The large transformer shortage has been a problem for years. Large transformer making is a craft, where the winding supports are made of hardwood, like furniture, and wound by hand. Then the windings go into a case that's an oil tank.
The build teams aren't that big - 30-50 people. The main barrier to entry is that it takes people who know how to hand-build big transformers. Utility buyers want a supplier who's going to be around half a century from now, since these things last that long.
Here's a summary of the market, from a transformer maker in China.[1]
Here's an AI-generated fake video of large transformer manufacturing. It's about half wrong.[2] But right enough to be worth watching. I'd like to see the prompts for this.
Virginia Transformer is the US's biggest maker of large transformers.[3] They advertise their "short lead times" of two years. The margins are low, and makers don't want to go idle between orders. This is a problem with much heavy machinery. It could be built faster, but when you catch up, everybody gets laid off and the factory sits idle. There goes your profit margin.
That's a good point. The AI slop video is inaccurate, but entertaining.
For comparison, here's the real deal - transformer winding at Virginia Transformer in the US.[1]
That video provides a good sense of why these things take so long to make.
All those wooden parts. All that slowly and carefully hand wound heavy wire. As they point out, if that wire can move at all, as the magnetic fields pushes and pulls on it, the vibration will, over time, wear out the transformer. It's a very fussy job to get the position and tension right, with wire firmly supported against movement in all directions. That's the difference between a lifetime of a few years and many decades.
It's a boring video.
Here's the whole manufacturing process at ETD in the Czech Republic.[2]
This shows roughly the same sequence of steps as the fake video, but it's real.
Big industrial bay with lots of transformers and overhead cranes. Sheets of lamination steel.
Winding. The moving and shipping of the big transformer.
All that is in both the real video and the AI slop.
This is the real video from the manufacturer, and it assumes that if you're watching, you know what you're looking at. There's little narration.
It's a confusing video.
Here's a small open frame transformer.[3] If you've done much electrical or electronics work, you've seen one, and may have replaced or installed one. When you see the big ones being built, the process makes sense. Same concept, with a laminated core, windings, insulation, and lead wires. The big ones have the same key parts, just much bigger. But if you don't know a transformer from a transistor, the manufacturer videos are just wallpaper.
And there's the problem. The AI slop version will give the average viewer a general idea of the process. The accurate videos from manufacturers require more background knowledge to comprehend.
The target audience is different. The manufacturers don't make those videos for the general public.
As far as I can tell, the video itself is 100% fake. A bad fake. I particularly love the part where the worker levitates a large coil of steel with his hands. The narration sounds OK, so just turn off your monitor.
I worked in a machine shop of a large shipyard and 20 years ago they had CNC Winders for rebuilding armatures for Navy ships.
They replaced older versions that were NC winders.
So this "hand wound" story is just that.
Windings going into Oil Tank? I think you mean varnish tank... After the rotating assembly is balanced they go into a protective coating tank that is a varnish.
> Here's an AI-generated fake video of large transformer manufacturing. It's about half wrong.[2] But right enough to be worth watching. I'd like to see the prompts for this.
I'd like some sort of shared blocklist support for YouTube and Instagram. I'm sick and tired of content thieves and AI slop farms.
> So how did we get to a point where one component can hold trillion-dollar industries hostage? Turns out, a quirk of history made the entire world’s electricity systems reliant on transformers.
> At the end of the 19th century, when electricity was just starting to become a commercial source of energy, two businessmen fought to control its future in what came to be known as “the war of the currents.” Thomas Edison promoted the use of direct current (DC) and George Westinghouse, inventor and industrialist, was convinced that alternating current (AC) would prove more practical.
> In a clash of personality, finance and some genuine technical advantages, Westinghouse won out and the world has been mostly stuck with using AC as a means of generating and transmitting electricity. Transformers are necessary to make the AC system work.
This entire section is a glaring load of nonsense and needs to be removed. We had to start with AC for a variety of technical reasons, the main one being that boosting DC voltage pre-switching technology was impossible. DC cant pass through a transformer unless it is converted to some form of AC, usually in the form of PWM square waves these days. Before the invention of the mercury arc rectifier (And later valve) in 1902 you had boost DC using mechanical methods: generators. The problem there is physical, they did not have the ability to insulate the generator windings at high voltage potentials. They also had problems with DC voltages over 2000 volts on commutators [1] citing excessive arcing. Commutators are also a limiting factor in machine size as beyond several MW they dissipate too much power. So with all this the highest practical voltage for a DC grid using early electrical machinery is around 2 kV. Now imagine all that mechanical complexity on the distribution end. Meanwhile, early AC transmission was already in the tens of kilovolts: 11/22/33 kV (multiples of the early Edison 110 volt standard.)
