Beginning on the 3rd of March, 2008 residents of South Australia endured a lengthy 15 consecutive daytime Adelaide temperatures in excess of 35ºC (95ºF).
This was the longest recorded heat wave for an Australian capital city.
As could be expected, the heatwave caused a wide variety of issues for residents of, and businesses operating in, Adelaide (and beyond) – ranging from inconveniences to significant safety issues.
The heatwave was also significant for the South Australian region of Australia’s National Electricity Market (NEM), including the following:
- Demand for electricity in South Australia created a new all-time record on three separate occasions;
- ETSA had issues maintaining supply in the distribution system;
- The Instantaneous Reserve Plant Margin (IRPM) for the South Australian Economic Island dropped as low as 7%;
- Spot prices in the market jumped on six separate occasions over the period of the 15-day event:
- In total, 26 separate trading (30-minute) intervals experienced prices above $5000/MWh;
- South Australia’s average pool price for March increased to $353/MWh;
- These price spikes had the effect of raising the Cumulative Price Total (CPT) over $150,000 – at which point NEMMCO issued and Administered Price Cap (APC).
Of these the last is perhaps most significant.
The Cumulative Price Total is a running total of the pool prices over the previous 336 trading periods (i.e. 7 days of 48 half-hourly prices).
To put things in perspective, the following graph (figure 1) shows the trend in South Australia’s CPT since the beginning of 2007:
Once the CPT passes $150,000 NEMMCO puts in place restrictions to prevent further high prices. By definition, the threshold is reached when the time-weighted average spot price for the week is above $892/MWh.
This occurred on the 17th of March at 17:00 (NEM time). This was the only time we have seen this occur since the NEM started in December 1998.
This report considers these effects in further detail.
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