3.2M views · Dec 6, 2022 · 17:06 · 6 HN recommenders · 10 mentions · discussed 2022–2025
Practical Engineering explains what a black start is: restarting a power grid after total collapse. It shows why most plants need outside power to start and why rebuilding a synchronized grid is delicate and high-stakes.
Why Hacker News points people here: Go-to reference whenever a major blackout happens, recommended as an excellent explanation of why black starts are hard.
“Practical Engineering did a really great video a few years ago on why black starts are hard”HN comment, 2025
“Practical Engineering did a really great video a few years ago on why black starts are hard”
Why black starts are hard, with a tabletop generator demo.
Practical Engineering did a really great video a few years ago on why black starts are hard, complete with a tabletop demo about the physics of synchronizing large spinning generators: this video
“Practical engineering has a great video about power black starts”
Insight into the complexity of restarting a synchronized grid.
Heh, it's easy to model when you have a few generators, especially when one is much bigger than the others on the grid. But what's fun these days is you can have an absolutely huge number of generators. Keeping things in phase just seems insane to me. Practical engineering has a great video about power black starts that give some insight into this complicated machine. this video
“has a very interesting video on black starts of an electrical grid”
Interesting overview of black starting an electrical grid.
The Practical Engineering Youtube channel has a very interesting video on black starts of an electrical grid [0]. Are there any additional challenges in turning a grid off? [0] this video
“excellent video on how catastrophic a black start is”
Shows how catastrophic a grid black start is.
The "turning the grid up to 11" attack isn't really possible. I know it seems like it is, but the inverters will only advance frequency so much before they back off, the inverters will only increase voltage so much. Etc. Sounds scary, isn't practical. Turning everything off when the panels are at peak output? That lets frequency sag enough that plants start tripping offline to protect themselves and the grid and it'll cascade across the continent in just a few minutes. Then you have a black start which might take months. There's an excellent video on how catastrophic a black start is. this video
“This one in particular is a good explanation on what they had to go through to get power back on”
Explains what is involved in restoring power after a blackout.
Practical Engineering on youtube has some good videos on the electrical grid. This one in particular is a good explanation on what they had to go through to get power back on: this video
“Grady has a good explanation”
Good explanation of how close grids can come to failure.
The power grid absolutely can fail catastrophically and is a lot more fragile than people think. Texas nearly ran into this during their blackout a few years ago -- their grid got within a few minutes of complete failure that would have required a black start which IIRC has never been done. Grady has a good explanation and the writeup is interesting reading too. link this video
“practically none of them can start if the grid power is not available”
Explains why most power plants cannot start without grid power.
> Actual power plants are self sustaining Actual power plants are not necessarily self-sustaining and practically none of them can start if the grid power is not available. See: black start power plants and this video
Explains the black start of the power grid.
It goes back a ways to when power companies couldn't offer power in adjacent states. NPR's podcast: The Disconnect: Power, Politics and the Texas Blackout link ... and the files for that appear to be missing... (if you have Apple Podcasts link ; Spotify: link ; Amazon music: link ). I especially suggest listening to the episode "The Fallout" Texas set up an energy market that was to eliminate waste and in doing so set up their grid so that it was constantly almost at load shedding (as that has the least waste). The problem is there were minutes away from a black start in which Texas would have been without power for an extended period of time - not days but weeks or months (and that the black start generators were also failing). Practical Engineering: * What Is A Black Start Of The Power Grid? this video * What Really Happened During the Texas Power Grid Outage? link And that when that happens, given the way that the Texas grid is set up, the rest of the country would be unable to help. And as that "hip to hate on Texas by costal elites"... utilities were trying to charge Minnesota for the part of the cost of the Texas outage ( link --- link ).
“a lot of power plants need power to be re-started”
Why power plants need outside power to restart.
And, don't forget, a lot of power plants need power to be re-started. They don't all have backup gas turbines to get going again. That made me think of this Everyday Engineering video "What Is A Black Start Of The Power Grid?" this video
Black start differs from restoring a partial grid failure.
A "black start" of a power grid is a completely different situation than restoring a partial grid failure. link this video
