Market report for Sunday, 14 October: Multiple negative price intervals knock Tas average down 44pc, with NSW, Vic, SA and Qld falling 23-32pc to $10.55-$22.00/MWh range on falling demand

Eleven successive negative price intervals from the start of the trading day in the 0430EST interval knocked Tasmania’s average price down 44 per cent, with NSW, Victoria, South Australia and Queensland falling 23-32 per cent to a range of $10.55-$22.00/MWh.

System-wide maximum demand was down 493MW (2.0 per cent) to 23,582MW, with falls in all regions. Top price of the day was the $30.16/MWh in the 30-minute trading interval ended 1100EST. Tasmania also had the lowest average price and NSW the highest. 20-24 top temperatures in NEM capitals Temperature ranges in the NEM capitals were: Sydney 11-23 degrees (11-19 on Saturday); Melbourne 11-23 degrees (8-16), Adelaide 9-21 degrees (11-17); Brisbane 15-24 degrees (18-27); and Hobart 10-20 degrees (5-17).

Vic unplanned outage ends: NEMMCO advised at 1239EST on Sunday,1 4 October that an unplanned outage of the Eildon to Thomastown 220kV transmission line in Victoria occurred for 13 hours 35 minutes from 2305EST on Saturday, 13 October to 1240EST on Sunday, 14 October and that constraint sets V–DBUSS_L and V–EPTT_R were invoked for this period. NEMMCO said that in order to maintain voltage levels to a secure limit the Eildon power station to Mount Beauty terminal station No.1 and No. 2 220kV transmission lines had been opened and constraint set V-X_EPMB_R, which had the QNI, Basslink, Murraylink, Heywood and Vic-Snowy interconnectors on the left hand side, was invoked for 13 hours 25 minutes from 2315EST on Saturday until 1240EST on Sunday.

Today in detail
• NSW: Average price $22.00/MWh, down 23 per cent on the $28.71/MWh of Saturday, down 6 per cent on the $23.47/MWh of the comparable Sunday last year; maximum price $29.51/MWh for the trading interval ended 1900EST. Average demand 7571MW, down 3.7 per cent on Saturday, down 1.4 per cent on a year ago; maximum demand 8865MW for the 1900EST interval, down 1.2 per cent on the 8992MW of Saturday.

• Victoria: Average price $20.33/MWh, down 32 per cent on the $30.05/MWh of Saturday, down 21 per cent on the $25.72/MWh of the comparable Sunday last year; maximum price $27.30/MWh for the trading interval ended 0930EST. Average demand 5161MW, down 6.6 per cent on Saturday, up 2.4 per cent on a year ago; maximum demand 5905MW for the 1930EST interval, down 4.0 per cent on the 6152MW of Saturday.

• South Australia: Average price $21.47/MWh, down 30 per cent on the $30.50/MWh of Saturday, down 21 per cent on the $27.23/MWh of the comparable Sunday last year; maximum price $28.72/MWh for the trading interval ended 1930EST. Average demand 1289MW, down 5.5 per cent on Saturday, up 3.2 per cent on a year ago; maximum demand 1575MW for the 0000EST Monday interval, down 2.6 per cent on the 1617MW on Saturday.

• Queensland: Average price $19.89/MWh, down 26 per cent on the $26.81/MWh of Saturday, down 6 per cent on the $21.12/MWh of the comparable Sunday last year; maximum price $28.22/MWh for the 1900EST trading interval. Average demand 5061MW, down 3.9 per cent on Saturday, down 4.3 per cent on a year ago; maximum demand 6017MW for the 1900EST interval, down 0.2 per cent on the 6027MW of Saturday.

• Tasmania: Average price $10.55/MWh, down 44 per cent on the negative price-affected $18.88/MWh of Saturday, down 70 per cent on the $34.65/MWh of the comparable Sunday last year; maximum price $30.16/MWh for the 1100EST trading interval. There were also 11 negative price intervals, with the highest of minus $34.34/MWh in the 0730EST interval. Average demand 1053MW, down 4.9 per cent on Saturday, down 8.1 per cent on a year ago; maximum demand 1177MW for the 1930EST interval, down 5.0 per cent on the 1239MW on Saturday.

Sunday non-conformists: NEMMCO declared the following scheduled generating units non-conforming over rebids not received during the trading day of Sunday, 14 October:
• The 280MW capacity Queensland generating unit Gladstone 4 for 20MW from 0635EST to 0725EST.

• The 168MW capacity Queensland generating unit Braemar 1 for 36MW from 0830EST to 0855EST.

• The 280MW capacity Queensland generating unit Gladstone 3 for -14MW from 0835EST to 0905EST.

• The 80.5MW capacity South Australian Lake Bonney wind far for 13MW from 1135EST to 1140EST.

• The 500MW capacity Victorian generating unit Loy Yang A3 for 83MW from 1105EST to 1255EST.

Generation picture:
In NSW, Liddell 1, Liddell 4, Wallerawang C8, Vales Point B5, Munmorah 3 and Redbank 1 remained idle all day.

In Victoria, Loy Yang A3 came back in the 1100EST interval. Hazelwood 5 and Newport were off all day. The two West Kiewa units, Bairnsdale 2, Eildon 2 and the two McKay units operated at various times during the day.

In South Australia, Torrens Island B2 came back online in the 0900EST interval. Ladbroke Grove 1, Ladbroke Grove 2, Torrens Island B1, Torrens Island B4, 4 Torrens Island A1, Torrens Island A3 and Torrens Island A4 were offline all day.

In Queensland, Millmerran 2 returned to the grid in the 0500EST interval. Tarong 4, Swanbank B4, Callide B1, Gladstone 5, Gladstone 6 and Collinsville 5 were off the grid all day.

In Tasmania, Cethana came back in the 0700EST interval. Tribute returned in the 0930EST interval. Gordon went offline in the 2200EST interval. Trevallyn operated briefly during the day. Bell Bay 2, the three Bell Bay Three units, Poatina 220, Woolnorth, Lake Echo, Repulse, Paloona, Cluny and Butler’s Gorge were offline all day.

Interconnector flows: The Victoria-South Australia Heywood interconnector averaged 115MW west, up from the average 2.18MW west on Saturday. Murraylink averaged 1.43MW east, down 88.7 per cent on the average 12.71MW east on Saturday. Vic-Snowy exports averaged 689MW, up from average exports of 0.03MW on Saturday. Snowy-NSW exports averaged 469MW, compared to average imports of 191MW on Saturday. QNI averaged 719MW south, up 44.1 per cent on the average 419MW south on Saturday. Terranora averaged 80.81MW south, up 24.4 per cent on the average 64.95MW south on Saturday. Basslink averaged 101MW north, compared to an average 158MW south on Saturday.

Erisk Net, 15/10/2007