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0 pointsmartinald11mo ago0 comments

Interestingly it seems that the black start drill is considering a smaller zone of impact than what has happened here.

Also I suspect there is far more renewables on the grid now than in 2016.

This is potentially the first real black start of a grid with high renewable (solar/wind) penetration that I am aware of. Black starts with grids like this I imagine are much more technically challenging because you have generation coming on the grid (or not coming on) that you don't expect and you have to hope all the equipment is working correctly on "(semi)-distributed" generation assets which probably don't have the same level of technical oversight that a major gas/coal/nuclear/hydro plant does.

I put in another comment about the 2019 outage which was happened because a trip on a 400kV line caused a giant offshore wind farm to trip because its voltage regulator detected a problem it shouldn't have tripped the entire wind output over.

Eg: if you are doing a black start and then suddenly a bunch of smallish ~10MW solar farms start producing and feeding back in "automatically", you could then cause another trip because there isn't enough load for that. Same with rooftop solar.

0 comments

caf11mo ago

This is potentially the first real black start of a grid with high renewable (solar/wind) penetration that I am aware of.

The South Australia System Black in 2016 would count - SA already had high wind and rooftop solar penetration back then. There's a detailed report here if you're interested:

https://www.aemo.com.au/-/media/Files/Electricity/NEM/Market...

genewitch11mo ago

Grid tied solar won't put power into the grid when the grid is down. It's the one reason I didn't grid tie.

Non tied solar won't affect the grid at all. So this is a non-issue.

Grid tie requires the grid to tie to, otherwise it can't synchronize. So it stays disconnected.

sponaugle11mo ago

"Grid tied solar won't put power into the grid when the grid is down. It's the one reason I didn't grid tie."

Why would that prevent you from being grid-tie? I have 53 panels (~21kw) grid tied and pushing to the grid, but in the event of grid failure my panels will still operate and push into my 42kwh battery array which will power the entire house. ( The batteries take over as the 'virtual grid source). I can then augment the batteries with generator and run fully off grid for an extended amount of time ( weeks in my case ).

genewitch11mo ago

> grid tied

> 42kwh battery array

these are mutually exclusive. What you have is a hybrid system, which is something i explicitly did not mention. A grid-tie system is not generating an AC waveform when the grid is down, at all. it cannot, by definition, and by design, as the AC waveform requires the grid to synchronize to.

Hope this clears this up.

martinaldOP11mo ago

Youre missing my point. I know that; I mean if you are restarting the grid and say you have a segment you think has 5MW of load that will come online, but you connect it and a minute or two later suddenly 2MW of grid tied solar detects the grid and starts exporting and you now have 3MW of load it is going to make it much more tricky to balance the restart. I'm not sure how much of a problem this is in reality but it seems to me restarting a grid is made much more tricky when you have millions of generation assets with no control over.

christkv11mo ago

This is why most of the restart of the grid is being done as the solar input tappers out I suspect. The grid was pretty much down during peak sun and started coming back online around 5:30 pm or later.

Dylan1680711mo ago

> I mean if you are restarting the grid and say you have a segment you think has 5MW of load that will come online, but you connect it and a minute or two later suddenly 2MW of grid tied solar detects the grid and starts exporting and you now have 3MW of load it is going to make it much more tricky to balance the restart.

I really thought that sentence was going to end with "it makes it a lot easier to handle that segment".

Yeah you have some big problems if it's a complete surprise, but your status quo monitoring would have to be very strangely broken for it to be a complete surprise. Instead it should be a mild complicating factor while also being something that reduces your load a lot and lets you get things running quicker.

Tireings11mo ago

Those small solar panels probably go directly to the next consumer.

You need to calculate for it but I don't think this would be a problem

j / k navigate · click thread line to collapse

0 pointsmartinald11mo ago0 comments

Interestingly it seems that the black start drill is considering a smaller zone of impact than what has happened here.

Also I suspect there is far more renewables on the grid now than in 2016.

0 comments

caf11mo ago

This is potentially the first real black start of a grid with high renewable (solar/wind) penetration that I am aware of.

The South Australia System Black in 2016 would count - SA already had high wind and rooftop solar penetration back then. There's a detailed report here if you're interested:

https://www.aemo.com.au/-/media/Files/Electricity/NEM/Market...

genewitch11mo ago

Grid tied solar won't put power into the grid when the grid is down. It's the one reason I didn't grid tie.

Non tied solar won't affect the grid at all. So this is a non-issue.

Grid tie requires the grid to tie to, otherwise it can't synchronize. So it stays disconnected.

sponaugle11mo ago

"Grid tied solar won't put power into the grid when the grid is down. It's the one reason I didn't grid tie."

genewitch11mo ago

> grid tied

> 42kwh battery array

Hope this clears this up.

martinaldOP11mo ago

christkv11mo ago

Dylan1680711mo ago

I really thought that sentence was going to end with "it makes it a lot easier to handle that segment".

Tireings11mo ago

Those small solar panels probably go directly to the next consumer.

You need to calculate for it but I don't think this would be a problem

j / k navigate · click thread line to collapse