SLIDE 1 SRAS REVIEW NEW SOUTH WALES REGION July 2013 PRESENTED BY PETER BIDDLE

SLIDE 2 AGENDA 1.The System Restart standard 2.What are the proposed changes a)Main assumptions b)Electrical sub-networks c)Quantity of SRAS d)SRAS Definition 3.Restart process a)North b)South 4.Questions 5.Summary

SLIDE 3 SYSTEM RESTART STANDARD Procure sufficient SRAS to achieve the following targets in each electrical sub-network; o Provide auxiliary supply to sufficient generation within 90 minutes to provide generation & transmission capacity to meet 40% of peak demand within 4 hours For NSW South peak demand = 11,000MW o Need to supply 4400MW capacity within 4 hours For NSW North peak demand = 3700 o Need to supply 1480 MW capacity within 4 hours The restoration timeframe represents the target timeframe to be used by AEMO in the procurement process. It is not a specification of any operational requirement that should be achieved in the event of a black system condition

SLIDE 4 RECOMMENDED CHANGES Current assumption is that SRAS is procured to manage a NEM wide shutdown o Changing to a Region only shutdown NEM wide shutdown requires each region to be self- supporting for SRAS o Region only shutdown allows use of adjoining regions as a restart supply Currently two electrical sub-networks in NSW o NSW North & NSW South o No change to electrical sub-networks Currently 5 SRAS in NSW – 2 x south, 3 x north o Proposing a minimum of 1 SRAS in each sub-network

SLIDE 5 RECOMMENDED CHANGES (CONT.) Current definitions of primary & secondary SRAS has led to a number of perverse outcomes o small gas turbines starting large thermal units at the same power station that do not assist in AEMO meeting the System Restart Standard because:  No output to transmission network for several hours  Does not assist in restarting other generating units o Contracting with diesel units used to restart hydro and gas turbine generating units  Makes testing difficult and inefficient

SLIDE 6 RECOMMENDED CHANGES (CONT.) Recommending a single SRAS definition Objective is to ensure contracted services assist AEMO in meeting the System Restart Standard o ≥ 100MW delivered to the local transmission bus within 60 minutes.  Availability/reliability ≥ 90%  Could be delivered by TTHL Hydro Gas Turbines Other o Testing would involve black starting the unit, connecting to the power system and increasing output to contracted output within the contracted timeframe. AEMO is currently consulting with a number of generators to see if changes to this proposal are warranted.

SLIDE 7 RESTART PROCESS Under AEMO’s proposal NSW will have a minimum of four restart sources o From Queensland o From Victoria o At least 1 SRAS in south o At least 1 SRAS in north A restart would normally start from all four sources concurrently. o For the purpose of this exercise we will look at two scenarios  Connection to Queensland not available – restart NSW north from SRAS only  SRAS not available – restart NSW north from Queensland only. The aim is to provide auxiliary supply to the majority of power stations within 90 minutes. o If this is done then the time to restore supply capacity is minimised but is then outside AEMO’s control.  Load restoration determined by rate at which power stations can restore capacity

SLIDE 8 SOME ASSUMPTIONS No change from current process o All generation & transmission equipment is available for service o Generation capability is in accordance with Local Black System Procedures as provided by Generators o Reasonable time frames allowed for restoration of transmission elements o Load may be restored for voltage control o Major generation  North – Bayswater, Liddell. Eraring, Vales Point, Colongra  South – Mt Piper, W’wang, Snowy, Uranquinty, Tallawarra. o There are potentially a number of ways to do this

SLIDE 9 RESTORATION – NORTH FROM QUEENSLAND Energise Bulli Creek to Dumaresq to Armidale – all reactors in service Restore 132KV bus at Armidale and restore load Start SVC at Armidale Energise 85 line to Tamworth, restore 132KV bus and restore load. Energise 84 line to Liddell o Auxiliary supply for Liddell and Bayswater (33 or 34 line to Bayswater can also be restored if required)

SLIDE 10 BULLI CREEK TO LIDDELL

SLIDE 11 RESTORATION – NORTH FROM QUEENSLAND Energise from Armidale to Coffs Harbour, 87 line and then on to Lismore, 89 line. Restore load at Coffs Harbour and start SVC at Lismore Reduce voltage levels at Lismore (315KV and Armidale 340KV) Energise Newcastle from Liddell, 81 line. Restore 132KV bus and load at Newcastle Energise 132KV 95A, 95G and 9F3 lines to Eraring o Auxiliary supply to Eraring Energise 95 line to Tomago and restore auxiliary supply. Energise 90 line to Eraring Energise 24 Line to Vales Point o Auxiliary supply to Vales Point Energise 23 line to Munmorah o Auxiliary supply to Colongra

SLIDE 12 LIDDELL TO COLONGRA

SLIDE 13 TIMING ESTIMATES TO MAKE AUXILIARY SUPPLY AVAILABLE Elapsed time = 60 minutes o Bayswater 2640 MW o Liddell 2000 MW Elapsed time = 90 minutes o Eraring 2820 MW Elapsed time = 120 minutes o Vales Point 1320 MW o Colongra 720 MW

SLIDE 14 AFTER 4 HOURS – LIKELY SUPPLY CAPACITY Colongra 720 MW Vales Point 660 MW Eraring 1400 MW Bayswater 0 MW Liddell 500 MW Total = 3280 MW (1480 MW required to meet SRS)

SLIDE 15 RESTORATION - SOUTH No change to current documented procedures Starting from Victoria or Snowy SRAS (Tumut/Murray) is essentially the same process. Expected timing to make auxiliary supply available o Elapsed time = 30 minutes  Tumut 2400 MW  Murray 1500 MW o Elapsed time = 60 minutes  Shoalhaven 240 MW o Elapsed time = 90 minutes  Uranquinty 660MW  Tallawarra 460 MW o Elapsed time = 110 minutes  Mt Piper 1400 MW  W’wang 1000 MW

SLIDE 16 AFTER 4 HOURS – LIKELY SUPPLY CAPACITY Snowy 2500 MW (limited by transmission capacity) Uranquinty 660 MW Tallawarra 460 MW Shoalhaven 240 MW Mt Piper 1000 MW W’wang 0 MW Total = 4860 MW (4400 MW required to meet SRS)

SLIDE 17 QUESTIONS

SLIDE 18 SUMMARY Region only shutdown No change to electrical sub-networks Minimum of one SRAS to be procured per sub-network Still four sources of restart supply New definition of SRAS Expect to be able to provide auxiliary supply/connection to the majority of major generation within 90 minutes. Rate of load restoration will depend on rate of generation restoration and is outside AEMO’s control.