As for the whole war of currents, I feel it is vastly overstated and was more a public spectacle than serious scientific dispute. It was already known from early on that AC was the future thanks to its ability to easily be transformed to higher voltages for transmission and back again with no moving parts. The "war" was likely Edison marketing to sell off the remaining inventory less desirable DC machinery.
I think the article has things backwards. It's the shortage of stable demand that is holding back the building of transformers. A transformer factory that can make reliable, efficient, large transformers takes a long time to create because a lot of it relies on institutional memory. But it can be destroyed much more quickly by adverse market conditions and impatient investors.
Remember that the product has a typical lifetime measured in decades, there are huge numbers of large power transformers that have been in near continuous operation for over half a century. When one of those fails it is often more economical to repair it than replace it with a new one but that depends on there being institutions that understand what was done fifty years ago. All this requires the opposite of modern move fast and break things investing.
Possibly the easiest way to bring any metropolitan area or region into the Stone Age for unknowable amounts of time is simply to destroy large, bespoke transmission (rather than distribution) transformers. Crazy people shooting out the cooling systems have done this several times.
Meaningful grid security means these items need rapid, standardized, domestic production capacity and cold spares distributed offsite and ready to be deployed should anything happen to ones in use. These are critical items that must not be neglected to reactive actions disaster recovery.
I've been wondering for awhile about the economics of the AC vs DC grid thing. Historically, AC made a lot more sense because transformers are simple and relatively straightforward to make. But now we have amazing capabilities to handle enormous amounts of power with modern IGBTs and similar power-switching transistors. (A modern high-end EV motor controller, for instance, might be able to handle a megawatt of power. Not continuously, but still.) Is a DC-DC converter now more economically viable than an equivalent transformer? The former is more techincally complicated, but the latter is bulky and requires large quantities of expensive input materials like copper.
If you are not ready to lock yourself in a bunker after reading the article and watching that short, I strongly suggest you consider the inclined plane.
You’d better do it now. Very few locks work in the absence of transformers, springs and inclined planes.
transformers are infrastructure, 100% duty cycle with a significant overload capacity that can be 3 times name plate, right there with dams and bridges, and if one developes a fault, realy bad things happen and you get a crater.
There very nature makes them imensely heavy and very compact, all of the equipment used to form the parts is gargantuan, and materials to build them come in units that must be moved by house sized forklifts, consider changing a tire on such a forklift.
Remember that the largest transformers travel on the heaviest rail cars, specials, these things are way heavier than anything else per ft³.
Which gets us to cold,warm, or hot idle, or decomisioning, which are your choices when a huge factory has no work, hot idle means limited production, warm means some of the guys hang out and tinker with stuff, cold means, locked up,no employees but security, as decomisioning something like this has strategic considerations, or should.
That's in the ballpark of the Heathrow transformer that blew, I think.
I understand they will be not cheap, with tariffs and all, but nothing the Magnificent 7 or Heathrow could not afford.
It seems to me that (as the article points out) that production facilities are pretty old and production COULD be much more automated, and products improved if there was a will.
However, "Now those firms are seeing a rise in demand for transformers alongside the buildout of data centers for AI, but remain unsure if the trend will continue, says Gonzalez Isla. “Transformer companies aren’t going to open new plants only to shut it down after 10 years of business,” she says."
And THAT seems to be the crucial difference here between the transformer industry and, say, NVIDIA.
"Transformers are necessary to make the AC system work."
This isn't quite wrong but the motivation is backwards: AC is necessary to make transformers work.
1. All grids need to move energy at high voltage and low current to minimize losses.
2. This requires a mechanism to step voltages up and down for transmission.
3. In 1890 the only such mechanism was the transformer.
4. Transformers only work on AC, not DC.
Hence our legacy grid is AC.
Nowadays we have an additional mechanism: Power electronics. Power electronics work on both AC and DC, so transformers with their huge requirements for copper and steel are no longer necessary.
We need to accelerate the transition of our grid to DC because DC grids are simpler and cheaper than AC grids.
This problem threatens more than just business as usual. In the past, intense geomagnetic storms have caused big transformers to explode. Without a backup transformer supply, entire regions may face long-term power outages.
The basic problem is easy to grasp, like the mess with charging cords for laptops before it, every large power transformer is a custom design. The fix would be to standardize on a much smaller number of options, and parallel them for the desired loads.
Think of it as analogous to USB-C power, on the megawatt/gigawatt scale. ;-)
And if we didn't have all these data centers would we still be "bottlenecked?"
