You’ve probably seen a grid battery by now, even if you weren’t looking for one. A row of white lithium cabinets in a field behind a chain-link fence, waiting for the evening peak. That’s what the words mean to most of us.<\/p>\n
There’s an older kind that almost nobody sees. It’s a steel box full of sodium and sulfur, both of them liquid, held at a temperature well past anything your kitchen oven can manage. One of the last of them got wired into the grid on the eastern edge of Brisbane this week, and the company that builds them has already voted to stop.<\/p>\n
The battery is rated at 250 kilowatts and 1.45 megawatt-hours, which comes out to about six hours of run time. It sits at a minerals processing plant called PRiSM, run by an Australian outfit named Lava Blue, and it’s connected to the Energex distribution network alongside a 200 kW solar array that was already on site. RenewEconomy<\/a> reported the commissioning on September 9 and called it Australia’s first grid-connected, industrial-scale sodium-sulfur battery. Between the panels and the box, the plant can now cover up to 100 percent of its own peak load.<\/p>\n That last part is the bit I’d care about if I ran a factory. Your worst hour of the afternoon stops being your worst hour.<\/p>\n A sodium-sulfur cell keeps liquid sodium on one side and liquid sulfur on the other, with a thin ceramic wall in between that only lets sodium ions through. Discharging pushes sodium across to the sulfur. Charging drags it back. Both materials have to stay melted for any of that to happen, which is the whole reason the thing runs hot.<\/p>\n How hot is settled, because the manufacturer publishes it. The data sheet for this model puts the inside of the module between 305 and 340 degrees Celsius, or roughly 580 to 645 Fahrenheit, and the entire unit is a single 20-foot shipping container.<\/p>\n A battery that burns electricity to keep itself warm sounds like a design flaw, and I assumed it was one until I looked at the numbers. Heating it up from cold pulls as much as 30 kilowatts. Holding it there while it cycles once a day takes under three. It runs a slow fever it mostly generates itself, and unlike the lithium cabinets you’ve driven past, it doesn’t need a chiller bolted to the side. The first one Australia installed, at a nickel mine southeast of Kalgoorlie, spent its life in the outback with no air conditioning at all.<\/p>\n NGK makes these, and its board resolved to discontinue manufacturing and sales and to stop accepting new orders. The company’s own explanation, quoted by RenewEconomy, comes down to three things: material costs went up, lithium-ion got harder to compete with, and steady demand for long-duration storage is taking longer to show up than anyone hoped. It booked roughly 18 billion yen, about $117 million, in extraordinary losses over the decision. Talks with BASF about building a much bigger factory had already collapsed a month earlier.<\/p>\n Look at the two cards above and the reasoning stops being mysterious. Twenty-plus years of sodium-sulfur adds up to around 5,000 megawatt-hours installed. Tesla shipped 13,500 megawatt-hours in a single quarter. The entire global fleet of this chemistry is roughly a third of what one competitor moves between April and June.<\/p>\n As far as I can tell, nobody else builds them commercially. Which means when that last container leaves the factory, that’s very likely it for hot sodium at this scale, at least until somebody decides it’s worth restarting.<\/p>\n Frankly, that’s a shame. The NGK product page<\/a> is now headed “Sales Discontinued,” which is a fairly bleak thing to read on a page still explaining how the chemistry works.<\/p>\n Lava Blue leaches kaolin clay with hydrochloric acid to produce high-purity alumina, better than 99.99 percent pure. That material goes into every LED you own, and it gets used as a coating inside lithium-ion cells to make them safer and last longer. So a sodium-sulfur battery is now shaving the peak off a plant that makes a component for the chemistry that put it out of business. Nobody planned that.<\/p>\n Michael McCann, Lava Blue’s managing director, put the site’s logic to RenewEconomy this way: “The transition to renewable energy is also a materials transition”<\/a>. High-purity processing runs hot and eats power, so it’s a genuinely useful place to test whether six hours of storage pays for itself.<\/p>\n If long-duration storage that isn’t lithium interests you, we’ve covered a silo of hot sand heating a Finnish town<\/a> and the Swiss pit being dug for a giant flow battery<\/a>. Same basic argument, wildly different hardware.<\/p>\n QUT and the installer, Allset Energy, want to put a 1.5 MW sodium-sulfur battery with at least six hours of storage at Swanbank, a retired coal site near Ipswich. It’s still a study rather than a build. State generator CleanCo<\/a> has been assessing it for a while and hasn’t turned a shovel.<\/p>\n Meanwhile, on the same patch of ground, 138 Tesla Megapacks reached full output in February. That’s 250 megawatts and 500 megawatt-hours of lithium already earning money, against a proposed 1.5 megawatts and roughly 9 megawatt-hours of sodium that’s still on paper. RenewEconomy points out the bigger project may not use NGK hardware at all, which is a polite way of saying they might have to shop elsewhere.<\/p>\n You’d expect the cheap, fast, proven option to win that argument, and so far it has. What the Brisbane container is really testing is whether six hours beats two often enough to matter.<\/p>\n NGK stopped taking orders when its board voted, and it says the last NAS battery it will ever build ships in January 2027. The one now running outside Brisbane is rated for 20 years.<\/p>\n","protected":false},"excerpt":{"rendered":" You’ve probably seen a grid battery by now, even if you weren’t looking for one. A row of white lithium … <\/p>\nSo what’s actually in the box?<\/h2>\n
Why walk away from a battery that works?<\/h2>\n
The plant it powers makes an ingredient for lithium batteries<\/h2>\n
The next one is bigger, and it may not be an NGK<\/h2>\n