Transformers and power electronics: Value chain

From electrical steel to the Chinese inverter giants

What this tab covers Who does what, from equipment makers to builders, owners, operators, traders and users, with the leading companies at each step.

Steel and copper makers and semiconductor firms supply transformer, inverter and charger manufacturers, who sell to utilities, solar and wind developers, carmakers and building owners.

The chain

Materials Power semiconductors Transformer makers Inverter makers EV charger makers and operators Owners and operators

Stage	What happens	Leading companies
Materials	Grain-oriented electrical steel (or amorphous alloy) for cores, copper or aluminium windings, insulating oil and paper. In large power transformers, electrical steel and copper conductor are each roughly 25% of production cost; Cleveland-Cliffs is the only active US maker of grain-oriented steel and Nippon Steel the sole source of its highest grade.	Cleveland-Cliffs (United States) Nippon Steel (Japan)¹³
Power semiconductors	IGBT and MOSFET chips and modules, in silicon, silicon carbide and gallium nitride. 2024 global market for power discretes and modules: USD 32.8 billion.	Infineon (Germany), 17.4% onsemi (United States), 8.5% STMicroelectronics (Switzerland), 6.9% Mitsubishi Electric (Japan), 4.6% Fuji Electric (Japan), 3.9%⁶
Transformer makers	Design and build large power and distribution transformers. A 2012 DOE study named ABB, Siemens and Alstom Grid as dominant, with Korean, Indian and Chinese firms rising; those businesses now trade as Hitachi Energy, Siemens Energy and GE Vernova. The US imported about 82% of the large power transformers it installed in 2019.	Hitachi Energy (Switzerland, owned by Hitachi of Japan) Siemens Energy (Germany) GE Vernova with Prolec GE (United States) HD Hyundai Electric and Hyosung Heavy Industries (South Korea) TBEA and China XD Electric (China) CG Power (India)³¹³
Inverter makers	Solar, battery and drive inverters. Global PV inverter shipments were 589 GWac in 2024, with Huawei (176 GWac) and Sungrow (148 GWac) holding about 55%. Wood Mackenzie's separate H1 2025 supplier ranking (scored on quality criteria such as ESG, service and R&D, not volume) put these first; the top ten held about 71% of the market.	Huawei (China) Sungrow (China) SMA (Germany) Fronius (Austria) Ginlong Solis (China) SolarEdge (Israel) Enphase (United States)⁷⁸¹⁴
EV charger makers and operators	DC fast chargers for public hubs and depots. No independent global ranking of makers was found. Kempower estimates its installed base at over 35,000 DC units and places itself among Europe's top three (company claims); ABB E-mobility sold control of its Chinese AC charger maker Chargedot in 2025 to focus on DC charging. In China, TELD and Star Charge ran the most public charging points in July 2025 (about 807,000 and 703,000).	ABB E-mobility (Switzerland) Kempower (Finland) Alpitronic (Italy) Tesla (United States) TELD and Star Charge (China)¹⁶¹⁷¹⁸¹⁹²⁰²¹
Owners and operators	Utilities own most transformers (60-80 million distribution transformers in US service, NREL estimate); solar farms, factories, data centres and drivers own inverters and chargers. NREL projects that US distribution transformer capacity must rise 160-260% above 2021 levels by 2050.	²¹²

Charger rankings are company claims; installers and charge-point operators are fragmented by region.

Sources

DOE Finalizes Energy Efficiency Standards for Distribution Transformers (press release, 4 April 2024) US Department of Energy, 2024
Large Power Transformers and the U.S. Electric Grid US Department of Energy, Office of Electricity, 2012
Infineon investor presentation Q4 FY2025 (citing Omdia, October 2025) Infineon Technologies, 2025
Global solar inverter manufacturer ranking H1 2025 Wood Mackenzie, 2026
Huawei, Sungrow lead Wood Mackenzie's inverter market ranking pv magazine USA, 2026
Major Drivers of Long-Term Distribution Transformer Demand National Renewable Energy Laboratory, 2024
Large Power Transformer Resilience: Report to Congress US Department of Energy, 2024
Global PV inverter shipments grew by 10% in 2024 to 589 GWac (press release, 10 July 2025) Wood Mackenzie, 2025
China's EV charging network hits 16.7 million units (operator ranking from NE-time, July 2025) CarNewsChina, 2025
Kempower Annual Report 2025 Kempower, 2026
Kempower Capital Markets Day 2026 presentation Kempower, 2026
ABB sells majority of Chinese charging specialist Chargedot electrive, 2025
About us Alpitronic, 2026
Tesla Form 10-K for fiscal year 2025 Tesla / US SEC, 2026