Tech Briefs Magazine - January 2023 - 41

SPINOFF
S
olar power is abundant - when the
Sun is shining. Wind power is steady
- when the wind is blowing. And a power
grid is extremely convenient - until
there's an outage. But creating a steady
supply of electricity from intermittent
power sources is a challenge. NASA was
focused on this problem more than 45
years ago, when the agency designed a
new type of liquid battery during the energy
price shocks of the 1970s.
And while engineers continued over
the following decades to develop flow
batteries, as they're called, the technology
has drawn even more attention in
recent years, with the urgency of climate
change powering a larger-scale transition
to renewables like solar and wind.
Wilsonville, Oregon-based ESS Inc.
built on NASA's early work as the company
developed its own flow batteries using
only iron, salt, and water.
Requiring no heavy-metal mining or
disposal, the systems are among the safest
energy storage solutions available,
according to the company. With no corrosive
parts, they provide like-new performance
after daily use for more than
20 years and necessitate only simple
upkeep to go longer. They can easily be
scaled up as needed.
NASA's decades-old work on flow batteries,
much of which is public-facing
and easy to access, provided the ESS
team with creative ways of looking at
common problems with the technology,
said Craig Evans, the company's Founder
and President.
" It always goes back to research, "
he said. " If you don't have to reinvent
the wheel, you can certainly get things
done faster. "
It's probably fair to say that all flow
batteries today owe something to the major
push the technology got in the 1970s
and 1980s, when a NASA team of chemical,
electrical, and mechanical engineers
developed an iron-chromium flow battery
at Lewis Research Center - now
Glenn Research Center - in Cleveland.
Tech Briefs, January 2023
Spinoff is NASA's annual publication featuring
successfully commercialized NASA technology. This
commercialization has contributed to the development
of products and services in the fields of health and
medicine, consumer goods, transportation, public safety,
computer technology, and environmental resources.
Giant Batteries Deliver Renewable Energy When It's Needed
An Oregon-based battery company built on NASA's decades-old work to develop its own flow
batteries using only iron, salt, and water.
The NASA system, which won agency
awards, involved two tanks of liquid
electrolyte solutions, one infused
with iron chloride and the other with
chromium chloride. These electrolytes
were pumped through the battery cell,
triggering a chemical reaction through
a membrane that separated the two
solutions inside the battery.
During charge, electrical energy was
converted to chemical energy and stored
in the electrolyte liquid. To discharge
the energy, the process was reversed.
When the team at ESS began developing
its own flow battery in 2011, the
company founders wanted to use iron,
the most abundant element on Earth, as
NASA had. They found they could pair
it with a simple salt solution, which was
cheaper and easier to work with than the
chromium mixture NASA had used.
ESS flow batteries are designed for
grids that are increasingly powered by
intermittent wind and solar generation.
The company's systems store up to 12
hours of energy and discharge it when
needed. They have been deployed, for
example, by San Diego Gas & Electric in
a microgrid designed to provide backup
power to critical community facilities, fueled
by an on-site solar array.
Additional utilities and developers,
including Portland General Electric and
Enel Green Power, plan to install ESS
systems as well.
They also work at businesses and factories
- for example, Sycamore International,
a commercial facility in PennIn
developing its flow battery, ESS drew from groundbreaking research and development conducted
by the space agency more than 40 years ago. Pictured above is a 200-watt demonstration unit
of the flow battery NASA built in the 1970s and 1980s. (Image: NASA)
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Tech Briefs Magazine - January 2023

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