Wind Power Capacity Credit in South Australia

Previous posts have dealt with low wind power output during certain South Australian heatwaves. This post shows more examples, the aim being to establish an approximate figure for the wind power that can be relied upon during heatwaves.

In summer 2015/16 (December, January, February) there were seven days with maximum temperature above 40C at Adelaide Kent Town, all in December. I have used archive data available from the AEMO (see the sources section below for details) to extract and sum the outputs from each wind farm in South Australia, sampled at 30-minute intervals, for each of these seven hot days. Four of the seven resulting total wind power profiles have a similar shape:

The seven hot days occurred in three heatwaves, and each of the three heatwaves had at least one of the profiles shown above (one heatwave had two, 17th and 18th December 2015). On these days wind power dropped towards noon, and only started to recover well after the start of the peak demand period. These examples suggest that a total wind power of no more than around 100 MW can be assumed for assessing reserve capacity.

The wind power profiles for the remaining three days were more varied:

On two of the days shown above wind power did not drop below about 200 MW during the peak demand period, but on one of the days it fell to around 100 MW at the end of the period.

Past electricity data is only available at the nemweb archive back to around March 2015, but we can see the wind contribution during the January 2014 heatwave via a report written about it by the AEMO (see below for link), which contains this figure:

The wind power (the portion in white) was substantial for most of the heatwave, but fell to around 50 MW at times during the peak demand periods of the first and third days.

Conclusions

In assessing the reserve capacity of the electricity system in South Australia a “firm” capacity for total wind power of no more than around 50 MW can be assumed. It may be necessary to lower this estimate if the heatwaves of other years were (or become) significantly less windy than those of January 2014 and December 2015.

Sources

See the NEM ELECTRICITY DATA page above for links to the archived electricity data used.

The list of wind farms in South Australia, using their NEM code names is: ‘CATHROCK’; ‘LKBONNY1’; ‘LKBONNY2′;’LKBONNY3’; ‘CNUNDAWF’; ‘MTMILLAR’; ‘STARHLWF’; ‘WPWF’; ‘BLUFF1’; ‘CLEMGPWF’;’HALLWF1′; ‘HALLWF2’; ‘NBHWF1’; ‘SNOWNTH1’; ‘SNOWSTH1’; ‘SNOWTWN1′;’WATERLWF’.

The AEMO report on the January 2014 heatwave can be downloaded via this page: http://www.aemo.com.au/News-and-Events/News/2014-Media-Releases/Heatwave-13-to-17-January-2014