# Hydro One and IESO Break Ground on 500 kV Clean Energy Transmission Corridor in Ontario > Hydro One and Ontario's Independent Electricity System Operator (IESO) have begun construction on a 120 km 500 kV transmission line and switching facility to supply 2000 MW of industrial capacity. - **Source date:** 2026-10-03 - **Original source:** [Hydro One Media Relations](https://www.hydroone.com/news/southwestern-ontario-500kv-transmission-october-2026) - **Reading time:** 1 min - **Language:** en - **URL:** https://voltformer.com/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026 - **Markdown:** https://voltformer.com/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026.md ## Southwestern Ontario Grid Expansion The new 500 kV double-circuit corridor connects Chatham switching station to the Lambton transmission hub across 120 km of upgraded rights-of-way. Steel lattice towers with bundled 4-conductor arrangements are engineered to deliver 2000 MW of continuous transmission capacity. ## Reactive Power and Substation Automation 2 shunt reactors rated at 500 kV and rated at 150 Mvar each are being installed at terminal substations to provide voltage control and dynamic reactive power balancing. Full digital substation architecture utilizing IEC 61850 protocol reduces copper cabling by 70 % and enables automated remote switching. ## Other languages - [en](https://voltformer.com/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) - [tr](https://voltformer.com/tr/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) - [de](https://voltformer.com/de/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) - [ru](https://voltformer.com/ru/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) - [es](https://voltformer.com/es/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) - [ar](https://voltformer.com/ar/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) - [it](https://voltformer.com/it/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) - [pt](https://voltformer.com/pt/news/hydro-one-ieso-break-ground-500kv-transmission-corridor-october-2026) [Company and energy news](https://voltformer.com/news.md) ยท [Voltformer catalog](https://voltformer.com/catalog)