H2Tech - Q3 2022 - 15

SPECIAL FOCUS: PATHWAYS FOR SUSTAINABLE H2
H2 2022: The road to long-duration
energy storage
J. ROWELL and J. CRISTIANI, Victaulic, Raleigh, North Carolina; F. JAKOB, Victaulic, Overland Park, Kansas
Aggressive decarbonization and sustainability goals are
driving unprecedented amounts of renewable energy onto
the grid as the world scrambles to move toward low-carbon
and zero-carbon generation, with negative-carbon goals not
too far behind. Throughout 2021, renewable energy capacity
additions in the U.S.-led by solar power, with an increasing
growth of wind and hydropower generation-reached record
highs. Building on these trends, U.S. federal estimates forecast
that renewable energy will provide 75% of U.S. electricity by
2035 and 90% by 2050.
However, the full-scale adoption of carbon-free electricity
still hinges on successfully overcoming the notorious " v "
word: variability. Since the powers of nature are not always
aligned with the hourly demands of our global electricity
needs, variability issues remain a constant threat. Simply put,
wind and solar produce energy on a schedule that is out of
sync with consumer demand. While solar supply peaks at
noon and onshore wind turbines peak in the middle of the
night, consumers tend to use the most electricity in the mornings
and evenings as they start and end their day-thus introducing
the need for energy storage.
Lithium-ion batteries represent the primary focus for most
consumer-level battery storage solutions such as portable
electronics, automobiles and residential storage. Lithium-ion
batteries support the day-shifting of energy, charging and discharging
rapidly following variable renewable generation to
offer 4 hr-8 hr of grid-deployable power.
However, the physical limitations of lithium-ion chemistry
cannot extend past 8 hr of storage discharging at rated power-this
is not particularly helpful when the power cuts out
and consumers are left without electricity for days, or when
market economics encourage seasonal shifting (such as energy
storage that would enable the use of electricity generated in
warm, sunny July during the cold, dark months of February).
To unlock the full potential of renewable energy to cut carbon
emissions, cost-effective, utility-scale and long-duration
energy storage systems are needed. While the U.S. Department
of Energy (DOE) defines these systems as anything that
can hold more than 10 hr of storage, consumers require systems
that can store days' worth of capacity.
Unfortunately, there is one tiny roadblock to achieving sufficient
energy storage-there are few commercially feasible,
economically viable and technically scalable long-duration
energy storage technologies on the market. Pumped hydroelectric
storage is currently the only solution, but this type of
energy storage remains constrained by geography and access to
water, and can take many years to design, permit and construct.
In recent decades, power providers have turned to natural
gas as the standby/backup fuel of choice. With hydraulic
fracturing technology, natural gas is low-cost and abundant,
and lower in carbon than alternatives (oil, coal and wood).
Additionally, natural gas already has a developed infrastructure
for transportation (including pipelines for its gaseous
form, underground salt caverns for its compressed form and
tanks for its liquefied form). California-which increasingly
struggles to meet its energy needs and is forced to curtail huge
amounts of solar power when generation exceeds demand-is
fast-tracking the development of gas-fueled generators to obtain
more power on the grid, even as it continues its efforts to
achieve the state's net-zero-carbon goal by 2045.
H2 production. In the zero-carbon future, a zero-carbon fuel
is a solution-and H2
is that fuel. H2
on earth the way natural gas (methane) does. H2
does not occur by itself
must be manufactured
from either hydrocarbon fuels (which is the current
pathway, but this method emits carbon dioxide)-or it can be
extracted from water (the future pathway), involving no carbon
emissions.
Therefore, power-to-gas (P2G) technology uses renewable
electricity to decompose water into its elemental constituents
that can be stored, transported and combusted to produce
power as compressed gas or as liquid ammonia by combining
H2
with the nitrogen in the air to produce ammonia. H2
, either
as a compressed gas or as liquid ammonia, can be used as a
zero-carbon pathway to bridge the future gaps between supply
and demand.
Decarbonization targets aside, S&P Global reported that
the economics around natural gas are not necessarily working
out anymore: " At an all-in electricity production cost of
$132/MWh, a 4-hr utility-scale battery is now priced below
the global gas-peaker plant average at $173/MWh. " Also, it is
important to note that " levelized cost of electricity " is typically
$/MWh of electricity produced over the life of a facility.
This makes natural gas far less attractive than it used to be,
particularly since accessibility and duration are not factored
into the cost comparison.
Advanced battery technologies. Lithium-ion batteries are
the most popular energy storage option today, controlling
more than 90% of the global grid battery storage market. HowH2Tech
| Q3 2022 15

H2Tech - Q3 2022

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