2021 Texas power crisis
As the demand soared and regional power generators crashed, the frequency of the system also started to drop from the normal 60 Hz to 59.3 Hz. Had the system frequency’s fallen below 59 Hz, the state’s electrical system would have suffered from cascading blackouts which would have lasted for weeks or months and could have caused physical damage to equipment. This would have been much more difficult to recover so to protect the system, load was deliberately shed by the system operator.