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USA isn't in much of a better position. Large scale transformer blowouts are a nightmare scenario due to how long they take to replace / repair.

by lugg 7y ago

cronix 7y ago
Even worse when a generator goes out (or is destroyed). It can take months to get a new one. Hope we don't have multiple generators go out at once. They're not just sitting on a shelf somewhere waiting to be picked up.
- agumonkey 7y ago
  how much redundant capacity does the grid have ?
  - 6thaccount2 7y ago
    It depends on what time of the year it is. During Winter Peak on the East Coast (ISO-NE/PJM/NYISO) or Summer Peak in the ERCOT/SPP regions, you might not have a huge amount of reserves left. The shoulder months would be much nicer, but that is when many generators go on outage for repairs, so you have other problems. One of the biggest issues is that traditional resources (coal, nuclear, gas) can run for long periods of time and in many places have a pretty reliable fuel supply. Renewables are great, but you could be generating lots of power one minute and then it's all gone the next hour. This causes a lot of stress on traditional resources which need to be ready to counteract this. Coal plants and gas plants were never designed for that either and it's causing issues.
- powerbroker 7y ago
  This is the nightmare scenario that we would have if a Carrington-class solar flare hit the earth. Many transformers would be blown out by the induced electricity in power lines. The attached article describes economic losses in the trillions. https://en.wikipedia.org/wiki/Solar_storm_of_2012 https://en.wikipedia.org/wiki/Solar_storm_of_2012
  - woodgrainz 7y ago
    Additional reading on the Carrington event: https://en.wikipedia.org/wiki/Solar_storm_of_1859 https://en.wikipedia.org/wiki/Solar_storm_of_1859
ics 7y ago
I work on one of the densest power grids in the world (NYC) on the team which does emergency transformer replacements and can possibly answer questions about this. From failure to in service for a single transformer in Manhattan is down to 2-3 weeks. That includes design and engineering (my part), permitting, and construction. For fast transformer replacements we rely on two paths, either system spares (identical units, sometimes refurbished or like in kind replacements) and more recently mobile resiliency transformers. Resiliency transformers are trucked in on semis and can operate at 69, 138, or 345KV in our case. (There's some lightweight reading on them here: https://www.tdworld.com/overhead-transmission/siemens-introduces-demand-mobile-resilience-transformer-leasing https://www.tdworld.com/overhead-transmission/siemens-introd...)
- MisterTea 7y ago
  Neat job. I've always wanted to poke my head into ConEd's system and see the whole thing from behind the scenes. Years back I remember ConEd was replacing two or three very large transformers down the street of a large venu I was working an event. Turns out we worked the same event the next year and amazing the same day ConEd again had the second transformer scheduled to moved into place. What an operation. Huge trailer from Bay Crane along with one of their giant hydraulic cranes. Was told the transformer weighed in at 240,000 pounds.
  - ics 7y ago
    Heh, our most recent replacement a few weeks ago came in at almost 900,000lbs with oil. Depending on the speed of the replacement you can't always move the transformer dry because you need a certain amount of time between filling it and putting it in service.
    - jacobush 7y ago
      Air bubbles need to rise first?
    - MisterTea 7y ago
      That sounds like quite the transformer. That must have been at one of the big 345kV subs. And I assume shipping filled is to avoid the time needed to remove air bubbles. I know a few people in the ConEd trenches, one guy is a lineman who does all the >=69kV stuff and the other guy worked in substations and was in mott haven last I spoke to him (cushy job). I'm always amazed how much new tech con ed has installed and how much old stuff is still kicking around. I live in south queens and we're all 4kV overhead fed from area subs in turn fed by 27kV. Some of those 4kV poles have westinghouse transformers from the 30/40's still in service, glass insulators, and leftover wooden pins from older insulators. Some are so old the primaries have fallen off and just hang between two adjacent poles, some the crossarms are half falling off. Amazing this grid doesn't go down more. Then the next pole is brand new, composite strain insulators, cutouts, reclosers, metering, etc. All modern hardware. And I know some areas they upgraded the 4kV overhead to 27kV. The secondaries are in even worse condition, ancient cloth insulation half weatherd/baked off. But it all still works. I really love how there's this massive network of cabling and systems which orchestrate the flow of power from multiple synchronized generators so it can get to your humble wall socket and charge a phone or turn a light bulb on.

