NSW power supply problems November 2020 (part 1)

The summer hasn’t even started yet and the first lack-of-reserve and outage notices have appeared.

16 November 2020

(1) Line Outage Upper Tumut- Stockdill

AEMO market notice 80022 16/11/2020 01:39:08 PM

“An un-planned outage of Upper Tumut – Stockdill 1 330 kV Line in the NSW region occurred 12:52 hrs 16/11/2020

Constraint sets invoked: N-SDUT_1 and N-CNSD_3C

This constraint sets contains [linear] equations with the following interconnectors on the LHS [left hand side with controllable variables].

V-S-MNSP1 [Murraylink, 200/220 MW nominal capacity]

VIC1- NSW1 [Victoria to New South Wales, VIC->NSW 700-1600 MW, NSW->VIC 400-1350 MW]“

https://aemo.com.au/market-notices

Fig 1: Power supply by type shows drop in NSW imports
https://opennem.org.au/energy/nsw1/?range=1d&interval=30m

Fig 2: Corresponding drop in exports from Victoria
https://opennem.org.au/energy/vic1/?range=1d&interval=30m

Let’s have a look at the Upper Tumut – Stockdill line in a slideshow of ActewAGL:

Fig 3: Diversion/Bypass of Upper Tumut line 01 to the new Stockdill substation (West Belconnen)
https://slideplayer.com/slide/11936658/

The Stockdill substation is part of the ACT Second Electricity Supply Project which provides the Australian Capital Territory with a 2^nd geographically separate supply point including for new suburbs in Ginninderry (Joint venture between the ACT government and Riverview Developments).

June 2018

Transgrid and Evoenergy

ACT Second Electricity Supply Project EIS Volume 1 Main Report by WSP

Fig 4: Project Overview
https://www.environment.act.gov.au/__data/assets/pdf_file/0004/1471873/19_32808-Documents-Part-04.pdf

The next graph shows us how the above maps fit into the NSW network:

Fig 5: TransGrid’s southern NSW network

The Canberra substation connects to the Capital Wind Farm (140 MW, 67 turbines, 360 GWh pa, line 6), Yass substation (line 9), Lower Tumut (line 07) and Upper Tumut (line 01)

This network plan is from the following report on the Upper Tumut substation which connects 616 MW of hydro power, supports 4 transmission lines and provide electricity flow paths between the Snowy Mountains, Canberra and Sydney.

Maintaining a reliable Upper Tumut substation
RIT-T –Project Specification Consultation Report
Region: Southern New South Wales
Date of issue: 26 March 2019
https://www.transgrid.com.au/what-we-do/projects/regulatory-investment-tests/Documents/TransGrid%20PSCR%20-%20Maintaining%20a%20reliable%20Upper%20Tumut%20substation.pdf

AEMO did not say what caused the outage. The line was returned to service at 14:00 hrs (AEMO market notice 80038)

(2) Price spike $7,495/MWh

AEMO dashboard 16 Nov 2020 13:00 – 13:30

Fig 6: AEMO dashboard screenshot
https://www.aemo.com.au/energy-systems/electricity/national-electricity-market-nem/data-nem/data-dashboard-nem

(3) Actual LOR1 condition in NSW

“An Actual LOR1 condition has been declared under clause 4.8.4(b) of the

National Electricity Rules for the NSW region from 1500 hrs.

The Actual LOR1 condition is forecast to exist until 1700 hrs.

The capacity reserve requirement is 1320 MW

The minimum capacity reserve available is 766 MW”

https://aemo.com.au/market-notices [Filter by reserve notices]

There were several forecast LOR1 notices and cancellations, on and off

Forecast LOR1 (1053 MW vs 1476 MW) for 15:00 – 18:30 (reserve notice 79949 18:48 15 Nov 2020)
Forecast LOR1 (1133 MW vs 1476 MW) for 15:00 – 18:00 (reserve notice 79955 12:37)
Cancellation Forecast LOR 1 (reserve notice 79990 8:27)
Forecast LOR1 (1279 MW vs 1340 MW) for 15:30 to 16:00 (reserve notice 80040 14:25)
Cancellation Forecast LOR1 (reserve notice 80041 14:53)