Energy

Disruptive iron-air grid-scale battery is 10% the cost of lithium

Disruptive iron-air grid-scale...
Boston's Form Energy says its iron-air battery systems will provide long-term grid-scale energy storage at a tenth the price of lithium "big battery" installations
Boston's Form Energy says its iron-air battery systems will provide long-term grid-scale energy storage at a tenth the price of lithium "big battery" installations
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Boston's Form Energy says its iron-air battery systems will provide long-term grid-scale energy storage at a tenth the price of lithium "big battery" installations
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Boston's Form Energy says its iron-air battery systems will provide long-term grid-scale energy storage at a tenth the price of lithium "big battery" installations
The charge cycle turns rust into metallic iron, storing energy and releasing oxygen. The discharge cycle accepts oxygen and produces energy and rust
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The charge cycle turns rust into metallic iron, storing energy and releasing oxygen. The discharge cycle accepts oxygen and produces energy and rust

Boston's Form Energy is building a commercial-scale pilot of a remarkable new grid-scale battery project that could make a huge contribution to long-term energy storage as the world moves away from fossil fuels. These simple iron-air batteries store up to 100 hours of energy at a tenth the cost of a lithium battery farm.

The big picture here is of course renewable energy. Solar, wind and other forms of green energy produce power as and when it's available, rather than when it's needed. Sometimes they may not produce much at all, for days at a time. So as the world starts to transition away from cheap, responsive and heavily polluting energy sources like coal, one of the great challenges is creating buffer facilities that can cheaply store and release energy as required.

Tesla more or less kicked the grid-level energy storage sector off in 2017 when it built the world's biggest battery in South Australia. The project was a huge success, and spawned many similar, larger developments worldwide. But there are inherent issues with lithium batteries. They're expensive, they wear out, they're better suited to quick turnaround than long-term storage. Not to mention, China's near-stranglehold on the lithium battery industry presents genuine energy security issues for other countries in the race to zero carbon by 2050.

Form Energy believes it has the answer: an iron-air battery capable of mass deployment at very low cost, using extremely common materials, capable of supplying power for up to 100 hours in an emergency situation. At "less than 1/10th the cost of lithium-ion," a system like this could feed stored energy back into the grid at a price "competitive with conventional power plants,"

Iron-air batteries essentially work by initiating and reversing the rust process. Metallic iron combines with oxygen to release energy in the discharge cycle, and then when energy is applied to this rust, it converts back into metallic iron and releases its oxygen. It's a technology that's lain dormant for many decades due to a wasteful hydrolysis issue, which reduced the battery's efficiency by half until it was addressed in 2012.

The charge cycle turns rust into metallic iron, storing energy and releasing oxygen. The discharge cycle accepts oxygen and produces energy and rust
The charge cycle turns rust into metallic iron, storing energy and releasing oxygen. The discharge cycle accepts oxygen and produces energy and rust

Form hasn't put a figure on the efficiency of its units as yet, but its large batteries use a giant iron anode the company says is the biggest anode ever made. The cells, about a meter square, are slotted into battery modules around the size of a washing machine, bathed in a liquid electrolyte, and they can be rolled out en masse in installations delivering between 1-3 megawatts of continuous power per acre.

The company says its solution will work well alongside big lithium batteries; presumably, the lithium might be better for fast discharge events like load spike smoothing, and the iron-air batteries will offer a slower-acting energy solution better suited to the times when renewable energy sources aren't delivering enough grunt to power the grid. 100 hours, or four and a bit days, is a useful period for covering heavy storms, for example, that might take wind and solar mostly offline for long stretches.

Another key advantage of a system like this comes at the end of its service life; the materials are highly recyclable.

Form Energy has now raised more than US$300 million to commercialize the system, with steel giant ArcelorMittal and Gates/Bezos-backed Breakthrough Energy Ventures among a large cohort of investors. The first project was announced last year: a commercial-scale project in Minnesota capable of delivering a constant megawatt of power for 150 hours.

Source: Form Energy

13 comments
13 comments
paul314
Are they limited to single-level installation? At the numbers they quote, a power plant equivalent will be up in the square miles of space. (Not that modern power plants are particularly small either.)
Food4Thought
What is the useful life of the Battery? In terms of days/years or cycles?
Karmudjun
The complex looks like a big-ass shipping complex. Why would it have to be among wind turbines and solar complexes? And why don't they build a roof covered with arrays of solar cells?

Sorry Loz, I couldn't help myself. You wrote a nice article - I especially like the link to the Bismuth Sulfide to the iron in fabrication led to reduced hydrolysis losses. There was a mention of the meter square anode being placed in washing machine size batteries with a 1-3 megaW/acre rate of discharge capacity. But how much do they weigh? A square mile comlex (640 acres) would be a massive amount of MW storage. If Paul314 wants to crunch the numbers, almost any industrial manufacturing building would have up to 3-5 floors that could tolerate the battery placement. But you have to give us more to go on (and I'm sorry Paul314 - the non-sequitur question is a little inane) then maybe we could get excited about the possibility. It obviously isn't built yet, the cost of square footage is ridiculous for just storing energy anywhere tornadoes or floods or earthquakes occur. But don't put them on the coast with hurricanes and the threat of tsunamis!

Even with triggers for hypothetical questions absent in your article, it is well written and gives those of us who look forward to a next generation power grid and greater renewable energy production future a grand glimmer of hope. Keep writing like this, we need it to maintain faith in the future. Even if a bunch of Millennials will run off with it....
Paul Anderson
Any clue on how the recharging is supposed to work? AFAIK there's no electrochemical way to recharge iron-air batteries: "recharging" means replacing the anode.
Jorel
As @Paul314 mentions, building it as a single layer seems highly wasteful. And even if you build it to multiple stories, that's still a lot of square footage of roof where solar could be well employed. And come to think of it, this might be a better use for abandoned salt mines and such than storing old documents, a la Iron Mountain. Maybe this is a business opportunity for them, or a competitor...
John Banister
Because it's Iron batteries, one has to ask: What percentage of the power that you put in do you get back? And, what percent of the power stored is lost to self discharge in a day / week / month? For example, Nickel-Iron batteries are comparatively inexpensive and very durable, but their charge/discharge efficiency is less than 65% and they lose 20-30 percent a month to self discharge. It would be interesting to see comparative numbers on these Iron-Air batteries.
Lamar Havard
I think Loz Blain needs to research just how bad manufacturing and disposal of turbines and solar panels are for the environment before he knocks coal and oil out of the equations.
The Doubter
The self discharge might not be very important in grid storage batteries where discharge cycles are at the most a day or two.
christopher
@Food4Thought - the linked 2012 article says 5000 charge/discharge cycles (so - 13 years if used every day).
@Paul Anderson - adding bismuth makes them rechargeable (presumably with some kind of forced airflow for the oxygen part)
@John Banister - the linked article says 4% is lost when charging

1kwh of 18650's is 6kg - while 1kwh of these only need 3kg of iron (I've no idea how much the electrolyte weighs) - but that's an interesting start.
CAVUMark
I love the word "Disruptive". Wish I knew about the power of this word in my working days. Only thing disruptive now is when I overindulge in chips and salsa.

Fan of distributed power systems, creating what you consume.
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