Yale Environment 360
- Jim Robbins
Green hydrogen, which uses renewable energy to produce hydrogen from
water, is taking off around the globe. Its boosters say the fuel could
play an important role in decarbonizing hard-to-electrify sectors of the
economy, such as long-haul trucking, aviation, and heavy manufacturing.
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Green hydrogen can be stored in a liquid form. Wolfgang Kumm/picture-alliance/dpa/AP Images
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Saudi Arabia is contructing a futuristic city in the desert on the Red Sea
called Neom. The $500 billion city — complete with flying taxis and
robotic domestic help — is being built from scratch and will be home to a
million people. And what energy product will be used both to power this
city and sell to the world? Not oil. The Saudis are going big on something
called green hydrogen — a carbon-free fuel made from water by using
renewably produced electricity to split hydrogen molecules from oxygen
molecules.
This summer, a large U.S. gas company, Air Products & Chemicals,
announced that as part of Neom it has been building a green hydrogen
plant in Saudi Arabia for the last four years. The plant is powered by 4
gigawatts from wind and solar projects that sprawl across the desert. It
claims to be the world’s largest green hydrogen project — and more Saudi
plants are on the drawing board.
Green hydrogen? The Saudis aren’t alone in believing it’s the next big
thing in the energy future. While the fuel is barely on the radar in the
United States, around the world a green hydrogen rush is underway, and
many companies, investors, governments, and environmentalists believe it
is an energy source that could help end the reign of fossil fuels and
slow the world’s warming trajectory.
“It is very promising,” said Rachel Fakhry, an energy analyst for the
Natural Resources Defense Council. Experts like Fakhry say that while
wind and solar energy can provide the electricity to power homes and
electric cars, green hydrogen could be an ideal power source for
energy-intensive industries like concrete and steel manufacturing, as
well as parts of the transportation sector that are more difficult to
electrify. “The last 15 percent of the economy is hard to clean up —
aviation, shipping, manufacturing, long-distance trucking,” Fakhry said
in an interview. “Green hydrogen can do that.”
Germany has allocated the largest share of its clean energy
stimulus funds to green hydrogen.
Europe, which has an economy that is saddled with high energy prices and
is heavily dependent on Russian natural gas, is embracing green hydrogen
by providing funding for construction of electrolysis plants and other
hydrogen infrastructure. Germany has allocated
the largest share of its clean energy stimulus funds
to green hydrogen. “It is the missing part of the puzzle to a fully
decarbonized economy,” the European Commission wrote in a July strategy
document.
Hydrogen’s potential as a fuel source has been touted for decades, but
the technology has never gotten off the ground on a sizeable scale — and
with good reason, according to skeptics. They argue that widespread
adoption of green hydrogen technologies has faced serious obstacles,
most notably that hydrogen fuels need renewable energy to be green,
which will require a massive expansion of renewable generation to power
the electrolysis plants that split water into hydrogen and oxygen. Green
hydrogen is also hard to store and transport without a pipeline. And
right now in some places, such as the U.S., hydrogen is a lot more
expensive than other fuels such as natural gas.
While it has advantages, says Michael Liebreich, a Bloomberg New Energy
Finance analyst in the United Kingdom and a green hydrogen skeptic, “it
displays an equally impressive list of disadvantages.”
“It does not occur in nature so it requires energy to separate,”
Liebreich wrote in a pair of
recent essays
for BloombergNEF. “Its storage requires compression to 700 times
atmospheric pressure, refrigeration to 253 degrees Celsius… It carries
one quarter the energy per unit volume of natural gas… It can embrittle
metal; it escapes through the tiniest leaks and yes, it really is
explosive.”
In spite of these problems, Liebreich wrote, green hydrogen still “holds
a vice-like grip over the imaginations of techno-optimists.”
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Green hydrogen is produced using renewable energy, making
it a CO2-free source of fuel. SGN
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Ben Gallagher, an energy analyst at Wood McKenzie who studies green
hydrogen, said the fuel is so new that its future remains unclear. “No one
has any true idea what is going on here,” he said. “It’s speculation at this
point. Right now it’s difficult to view this as the new oil. However, it
could make up an important part of the overall fuel mix.”
Hydrogen is the most abundant chemical in the universe. Two atoms of
hydrogen paired with an atom of oxygen creates water. Alone, though,
hydrogen is an odorless and tasteless gas, and highly combustible.
Hydrogen derived from methane — usually from natural gas, but also coal
and biomass — was pioneered in World War II by Germany, which has no
petroleum deposits. But CO2 is emitted in manufacturing hydrogen from
methane and so it’s not climate friendly; hydrogen manufactured this way
is known as gray hydrogen.
Green is the new kid on the hydrogen block, and because it’s
manufactured with renewable energy, it’s CO2-free. Moreover, using
renewable energy to create the fuel can help solve the problem of
intermittency that plagues wind and solar power, and so it is
essentially efficient storage. When demand for renewables is low, during
the spring and fall, excess electricity can be used to power the
electrolysis that is needed to split hydrogen and oxygen molecules. Then
the hydrogen can be stored or sent down a pipeline.
Such advantages are fueling growing interest in global green hydrogen.