Or is this a case of blind greedy investment outcompeting civilian life once again? Probably given that Bloomberg feels the need to throw it's voice for the cause.
An article that deeply buries the lede under elementary facts about electrical transmission.
Transformers are made in specialized factories and use specialized components made in even more specialized factories. Expanding production requires not just immediate demand but commitment to future demand because a factory is a very expensive thing. The big thing is that increased demand often involves a demand that won't continue for a long period of time.
You could see the same thing with both masks and vaccines during covid - ramping up ten factories to meet a temporary demand would be very expensive.
It's a well known bottleneck for the entire grid stability, not just the EV future. We even had a way to improve the losses but Congress decided that was too progressive and we're back to just not having enough.
129 comments
The build teams aren't that big - 30-50 people. The main barrier to entry is that it takes people who know how to hand-build big transformers. Utility buyers want a supplier who's going to be around half a century from now, since these things last that long.
Here's a summary of the market, from a transformer maker in China.[1]
Here's an AI-generated fake video of large transformer manufacturing. It's about half wrong.[2] But right enough to be worth watching. I'd like to see the prompts for this.
Virginia Transformer is the US's biggest maker of large transformers.[3] They advertise their "short lead times" of two years. The margins are low, and makers don't want to go idle between orders. This is a problem with much heavy machinery. It could be built faster, but when you catch up, everybody gets laid off and the factory sits idle. There goes your profit margin.
[1] https://energypowertransformer.com/2025-u-s-power-transforme...
[2] https://www.youtube.com/watch?v=ZVVCCG0KkaE
[3] https://www.vatransformer.com/shortest-lead-times/
You probably got a lot from this video, because you know which half is wrong. I'd probably get negative knowledge from this video, because I don't.
This may be a new incarnation of the "curse of knowledge," where one over-estimates the value of AI slop if they already know the subject...
For comparison, here's the real deal - transformer winding at Virginia Transformer in the US.[1] That video provides a good sense of why these things take so long to make. All those wooden parts. All that slowly and carefully hand wound heavy wire. As they point out, if that wire can move at all, as the magnetic fields pushes and pulls on it, the vibration will, over time, wear out the transformer. It's a very fussy job to get the position and tension right, with wire firmly supported against movement in all directions. That's the difference between a lifetime of a few years and many decades.
It's a boring video.
Here's the whole manufacturing process at ETD in the Czech Republic.[2] This shows roughly the same sequence of steps as the fake video, but it's real. Big industrial bay with lots of transformers and overhead cranes. Sheets of lamination steel. Winding. The moving and shipping of the big transformer. All that is in both the real video and the AI slop. This is the real video from the manufacturer, and it assumes that if you're watching, you know what you're looking at. There's little narration.
It's a confusing video.
Here's a small open frame transformer.[3] If you've done much electrical or electronics work, you've seen one, and may have replaced or installed one. When you see the big ones being built, the process makes sense. Same concept, with a laminated core, windings, insulation, and lead wires. The big ones have the same key parts, just much bigger. But if you don't know a transformer from a transistor, the manufacturer videos are just wallpaper.
And there's the problem. The AI slop version will give the average viewer a general idea of the process. The accurate videos from manufacturers require more background knowledge to comprehend. The target audience is different. The manufacturers don't make those videos for the general public.
[1] https://www.youtube.com/watch?v=Bodj4f3L4RU
[2] https://www.youtube.com/watch?v=G3O979En_kQ
[3] https://www.mscdirect.com/product/details/20594073
They replaced older versions that were NC winders.
So this "hand wound" story is just that.
Windings going into Oil Tank? I think you mean varnish tank... After the rotating assembly is balanced they go into a protective coating tank that is a varnish.
>
Large transformer making is a craftDumb question: why can’t we mass manufacture smaller transformers and join them up?
> Here's an AI-generated fake video of large transformer manufacturing. It's about half wrong.[2] But right enough to be worth watching. I'd like to see the prompts for this.
I'd like some sort of shared blocklist support for YouTube and Instagram. I'm sick and tired of content thieves and AI slop farms.
> So how did we get to a point where one component can hold trillion-dollar industries hostage? Turns out, a quirk of history made the entire world’s electricity systems reliant on transformers.
> At the end of the 19th century, when electricity was just starting to become a commercial source of energy, two businessmen fought to control its future in what came to be known as “the war of the currents.” Thomas Edison promoted the use of direct current (DC) and George Westinghouse, inventor and industrialist, was convinced that alternating current (AC) would prove more practical.
