fossil fuels, at least for the next 20 to 30 years.”
Those would be the same 20 to 30 years when humanity will be in an all-out scramble to get climate change under control.
The article provides yet another cogent reason for using green hydrogen in the hydrogen carrier methanol [CH3OH] – which not only avoids the many demerits of pure hydrogen as a fuel, but also its issues of embrittlement and leakage.
With the “Reformer Methanol Fuel Cell” now in early production by firms in Denmark, Germany, USA & China, methanol is an efficient liquid fuel for road and rail-freight and shipping, as well as being suitable as a stored fuel for back-up-power on a scale from remote phone masts to hospitals to Strategic Sustainable Energy Reserves. In addition, for that fraction of buildings where heat-pumps would be problematic, the clean-burning fuel-gas DME [CH3OCH3] can be made from methanol feedstock and delivered by gas grid or road tanker.
Avoiding the demerits of hydrogen fuelling will allow a far more rapid deployment both in industrialised and developing nations, in terms both of social acceptance and economic viability. Methanol’s potential role in accelerating the end of fossil fuel dependence thus warrants far more attention – particularly across leading green journals like “The Energy Mix.”
Good article. But I have one quibble that has significant practical / policy implications. Its all well and good to say that green hydrogen should only be produced with renewables that are new and purpose built, and is nearby. That IS the goal.
But you cannot decide and regulate this case by case. Regulations can only make sure that this happens in the aggregate. We cannot manage and regulate this at the micro level.
Getting macro regulations right is going to be tricky and uncertain. It is necessary to understand what we aspire to achieve in tangible (micro) terms . But pretending we can make it work like in a micro level model is just going to lead to grief. Here is a more a fuller and nuanced approach with the same goal:
Why the success of the US hydrogen tax credit will hinge on how emissions are determined
A weak system that unreasonably allows dirty electricity to offset renewable energy means ‘green’ H2 could actually have higher emissions than grey hydrogen, writes Rachel Fakhry. https://www.hydrogeninsight.com/policy/opinion-why-the-success-of-the-us-hydrogen-tax-credit-will-hinge-on-how-emissions-are-determined/2-1-1373163