USA isn't in much of a better position. Large scale transformer blowouts are a nightmare scenario due to how long they take to replace / repair.

by lugg 7y ago

USA isn't in much of a better position. Large scale transformer blowouts are a nightmare scenario due to how long they take to replace / repair.

cronix 7y ago

Even worse when a generator goes out (or is destroyed). It can take months to get a new one. Hope we don't have multiple generators go out at once. They're not just sitting on a shelf somewhere waiting to be picked up.

agumonkey 7y ago
how much redundant capacity does the grid have ?
- 6thaccount2 7y ago
  It depends on what time of the year it is. During Winter Peak on the East Coast (ISO-NE/PJM/NYISO) or Summer Peak in the ERCOT/SPP regions, you might not have a huge amount of reserves left. The shoulder months would be much nicer, but that is when many generators go on outage for repairs, so you have other problems. One of the biggest issues is that traditional resources (coal, nuclear, gas) can run for long periods of time and in many places have a pretty reliable fuel supply. Renewables are great, but you could be generating lots of power one minute and then it's all gone the next hour. This causes a lot of stress on traditional resources which need to be ready to counteract this. Coal plants and gas plants were never designed for that either and it's causing issues.
powerbroker 7y ago
This is the nightmare scenario that we would have if a Carrington-class solar flare hit the earth. Many transformers would be blown out by the induced electricity in power lines. The attached article describes economic losses in the trillions. https://en.wikipedia.org/wiki/Solar_storm_of_2012 https://en.wikipedia.org/wiki/Solar_storm_of_2012
- woodgrainz 7y ago
  Additional reading on the Carrington event: https://en.wikipedia.org/wiki/Solar_storm_of_1859 https://en.wikipedia.org/wiki/Solar_storm_of_1859

ics 7y ago

I work on one of the densest power grids in the world (NYC) on the team which does emergency transformer replacements and can possibly answer questions about this. From failure to in service for a single transformer in Manhattan is down to 2-3 weeks. That includes design and engineering (my part), permitting, and construction. For fast transformer replacements we rely on two paths, either system spares (identical units, sometimes refurbished or like in kind replacements) and more recently mobile resiliency transformers. Resiliency transformers are trucked in on semis and can operate at 69, 138, or 345KV in our case. (There's some lightweight reading on them here: https://www.tdworld.com/overhead-transmission/siemens-introduces-demand-mobile-resilience-transformer-leasing https://www.tdworld.com/overhead-transmission/siemens-introd...)

MisterTea 7y ago
Neat job. I've always wanted to poke my head into ConEd's system and see the whole thing from behind the scenes. Years back I remember ConEd was replacing two or three very large transformers down the street of a large venu I was working an event. Turns out we worked the same event the next year and amazing the same day ConEd again had the second transformer scheduled to moved into place. What an operation. Huge trailer from Bay Crane along with one of their giant hydraulic cranes. Was told the transformer weighed in at 240,000 pounds.
- ics 7y ago
  Heh, our most recent replacement a few weeks ago came in at almost 900,000lbs with oil. Depending on the speed of the replacement you can't always move the transformer dry because you need a certain amount of time between filling it and putting it in service.
  - jacobush 7y ago
    Air bubbles need to rise first?
  - MisterTea 7y ago
    That sounds like quite the transformer. That must have been at one of the big 345kV subs. And I assume shipping filled is to avoid the time needed to remove air bubbles. I know a few people in the ConEd trenches, one guy is a lineman who does all the >=69kV stuff and the other guy worked in substations and was in mott haven last I spoke to him (cushy job). I'm always amazed how much new tech con ed has installed and how much old stuff is still kicking around. I live in south queens and we're all 4kV overhead fed from area subs in turn fed by 27kV. Some of those 4kV poles have westinghouse transformers from the 30/40's still in service, glass insulators, and leftover wooden pins from older insulators. Some are so old the primaries have fallen off and just hang between two adjacent poles, some the crossarms are half falling off. Amazing this grid doesn't go down more. Then the next pole is brand new, composite strain insulators, cutouts, reclosers, metering, etc. All modern hardware. And I know some areas they upgraded the 4kV overhead to 27kV. The secondaries are in even worse condition, ancient cloth insulation half weatherd/baked off. But it all still works. I really love how there's this massive network of cabling and systems which orchestrate the flow of power from multiple synchronized generators so it can get to your humble wall socket and charge a phone or turn a light bulb on.