ETA 2021 Strategic Plan - Flipbook - Page 61
Focus Areas
This work consists of five focus areas: (1) Novel
Desalination Technologies, (2) Critical Material
Recovery, (3) Water and Energy-Use Efficiency,
(4) Systems Modeling and Data Analytics, and
(5) Leveraging the Water–Energy Nexus to
Support Our Energy Future.
Novel Desalination Technologies
Desalination offers an opportunity to convert
unusable brackish or seawater to fresh water,
and to supply it to water-stressed regions.
The industry achieved major improvements
in desalination technologies following
breakthrough inventions in research labs in the
1950s. Those achievements allowed state-of-theart reverse osmosis (RO) efficiency to approach
theoretical limits (3.05 kilojoules per kilogram
[kJ/kg]-fresh for seawater) and practical limits
(about $2,250 per acre-foot for the Carlsbad RO
plant). However, at present, the cost and energy
intensities of desalinated water are prohibitive
for many industrial sectors and communities.
However, there is still a considerable margin of
opportunity for incremental improvements in
the classic distillation and RO membrane-based
technologies, and for further cost reduction
through advanced membrane manufacturing
and/or better system integration. Energy is a
large cost factor in the desalination process. The
use of renewable power or waste heat offers
opportunities to reduce energy costs. In fact,
these emerging integrated desalination systems
can already deliver fresh water at electrical
usage of less than 1 kilowatt-hour per cubic
meter by making use of lower-grade thermal
energy.
Developing new desalination technologies
operating at cost, electricity, and emission
parity with the average price of municipal water
today ($100–500 per acre-foot) could increase
our overall supply of fresh water, even through
extended periods of severe drought. In other
words, new technologies must achieve “pipe
parity” — that is, when technology solutions are
equally desirable as the next best option (i.e.,
the marginal water source for the targeted enduse application). Pipe parity metrics are useful
to decision-makers making investments on
different source water types. However, decisionmakers may also consider a technology’s energy
efficiency, carbon footprint, reliability, improved
water recovery, ability to reduce stress on
freshwater resources, and other factors.
ETA’s research vision also relies on alternative
concepts to RO and traditional thermal
technologies that may offer high-impact
solutions in terms of cost and energy reductions.
Technologies such as forward osmosis,
membrane distillation, freeze separation,
and capacitive deionization can be used in
commercial desalination of both brackish
and seawater, but these methods still require
significant advances to achieve pipe parity.
New breakthrough desalination/separation
concepts based on recent advances in
nanotechnology, metal coordination chemistry,
photonics, and thermionics can lead to
sustainable desalination techniques that enable
frugal use of nontraditional water reserves.
Critical Material Recovery
The assured supply of critical elements is
essential to U.S. economic prosperity and
national security. For example, lithium (Li)
demand will increase significantly over the next
decades, with estimates of 56 million annual
electric vehicle (EV) sales and energy-storage
deployment of more than 1,095 gigawatts
(GW) globally by 2040. At present, the majority
of Li production in the world originates from
overseas natural land reserves; there is only
one active U.S. brine site producing Li. However,
the United States has significant resource
potential in the form of unconventional sources
(e.g., geothermal brines, ores and clays,
mine tailings, seawater), which motivates the
development of cost-competitive technologies
for Li extraction and its conversion to high-grade
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