A closer look at Goyder South Wind Farm on Thursday evening 17th October 2024 (not affected by the storm?)

As noted in this ‘(Initial) Replay of Thursday evening 17th October 2024 in SA’:, there were some Wind Farms whose output appeared affected by the storm activity (and transmission disruptions) on Thursday evening 17th October 2024.

1)  the Snowtown 1 Wind Farm came sharply offline in the 18:45 dispatch interval (NEM time)

… but we noted earlier that it’s back online this morning.

2)  additionally, the Clements Gap Wind Farm came offline in the 18:50 dispatch interval.

… we noted earlier that the unit remains offline this morning.

3)  We also noted that the Goyder South Wind Farm dropped output to ~1MW in the 18:55 dispatch interval

… so in this short article, we similarly take a quick look.

Here’s the ‘Unit Dashboard’ widget in ez2view at the 11:55 dispatch interval on Friday 18th October 2024 looking back the past 24 hours:

There’s a bit of up-and-down in the output profile in this image, with two particular periods highlighted:

1)  The first period was approximately the time-range covered in the earlier review;

2)  The second period (from 02:20 this morning) we’ve highlighted but won’t delve into

3)  Coincidentally the unit output has just dropped to ~1MW in the 11:50 dispatch interval immediately preceding the snapshot.

However the main take-away is that the unit performance is different than that for SNOWTWN1 and CLEMGPWF in that there’s no prolonged period of outage overnight.

Drilling into the time period of interest yesterday evening, we see the following:

In this case we see:

1)  at 18:50 we see:

(a)  The unit is unconstrained

(b)  It receives a Target (80MW) and lands that target with no ‘Dispatch Error’.

2)  at 18:55 we see:

(a)  Two bound constraint equations take effect on the unit:

i.  The ‘S>>NIL_TWPA_TPRS’ constraint equation; and

ii.  The ‘S>>NIL_RBTU_RBTU’ constraint equation.

(b)  This drives the CPD Price for the unit (-$43.95/MWh at the RRN) below the bid price for the Unit (-$42/MWh at the RRN).

(c)  Which means that the unit is ‘constrained off’.

(d)  The unit successfully follows the target down, so no ‘Dispatch Error’.

3)  At 19:00 we see that:

(a)  The ‘S>>NIL_TWPA_TPRS’ constraint equation is still bound;

(b)  But, with the other constraint unbinding, the CPD Price (-$34.69/MWh) rises above the Bid Price (-$42/MWh at the RRN).(c)

(c)  The unit gets a Target (of 84MW) but only reaches 15MW (FinalMW), meaning a significant ‘Dispatch Error’ (+69MW).

So, unlike what we saw for SNOWTWN1 and CLEMGPWF, the drop in output was expected inside of NEMDE … albeit the underperformance at 19:00 on the way back up was unexpected.