# Generators and alternators: Value chain

Who builds the giant machines that feed the grid

Source page: https://www.materialinsights.org/energy/e_generators/valuechain/

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

Large generators are made by the same groups that make turbines, and are usually sold as part of the turbine-generator set. Smaller alternators are built into gensets by engine packagers.

#### The chain
 Materials and components Large turbo-generator makers Hydro and smaller generator makers Genset alternator packagers Owners and service

| Stage | What happens | Leading companies |
|---|---|---|
| **Materials and components** | Copper conductor, laminated electrical steel for the core, large steel rotor forgings, insulation systems and, for wind machines, rare-earth permanent magnets. | ^[1](https://arabellesolutions.com/our-technology/generators-for-nuclear-power-plants/gigatop-generators) |
| **Large turbo-generator makers** | Design and build generators for steam, gas and nuclear turbines, usually sold inside the turbine-generator package. In 2025 Dongfang Electric produced about 58 GW of steam turbine generators and Harbin Electric about 28 GW. | GE Vernova (United States) Siemens Energy (Germany) Arabelle Solutions (France) Toshiba (Japan) Dongfang Electric (China) Harbin Electric (China) Shanghai Electric (China) Bharat Heavy Electricals (India)^[1](https://arabellesolutions.com/our-technology/generators-for-nuclear-power-plants/gigatop-generators)^[2](https://www.gevernova.com/gas-power/products/generators/air-cooled)^[3](https://www.siemens-energy.com/global/en/offerings/power-generation/generators.html)^[4](https://www.enerdata.net/publications/daily-energy-news/harbin-electric-wins-bids-two-2-gw-coal-fired-power-projects-china.html)^[5](https://www.powermag.com/ge-ha-turbine-snags-another-world-record-for-ccgt-efficiency)^[8](https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0331/2026033103547.pdf)^[9](https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0326/2026032603158.pdf)^[11](https://www.shanghai-electric.com/group_en/dqdzjtwmdqy)^[10](https://nsearchives.nseindia.com/corporate/BHELCC_03092025171754_BHELOrderReceipt.pdf) |
| **Hydro and smaller generator makers** | Supply generators for hydro, industrial turbines and wind. Dongfang and Harbin each made about 8 GW of hydro generating units in 2025. | Dongfang Electric (China) Harbin Electric (China) Siemens Energy (Germany, wind generators up to 10 MW)^[3](https://www.siemens-energy.com/global/en/offerings/power-generation/generators.html)^[8](https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0331/2026033103547.pdf)^[9](https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0326/2026032603158.pdf) |
| **Genset alternator packagers** | Pair engines with alternators for backup and prime power. | Caterpillar (United States) Cummins (United States, also makes alternators) Generac (United States) Rehlko, formerly Kohler Energy (United States) Rolls-Royce Power Systems, mtu (Germany) Volvo Penta (Sweden)^[6](https://www.powermag.com/engine-power-plants-surge-as-data-centers-drive-unprecedented-demand/)^[12](https://investors.generac.com/news-releases/news-release-details/generac-reports-fourth-quarter-and-full-year-2025-results)^[13](https://www.equipmentworld.com/business/article/15704847/kohler-energy-changes-name-to-rehlko)^[14](https://www.sec.gov/Archives/edgar/data/26172/000002617226000009/cmi-20251231.htm) |
| **Owners and service** | Plant owners run generators for decades; makers rewind stators, re-wedge rotors and upgrade insulation during outages. GE Vernova reports an installed fleet of over 6,700 air-cooled units. | GE Vernova (United States) Siemens Energy (Germany) Arabelle Solutions (France)^[1](https://arabellesolutions.com/our-technology/generators-for-nuclear-power-plants/gigatop-generators)^[2](https://www.gevernova.com/gas-power/products/generators/air-cooled)^[3](https://www.siemens-energy.com/global/en/offerings/power-generation/generators.html) |

#### Sources

1. [GIGATOP generators](https://arabellesolutions.com/our-technology/generators-for-nuclear-power-plants/gigatop-generators) Arabelle Solutions, 2025
2. [Air-cooled generators (GEN-A)](https://www.gevernova.com/gas-power/products/generators/air-cooled) GE Vernova, 2025
3. [Generators for power generation (product overview and references)](https://www.siemens-energy.com/global/en/offerings/power-generation/generators.html) Siemens Energy, 2025
4. [Harbin Electric wins bids for two 2 GW coal-fired power projects in China](https://www.enerdata.net/publications/daily-energy-news/harbin-electric-wins-bids-two-2-gw-coal-fired-power-projects-china.html) Enerdata, 2024
5. [GE HA Turbine Snags Another World Record for CCGT Efficiency](https://www.powermag.com/ge-ha-turbine-snags-another-world-record-for-ccgt-efficiency) POWER Magazine, 2018
6. [Engine Power Plants Surge as Data Centers Drive Unprecedented Demand](https://www.powermag.com/engine-power-plants-surge-as-data-centers-drive-unprecedented-demand/) POWER Magazine, 2026
7. [Dongfang Electric Corporation Limited: Annual results announcement for the year 2025](https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0331/2026033103547.pdf) Dongfang Electric (HKEX filing), 2026
8. [Harbin Electric Company Limited: Annual results announcement for the year ended 31 December 2025](https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0326/2026032603158.pdf) Harbin Electric (HKEX filing), 2026
9. [BHEL: order for 1x800 MW Anuppur thermal power project (stock exchange disclosure)](https://nsearchives.nseindia.com/corporate/BHELCC_03092025171754_BHELOrderReceipt.pdf) Bharat Heavy Electricals Ltd (NSE filing), 2025
10. [Shanghai Electric Power Generation Group (company profile)](https://www.shanghai-electric.com/group_en/dqdzjtwmdqy) Shanghai Electric, 2025
11. [Generac reports fourth quarter and full-year 2025 results](https://investors.generac.com/news-releases/news-release-details/generac-reports-fourth-quarter-and-full-year-2025-results) Generac Holdings, 2026
12. [Kohler Energy changes name to Rehlko](https://www.equipmentworld.com/business/article/15704847/kohler-energy-changes-name-to-rehlko) Equipment World, 2024
13. [Cummins Inc. Form 10-K for fiscal year 2025](https://www.sec.gov/Archives/edgar/data/26172/000002617226000009/cmi-20251231.htm) Cummins / US SEC, 2026

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_generators/index.md)
- [Overview](https://www.materialinsights.org/energy/e_generators/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_generators/correlation/index.md)
- [Science and limits](https://www.materialinsights.org/energy/e_generators/science/index.md)
- [Unit economics](https://www.materialinsights.org/energy/e_generators/economics/index.md)
- [Engineering methods](https://www.materialinsights.org/energy/e_generators/methods/index.md)
- [Equipment and suppliers](https://www.materialinsights.org/energy/e_generators/equipment/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_generators/links/index.md)