Across Europe, the Middle East, and Asia, more countries and companies
are embracing this high-quality fuel. The U.S. lags behind because other
forms of energy, such as natural gas, are much cheaper, but several new
projects are getting underway, including a
green hydrogen power plant in Utah
that will replace two aging coal-fired plants and produce electricity
for southern California.
The Middle East, with the world’s cheapest wind and solar power, is
angling to be a major player in green hydrogen.
In Japan, a new green hydrogen plant, one of the world’s largest, just
opened near Fukishima — an intentionally symbolic location given the
plant’s proximity to the site of the 2011 nuclear disaster. It will be
used to power fuel cells, both in vehicles and at stationary sites. An
energy consortium in Australia just announced plans to build a project
called the Asian Renewable Energy Hub near Pilbara that would use 1,600
large wind turbines and 30 square miles of solar panels to run a
23-gigawatt electrolysis factory that would create green hydrogen to
send to Singapore.
As Europe intensifies its decarbonization drive, it, too, is betting big
on the fuel. The European Union just drafted a strategy for a
large-scale green hydrogen expansion, though it hasn’t been officially
adopted yet. But in its $550-billion clean energy plan, the EU is
including funds for new green hydrogen electrolyzers and transport and
storage technology for the fuel. “Large-scale deployment of clean
hydrogen at a fast pace is key for the EU to achieve its high climate
ambitions,” the European Commission wrote.
The Middle East, which has the world’s cheapest wind and solar power, is
angling to be a major player in green hydrogen. “Saudi Arabia has
ridiculously low-cost renewable power,” said Thomas Koch Blank, leader
of the Rocky Mountain Institute’s Breakthrough Technology Program. “The
sun is shining pretty reliably every day and the wind is blowing pretty
reliably every night. It’s hard to beat.”
BloombergNEF estimates that to generate enough green hydrogen to meet a
quarter of the world’s energy needs would take more electricity than the
world generates now from all sources and an investment of $11 trillion
in production and storage. That’s why the focus for now is on the 15
percent of the economy with energy needs not easily supplied by wind and
solar power, such as heavy manufacturing, long-distance trucking, and
fuel for cargo ships and aircraft.
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The Fukushima Hydrogen Energy Research Field (FH2R), a
green hydrogen facility that can generate as much as 1,200
normal meter cubed (Nm3) of hydrogen per hour, opened in
Japan in March. Toshiba ESS
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The energy density of green hydrogen is three times that of jet fuel,
making it a promising zero-emissions technology for aircraft. But
Airbus, the European airplane manufacturer, recently released a
statement
saying that significant problems need to be overcome, including safely
storing hydrogen on aircraft, the lack of a hydrogen infrastructure at
airports, and cost. Experts say that new technologies will be needed to
solve these problems. Nevertheless, Airbus believes green hydrogen will
play an important role in decarbonizing air transport.
“Cost-competitive green hydrogen and cross-industry partnerships will be
mandatory to bring zero-emission flying to reality,” said Glen
Llewellyn, vice president of Zero Emission Aircraft for Airbus.
Hydrogen-powered aircraft could be flying by 2035, he said.
In the U.S., where energy prices are low, green hydrogen costs about
three times as much as natural gas, though that price doesn’t factor in
the environmental damage caused by fossil fuels. The price of green
hydrogen is falling, however. In 10 years, green hydrogen is expected to
be comparable in cost to natural gas in the United States.
A major driver of green hydrogen development in the U.S. is California’s
aggressive push toward a carbon-neutral future. The Los Angeles
Department of Water and Power, for example, is helping fund the
construction of the green hydrogen-fueled power plant in Utah. It’s
scheduled to go online in 2025.
A company called SGH2 recently announced it would build a large facility
to produce green hydrogen in southern California. Instead of using
electrolysis, though, it will use waste gasification, which heats many
types of waste to high temperatures that reduce them to their molecular
compounds. Those molecules then bind with hydrogen, and SGH2 claims it
can make green hydrogen more cheaply than using electrolysis.
California officials see green hydrogen as an alternative to fossil
fuels for diesel vehicles.
California officials also see green hydrogen as an alternative to fossil
fuels for diesel vehicles. The state passed a Low Carbon Fuel Standard
in 2009 to promote electric vehicles and hydrogen vehicles. Last month,
a group of heavy-duty vehicle and energy industry officials formed the
Western States Hydrogen Alliance
to press for rapid deployment of hydrogen fuel cell technology and
infrastructure to replace diesel trucks, buses, locomotives, and
aircraft.
“Hydrogen fuel cells will power the future of zero-emission mobility in
these heavy-duty, hard-to-electrify sectors,” said Roxana Bekemohammadi,
executive director of the Western States Hydrogen Alliance. “That fact
is indisputable. This new alliance exists to ensure government and
industry can work efficiently together to accelerate the coming of this
revolution.”
Earlier this year, the U.S. Department of Energy announced a $100
million investment to help develop large, affordable electrolyzers and
to create new fuel cell technologies for long-haul trucks.
In Australia, the University of New South Wales, in partnership with a
global engineering firm, GHD, has created a home-based system called
LAVO that uses solar energy to generate and store green hydrogen in home
systems. The hydrogen is converted back into electricity as needed.
All these developments, says Blank of the Rocky Mountain Instiute, are
“really good news. Green hydrogen has high potential to address many of
the things that keep people awake at night because the climate change
problem seems unsolvable.”
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