Spot prices were aligned across the mainland for 90 per cent of the time, ranging from $22/MWh in Queensland to $29/MWh in South Australia. These prices were consistent with the previous week. Mild spring conditions were reflected in lower peak demand across the market.
In Tasmania, spot prices averaged $73/MWh, up slightly from the previous week.
Turnover in the energy market for the mainland was $84 million, with a total cost of ancillary services for the week of around $423 000 or 0.5 per cent of turnover. In Tasmania turnover in the energy market was $14 million, with ancillary services totaling $138,000 or one per cent of turnover.
Demand forecasts produced 4 and 12 hours ahead varied from actual by more than 5 per cent in 18 per cent of all trading intervals across the market. In South Australia demand errors occurred in around half of all trading intervals on the same basis. Significant variations between forecast and actual prices occurred in 47, or 14 per cent of all trading intervals. Changes to generator availability was the main contributor.
The AER would welcome comments on the information contained in, or the layout of, the report. Comments should be sent to Peter Adams or Mark Wilson, AER, 14th floor, 13 Grenfell Street, Adelaide SA 5001 (email peter.adams@aer.gov.au; mark.wilson@aer.gov.au; fax (08) 8213 3414).
Figure one sets out national demand and spot prices in each region for each trading interval. Figure two compares the volume weighted average price with the averages for the previous week and the same quarter last year. Figure three compares the weekly price volatility index on the same basis.
Figure 1 National demand and spot price all regions
Figure 2 Volume weighted average spot price for energy market ($/MWh)
The total cost of ancillary services on the mainland for the week was $423 000 or 0.5 per cent of the total turnover in the energy market.
Figure 4 Volume weighted average frequency control ancillary service prices (excluding Tasmania)
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
2.39
1.43
1.33
1.55
0.25
0.36
1.52
1.57
Previous week ($/MW)
2.02
1.38
1.02
1.2
0.2
0.28
1.25
1.39
Last quarter ($/MW)
1.43
0.69
0.98
1.36
0.16
0.12
1.16
1.58
Market cost($1000s)
136
81
95
34
3
4
37
34
% of energy market
0.16%
0.1%
0.11%
0.04%
0%
0%
0.04%
0.04%
In Tasmania, ancillary service costs totalled $138 000 or one per cent of turnover. At times on Tuesday, despatch for raise and lower regulation was zero as a result of a failure of the SCADA system. The price for these services reached $10 000/MWh at the time. This had no impact on the cost of these services for the week.
Figure 5 Tasmanian volume weighted average frequency control ancillary service prices
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
2.73
1.05
1.06
1.08
1.1
1.06
1.07
1.07
Previous week ($/MW)
2.45
1.05
1.05
1.07
1.66
1.05
1.05
1.08
Tasmania Market cost($1000s)
26
10
11
9
14
32
27
9
% Tasmania of energy market
0.19%
0.07%
0.08%
0.07%
0.1%
0.23%
0.19%
0.07%
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.
