Nearly all the state's gas capacity was not available:
AGL's Torrens Island [Gas Thermal]
? Units A1, A2, A3, A4 and B2 ? All cold (480+240MW unused capacity)
? Units B1, B3, B4 ? Running at roughly 33% capacity (delivering 250MW of 600MW spinning capacity)
Engie's Pelican Point [Gas Turbine]
? Units A & B + CGST ? Both Cold (160+160+165MW available capacity)
At 16:18 Transmission Towers get flattened, SA generating capacity & Victorian Interconnector overloads and trips ? SA grid collapses.So, let's start with Plan A of the Back Start procedure.
At 16:32 SRAS #1 (Presumably Origin's Quarantine PS Unit), black-start capable with multiple units (216MW in total), ordered to power up with ElectraNet switching to facilitate power to auxiliaries and main units at Torrens Island PS next door.
At 17:13 SRAS #1 starts supplying power to Torrens PS to enable auxiliaries, but by 17:55 it is diagnosed they can't supply enough power to enable any Torrens PS main unit restarts. [Suspect one of the Quarantine PS units not available].
Oops ?. let's go to Plan B
SRAS #2 (Origin's Osborne PS), black-start capable, but advised they can't deliver power to Torrens PS due lightening strike to their plant. Would also require ElectraNet to facilitate HV route to Torrens PS to enable a power-up. Plan ditched?. Ditto 210MW of Gas capacity
Oops again. Let's go to Plans C (D & E)
At 17:23 Torrens PS restart from Victorian supply initiated requiring 275kv route switched from Heywood thru South East, Tailem Bend, Cherry Gardens, Mt Barker South, Magill, Torrens Island bulk substations.
At 18:36 Engie, which owns Pelican Point Point Station, offer to make their ?off-line? units available with 4 hours notice.
At 18:43 Torrens Island PS auxiliaries switched from Quarantine PS power to Victorian Interconnector supply, and Torrens PS begins main unit power ups procedures at 18:54.
At 19:00 Adelaide CBD commences limited re-connection via Victorian Interconnector and to provide load for Torrens (& Pelican Point re-connections).
At 19:50 Pelican Point PS has auxiliaries connected to Victorian Interconnect power, and prepares for start-up.
At 19:55 Quarantine PS quoted as on having only 4 (of 5?) gas units on-line
At 20:58 Torrens Island PS gets ?A2? unit on-line. Capable of 120MW? Hang on, all the ?A? units were cold at 16:18!!!
At 22:02 Torrens Island PS gets ?A4? unit on-line Capable of 120MW? Hang on again, another ?A? unit, what about the warm ?B?? units..
At 22:05 Pelican Island PS gets ?GT #1″ unit on-line Assume GT-stage only delivery of 160MW
At 22:08 Snuggery Point PS quoted as being on-line Assume Delivery 63MW (Diesel) [still running at 00:005]
At 23:31 Torrens Island PS gets ?B1? unit on-line?. Capable of 240MW
Confirming the NEM Watch chart captured at 00:05 ? SA Gas & Diesel providing >800MW + Victorian Interconnector
South-East Wind zone 100-250MW reconnected before 03:50, releasing diesel & some gas capacity to return to reserve.
Okay at this point some questions?
1) What happened to Torrens Island B3 [240MW] and B4 [240MW] Units? did they get broken during outage event, and B1 which was an operational unit, but took five (5) hours to return to service.
Additionally, why were these SA Gas units NOT used?..
* Torrens A1 [120MW], A3 [120MW], B2 [240MW]? unused cold = Total 480MW
* Pelican Point #2 & CGST capacity [160+165W]? unused cold = Total 240MW
To sum up, the best part of 1.2 ? 1.5GW of gas generation capacity remained unused, off-line or was outright unusable for various reasons.
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