Page 43 - North American Clean Energy September October 2015

salt caverns. (Figure 3) Multiple caverns may RE. he goal is to deliver irm and dispatch-able electricity with system economically feasible. Before billions of dollars are invested in a larger
be manifolded together, operating at the same stability, while displacing fossil generation. his is costly and technically and smarter electricity Grid, other alternatives must also be considered.
pressure, allowing them to share a surface diicult on both the generation and transmission sides. We have only Unfortunately, this serious consideration has never been done, and any

facility, which will reduce capital costs to
begun to ask how RE may serve energy markets beyond the electricity proactive attempts, thus far, have been inadequate and unpersuasive.
well below $ 1.00 / kWh at on a multi - 100 sector, whether via an expanded electricity sector and Grid, or perhaps
GWh scale. Two GH2 storage salt caverns, via alternatives to electricity. Imagine a day when all of humanity’s en- Bill Leighty is a director of he Leighty Foundation and a principal in
near Moss Bluf, TX, have operated for several Alaska Applied Sciences, Inc., Juneau, AK, USA, with EE and MBA
ergy is supplied from a diverse array of RE sources.
years with low O&M.
To achieve this, it’s necessary to assemble a collection of private enter- degrees from Stanford.
he USA has enough domal salt geology prises, academia, national labs, funders, and others who can focus on de-
along the coast of the Gulf of Mexico to install veloping a thorough and expert RE model, which is both technically and
The Leighty Foundation | www.leightyfoundation.org/earth.php

15,000 large GH2 storage caverns, providing
enough storage to irmly support the entire P
Great Plains wind resource and all 100 quads U
of energy demand.
N
he large, nascent H2 fuel market for fuel
cell buses and light duty vehicles (LDV's) E
should motivate interest in integrated, op-
timized, RE-source systems. Transportation T
H
fuel may be a larger market, and may mo- G
tivate turbine suppliers to ofer equipment
optimized for of-grid Hand NHfuel utili- I
2 3 zation, with simpler, more robust, and less- L

costly electric generating systems, which use
variable-speed induction motors (igure 4).
Polymer-metal tubing and line pipe developed
at Oak Ridge National Laboratory (ORNL)

may replace steel for high-pressure transmis-
sion pipelines, which will solve the hydrogen
embrittlement and other corrosion problems.
NH, the "other hydrogen,” is a higher-
3
hydrogen-density energy carrier than liquid
hydrogen, LH2. A liter of NH3 contains more
hydrogen atoms than a liter of LH2. he modi-
ied internal combustion engine, combustion

turbine, and fuel cell run well on NH3, while
RE transmission and storage costs are even
lower than for GH2.
Twin mild steel tanks hold 80,000 tons

of refrigerated, liquid anhydrous ammonia,
NHat the Agrium terminal in Iowa, storing
3 approximately 500,000 MWh, which may

be directly used as fuel or easily reformed
Finally, a safety harness
to H2 fuel, and harmless, vented N2. At this
scale, energy storage costs approximately that won’t weigh you down.
$0.10 / kWh. Over 4,000 km of NHtransmis-
3
sion pipeline is already in place in the USA, From the Ultimate in Fall Protection
where NH3 is used primarily as nitrogen-fer- comes the most comfortable, lightest-
tilizer. hese pipelines are low-cost, mild steel,
and operate at approximately 15 bar.
wearing, truly innovative safety harness
ever created: the DBI-SALA® ExoFit
Great Plains wind is seasonally-variable,
producing about 20% more in the winter and STRATAM. Featuring groundbreaking
spring, and 30% less in the summer. Firming technologies that literally take the
1,000 MW, to allow energy delivery every day
weight of your shoulders and keep you
of the year, would require 300,000 MWh of cool on the job, the ExoFit STRATAM
storage: approximately 4 GH2 salt caverns, or
the equivalent of 2 NHtanks. In either case, helps you power through your day
3 the storage incremental capex is roughly 3% like no other harness can.

of the total wind plant cost. Compressed air
or relow battery storage is many times higher
too. Investing in energy conversion equipment EXOFITSTRATA.COM
to utilize the low-cost storage, as well as the

transmission and integration problems as well
can be accomplished via complete, integrated,
optimized, RE systems; from sources to deliv-
ered energy services, employing GH2 and NHVisit NSC Booth #2439
3 and try it yourself.
as the transmission and storage media. Stor-
age should not have a limited deinition as an
appurtenance to the electricity Grid.
For over a decade, researchers have been en-

gineering wind turbines, solar PV, and CSP sys-
tems as well as making modiications to the
Grid to accommodate an increasing share of

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North American Clean Energy