Average spot prices for the week, across the mainland, ranged from $24/MWh in Queensland to $32/MWh in South Australia. In Tasmania spot prices averaged $73/MWh. These prices were consistent with the previous week.
Turnover in the energy market for the mainland was $89 million, with a total cost of ancillary services for the week of around $640 000 or 0.7 per cent of turnover. The coincident loss of three 500kV lines in Victoria on Monday led to increased requirements for lower 60 second and 5 minute contingency services across the mainland until Thursday, adding around $200 000 to the total cost. There was however, little impact on the energy market price. In Tasmania turnover in the energy market was $14 million, with ancillary services costs totaling $150 000 or one per cent of turnover.
Demand forecasts produced 4 and 12 hours ahead varied from actual by more than 5 per cent in 28 per cent of all trading intervals across the market. These variations were most frequent in South Australia and Tasmania, occurring in more than two thirds and almost half of all trading intervals in those regions respectively. Significant variations between forecast and actual prices occurred in 51, or 15 per cent, of all trading intervals. Demand variations were the main contributor.
The AER would welcome comments on the information contained in, or the layout of, the report. Comments should be sent to Peter Adams or Mark Wilson, AER, 14th floor, 13 Grenfell Street, Adelaide SA 5001 (email peter.adams@aer.gov.au; mark.wilson@aer.gov.au; fax (08) 8213 3414).
Figure 1 sets out national demand and spot prices in each region for each trading interval. Figure 2 compares the volume weighted average price with the averages for the previous week and the same quarter last year. Figure 3 compares the weekly price volatility index on the same basis.
Figure 1 National demand and spot price all regions
Figure 2 Volume weighted average spot price for energy market ($/MWh)
Maximum spot prices for the mainland ranged from $59/MWh in Queensland to $79/MWh in South Australia. In Tasmania the maximum spot price for the week was $86/MWh on Friday morning.
In Tasmania, demand reached a maximum of 1424MW at 7.30am on Tuesday. The spot price at the time was $83/MWh.
There were no low reserve conditions forecast throughout the week.
The total cost of ancillary services on the mainland for the week was $637 000 or 0.7 per cent of the total turnover in the energy market. A non-credible contingency event occurred on Monday evening, when three 500kV lines in Victoria tripped. Flows into South Australia along the Heywood interconnector were reduced until Thursday as a result. Tradeoffs between imports and lower contingency frequency requirements set the reduced limit, at times forcing exports into Victoria. The increased requirements for lower 60 second and 5 minute contingency services added around $200 000 to the total cost.
Figure 4 Volume weighted average frequency control ancillary service prices (excluding Tasmania)
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
2.56
1.24
1.23
1.71
0.32
2.77
5.17
1.76
Previous week ($/MW)
2.39
1.43
1.33
1.55
0.25
0.36
1.52
1.57
Last quarter ($/MW)
1.62
0.91
1
1.36
0.2
0.64
2.29
1.56
Market cost($1000s)
143
70
87
37
4
79
180
38
% of energy market
0.16%
0.08%
0.1%
0.04%
0%
0.09%
0.2%
0.04%
In Tasmania, ancillary service costs totalled $148 000 or one per cent of turnover. At times increased requirements for lower and raise regulation were required to maintain the frequency within Tasmania.
Figure 5 Tasmanian volume weighted average frequency control ancillary service prices
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
2.2
1.05
1.05
1.05
2.13
1.08
1.07
1.05
Previous week ($/MW)
2.73
1.05
1.06
1.08
1.1
1.06
1.07
1.07
Tasmania Market cost($1000s)
22
11
11
9
28
32
26
9
% Tasmania of energy market
0.16%
0.08%
0.08%
0.06%
0.2%
0.23%
0.19%
0.06%
Figure six shows the daily breakdown of price for each frequency control ancillary service. It also includes the cost of services sourced locally and in Tasmania.
Figure 6 Daily frequency control ancillary service prices
Figure seven shows the weekly participation in each of the ancillary service markets on a regional basis.
Figure 7 Regional participation in ancillary services
Figures eight and nine show 30-minute prices for each of the ancillary services.
Figure 8 Prices for raise services
Figure 9 Prices for lower services
Figures 10 and 11 show the 30-minute Tasmanian price for each or the ancillary services.
Figure 10 Tasmanian prices for raise services
Figure 11 Tasmanian prices for lower services
Figures 12 and 13 present both the raise and lower requirements for each service over the week.
Figure 12 Raise requirements
Figure 13 Lower requirements
Figures 14 and 15 present both the raise and lower Tasmanian requirements for each service over the week.
