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Leaky
Hydrogen....No warning, Miracle Fuel Hydrogen Can Actually Make
Climate Change Worse
June 6,2022
Photo illustration: Stephanie Davidson; Photo: Getty
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The Big Take
Miracle Fuel Hydrogen Can Actually Make Climate Change Worse
If it escapes into the air, this green fuel can contribute to global
warming — which is why scientists say we need to limit leaks.
By
David R Baker
May 30, 2022, 9:01 PM PDT
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A world desperate for a climate-friendly fuel is pinning its hopes on
hydrogen, seeing it as a way to power factories,
buildings, ships and planes without
pumping carbon dioxide into the sky.
But now scientists are warning that hydrogen leaked into the
atmosphere can contribute
to climate change much like carbon. Depending on how it’s
made, distributed and used, it could even make warming worse over the
next few decades, even if carbon poses the bigger long-term threat.
Any future hydrogen-based economy, they say, must be designed from the
start to keep leaks of the gas to a minimum, or it risks adding to the
very problem it’s supposed to solve. Some ideas now being tested,
like shipping
hydrogen in pipelines built to hold natural gas or burning
it in individual homes, could cause an unacceptable level of leaks.
“The potency is a lot stronger than people realize,” said Ilissa Ocko,
a climate scientist with the Environmental Defense Fund, a non-profit
group. “We’re putting this on everyone’s radar now not to say ‘no’ to
hydrogen but to think about how we deploy it.
”Hydrogen doesn’t trap heat directly, the way CO₂ does. Instead, when
leaked it sets off a series of chemical reactions that warm the air,
acting as an indirect greenhouse gas.
And though it cycles out of the atmosphere
far faster than carbon dioxide, which lingers for centuries, it can do
more damage than CO₂ in the short term. Over 20 years, it has 33 times
the global warming potential of an equal amount of carbon dioxide,
according to a recent UK government report. Over hundreds of years,
carbon is more dangerous, due to its longevity.
Hydrogen’s warming potential was never a problem before, as its use
was largely limited to oil refineries and chemical or fertilizer
plants. But now governments worldwide are investing billions to build
a hydrogen economy, seeing the gas as one of the only options for
decarbonizing many industries that can’t easily run on electricity.
President Joe Biden has set
aside $8 billion to build at least four “hydrogen hubs”
where the fuel will be produced and used, and states are gearing up to
compete. US utility companies that now deliver natural gas see it as a
savior, announcing more than two
dozen hydrogen pilot projects in the last two years.
Hydrogen Hustle
More than a dozen US states are vying for $8 billion in federal funds
to host hydrogen hubs
State announcements
“Now is when decisions are being made, and money’s being spent,” Ocko
said. “We can get ahead of this issue now, so it doesn’t become a
problem.”
She and others sounding this alarm insist it’s no reason to give up on
hydrogen. Rather, hydrogen’s heat-trapping power means any future
system for producing, distributing and using the gas must be built to
minimize leaks.
“There
is great potential using hydrogen to save a lot of emissions of carbon
dioxide, but it’s really important to keep the hydrogen leakage rates
down,”
said Nicola Warwick, lead author of the UK study and a National Centre
for Atmospheric Science research scientist at the University of
Cambridge.
A green hydrogen plant in Puertollano, Spain.Photographer:
Angel Garcia/Bloomberg
The hydrogen industry acknowledges the problem, even if companies
disagree on the potential scope. Dave Edwards, with industrial gas
company Air Liquide, said the effects of hydrogen leaks on the
atmosphere should be far less than the traditional fuels they
displace. Running cars and trucks on hydrogen fuel cells would have
less atmospheric impact than running them on gasoline and diesel, even
if the system for making and delivering that hydrogen leaks.
“It doesn’t mean it’s not still important, it doesn’t mean we don’t
need to understand more about it, but our first impression is it’s
much, much smaller,” said Edwards, a director with the company and its
chief hydrogen advocate in the US. Hydrogen leaks, he said, “are
manageable problems to address.”
