The 100-Hour Battery Is Real — Iron-Air Just Took a Huge Step Forward!

Back in early twenty-twenty-two we took a look at what was then one of the most intriguing new ideas in long-duration energy storage: the iron-air battery developed by a U. S. company called Form Energy. It was a simple concept — almost elegantly crude in a way — based on nothing more exotic than iron, water and air. The idea promised days of energy storage at a fraction of the cost of lithium-ion, using materials so abundant they make lithium look like rocking horse do-do. Then in early twenty-twenty-three we took another look to see what progress had been made, and, you know, it was promising but pretty limited. Now, those two videos got a lot of attention, but they also prompted plenty of you to leave comments like “Sounds great, Dave… but will it actually happen? ” We’re almost three years down the line now from that last video, so I thought it might be time to have a look at what’s been built, what hasn’t, what’s working, and what’s still to come in what I reckon is a fascinating little niche of the clean-tech landscape that has the potential to become a very big player indeed. Hello and welcome to Just Have a Think So, let’s start with the problem that iron-air energy storage is trying to solve. And to be blunt – it’s intermittency. Unless you’ve been living in a cave for the last few years you can’t fail to have noticed that wind and solar power have been climbing relentlessly upwards along an exponential adoption curve. According to the energy think tank EMBER, In twenty-twenty-FOUR, while hydro, nuclear and other renewables remained flat or falling, growth in wind and solar pushed ALL clean energies to more than FORTY percent of total global electricity generation. Despite the misguided ramblings of the US president during his recent speech at the World Economic Forum… “China makes almost all of the windmills and yet I haven't been able to find any wind farms in China. Did you ever think of that? ” China actually has more wind power capacity than the next EIGHTEEN countries combined, AND since twenty-twenty it’s has been adding more SOLAR power each year than the rest of the world combined as well, reaching its overall twenty-thirty renewables capacity target six years early in twenty-twenty-four. I could keep going with record breaking stats from other regions like India, Pakistan and Europe. And EVEN in the United States, renewable capacity is on the up and up, supplying just over TWENTY percent of electricity in the first half of twenty-twenty-five. Now I’m not going to patronise you by explaining what the limitations of wind and solar technologies are – you know what they are. So, although in the future, when the world has massively over-built wind and solar to largely cope with the lulls in energetic weather that our German friends call the Dunkelflaute, in the near-term we are going to need to plug the gaps if we want to keep the lights on 24-7. You’ve no doubt seen these types of chart before, with a logarithmic scale going up the Y-axis representing the most economically optimum discharge times for various energy storage technologies. I won’t show you every option here because it would get too busy, but you’ve got things like flywheels down here that can discharge relatively small amounts of residual energy for short periods to help with a bit of grid frequency regulation, then at the other end of the scale you’ve got so-called power-to gas which typically uses excess electricity to combine hydrogen with carbon dioxide to make methane. Lithium-ion batteries — fantastic as they are — don’t generally get used to cover multi-day lulls. The economics don’t stack up particularly well after about 6 to 8 hours of discharge. Pumped hydro works beautifully where there those topological features, aren’t there? So long-duration energy storage — anything from fifty to a HUNDRED and fifty hours — is no longer a “nice to have”. It’s becoming a structural requirement for our increasingly renewables-dominated grids And that’s exactly the niche iron-air aims to occupy. Back in twenty-twenty-three FORM energy was THE big player in the sector. They’d already announced plans to build a large-scale manufacturing facility in Weirton, West Virginia — what they call Form Factory 1. The idea was to mass-produce their iron-air battery modules by the tens of thousands, turning a promising technology into an actual industry. Quick recap of how it works? Why not. Here’s a snippet from my previous video The two main ingredients are basically nothing more sophisticated than good old iron, and fresh air. Both are extremely abundant, both are easily accessible, and importantly, both are cheap. The principle of Form’s technology is something they refer to as ‘Reversible rusting’. One of their batteries contains between ten and twenty stacks of cells, each of which has an anode consisting of pebble-sized pellets of metallic iron on one side, and an air breathing cathode on the other side, all immersed in a water-based, non-flammable electrolyte. As oxygen from the air floods into the battery cell, it reacts with the iron via the liquid electrolyte. That reaction reduces the air to hydroxide and oxidises the iron firstly into iron-hydroxide which releases electrons, and then into iron oxide, which releases more electrons, all of which can then be harvested to provide electrical energy. As the battery discharges, that rust slowly builds up

