During the major Texas electrical power outage back in February, large swaths of the grid were shut down in a controlled manner to avoid a catastrophic failure that reportedly could have taken months to recover from.
So now I’m thinking of this other humungous blackout:
After this blackout started, most customers had their power restored within a day or two.
So what was the difference between these two blackouts that allowed for such a rapid recovery in one case, but would have, in the case of Texas (without a deliberate controlled shutdown), resulted in a months-long recovery?
I believe the Northeast has many electrical transmission cables underground. Arkansas and presumably Texas, with greater distances to cover and less money, have electrical cables above ground where they are easily damaged by weather and difficult to repair. I’ve seen repair crews in rural Arkansas on county roads, removing ice and checking connections on every pole along very long roads.
I do know the water problem was from losing power. They lost their pumps, and the pipes became contaminated with ground water seeping into pipes that had no pressure.
I believe that in most places they disconnected from the grid very quickly before any real damage was done and what they had to do was reconnect in a controlled way. I do not think there is much long distance transmission buried. Even in Quebec with its severe winter storms it is all above ground. In the ice storm in Jan., 1997, it took a week to get most power back in Montreal and there were places that went more than a month without power.
I think another factor is that the northeast is plugged into the power grid, so greater opportunities to get power from other parts of North America. For example Quebec has its own grid and didn’t go down in the blackout, but is connected to Ontario and then could share power.
Texas is independent, so if it’s grid goes down, it’s harder for it to get power from other sources.
In my experience living in New Hampshire the worst power outages in the New England are not summer blackouts but the ones in the winter caused by severe ice storms where ice build ups and can knock down trees, poles and power lines alongside roads for miles. Which means poles and wire have to put back up repeatedly to restore power to everyone. In isolated rural areas where there are only two to three houses alongside dirt roads this means they could be out of power for up to three to four weeks. Luckily ice storms that severe are not that common–maybe one every four to five years.
You never know how well your protective systems work until you need them. One interesting thing about the 2003 blackout is that if all of the protective systems had worked properly, there wouldn’t have been a blackout.
The 2003 blackout was caused by a heavily loaded transmission line sagging due to wire expansion from heat (from the heavy load) to the point where the wires drooped down low enough to contact foliage. Meh, stuff happens. The grid was designed to handle this type of failure though, and while a local blackout was unavoidable at that point, the system operators should have been able to re-route power and avoid a much larger blackout. However, due to some software bugs the system didn’t work, and the overload ended up causing a cascade failure which put a lot of places in the dark.
One funny thing is that I remember engineering articles in the 1990s discussing cascade failures, with the northeast being a common example of how cascade failures happen (the blackouts of 1965 and 1977 both involved cascade failures, though the 1977 one was at least contained to the NYC area). The articles very confidently discussed how the new fast-acting control systems would prevent cascade failures from ever happening again in the northeast. Oops. Guess not.
Anyway, in 2003 a lot of the protective systems did actually work, and generating plants simply disconnected from the grid and did not suffer any major damage. If those protective systems had failed, recovering from the blackout would have been much more difficult and would have taken a lot more time.
So, how was service restored so quickly? Partly because there wasn’t a lot of damage (since the protective systems mostly worked), partly because the NE has historically had a lot of experience recovering from cascade failures, and partly because the power companies asked folks to keep their power usage to a minimum during the recovery and people actually listened. Generating plants were able to be quickly brought back online and did not get overloaded as more and more areas were reconnected to the grid.
The Texas “might take months to recover” scenario was just one way the situation could have played out. If they had literally just left everything connected, the damage could have taken years to fix. (Burned out transformers and seized up turbines).
The “might take months to recover” scenario was a more realistic scenario like what you might choose to do to your car (keep driving for a while even though the oil-temperature light is on). Leave power on until things start to fail, but turned off before anything really big was damaged. Sometimes that doesn’t work out so well, and your car is in for an engine replacement.
“Might take weeks to recover” could have been just an inability to do a cold start: one of the reasons some of the power was out recently in SA.australia was because the cold-start generator … didn’t work.
In the 2003 NE Blackout, they didn’t “fail to shut down until it was too late”, so they didn’t have months-long damage to fix.
And they didn’t have any problem reconnecting, so they didn’t have weeks-long outage while they brought in ships to run generators – which is the kind of thing that sometimes happens when there is nothing to reconnect to.
The critical point is that damage to equipment from not shutting down is what can take months to recover from. Transformers with burned out windings, switch gear with blown fuses and linkages, even turbines and generators with melted coils and seized bearings. Replacement equipment has to be manufactured from scratch, which is a months-long process. There’s no warehouse of large substation transformers and switch gear just sitting around waiting because most of it is custom made to order, then it has to be installed and commissioned once it is finally built and shipped. If the grid can be shut down before damage is done, then it’s just a matter of restarting the grid, which can still take days, but not months.