Hydrogen has big advantages as a clean fuel. Burn hydrogen in a
turbine, and it will generate power without carbon dioxide. Run it
through a fuel cell, and it will produce electricity with water vapor
as the only exhaust. Unlike solar and wind power, it can be stored in
large amounts for when it’s needed. While the vast majority of the
hydrogen produced today is stripped from natural gas, in a process
that releases carbon dioxide, it can also be separated from water
using renewable power, with no emissions but oxygen.
But for all its benefits, hydrogen can also slip easily through
equipment designed to contain larger molecules like the methane in
natural gas.
Once it escapes, much of the leaked hydrogen will be absorbed by
microbes in the soil. Some of what’s left in the air will react with a
substance that helps remove methane from the atmosphere. That’s a
problem, because methane is itself a powerful greenhouse gas, with
more than 80 times the global warming potential of carbon dioxide over
20 years. The reaction between hydrogen and that substance — known as
the hydroxyl radical, or OH — leaves less of the OH available to react
with methane. So methane entering the atmosphere will stick around
longer and do more damage than it would have if the hydrogen hadn’t
been there.
Leaked hydrogen has other warming effects as well. In the troposphere,
the atmospheric layer closest to the ground, it triggers a chain of
chemical reactions that produce more ozone, another greenhouse gas and
a key component of smog. Much higher up, in the stratosphere, the
hydrogen leads to an increase in water vapor, which has the overall
effect of trapping more thermal energy in the atmosphere.
These reactions happen over a short time span — a handful of years.
Excess carbon dioxide, in contrast, builds up atmospheric heat over
centuries. But with temperatures quickly rising worldwide, scientists
say short-term drivers of climate change can’t be ignored.
“These decades matter,” said Steven Hamburg, EDF’s chief scientist.
His group has been trying to raise the issue of hydrogen’s warming
potential with anyone who’ll listen, briefing academics, businesses
and the US Department of Energy. His colleague, Ocko, estimates
they’ve met with some 200 people to date. For EDF, it’s a logical
extension of the group’s work trying to direct public attention to
short-term climate pollutants like methane and black carbon, which
often get overlooked in the focus on carbon dioxide.
Hydrogen Hype
Companies, analysts and social media users can't stop talking about it
Source: Bloomberg's News Trends tool
Note: NT enables users to chart and analyze the number of articles
published on topics and companies over time, drawing on more than
150,000 news and social media sources.
Many utility companies are experimenting with blending hydrogen into
their existing natural gas pipelines, sprawling networks that feed
everything from power plants to household stoves. To Hamburg, that’s a
recipe for leaks. He also warns that mass-producing hydrogen from
fossil fuels could even lead to a short-term increase in warming, if
the systems for making and transporting the hydrogen leak enough
hydrogen and methane. There would still be a long-term benefit from
cutting carbon dioxide emissions, but over the span of a decade or
two, a leaky hydrogen system based on fossil fuels could cause more
warming than business as usual.
“Over several decades, you could be worse off — it’s very plausible,”
Hamburg said.
The issue hasn’t stopped gas utilities from exploring hydrogen
blending projects. But it may become one of the things those projects
study. California utility PG&E Corp. in May announced plans to try
different blends of hydrogen and natural gas in a dedicated pipeline
system separate from the company’s usual gas transmission network,
with the blends burned in a power plant south of Sacramento. PG&E
spokeswoman Melissa Subbotin said the company’s “Hydrogen
to Infinity” project will examine the potential for leaks.
“Extensive research needs to be done to understand the feasibility of
hydrogen injection within a natural gas pipeline system,” she wrote in
an email.
A hydrogen economy riddled with leaks would just undercut its own
effectiveness, Hamburg said,
delivering less of a blow against climate change than it could.
Clean-energy advocates point to how methane leaking from natural gas
wells and pipelines — leaking that turned out to be far more
widespread than once believed — undermined some of the benefits of
shifting power plants from coal to gas. They don’t want that to happen
with hydrogen.
“We’re at risk of proceeding with the build-out of new infrastructure
that’s essentially going to repeat all those past harms,” said Julie
McNamara, deputy policy director for climate and energy with the Union
of Concerned Scientists. “We don’t have the time or luxury to get it
wrong.”
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