demand · major
GB power blackout disconnects ~1.1 million customers
9 August 2019 → 9 August 2019
On 9 Aug 2019 at 16:52, near-simultaneous trips at Hornsea 1 (737 MW) and Little Barford CCGT (664 MW) cut frequency to 48.8 Hz — below the 48.9 Hz LFDD threshold. Auto-disconnection cut ~1.1 million customers. Trains stranded; exposed under-frequency response inadequacy.
Affected fuels: wind_offshore, gas
Countries: GB
Sources
- www.ofgem.gov.uk(accessed 2026-04-26)
- www.ofgem.gov.uk(accessed 2026-04-26)
- www.neso.energy(accessed 2026-04-26)