Iron-Air Utility Scale Stationary Battery at 1/10th the Cost of Lithium Ion

Form Energy has an iron-air battery technology that is optimized to store electricity for 100 hours at system costs competitive with legacy power plants. It is a cost-effective, multi-day energy storage systems. They use new iron-air battery chemistry for their irst commercial product and have a $200 million Series D financing round led by ArcelorMittal’s XCarb™ innovation fund.

Nextbigfuture covered Form Energy back in 2018.

They have 1/10th the cost of lithium-ion.

This is a “Reversible Rust” Battery that could transform energy storage.

They used a membrane repurposed from a zinc-air battery design. This membrane has a lower overpotential. They solve roundtrip efficiency concerns from earlier designs.

The iron-air battery takes in oxygen and then uses it to convert iron inside the battery to rust, later converting it back to iron again. Converting back and forth between iron and rust allows the energy that is stored in the battery to be stored longer than conventional batteries.

The batteries are much too big and heavy for use in small applications (or cars)—each battery is approximately the size of a washing machine. Instead, they are meant to be hooked together in massive grids capable of storing enormous amounts of electricity for days at a time. Cells are stacked inside of a water-based, non-flammable electrolyte, which the company claims is similar to that used in standard AA batteries—the cells are made of iron and air electrodes.

Thousands of the batteries could be used to store huge amounts of power—they suggest that a grid covering approximately one acre using their low-density batteries could provide power for a one-megawatt system. The high-density version, would be triple that.

These new battery technologies are more cost-effective for utility scale storage applications compared to current storage technologies. Lithium ion batteries typically cost up to $80 per kw/hour of storage. The new battery costs under $6 per kw/hour in its most basic form, and approximately $20 per kw/hour when outfitted as part of a total system—a price point. Bill Gates and Jeff Bezos have invested. They have already forged deals with some utilities, such as Great River Energy in Minnesota.

55 thoughts on “Iron-Air Utility Scale Stationary Battery at 1/10th the Cost of Lithium Ion”

  1. $20/KWH. Vs what, 2-3c/KWH for nuclear?

    So the batteries only need to survive 5-10 thousand charge/discharge cycles to match the cost of nuclear. Assuming you're charging them with free electricity, and buying them with zero interest loans.

    Generating power basically always beats storing it in batteries, because you still have to generate it to store it in batteries. Unless you're mindlessly committed to relying on unreliable, intermittent sources of power.

  2. Incredible growth (from a basis of practically zero is not grid scale and won’t ever be without major cost reductions.

  3. Agreed. Would be interesting to know the researcher numbers and dollar amounts. Just the PhD disserts and patent quantities must be mind-boggling. Thought I saw a stat saying that in Fall 2020, there were over 50,000 lab researchers/line techs (not medical workers) working on covid-related therapies at any given time… certainly a comparable Manhattan-style project, if anyone gets the ref.

  4. shotgun approach. very valuable to have the sheer number of academic labs, corporate R&Ds, and government funding initiatives seek out not only the best chemistry but best manufacturing, recycling, and reduced-supply line bottlenecks/ scarcities as possible. Electricity storage's ability to service all scales of devices, societies, and country-development levels will probably have a comparable economic and knowledge growth impact as internet/cel service 1995 to now.

  5. Brian Wang: "… the batteries could be used to store huge amounts of power […] a grid covering approximately one acre […] could provide power for a one-megawatt system."
    One megawatt of power, but for how long? You store energy, measured for example, in megawatthours. Energy, not power, is stored. OK?

  6. Lithium-ion batteries are at ~$140/kWH. Storage needs to be at ~$10/kWH to beat natural gas plants, $5/kWh to beat natural gas peaker plants.

    There is a pilot thermal storage plant in Germany, 800 cubic meters of volcanic rock-fill with a mass of 1,000 tons and heated to 1,382F. It can store up to 130 MWh of thermal energy for a week. The plant has a generator rated at 1.4 MW that produces energy for up to 24 hours. It can provide electricity, heat, and process steam while discharging.

    There is a lot of potential in thermal storage, using rocks, carbon, salt, silicon etc.
    Silicon can store 1 MWh of energy per cubic metre at 1400 °C

  7. Capital cost is manageable if it can run on nearly-free electricity. From what I could gather, in 2011 electrolyzers capital cost contributed $0.70/kg to the cost of H2, vs $3 for the electricity. And I imagine some clever engineering could find some lower capital solutions even if it comes at the expense of worse efficiency. Efficiency is not so important if we are using 'waste' electricity.

