HV/EHV power transformers, materials and services

Why the concentration exists

A high-voltage or extra-high-voltage power transformer is a stationary electromagnetic device that steps voltage up or down at transmission substations. The U.S. ANSI C84.1 framework places HV at 115 kV to 230 kV, EHV at 345 kV to 765 kV, and UHV at 1,100 kV, so EHV units sit at the heart of long-distance transmission lines. Supply is concentrated because each unit requires large amounts of grain-oriented electrical steel for the core and copper for the windings, and because factory qualification, type testing, and customer-specific engineering extend production cycles. Over 90% of the world's electrical power passes through large power transformers containing GOES cores, which makes the upstream steel supply a structural input. New GOES facility capital expenditure exceeds $1 billion, and the timeline from site selection to commercial production of low-loss GOES runs four to six years, so the raw-material base scales slowly.[11][15][17][21]

What the evidence shows

Who supplies it

These same firms are the ones quoting the longest delivery windows. In June 2026, lead times for Tier 1 HV transformer manufacturers ABB, Siemens Energy, and Hitachi Energy were 48–60 months, with new orders targeting 2030–2031 delivery. GE Vernova was quoting 60+ months with delivery in 2031. Hyosung Heavy Industries states it has been the primary supplier of extra-high-voltage transformers in the North America market since the 1990s. Beyond the Tier 1 set, regional producers offer shorter queues, with Efacec in Portugal quoting 20–28 months for 2027–28 delivery, Pauwels in Belgium and Ireland at 24–32 months, and TMC Transformers in Italy at 22–30 months.[1][18]

What it depends on, and what depends on it

An HV/EHV power transformer is made primarily from grain-oriented electrical steel for the laminated core and from copper for the windings, with dielectric oil or an alternative fluid providing insulation and cooling. Two raw materials, copper and electrical steel, account for more than half of the total cost of a large power transformer. Global GOES consumption is approximately 3.5 to 4 million metric tons annually, and China accounts for approximately 56% of global output, which makes the transformer supply chain downstream of a single national metallurgy base. Cleveland-Cliffs is the only domestic U.S. maker of grain-oriented electrical steel for transformer cores, with plants in Pennsylvania and Ohio.[2][20][21][22]

The output of these factories is the set of equipment that connects generation, transmission, and load. Large power transformers sit between generator step-up units at power plants and the high-voltage transmission network, then step voltage down again at distribution substations. In the United States, transmission operates up to 500,000 volts on the high-voltage grid, while China is developing an 1,100,000 VAC system and currently uses 800,000 VAC transmission. Siemens Energy also produces HVDC converter transformers, with hundreds in operation globally, extending the same core-and-winding technology into long-distance direct-current links. Refurbishment and repair services form a parallel revenue stream, with Siemens overhauling 15 converter transformers at the Cahora Bassa HVDC link in Mozambique.[7][10][14][15]

Transformer design life is long, which makes installed base a strategic asset. Modern HV transformers achieve efficiency ratings exceeding 99 percent and offer service lives spanning 25 to 40 years or more. For every 1,000 transformers on a distribution system, there would likely be 200 or more different transformer designs, which fragments spare-parts demand and lengthens custom-build cycles. Siemens Energy markets mobile resilience transformers for rapid-response grid emergencies, temporary substations, or disaster recovery, and Hitachi Energy uses a shared TrafoStar platform across all of its power transformer factories with a 6-Sigma quality system covering over 6,000 documents. VG-100, a biodegradable dielectric fluid developed by Prolec GE, has been used in more than 500 units since 2009 as an alternative to mineral oil in new transformers.[3][5][6][9][16]

Where it sits in the stack

4 upstream · 18 downstream

What would break it

The supply picture is fragile because the input base is geographically narrow and the factories that turn steel and copper into transformers are themselves scarce. Roughly 80% of large transformers have historically been imported into the United States from Mexico, China, and Thailand. Cleveland-Cliffs is the only domestic U.S. producer of grain-oriented electrical steel, so any disruption at its Pennsylvania and Ohio plants would affect every U.S. transformer factory. Because new GOES facility capital expenditure exceeds $1 billion and the timeline from site selection to commercial production runs four to six years, no quick domestic substitute exists.[12][20][21][22]

Demand growth itself is the multiplier on top of these structural constraints. Approximately 50 GW of new solar capacity was installed in the U.S. in 2024, raising cumulative solar capacity to around 235.7 GW, and solar accounted for 66% of all new electricity-generation capacity added that year. Each renewable plant and each data center requires step-up transformers and substation transformers to interconnect. The result is a market where lead times are a binding constraint on interconnection queues, and where substitution is largely limited to refurbishment of existing units because the materials, the qualification cycles, and the physical scale of the equipment cannot be replaced quickly.[19][21]

What to watch

The first capacity additions under construction are concentrated at Siemens Energy's Charlotte, North Carolina facility. The expansion represents a $150 million investment to initially produce 24 new large power transformers per year, ultimately increasing to 57 units per year at full capacity, with the repair and refurbishment line starting at 12 units per year and eventually reaching 24 units. The expansion will create up to 559 direct operating jobs and 285 construction jobs in North Carolina. Siemens Energy expects to start U.S. production of large power transformers in 2027 at that site.[8][12]

The next signal is a larger Siemens Energy commitment announced for 2026. Siemens Energy announced a $1 billion investment in the U.S. on February 3, 2026, which includes increasing transformer production and servicing. The investment specifically raises manufacturing and servicing capabilities for large power transformers at Charlotte, Winston-Salem, and Raleigh in North Carolina. Because more than 80% of large power transformers are currently imported into the United States, the Charlotte ramp is the most concrete near-term source of domestic capacity relief.[12][13]

Federal funding for transmission siting will shape the order pipeline through the rest of the decade. In July 2024, the Department of Energy announced up to $371 million in projects to expedite the permitting of high-voltage interstate transmission projects as part of its $760 million Transmission Siting and Economic Development Grant Program. MISO released its Tranche 2 plan for $17 billion to $23 billion to expand 765 kV transmission in early 2024, which translates directly into multi-year procurement schedules for EHV transformers. Siemens Energy expects a total of $2 trillion of investment in the U.S. grid by 2050, driven by power demand from data centers for AI technology, so transformer order books extending into 2030–2031 reflect expected, not speculative, build-out.[4][12][18]

Related nodes

On the plate

Sources

1. hyosungheavyindustries.com
2. discountpdh.com
3. gevernova.com
4. utilitydive.com · 2024-08-14
5. utilitydive.com · Aug. 6, 2024
6. siemens-energy.com
7. siemens-energy.com
8. siemens-energy.com · February 15, 2024
9. hitachienergy.com
10. en.wikipedia.org · 2019-06-27
11. en.wikipedia.org · 2020
12. transformers-magazine.com · June 30, 2025
13. publicpower.org · February 3, 2026
14. swartzengineering.com · 1989
15. generatorsource.com
16. cpepegroup.com
17. daelimtransformer.com
18. gridreadiness.com · June 2026
19. marksparksolutions.com · Sep 29, 2025
20. theconversation.com · 2024
21. energy-solutions.co
22. zerohedge.com · Q2 2025