Cooler temperatures across the mainland led to lower demands and average prices compared to the previous week. Spot prices averaged between $18/MWh in Victoria and $21/MWh in South Australia.
An unplanned transmission line outage in Tasmania on Tuesday afternoon led to $1000/MWh energy prices. The average price of $37/MWh was up compared to the previous week. The price for frequency control ancillary services exceeded $5000/MW for three services at the same time.
Turnover in the energy market for the mainland was $73 million with the cost of ancillary services totaling around $170 000, or 0.2 per cent of turnover. Turnover in Tasmania for the week was $6.3 million with the cost of ancillary services reaching just over $400 000 or 6 per cent of turnover reflecting the events of Tuesday.
Significant variations between actual prices and those forecast 4 and 12 hours ahead occurred in 22, or around 7 per cent of all trading intervals. Demand forecasts produced 4 and 12 hours ahead varied from actual by more than 5 per cent in around a quarter of all trading intervals across the market. These variations were most frequent in South Australia occurring in around half of all trading intervals.
The AER would welcome comments on the information contained in, or the layout of, the report. Comments should be sent to Peter Adams or Mark Wilson, AER, GPO Box 922, Adelaide SA 5000 (email AERInquiry@aer.gov.au; fax (08) 8213 3414).
Figure 1 sets out national demand and spot prices in each region for each trading interval. Figure 2 compares the volume weighted average price with the averages for the previous week and the same quarter last year. Figure 3 compares the weekly price volatility index on the same basis.
Figure 1 National demand and spot price all regions
Figure 2 Volume weighted average spot price for energy market ($/MWh)
Maximum spot prices for the week reached around $97/MWh in New South Wales and Queensland and around $78/MWh in Victoria and South Australia—all occurring on Monday afternoon. In Tasmania, the highest price for the week, of $1076/MWh, was recorded at 3.30 pm on Tuesday following the loss of the Sheffield to Farrell transmission lines.
There were no low reserve conditions forecast for the week. Directions were issued to Directlink on Monday and Friday to manage network issues associated with the Gold Coast and northern New South Wales.
The total cost of ancillary services on the mainland for the week was around $170 000 or 0.2 per cent of the total turnover in the energy market.
Figure 4 Volume weighted average frequency control ancillary service prices (excluding Tasmania)
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
0.47
0.41
0.99
0.45
0.15
0.19
0.71
1.57
Previous week ($/MW)
0.54
0.44
1.07
0.88
0.15
0.19
0.14
1.47
Last quarter ($/MW)
1.76
0.73
1.15
1.54
0.39
2.28
5
1.93
Market cost($1000s)
22
19
64
10
1
1
15
34
% of energy market
0.03%
0.03%
0.09%
0.01%
0%
0%
0.02%
0.05%
The total cost of ancillary services in Tasmania for the week was around $400 000 or 6 per cent of the total turnover in the energy market in Tasmania. An unscheduled transmission line outage on Tuesday led to a shortfall in the supply of some services, resulting in prices of $10 000/MW for the lower regulation, and the raise 6 second services for the period from 3.30pm to 3.40pm. The price for the raise regulation service increase to around $5000/MW at the same time.
Figure 5 Tasmanian volume weighted average frequency control ancillary service prices
Raise
Lower
6 sec
60 sec
5 min
Reg
6 sec
60 sec
5 min
Reg
Last week($/MW)
18.59
0.25
0.25
9.39
0.25
0.25
0.25
15.66
Previous week ($/MW)
0.6
0.25
0.25
0.25
0.25
0.25
0.25
0.27
Last quarter ($/MWh)
7.89
1.05
1.05
1.58
4.43
1.06
1.06
1.97
Tasmania Market cost($1000s)
174
3
3
79
4
8
6
132
% Tasmania of energy market
272.63%
4.58%
4.42%
123.94%
6.18%
12.83%
9.71%
206.39%
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.
