Notable Grid Failures in History
6 notable electricity grid failures, from The 2003 Northeast Blackout to The 2025 Iberian Peninsula Blackout, what caused each one and what changed afterwards. Each page is independently researched from public investigations and reports, not from the site's own Ember, EIA or ENTSO-E data, and cites the report it draws on.
Key Facts
- 6 notable grid failures are covered, from 2003 to 2025.
- The 2025 Iberian Peninsula Blackout (28 April 2025): A sudden loss of about 15 gigawatts of generation, more than half of what the two countries were supplying at the time, cascaded into a near total blackout with no single equipment failure to blame.
- The 2021 Texas Winter Storm Blackouts (14 February 2021): A grid built for heat froze along with the gas supply that feeds it, and Texas came within minutes of a total collapse that could have taken weeks to recover from.
- The 9 August 2019 Great Britain Power Cut (9 August 2019): A lightning strike caused two power stations to disconnect within two minutes of each other, a coincidence the grid's safety margin was not built to survive.
Every Event, Newest First
| Event | Date | Region | Cause |
|---|---|---|---|
| The 2025 Iberian Peninsula Blackout | 28 April 2025 | Spain and Portugal | Insufficient reactive power margin leading to a voltage instability cascade |
| The 2021 Texas Winter Storm Blackouts | 14 February 2021 | Texas (ERCOT) | Extreme cold freezing gas supply and power plants that were not winterized |
| The 9 August 2019 Great Britain Power Cut | 9 August 2019 | Great Britain | Two generators failing to ride through a lightning strike within minutes of each other |
| The 2016 South Australia Blackout | 28 September 2016 | South Australia | Storm damage to transmission towers, followed by generator protection settings and loss of the interconnector |
| The July 2012 India Blackouts | 30 July 2012 | Northern, Eastern and Northeastern India | Grid discipline: states overdrawing a shared grid under heatwave and drought demand |
| The 2003 Northeast Blackout | 14 August 2003 | Midwest and Northeast United States, and Ontario | Cascading failure after an alarm system fault and a line contacting trees |
This is a short, deliberately incomplete list of well documented events with an official or authoritative investigation, not a record of every blackout there has been.