Hydrogen, long used as an industrial gas, will be key in global efforts to decarbonize fuels, say a trio of engineers with the John Wood Group, a global engineering and consulting company headquartered in Scotland.

The warning from the U.N.’s Intergovernmental Panel on Climate Change that global carbon dioxide emissions must be significantly reduced as quickly as possible has added urgency to the task. And the bipartisan infrastructure legislation allocating up to $10 billion on hydrogen projects has significantly increased interest in hydrogen across a spectrum of U.S. companies trying to become more sustainable.

“This new urgency to cut emissions drastically … adds quite a bit of pressure on the public and private sectors to act now, and regardless of geography. Hydrogen has a key role to play in the journey to decarbonize,” Brittney Drake, a Wood business development director based in Houston, said during a Sept. 2 webinar organized by Reuters.

William Zobel, executive director of the California Hydrogen Business Council, moderated the webinar, which was attended by 1,200 people.

Brian McCarthy, vice president for technology and products at Wood in New York City, said at this point, industry is waiting to see what Congress does. Noting that there is bipartisan support for hydrogen development, he predicted there will be “real, concrete actions and policies for hydrogen uptake in the United States.”

“But what has not yet been done is to engage with industry [and] with other stakeholders throughout the economy to build out that plan” and develop a consensus about what hydrogen’s role will be, he said.

Because the nation has strong natural resources to support hydrogen production both through methane reforming and hydrolysis using electricity produced from renewables, McCarthy predicted both technologies will be federally funded.

He added that methane reforming will probably include carbon capture, the technologies for which will improve over time, reducing the hydrogen production’s carbon footprint.

McCarthy predicted that by 2040, the U.S. will be a global leader in hydrogen production and use.

Netherlands-based Josh Carmichael, vice president of hydrogen at Wood, said the issue at this point is reaching an agreement about how exactly the substance should be used.

“I think the biggest issue for hydrogen is defining what it is, because it means so many different things to different people, as a molecule. And I think that’s the journey that needs to go on [in order] to really start to define what it is as a fuel, as an electricity provider or otherwise,” he said.

Carmichael added that hydrogen will become a commodity as production technologies improve and it is integrated with other fuels. He also mentioned research into using ammonia (NH₃) to store and ship hydrogen. U.S. Department of Energy research has shown, however, that even a trace of ammonia in hydrogen can ruin a polymer fuel cell, which is the fuel cell of choice for vehicles.

Both Drake and McCarthy referenced discussions to convert shale gas into hydrogen and carbon dioxide and then inject the CO₂ into the ground near the region where the natural gas was extracted, provided the geology is favorable.

Zobel posed a question about the usefulness of calling hydrogen green, blue or gray, as a way to describe how environmentally friendly it actually is; that is, how much carbon is released in its production and use and where that carbon goes.

“There’s another way to categorize hydrogen that’s used in some markets called a carbon intensity standard that ranks these hydrogen production pathways based on their relative carbon intensity versus other fuels in that same marketplace,” he said.

Carmichael said the color distinction can get in the way of the development of a hydrogen infrastructure.

“I think it distorts a lot of the conversation. It gives different sides of the fence ammunition to criticize other parties while we’re actually trying to just get along together and build out the hydrogen network that’s required,” he said. “We talk about colors because obviously that’s what’s been discussed in the market, but going forward … even at net zero, there are still emissions but there are less, and in the end it’s net.”

Getting to a “net carbon situation” with hydrogen production will require proof of its origin, which would be used to determine its taxation level.

“That certification and concomitant tax will determine the final price of the hydrogen. I have faith that the market will actually come to its senses and figure it out,” Carmichael said.

Whether hydrogen will be used to fuel combustion turbines or as a motor fuel for vehicles will also be market driven and in part determined by the robustness of the nation’s electric distribution and transmission grids. Those will have to be significantly strengthened to accommodate battery electric cars using power generated at distant locations.

“It’s actually very difficult to look at hydrogen alone … in a silo without looking at the rest of the U.S. energy system,” McCarthy said. “The complexity of policies is extraordinarily challenging, but it is heartening to see that some of these policy actions are being taken.”