Page 27 - EngineerIT January 2022

SCIENCE

Capturing the Sun in a box

By Kevin Fitchard

he winner of the 2021 Nokia Bell Labs Prize is proposing a remarkable new use for carbon, the
primary source of global greenhouse gas. Instead of burning carbon in the form of coal and
Tother fossil fuels to produce energy, Asegun Henry wants to use carbon as the primary means
of storing energy generated from renewable sources like solar. Such a technology could go a long way
to shedding our reliance on fossil fuels and cutting CO2 emissions.
An associate professor at MIT and director of the university’s Atomistic Simulation & Energy
Research Group, Henry has invented a thermal battery made of graphite, which is carbon in its Kevin Fitchard
crystallised form. This battery could store enormous amounts of energy in the form of intense heat.
This would make it a cheap alternative to traditional electricity storage systems like lithium-ion relate to any field of science or any industry, as
batteries, Henry said. was amply demonstrated by the second and
“What makes it inexpensive is the nature of the way we’re storing energy,” Henry said. “We’re third placing proposals.
storing it in the form of heat and not electro-chemically. What’s happening inside the thermal battery Yale University professor Amin Karbasi
is a completely different phenomenon compared to that in a lithium-ion battery. Instead of producing and summary analytics chief experience
a chemical reaction, we’re literally using the kinetic energy of atoms – they’re being heated up and officer Mehraveh Salehi won second prize and
cooled down repeatedly.” $50,000 for their research on the intersection
This means that thermal batteries can be created from inexpensive materials like graphite. While of combinational optimisation and machine
lithium-ion batteries need to be specially built from multiple materials, thermal batteries require only learning that de-complexifies the human
a single material to function. Henry’s battery works by using excess electricity on the power grid to brain. Their technology can summarise vast
heat up a graphite block to glowing white-hot levels (1900°-2400°C). When more electricity is needed quantities of functional magnetic resonance
on the grid, liquid-metal tin is pumped into the battery, transferring a portion of the stored heat to a imaging (fMRI) data, shedding new light on
power conversion unit. There, the tin heats up graphite pipes, causing them to emit light. That light is underlying neural processes to the point of
collected by photovoltaic cells, returning it to the power grid as electricity. reconstructing individual thoughts.
One of the more expensive aspects of the system is the insulation required to contain the University of California at Riverside
intense heat stored in the graphite, Henry said. The thermal batteries must be enveloped in porous computer science professor Eamonn Keogh
carbon insulation, but Henry also manages to mitigate heat loss by using very large graphite blocks. and FarmSense CTO Shailendra Singh won
Minimising surface area compared to volume makes for more efficient energy storage, but it also third prize and $25,000 for their research
means you won’t see thermal batteries connected to your home solar panels or in your car. Henry into insect sensors that could provide the
said these batteries are intended for grid-scale use, providing gigawatts of centralised storage for agriculture industry with the intelligence to
entire cities. control pest populations while minimising
costs, maintaining biodiversity and reducing
Decarbonising the power grid carbon emissions.
Despite the cost of insulation, the total cost of the thermal battery system is still far cheaper Though anyone who owns their idea is
than lithium-ion storage. While the lithium-ion technology keeps improving, its costs to store eligible to enter the Nokia Bell Labs Prize, most
electricity remain well over $100 per kilowatt-hour. Henry estimates his system can store electricity at entrants come from academia, showing the
a cost of $10 per kilowatt-hour. This would make thermal batteries an ideal complement to growing deep relationship Nokia Bell Labs has forged
sources of renewable electricity entering our power grids. with global higher learning institutions. Three
The costs of producing solar power and other renewables have dropped significantly in the last of this year’s finalists – including the winner
few decades, making it a competitive energy source to fossil-based generation. The problem is that – hail from institutions that are Nokia Bell
the costs of generating solar power don’t factor in storage, which is absolutely essential to ensuring Labs Distinguished Academic Partners: MIT,
electricity is available when it is needed. The sun doesn’t always shine and the wind isn’t always Carnegie Mellon University and the University
blowing, but electricity demand doesn’t follow nature’s schedule. Energy storage, Henry said, is the of Stuttgart. n
lynchpin to fully decarbonising the grid.
“If we can proliferate this technology, we can reach a high penetration of renewables,” About the author
Henry said. “That would comprise 25% of emissions. With a decarbonised grid we can electrify Kevin Fitchard is an experienced technology
transportation and charge electric vehicles from a clean grid, which could potentially abate another writer and editor, having worked at multiple
15% of emissions. Altogether, this one energy storage technology can enable a 40% reduction in trade and consumer tech publications
emissions, which is almost half the problem.” before coming to Nokia Bell Labs in 2019.
He first became fascinated with Bell Labs
And the winners are… and its applied research mission in 2008
For his submission, Henry won the Bell Labs Prize trophy and a cheque for $100,000. The Nokia while reporting a feature story for Telephony
Bell Labs Prize is an annual competition seeking innovative inventions and proposals that could Magazine. After following the research
solve the future problems facing humanity. As some of the most pressing issues facing the planet institution for many years, he jumped at
relate to climate change, many entrants have focused on sustainability technologies, which is in line the opportunity to write about Bell Labs
with Nokia’s own strategy to build a more sustainable networking future. Submissions, however, can innovation from within its walls.

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