  8. Nearly any process you can think of; even as simple as producing hydrogen in an electrolyser, uses expensive capital and won't be economical if they're only running some of the time. You *will* be throwing a lot of energy away that nobody will want even if it is free.

  9. Oh, and they claim a high density system with triple that, so I guess just 333 acres for 100GWhr of storage – a bit over half a square mile. Still big.

  10. Note that they are claiming a 1MW system requires an acre – that's the power, not energy.

    If their 100 hour of storage number is accurate and applicable, that'd be 100MWhr per acre, and for 1GWhr you'd need 10 acres, or 1000 acres to provide 100 hours of back-up power to a 1GW renewable energy power installation.

    Still pretty big, especially if they need to be housed in a building as illustrated.

  11. I'm pretty sure the $6 or $20 per kWhr is their PROJECTED cost.

    There's a huge amount of ramping up investment in equipment to get to the point that even one grid-scale project is possible (which it appears is where they are now), and then that has to be expanded a lot more to make lots of projects possible.

    So some patience is going to be required even for an ideal "real deal" battery tech.

  12. I was a bit unclear too due to the fact that I don't type very fast on my phone.. BroncoBet was not entirely wrong that a super low cost iron-air battery could ruin half of Teslas future value, if you would take Elons estimate that Tesla will be half energy and half automotive in the future as the ground truth. Presumably, the energy side of the business would grow a lot faster than the automotive side in the future…

    Of course, I don't think that this iron air battery will affect Tesla negatively, but that's a different issue…

  13. Agreed. Usually the mantra is "avoid the comments section at all costs." Here, the comments section is the draw.

  14. The real breakthrough here is a push into unknown territory of just how little actual information is needed in a press release to get widespread coverage.

  15. It's annoying that we haven't got any actual numbers for kW.h/kg or even cycle limits.
    And the "technical information" is presented as a kindergarten cartoon explaining what a battery is. I'm fairly sure anyone who is at the level of that cartoon is more concerned with playdough and barbie dolls than investing money in tech startups.

  16. I long ago lost count of the 'revolutionary' battery tech that was about to come down and make everything work for various green energy plans.

    What works in the lab, or on a small scale, may be prohibitively expensive to scale up to a usable level. We'll see how this one works out.

  17. A mothballed powerplant could be a perfect place. Large floor space and a switching station already connected.

  18. At 1/10 the cost of Lithium batteries, there should be hundreds of projects. Where are the projects? At a certain price point, fast start gas turbines and peakers are done with. They are gone because they are not economical anymore. The first companies that can install a large commercial unit will make hundreds of billions.

    I think is hype. There may be potential but there are still a lot of issues to iron out.

  19. So there is a dueling approach to making renewables the sole source of power: cheaper storage/batteries like we see here, to make upwards of a week of storage capacity more practical, and the RethinkX approach of overproducing renewables so that production rarely falls much below demand, or for long. This reduces the need for batteries, and creates a large supply of intermittent surplus power that could be used for industrial processes (hydrogen, methane, ammonia synthesis for chemical industry, for instance) that are practical even if they only operate say 30% of the year.

  20. An industrial building to house such a system is typically around $200/sqft to build. So per acre about $9M. You could definitely stack it, would just require a stronger floor.

  21. Exactly. You cannot back up each location fully with batteries for worst case. You need some way to move stuff in emergency (edit: big grid down). Both H pipelines and power beaming in smallish but regular use would do this. Diversity in backup soundz good to me.

  22. It may be that batteries for leveling the load and backup for emergency are different but related problems. Leveling the load is done all the time, and one can afford the size batteries needed to do that. Backup is open ended total demand, yet one is quite willing to pay in an emergency. But batteries get no cheaper as we buy enuf for that, and rarely use them. More expensive H fuel cells for emergency backup, store the H in tanks but don't routinely use it, as it is expensive to convert back and forth. Unlike batteries, however, it can be shipped out to industry on smallish pipelines if extra is made. Or, in long emergency, replenished thru those pipelines.
    The overall plan to have independent grids connected *up* to help each other is far better than everyone going down at once.

  23. Might as well put a roof on the batteries and then solar on the roof.

    1Acre/MWhr is a lot of building though.

  24. It is a lot of land. My first thought, looking at the drawing, was that they really need to put a sod roof on it for the win.

    And putting a few wind turbines on the building itself might also be an option, saving a few acres somewhere else from having them.

  25. I don't know where Brian gets the figure 6 USD per kWh. The statement "1/10:th of lithium batteries" is utterly meaningless unless they also provide a reference/hint to which lithium batteries they are referring to.