> In a clash of personality, finance and some genuine technical advantages, Westinghouse won out and the world has been mostly stuck with using AC as a means of generating and transmitting electricity. Transformers are necessary to make the AC system work.
This entire section is a glaring load of nonsense and needs to be removed. We had to start with AC for a variety of technical reasons, the main one being that boosting DC voltage pre-switching technology was impossible. DC cant pass through a transformer unless it is converted to some form of AC, usually in the form of PWM square waves these days. Before the invention of the mercury arc rectifier (And later valve) in 1902 you had boost DC using mechanical methods: generators. The problem there is physical, they did not have the ability to insulate the generator windings at high voltage potentials. They also had problems with DC voltages over 2000 volts on commutators [1] citing excessive arcing. Commutators are also a limiting factor in machine size as beyond several MW they dissipate too much power. So with all this the highest practical voltage for a DC grid using early electrical machinery is around 2 kV. Now imagine all that mechanical complexity on the distribution end. Meanwhile, early AC transmission was already in the tens of kilovolts: 11/22/33 kV (multiples of the early Edison 110 volt standard.)
As for the whole war of currents, I feel it is vastly overstated and was more a public spectacle than serious scientific dispute. It was already known from early on that AC was the future thanks to its ability to easily be transformed to higher voltages for transmission and back again with no moving parts. The "war" was likely Edison marketing to sell off the remaining inventory less desirable DC machinery.
1. https://en.wikipedia.org/wiki/Commutator_(electric)
Remember that the product has a typical lifetime measured in decades, there are huge numbers of large power transformers that have been in near continuous operation for over half a century. When one of those fails it is often more economical to repair it than replace it with a new one but that depends on there being institutions that understand what was done fifty years ago. All this requires the opposite of modern move fast and break things investing.
Meaningful grid security means these items need rapid, standardized, domestic production capacity and cold spares distributed offsite and ready to be deployed should anything happen to ones in use. These are critical items that must not be neglected to reactive actions disaster recovery.
https://en.wikipedia.org/wiki/Metcalf_sniper_attack
https://en.wikipedia.org/wiki/Moore_County_substation_attack
https://en.wikipedia.org/wiki/Electrical_grid_security_in_th...
I challenge you to name one that cannot and that also makes it into high school curricula or How Things Work.
https://mst3k.fandom.com/wiki/A_Case_of_Spring_Fever_(short)
https://m.youtube.com/watch?v=vzKfAFsbRSk
If you are not ready to lock yourself in a bunker after reading the article and watching that short, I strongly suggest you consider the inclined plane.
You’d better do it now. Very few locks work in the absence of transformers, springs and inclined planes.
E.g., https://lindahongli.en.made-in-china.com/product/SAapQolWVUY...
That's in the ballpark of the Heathrow transformer that blew, I think.
I understand they will be not cheap, with tariffs and all, but nothing the Magnificent 7 or Heathrow could not afford.
It seems to me that (as the article points out) that production facilities are pretty old and production COULD be much more automated, and products improved if there was a will.
However, "Now those firms are seeing a rise in demand for transformers alongside the buildout of data centers for AI, but remain unsure if the trend will continue, says Gonzalez Isla. “Transformer companies aren’t going to open new plants only to shut it down after 10 years of business,” she says."
And THAT seems to be the crucial difference here between the transformer industry and, say, NVIDIA.
This isn't quite wrong but the motivation is backwards: AC is necessary to make transformers work.
1. All grids need to move energy at high voltage and low current to minimize losses.
2. This requires a mechanism to step voltages up and down for transmission.
3. In 1890 the only such mechanism was the transformer.
4. Transformers only work on AC, not DC.
Hence our legacy grid is AC.
Nowadays we have an additional mechanism: Power electronics. Power electronics work on both AC and DC, so transformers with their huge requirements for copper and steel are no longer necessary.
We need to accelerate the transition of our grid to DC because DC grids are simpler and cheaper than AC grids.
https://pmc.ncbi.nlm.nih.gov/articles/PMC12303307/
Think of it as analogous to USB-C power, on the megawatt/gigawatt scale. ;-)
Or is this a case of blind greedy investment outcompeting civilian life once again? Probably given that Bloomberg feels the need to throw it's voice for the cause.
Transformers are made in specialized factories and use specialized components made in even more specialized factories. Expanding production requires not just immediate demand but commitment to future demand because a factory is a very expensive thing. The big thing is that increased demand often involves a demand that won't continue for a long period of time.
You could see the same thing with both masks and vaccines during covid - ramping up ten factories to meet a temporary demand would be very expensive.