This can lead to extended outages as we have no alternative source of supply; there is considerable line length to patrol; and it traverses difficult terrain ( over the Flinders Rangers from the Gulf).

The causes of the interruptions have all been unrelated (lightning strikes on three occasions; an Electranet outage; a substation transformer failure; and a hot joint), but clearly customers have had an unfortunate run of outages this year.

To manage reliability to customers in & surrounding Wilmington in 2018 we are planning to:

• Upgrade insulators on the Baroota – Bungama – Murray Town 33,000 Volt line to reduce impact of lightning (this has been successful in other areas impacted by lightning)

• Install animal guards on the PA10 Wilmington 11kv Town Supply Line ( where we have historical problems with Birds)

By chance, a Reliability Officer is going to Wilmington today to scope the animal guards job.

2017 Unplanned Outages that have impacted Wilmington & surrounds are:

1. 10/3/17 Wilmington Sub – Transformer Failure Off 2:36 – restored 19:00 (19:00hrs)
i. Equipment replaced & upgraded in Wilmington substation

2. 7/8/17 SD311 Baroota – Bungama – Murray Town 33kv – No cause found – later found Faulty Joint Off 15:09 – restored 17:29 (2.20 hrs)

3. 14/11/17 ElectraNet outage Baroota Substation 132Kv supply line FAULT– Off 17:33 – restored 19:57 (2.24 hrs)

4. 16/11/17 SD311 Murraytown – Wilmington – Insulator failure Lightning Off 1:54 – restored 10:03 (8.90 hrs)

5. 22/11/2017 PA11: WILMINGTON SOUTH 19kV SWER ONLY – Lightning Damaged Insulator Off 15:17 – major restored 18:16 (2.60 hrs)

6. 04/12/2017 PA11: WILMINGTON SOUTH 19kV SWER ONLY – Lightning Damaged TF 0ff 18:06 – 99% restored 21:15 (3:08 HRS) – TF isolated as customer has generator.

The incidents affecting Port Augusta supply have been random in location and caused either by bird activity or damage to insulators caused by lightning strikes (see damaged insulators in attached photo).

10/11/2017 – 09:18 to 14:54 ( 5:36 hrs to final restoration) Bird at TF61 on feeder PA02 
15/11/2017 – 09:36 to 10:44 ( 1:08 hrs) Bird at TF12 on PA04
19/11/2017 – 07:43 to 09:43 (01:60) Bird at TF16 on PA02
30/11/2017 – 21:11 to 01:05 (03:54) Damaged Disc Insulator past DF15259
03/12/17 – 04:35 to 10:20 (5:45) Failed insulator at TF7.

Both feeders have been affected by these events as they are currently tied together while we are undertaking works within the Port Augusta substation. Those works should be completed by Christmas.

We are aware of the inconvenience for customers and monitor repeat interruptions — in response to the latest outage a Reliability Operations Officer has been dispatched to Port Augusta this morning to:

Do a pole by pole inspection of sections of both feeders where we have had damage or events
Scope & issue jobs for animal guards at the locations affected & insulator upgrade works (we have a program of targeting lightning-prone sections of line for upgrade to lightning-resistant insulators)

We also are assessing the potential (not yet confirmed) to switch some load (major businesses on the highway) to a different source of supply to reduce the potential impact on them.

For your background, last week we had intensive lightning activity in SA — 800,000 strikes between 6pm Wednesday and 6am Friday. I have attached charts showing the extent of the strikes, which were responsible for a number of outages on Eyre Peninsula and in the mid to Far North.

I have never seen this amount of lightning in ten years with SA Power Networks and am surprised that we did not have more outages, given the intensity of the thunderstorm activity.