at the cathode. A full discharge cycle can take up to 100 hours, or roughly four days, and unlike lithium-ion batteries, these things can operate quite happily in a very wide temperature range without expensive cooling systems. To recharge the battery, an electrical current can be passed through the cells which reverses the reaction, liberating the oxygen from the rust and turning it back into iron. That process also takes about a hundred hours, so again, not suited to devices that pander to the human obsession with instant gratification, but still perfectly serviceable in a well-planned utility scale environment. So, it’s slow and heavy, and completely unsuitable for mobile applications. But for fixed grid storage? It has enormous potential. The chemistry naturally supports 100-hour discharge durations, and the materials cost is astonishingly low. So, what’s the latest state of play with Form Energy then? Well, like so many post-inflation reduction act clean-tech projects in the U. S., Form ran into supply chain bottlenecks, higher-than-expected construction costs, labour shortages, long lead times for heavy industrial equipment, and more stringent permitting than expected. All external pressures that delayed their original timeline. BUT, Form Energy’s factory is now operational. In Weirton. Right in the heart of the American rust belt. On the site of a former steel mill. And according to the company’s CEO Mateo Jaramillo speaking in November twenty-twenty-five on the YouTube channel of the investment firm SOSV, Form Energy is now fully up and running with manufacturing and has just shipped to its first major customer, Great River Energy, a generation transition cooperative in Minnesota, serving roughly a million members through twenty-two different cooperative outlets. One of the many advantages of Form’s configuration is that their modular units can be shipped dry – in other words WITHOUT the electrolyte. And because it’s a water-based electrolyte that can be easily mixed by large, well-established third-party suppliers, that liquid can simply be ordered in once the units are in place and basically poured straight into each battery. That’s a smart feature that vastly reduces shipping and handling costs. Jaramillo explained that the company now has a backlog of orders, with signed contracts filling up production capacity right through to twenty-twenty-eight, including partners like Xcel, Georgia Power and Dominion. Expansion has already begun at the Weirton site, bringing Form Energy one step closer to their goal of having an annual production capacity of five hundred megawatts, which don’t forget equates to fifty gigawatt-hours of energy discharge. The plan is to grow their vertically integrated supply and production chain from three hundred to seven hundred and fifty employees by twenty-twenty-eight. In fact, if you’re in the States and you fancy a career in this kind of thing then check out their website because they’re apparently hiring in West Virginia, Massachusetts and California. And iron-air technology appears to be gaining a bit of traction elsewhere in the world as well. In July twenty-twenty-five a Netherlands based company called Ore Energy launched Europe’s first grid-connected iron-air demonstrator in the city of Delft. It’s a pretty small-scale affair, but it’s a significant step. Operating conditions in high-humidity maritime climates are a great stress-test for the chemistry. Ore Energy are just as ambitious as Form Energy too. The company is also planning to ramp up production to fifty gigawatt-hours, with a twenty-thirty timeline for that goal. Over in India, where this sort of technology would surely be a real gamechanger in the energy transition, a start-up called Meine Electric raised new funding in twenty-twenty-four to push iron-air from lab to early deployment. They’re positioning themselves as Asia’s first iron-air manufacturer, targeting twelve-to-twenty-four-hour duration application. And there are apparently Iron-air research and development clusters in Japan, Israel and Germany. None of those have reached commercial operations yet, but they do give us a glimpse of a rising global interest in metal-air options as the energy transition ramps up at pace and stationary energy storage continues to strengthen its market position. So, can we get all giddy and excited yet? Well, maybe! Three things have shifted since I first took a look at Form energy back in twenty-twenty-two. Firstly, grid limitations and storage requirements are now crystal clear. Multi-day storage isn’t optional in a deeply renewable grid. All the major grid operators around the world are now actively modelling multi-day storage as a core requirement. Secondly. Form Energy has moved from concept through to construction and real-world deployment. That’s a big deal. Unlike many other optimistic tech startups in recent years Form has successfully crossed the dreaded valley of death that kills off roughly ninety percent of energy tech newcomers. Thirdly, the economics look increasingly compelling. If Form can hit the generally accepted target price of around twenty dollars per kilowatt-hour at system level

then iron-air represents one of the cheapest forms of long-duration storage ever devised. Combine that with IRA incentives, or at least what’s left of them anyway, and iron-air battery storage could…just possibly… become a cornerstone of a U. S. grid transition that IS happening whether Mr Trump likes it or not. Let me know what you think in the comments section below, but that’s it for this week. Thanks, as always, to the fantastic folks over at patreon dot com forward slash just have a think, who enable me to keep ads and sponsorship messages out of all my videos, and I must just give an extra special thank you to some folks who’ve joined recently with pledges of ten dollars a month or more. They are John Spock, Steve Bell, Daniel Lichau, Gerry Beauregard, Ian Painter and Eran Shimson. And of course, a massive thank you to everyone else who’s joined recently too. Don’t forget to like and subscribe to help get us to our next target of seven hundred thousand subscribers. And most important of all, Thanks for watching this far. It’s very much appreciated. Have a great week, and remember to Just Have a Think