CESC Special Protection Scheme — Grid Islanding (Kolkata)
Kolkata's privately owned distribution utility, CESC (Calcutta Electric Supply Corporation, serving roughly 3.6 million consumers in and around the city), runs a Special Protection Scheme that automatically detaches its network from the wider regional grid — "islanding" — when it senses a severe external disturbance. The scheme proved itself on 31 July 2012, during the Northern/Eastern/North-Eastern grid collapse that cut power to over 600 million people, the largest blackout in history by population affected: while every other district of West Bengal went completely dark, according to the state's own chief minister at the time, CESC's islanded network kept Kolkata running (with a roughly 500-megawatt shortfall) and even continued to power the Kolkata Metro. The islanding logic runs on a SCADA/Distribution Management System that CESC's own technical disclosures date to "since the 1990s," alongside three other special protection schemes including under-frequency load shedding.
📊 Impact
Kept Kolkata largely powered (about a 500 MW shortfall) through the 31 July 2012 Eastern grid collapse, while every other district in West Bengal was blacked out, per the state government's own statements at the time.
🎓 Lesson
An automatic islanding scheme is only as good as the grid disturbance it's designed for — CESC's cut Kolkata loose cleanly from a collapsing regional grid in 2012, but islanding protects against external collapse, not failures inside the islanded network itself.
📖 Terms in this entry: ANPR (automatic number-plate recognition) · CBTC (communications-based train control) · Fuel cell
Sources
This overview was generated with AI from the public sources listed above and checked against them before publication. It has not had a complete human fact-check — treat it as a starting point and follow the sources.
Continue exploring
Compare this project
Explore the wider context
📎 Cite this project
1001 Smart Cities (2026). “CESC Special Protection Scheme — Grid Islanding (Kolkata)” — Kolkata, India. The Smart City Atlas. https://1001smartcities.org/projects/kolkata-cesc-grid-islanding/ (last verified 2026-08-02). Data: CC BY 4.0.
The underlying data is free to reuse with attribution — see the open data page.