Iron-Air Battery: From My 2021 Blog to NTPC Simhadri — Congratulations, Shri Gurdeep Singhji!
Dear Shri Gurdeep Singhji,
I read today's news with a very special sense of satisfaction.
NTPC Simhadri is going to host a pilot project for an indigenous Iron-Air Battery technology, developed by deep-tech startup Meine Electric, for Long-Duration Energy Storage (LDES).
The project is being implemented by Atal Incubation Centre–Anna University, with Meine Electric as technology partner. The stated objective is to test the system under actual utility operating conditions and generate the performance data needed for larger-scale deployment.
My congratulations to you and the entire NTPC team!
But there is another reason why this particular announcement caught my eye.
I HAVE BEEN WRITING ABOUT IRON-AIR BATTERIES SINCE 2021!
I searched my own blog archive today for “Iron Air Battery.”
And there it was.
In July 2021, I had already written extensively about Iron-Air batteries and their possible application as large-scale electricity-storage systems.
I was particularly fascinated by an apparently simple idea:
IRON + AIR + WATER → ELECTRICITY STORAGE
At that time, I was asking whether Iron-Air batteries could become a radically cheaper way of storing enormous quantities of electricity than conventional Lithium-Ion batteries.
And I was not thinking merely about electric cars.
I was thinking about the ELECTRICITY GRID.
I wrote about the possibility of:
“IRON-AIR GRID-SIZE BATTERIES”
and about using such batteries to store renewable electricity and make solar power available beyond the hours in which the sun is shining.
In other words, I was already asking the question that India is asking much more urgently today:
How do we store renewable electricity for LONG durations — economically?
FIVE YEARS LATER…
Here we are.
NTPC — India's largest power utility — is now providing a real-world platform at Simhadri Thermal Power Station for an Indian company to demonstrate an Iron-Air battery system.
Meine Electric says its Fast Charge Long Discharge technology is designed for 6 hours of charging followed by 18 hours of discharge. The system is also being evaluated for its electrochemical performance, capacity retention and operational stability.
That is a remarkable development.
Because this is no longer simply:
“Could Iron-Air batteries work?”
It is now:
“Can an Indian Iron-Air battery work at a POWER STATION?”
That is a completely different question.
WHY THIS COULD BE A BIG DEAL
India is adding solar and wind capacity at an enormous pace.
But renewable electricity has one inconvenient characteristic:
Electricity generation and electricity demand don't necessarily occur at the same time.
Solar electricity is plentiful during the day.
But millions of consumers need electricity:
after sunset.
Wind can be abundant at one time and weak at another.
Therefore, the next great energy revolution may not simply be about generating more renewable electricity.
It may be about:
STORING IT CHEAPLY.
And that is where Iron-Air technology becomes fascinating.
Iron is abundant.
Air is everywhere.
Water is readily available.
And the technology is based on a reversible oxidation process — essentially using the chemistry of rusting and reversing that process to store and release energy.
The attraction is not high energy density.
A stationary power plant doesn't care whether its battery is as light as a lithium-ion battery in an automobile.
It cares about:
₹/kWh
storage duration
cycle life
safety
reliability
availability of raw materials
and ultimately:
COST OF ELECTRICITY DELIVERED FROM STORAGE.
THIS IS WHERE NTPC'S ROLE IS SO IMPORTANT
A startup can invent.
A laboratory can demonstrate.
A battery manufacturer can build.
But a major utility can do something extraordinarily valuable:
PUT THE TECHNOLOGY THROUGH THE REAL-WORLD TEST.
That is precisely what makes the NTPC Simhadri pilot so important.
The project is expected to produce operational data that can determine whether the technology can move from demonstration towards commercial-scale deployment.
And I sincerely hope NTPC publishes as much of that data as possible.
Because the world does not need another battery brochure.
The world needs BATTERY DATA.
Actual:
- charging efficiency
- discharge efficiency
- degradation
- cycle life
- operating temperature
- maintenance requirements
- land requirement
- capital cost
- operating cost
- levelised cost of storage
- and, above all, ₹ per kWh actually delivered to the grid.
If Iron-Air passes those tests, India may have something extremely valuable.
A LITTLE “PRIOR ART” — WITH A DISCLAIMER!
I certainly do not claim that I invented Iron-Air batteries.
I didn't.
Nor do I claim that today's Meine Electric technology is the same technology I discussed in 2021.
It isn't my place to make that claim.
But I can make a much simpler and fully documented claim:
I was writing publicly about Iron-Air batteries and their potential for GRID-SCALE ENERGY STORAGE in July 2021.
Five years later, an Indian deep-tech company is taking an Iron-Air battery to an Indian power station.
That makes me smile.
Because sometimes an idea takes a very long journey before it reaches the power grid.
DEAR SHRI GURDEEP SINGHJI…
Please accept my congratulations for giving this experiment a platform inside NTPC.
And my humble suggestion:
Don't treat this merely as a battery pilot.
Treat it as a possible strategic technology mission for India.
If the Simhadri results are encouraging, why not progressively test the technology at larger scales?
Pilot → 1 MW → 10 MW → 100 MW → GW-scale
And perhaps one day we may look back at Simhadri and say:
“That was where India's Iron-Air Grid Storage journey really began.”
FROM COAL POWER TO STORED SOLAR POWER?
There is also a beautiful irony here.
The experiment is taking place at a thermal power station.
Perhaps one day, the same site could become part of a completely different electricity architecture:
SOLAR + WIND → IRON-AIR STORAGE → 24×7 ELECTRICITY
The power station of tomorrow may not necessarily burn fuel.
It may simply store electricity generated somewhere else and deliver it whenever India needs it.
That would be quite a transformation.
So, Shri Gurdeep Singhji — congratulations once again!
And congratulations to:
NTPC
Meine Electric
Atal Incubation Centre–Anna University
and all the researchers, engineers and entrepreneurs working to make long-duration energy storage commercially viable in India.
As for me, I am simply delighted to discover that something I was writing about in 2021 has now reached the gates of NTPC Simhadri.
Perhaps this is what blogging is really about.
You put an idea into the public domain.
You wait.
And sometimes, years later…
THE IDEA COMES BACK TO YOU — IN THE FORM OF REALITY.
Hemen Parekh
18 August 2026
My earlier Iron-Air Battery writings:
https://myblogepage.blogspot.com/search?q=Iron+air+battery
Today's NTPC Simhadri news:
https://www.pv-magazine-india.com/2026/08/17/meine-electrics-iron-air-battery-enters-utility-scale-pilot-at-ntpc-simhadri/