POWER May 2023 - 28

HYDROGEN
Overcoming Green
Hydrogen's Major
Operational Cost: Electricity
There are many ways to create hydrogen from renewable energy resources. The
challenge is to reduce the cost of such fuel production, in order to position green
hydrogen as a viable option to support decarbonization efforts.
Chad Mason
A
s governments and organizations
across the world race toward
achieving a more sustainable energy
future, the energy sector is increasingly
turning toward green hydrogen as a solution.
Adoption of green hydrogen-a fuel
generated by renewable energy or lowcarbon
power-is expected to accelerate
exponentially, with the market projected
to reach $72 billion by 2030, compared to
the current market size of $1 billion. However,
that adoption is contingent on two
significant hurdles-reducing the operating
costs associated with green hydrogen
production, and the ability to scale manufacturing
to meet demand.
Green hydrogen (Figure 1) is produced
from electricity and water with electrolyzer
systems using renewable energy,
such as solar, wind, hydro, and geothermal.
A closely related version of this are
those electrolyzers powered by nuclear
energy, which is sometimes referred to
as " pink hydrogen. "
The vast majority of today's hydrogen
is produced using fossil fuels, often
where methane or coal is combined with
water to produce hydrogen and carbon
dioxide (CO2
). Today, this industry accounts
for more than 2% of global CO2
emissions. This " gray hydrogen " from
fossil fuels costs three times less than
green hydrogen on average today.
Two Categories of Electrolyzers
Electrolyzers in today's market fall into
two categories-liquid water or gaseous
steam (cold and hot). Liquid water
electrolyzers include alkaline and PEM
(polymer electrolyte membrane) technologies.
They require large amounts of
electricity to electrolyze water, usually
more than 50 kilowatt-hours per kilogram
(kWh/kg) of hydrogen produced.
Conversely, steam electrolyzers,
such as solid oxide electrolyzers, work
with 700-degree superheated steam.
By working with steam, the electricity
requirements are significantly
lower-
well below 40 kWh/kg is possible. But
that
high-temperature steam requires
expensive equipment in the system,
along with additional maintenance, and
significant effort is required to prevent
heat loss. These solid oxide systems also
have struggled to scale up in size.
Regardless of the category, the main
driver of the exorbitant price of green hydrogen
production is electricity, at more
than 70% of the cost on average, which
will only grow larger as a share of total
cost in the future.
There are excellent ways to create
low-cost green hydrogen. However, it's
first important to understand why there
are so many reasons to do so. By transitioning
to industrial green hydrogen, we
can reduce our dependence on fossil fuels,
which are subject to supply risks and
unstable prices.
By decarbonizing existing hydrogen
production and using hydrogen in relevant
industries, such as green steel, green hydrogen
can help abate more than 10% of
CO2
emissions globally. In some localities,
the price of carbon emissions continues
to increase, thus the use of green hydrogen
in heavy industries (such as steel,
fertilizers, and chemical production) can
reduce the cost of these emissions, negating
the need for expensive carbon capture
and storage solutions, or the need to
pay for emissions credits.
Environmental Benefits
The implementation of electrolyzer
technology provides several other notable
environmental benefits, the most
important being that green hydrogen
production doesn't emit any harmful
pollutants, such as sulfur dioxide, nitrogen
oxides, or particulate matter, unlike
fossil fuels. Replacing gray and even
blue hydrogen (hydrogen produced
from fossil fuels but supported by carbon
capture and storage) with green hydrogen
in heavy industries will lead to
the elimination of dangerous pollutants
and improved air quality.
Another major advantage of green
1. Green hydrogen is a fuel produced using power from renewable energy, including solar and
wind power. Most hydrogen production today uses fossil fuels, often natural gas. Source: Shutterstock
28
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hydrogen
is its ability to be used in the
production of dense, easy-to-store fuels
such as ammonia and methanol. These
fuels can be used as backup power or
peaking power generation in situations
where a stable and reliable source of enPOWER
| May 2023

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POWER May 2023

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