    Other sources quote 20 USD/kWh [1], which would be fine. But lithium iron might just hit those price points.. Plus, 1 MWh per acre would equate to 250 MWh per km2, or 4 km2 for one GWh. To buffer a standard power plant – or an equivalent amount of wind/solar plant – for 100 hours you would thus need 400 km2…

    And of course, we don't know the number of cycles that this "battery" can withstand, the power density, if there are any rare metals (such as platinum) in the battery etc… in short, we know almost nothing…


  26. Tesla also has the "megapacks". In the Q2 earnings call, we learned that their "megapacks" are sold out through 2022…

  27. These batteries if widely adopted would dramatically cut the cost of Tesla's battery materials.

  28. Batteries where the constituents segregate by density used to be called "gravity batteries". They are fabulous, their lifetimes limited only by the durability of the containers that hold them.

  29. Using iron, or something else cheap for static applications would keep lithium chemistries cheaper for mobile usages. The chemistries don't compete, they complement each other.

  30. A washing machine sized battery would be fine with me, but with 20 cells the voltage would likely be a bit low. Nominal voltage should be at least 48, but 480 would be better. As usual, there's little real information, like nominal cell voltage, what the "washing machine" delivers in terms of kWh storage, and charge, and discharge power.

    There is a huge market out there for people who want their own storage, it's a shame that all these new technology battery companies neglect the behind the meter market. I'm very tired of paying for monopoly boondoggle costs, coal ash spills, the utilities arrogant attitudes, and the county holding the power to cut off my power if they don't like the way I choose to live, or the state passes some crazy law.

    The state of NC thinks the NEC isn't good enough for it, and puts in absurd requirements. Believe me, the NEC staff has forgotten much more about electrical engineering than the General Assembly of NC will ever know. For instance, the NEC requires one ground rod for my 200 amp, single phase service. When did my own service to the NEC standards, I was informed by the inspector the state requires two ground rods, six feet apart! I didn't mention that my other home had one rod, and that had passed inspection.

    It's just a matter of time before net metering goes away. I want some batteries to do my own net metering. Let Duke Energy be my backup, at least until a decent small scale, heat source agnostic, heat engine makes it's debut.

  31. These would have to be combined with quick store / quick release storage solutions. These kind of batteries are slow absorption / slow release. However, at these costs, they make sense as a reliable baseload, only needing quick release batteries for spikes and troughs in the grid.

  32. Indeed; I know some individual turbines with 5 MW of generating capacity. 5 acres are about 2 ha of land, which probably won't be marginal. Maybe if we build large buildings they may be stacked up, but generally you will need space for ventilation so oxygen can reach the lower levels to react with the iron.

    I actually can't see this actually coming to production, but I hope to be wrong! We certainly do need cheaper mechanisms for energy storage.

  33. Do they even mention capacity? Is it somewhere in that kindergarten level cartoon that they have presented as a "technical explanation"?
    What was it?

  34. They are claiming that Li batteries are not good enough, in terms of $/kW.h, to be used for lots of applications.

  35. The only Tesla product this competes with is the Power Wall.

    Power wall sales in the last quarter were $801 compared to nearly $12 billion in total revenue for the company. 

    So that's not remotely close to half.

  36. Just wanted to say thank you to those who comment regularly. A big part of why I read this site. Obviously thanks to Brian as well.

  37. Don't you only get like a dozen cycles out of the iron-air cycle? I guess that's why they mention price and capacity, but nothing about life time….

  38. Even at 1/10 the cost is it worth spooling up production capacity for a specialized battery to compete with ubiquitous lithium-ion batteries. Sometimes good enough is good enough.

  39. Well, you can see the prices for a 1 GWh of Tesla Grid batteries. If you need to buffer a whole week for worst case scenarios, you get Trillions of dollars cost…
    Of course there is not enough production capacity in the whole world to support something like that, even for a medium sized country like Germany.

  40. Really Brian, ‘Current battery technologies are not cost-effective for most utility scale storage applications’?  If they weren’t, they wouldn’t be utilized to the incredibly growing levels that were experiencing, all over the world, in dozens of countries, by hundreds of utilities.

  41. Rust – We have tendency to ignore the simplest solutions. 1 Acre per 1MW is still a lot of land though, maybe later they will develop taller stacks.

  42. These plus Earth to Earth power beaming plus H for aircraft, trucks, even high performance cars and industry and emergency back up. Say goodby to thermal electricity. Here come Space Solar added to power beams.

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