Spot prices for the week averaged between $39/MWh and $43/MWh.
Turnover in the energy market in the week ended 11 August was $170 million. The total cost of ancillary services for the week was $864 000, or 0.5 per cent of energy market turnover.
Significant variations between actual prices and those forecast 4 and 12 hours ahead occurred in 99, or around a third of all trading intervals. Demand forecasts produced 4 and 12 hours ahead varied from actual by more than 5 per cent in a fifth of all trading intervals across the market. These variations were most frequent in Tasmania, occurring in over a quarter of all trading intervals.
The Australian Energy Regulator welcomes comments on the information contained in, or the layout of, the report. Comments should be sent to AER, GPO Box 922, Adelaide SA 5000 (email AERInquiry@aer.gov.au; fax (08) 8213 3414).
Figure 1 sets out national demand and spot prices in each region for each trading interval. Figure 2 compares the volume weighted average price with the averages for the previous week and the same quarter last year. Figure 3 compares the weekly price volatility index on the same basis.
Figure 1 National demand and spot price all regions
Figure 2 Volume weighted average spot price for energy market ($/MWh)
Maximum spot prices for the week ranged from $91/MWh in South Australia to $378/MWh in Tasmania. At 6.30 am on Thursday the spot price in South Australia fell to -$889/MWh as a result of an outage of one circuit of the Victoria to South Australia (Heywood) interconnector. The market was first informed of this outage at around 6 pm the previous evening.
The total cost of ancillary services on the mainland for the week was $526 000 or 0.3 per cent of turnover in the energy market. From Friday evening as a result of sustained output from Kogan Creek at 750 MW, the requirement for and cost of mainland raise contingency services increased.
Figure 4 summarises the volume weighted average prices and costs for the eight frequency control ancillary services across the interconnected regions.
Figure 4 Volume weighted average frequency control ancillary service prices (excluding Tasmania)
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
4.66
1.1
1.91
5.06
0.05
0.04
0.2
1.96
Previous week ($/MW)
0.77
0.17
0.75
5.59
0.08
0.19
0.51
1.73
Last quarter ($/MW)
1.76
0.73
1.15
1.54
0.39
2.28
5
1.93
Market cost($1000s)
212
45
117
115
0
0
3
33
% of energy market
0.13%
0.03%
0.07%
0.07%
0.01%
0.01%
0.01%
0.02%
The total cost of ancillary services in Tasmania for the week was $339 000 or 4.1 per cent of the turnover in the Tasmanian energy market. At 6.10 pm on Friday raise 6 second services reached $10 000/MW when Basslink entered the no-go zone and Tasmania had to source their own services, but there was insufficient available.
Figure 5 Tasmanian volume weighted average frequency control ancillary service prices
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
22.36
1.61
4.53
8
4.68
1.94
1.72
1.86
Previous week ($/MW)
6.02
2
2.2
4.59
2
1.96
1.83
1.31
Last quarter ($/MWh)
4.97
0.49
2.93
3
12.67
0.43
0.82
0.45
Tasmania Market cost($1000s)
127
27
63
42
20
29
21
9
% Tasmania of energy market
1.54%
0.33%
0.76%
0.51%
0.24%
0.35%
0.25%
0.11%
Figure 6 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 7 shows the weekly participation in each of the ancillary service markets on a regional basis.
Figure 7 Regional participation in ancillary services
Figures 8 and 9 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 of 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.
