Average spot prices for the week across the mainland ranged from $23/MWh in Queensland to $29/MWh in South Australia. Turnover in the energy market for the mainland was $88 million, with a total cost of ancillary services for the week of around $400 000 or 0.5 per cent of turnover.
A failure of Transend’s monitoring systems in Tasmania on Tuesday saw NEMMCO issue directions to Hydro Tasmania to maintain security and a number of $10 000 five minute prices for both energy and ancillary services. On Wednesday, a planned network outage and limited availability of frequency control ancillary services led to similar prices for energy and ancillary services. As a result of these events, the average spot price in Tasmania increased to $136/MWh compared to $72/MWh the previous week. Turnover in Tasmania for the week more than doubled to $26 million. The cost of ancillary services increased five-fold to around $870 000. The majority of this cost is funded by Tasmanian generators.
Demand forecasts produced 4 and 12 hours ahead varied from actual by more than 5 per cent in 21 per cent of trading intervals across the market. These variations were most frequent in South Australia and Tasmania, occurring in around two thirds and one third of trading intervals, respectively. Significant variations between forecast and actual prices occurred in 17, or 5 per cent, of trading intervals. Demand variations were the main contributor.
The AER would welcome comments on the information contained in, or the layout of, the report. Comments should be sent to Peter Adams or Mark Wilson, AER, 14th floor, 13 Grenfell Street, Adelaide SA 5001 (email peter.adams@aer.gov.au; mark.wilson@aer.gov.au; fax (08) 8213 3414).
Figure 1 sets out national demand and spot prices in each region for each trading interval. Figure 2 compares the volume weighted average price with the averages for the previous week and the same quarter last year. Figure 3 compares the weekly price volatility index on the same basis.
Figure 1 National demand and spot price all regions
Figure 2 Volume weighted average spot price for energy market ($/MWh)
Maximum spot prices for the mainland ranged from $68/MWh in New South Wales to $55/MWh in Victoria and South Australia. In Tasmania, the maximum spot price for the week was $6691/MWh on Tuesday morning.
There were no low reserve conditions forecast throughout the week.
NEMMCO directed Hydro Tasmania to maintain frequency on two occasions on Tuesday.
In Tasmania, demand reached a maximum of 1412MW at 7.30am on Friday. The spot price at the time was $81/MWh.
The total cost of ancillary services on the mainland for the week was $403 000 or 0.5 per cent of the total turnover in the energy market.
Figure 4 Volume weighted average frequency control ancillary service prices (excluding Tasmania)
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
2.37
1.03
1.18
1.98
0.24
0.35
1.57
1.9
Previous week ($/MW)
2.56
1.24
1.23
1.71
0.32
2.77
5.17
1.76
Last quarter ($/MW)
1.62
0.91
1
1.36
0.2
0.64
2.29
1.56
Market cost($1000s)
133
58
83
43
2
3
39
41
% of energy market
0.15%
0.07%
0.1%
0.05%
0%
0%
0.04%
0.05%
In Tasmania, ancillary service costs totalled $866 000 or 3.3 per cent of turnover. This represents a five-fold increase from the previous week. On Tuesday there was insufficient plant available to supply the requirements for raise and lower regulation services. As a result prices reached $10 000/MW at 7.55am and 8am.
A planned network outage between Farrell and Sheffield on Wednesday led to increased requirements for raise 6 second services. At times the requirement could not be met with prices reaching $10 000/MW.
Figure 5 Tasmanian volume weighted average frequency control ancillary service prices
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
61.43
1.05
1.05
7.82
2.21
1.07
1.06
11.5
Previous week ($/MW)
2.2
1.05
1.05
1.05
2.13
1.08
1.07
1.05
Tasmania Market cost($1000s)
596
11
11
66
29
32
26
96
% Tasmania of energy market
2.29%
0.04%
0.04%
0.25%
0.11%
0.12%
0.1%
0.37%
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.
