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HVDC facilities look like something out of a scifi movie: * https://new.abb.com/news/detail/19701/abb-wins-600-mw-hvdc-order-to-reinforce-japanese-power-supply

HVDC facilities look like something out of a scifi movie: * https://new.abb.com/news/detail/19701/abb-wins-600-mw-hvdc-order-to-reinforce-japanese-power-supply-through-hvdc-jv-with-hitachi https://new.abb.com/news/detail/19701/abb-wins-600-mw-hvdc-o...

jacquesm 3y ago
Indeed, they do. The Wikipedia page photos are some of my favorite photos of power tech. Another thing that made a really strong impression was visiting a power dam and realizing that it was almost dead quiet while an enormous amount of power was being generated. Just a slight hum and a vibration in the floor, that was all.
- jeffrallen 3y ago
  But if those rotors were even a few grams out of balance, you'd feel it. Also, if something went wrong with the valves, you'd also hear it. Right before you drowned and/or were killed by flying concrete. Moving water does NOT like to stop.
  - jacquesm 3y ago
    Yes, the water hammer from a major dam must be quite impressive if you try to contain it by main force rather than to reduce the flow gradually.
    - cesarb 3y ago
      I've seen some videos which show, if I understood the description correctly, chambers which contain the overpressure from these water hammer events. For instance: https://www.youtube.com/watch?v=fJVBlhgt9j8 https://www.youtube.com/watch?v=fJVBlhgt9j8
      - jacquesm 3y ago
        That's impressive. I've seen a 2" butterfly valve attached to a stepper motor blown clear off the tube it was on because it closed too quickly. Oops... expensive lesson.
  - jeffrallen 3y ago
    Here's a documentary on one disaster: https://youtu.be/OjMtbkFF3RM https://youtu.be/OjMtbkFF3RM 75 deaths. RIP.
    - jacquesm 3y ago
      Oh, that's ugly. Not to be callous: but it could have been much worse still, in spite of all of the failing safety systems. The dam itself could have failed and the downstream effects would have been on a completely different level.
downrightmike 3y ago
Massive page overlay popup. Can't esc from it
- SECProto 3y ago
  > Massive page overlay popup. Can't esc from it Clicking the prominent "refuse all" button works
pcl 3y ago
... meanwhile, it's hard to believe that Japan still runs two separate grids at two separate frequencies. Seems like it'd be worth sorting out a transition plan instead of building that sort of facility, and (presumably) a bunch of others just like it.
- bee_rider 3y ago
  I think they might want HVDC either way, and since they’ll have to convert from DC to AC locally anyway, maybe it isn’t so bad? It does seem a little weird though.
- andylynch 3y ago
  It’s not worth the eye watering amount of money it would cost to change. It took nearly seventy years to transition users off the much smaller NYC DC grid, which was obsolete in the 1920s!
- lmm 3y ago
  On the contrary, as inverters and HVDC get cheaper, large synchronous grids are less worthwhile. Smaller grids are more resilient and easier to recover; that's the direction we're headed in, with plans to decouple some of these continental grids.
nielsbot 3y ago
Any time I see rooms like this, I think to myself "Do not touch ANYTHING in here"

jacquesm 3y ago

Indeed, they do. The Wikipedia page photos are some of my favorite photos of power tech. Another thing that made a really strong impression was visiting a power dam and realizing that it was almost dead quiet while an enormous amount of power was being generated. Just a slight hum and a vibration in the floor, that was all.

jeffrallen 3y ago
But if those rotors were even a few grams out of balance, you'd feel it. Also, if something went wrong with the valves, you'd also hear it. Right before you drowned and/or were killed by flying concrete. Moving water does NOT like to stop.
- jacquesm 3y ago
  Yes, the water hammer from a major dam must be quite impressive if you try to contain it by main force rather than to reduce the flow gradually.
  - cesarb 3y ago
    I've seen some videos which show, if I understood the description correctly, chambers which contain the overpressure from these water hammer events. For instance: https://www.youtube.com/watch?v=fJVBlhgt9j8 https://www.youtube.com/watch?v=fJVBlhgt9j8
    - jacquesm 3y ago
      That's impressive. I've seen a 2" butterfly valve attached to a stepper motor blown clear off the tube it was on because it closed too quickly. Oops... expensive lesson.
- jeffrallen 3y ago
  Here's a documentary on one disaster: https://youtu.be/OjMtbkFF3RM https://youtu.be/OjMtbkFF3RM 75 deaths. RIP.
  - jacquesm 3y ago
    Oh, that's ugly. Not to be callous: but it could have been much worse still, in spite of all of the failing safety systems. The dam itself could have failed and the downstream effects would have been on a completely different level.

downrightmike 3y ago

Massive page overlay popup. Can't esc from it

SECProto 3y ago
> Massive page overlay popup. Can't esc from it Clicking the prominent "refuse all" button works

pcl 3y ago

... meanwhile, it's hard to believe that Japan still runs two separate grids at two separate frequencies. Seems like it'd be worth sorting out a transition plan instead of building that sort of facility, and (presumably) a bunch of others just like it.

bee_rider 3y ago
I think they might want HVDC either way, and since they’ll have to convert from DC to AC locally anyway, maybe it isn’t so bad? It does seem a little weird though.
andylynch 3y ago
It’s not worth the eye watering amount of money it would cost to change. It took nearly seventy years to transition users off the much smaller NYC DC grid, which was obsolete in the 1920s!
lmm 3y ago
On the contrary, as inverters and HVDC get cheaper, large synchronous grids are less worthwhile. Smaller grids are more resilient and easier to recover; that's the direction we're headed in, with plans to decouple some of these continental grids.

nielsbot 3y ago

Any time I see rooms like this, I think to myself "Do not touch ANYTHING in here"