# RTE Launches Tender for Twelve 600 MVA 400/225 kV Autotransformers for the Dunkirk Industrial Decarbonization Corridor

> To supply gigawatts of clean nuclear and offshore wind power to massive new electric arc furnaces, hydrogen electrolyzers, and gigafactories in northern France, French transmission operator RTE has issued a tender for twelve 600 MVA 400/225 kV autotransformers.

- **Publish Date:** 2026-09-21
- **Category:** transformers-grid
- **Reading Time:** 4 min
- **Original Source Citation:** [Réseau de Transport d’Électricité (RTE) France](https://www.rte-france.com/actualites/appel-offres-transformateurs-400kv-decarbonation-dunkerque-septembre-2026)
- **Tags:** RTE, 400 kV, Autotransformers, France, Decarbonization, Green Steel, Substations
- **Canonical URL:** https://voltformer.com/news/rte-launches-tender-dunkirk-400kv-autotransformers-industrial-decarbonization
- **Markdown Source:** https://voltformer.com/news/rte-launches-tender-dunkirk-400kv-autotransformers-industrial-decarbonization.md

## Electrifying France’s Heaviest Industrial Carbon Emitter

The port of Dunkirk accounts for nearly 20% of France’s industrial greenhouse gas emissions. The conversion of conventional coal-fired blast furnaces to Direct Reduced Iron (DRI) electric arc furnaces requires an immediate 3,000 MW increase in electrical substation capacity.

RTE’s tender specifies twelve 600 MVA three-phase 400/225 kV autotransformers featuring ultra-low-noise acoustic enclosures, online bushing tan-delta monitoring, and on-load tap changers engineered for severe dynamic cyclic loading.

## Expanding the 400 kV Dunkerque-Lille Transmission Grid

The transformers will be allocated across expanded switching substations at Grande-Synthe, Mardyck, and Warande, reinforced by new 400 kV double-circuit underground cable corridors.

First unit deliveries will commence in late 2027, ensuring robust electrical commissioning in synchronization with ArcelorMittal’s electric furnace launch in 2028.

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