4 ms·

How likely is simultaneous failure of 9 out of 30 of them? Totally unlikely if you ask me. And some redundancy is built into the system, so it's not like failur

How likely is simultaneous failure of 9 out of 30 of them? Totally unlikely if you ask me. And some redundancy is built into the system, so it's not like failure of 3 will cause loss of power in 1/3 of the U.S. - most likely none at all (or maybe only scheduled blackouts in peak times in some of the places). In Cyprus, we had such an event in 2011, when 2000 tons of explosives Russian tried to smuggle into Syria, were intercepted by a U.S. Navy and redirected to be offloaded here (because the ship carrying them was formally registered here and flew a Cyprus flag - really being owned by the KGB), and these explosives went off in the summer heat, wrecking a power station that produced 70% of the electricity here. We only had about 2 hours of blackout per day and a recommendation to limit a/c use, for about a month. Power transmission is super resilient and relay protection is a whole science of it's own. Especially in the U.S. when there are many virtually independent, privately owned and loosely interconnected transmission systems, which puts it at a relative advantage.

jessriedel 7y ago
> how likely is simultaneous failure of 9 out of 30 of them? Totally unlikely if you ask me. It's quite possible because their failure probabilities aren't independent. A geomagnetic storm could take most of them out at once. Like respiratory pandemics, this is an event that happens every ~century. https://en.wikipedia.org/wiki/Geomagnetic_storm https://en.wikipedia.org/wiki/Geomagnetic_storm
- anovikov 7y ago
  But it will be known well in advance and can be mitigated by simply shutting the grid down for a few hours. Only places which will experience difficulties are those having a large fraction of nuclear power since a reactor can't be quickly restarted once shut down, so power will restore only in some days.
  - jessriedel 7y ago
    Do you have a cite? My impression was that we do not have sufficient preparations in place to do this. (E.g., we may have satellites that can be taken as weak indicators, but they are not designed for this, and there is no clear decision authority starting from possibly ambiguous satellite data to prophylactically shutting down power for 300M people against their will. Hopefully, recent events have made clear that "leaders will get their act together and act decisively during an emergency" cannot be the default assumption.)

jessriedel 7y ago

> how likely is simultaneous failure of 9 out of 30 of them? Totally unlikely if you ask me. It's quite possible because their failure probabilities aren't independent. A geomagnetic storm could take most of them out at once. Like respiratory pandemics, this is an event that happens every ~century. https://en.wikipedia.org/wiki/Geomagnetic_storm https://en.wikipedia.org/wiki/Geomagnetic_storm

anovikov 7y ago
But it will be known well in advance and can be mitigated by simply shutting the grid down for a few hours. Only places which will experience difficulties are those having a large fraction of nuclear power since a reactor can't be quickly restarted once shut down, so power will restore only in some days.
- jessriedel 7y ago
  Do you have a cite? My impression was that we do not have sufficient preparations in place to do this. (E.g., we may have satellites that can be taken as weak indicators, but they are not designed for this, and there is no clear decision authority starting from possibly ambiguous satellite data to prophylactically shutting down power for 300M people against their will. Hopefully, recent events have made clear that "leaders will get their act together and act decisively during an emergency" cannot be the default assumption.)