This post presents electricity data for South Australia, leading up to and including the state-wide blackout on 28th September 2016. The 5-minute data available to the public is insufficient to allow any conclusion to be reached about the cause of the blackout, but it illustrates several important characteristics of the electricity generation within the state, some of which may have had something to do with the blackout.
The AEMO are investigating the blackout, and so far have produced two interim reports, available here:
The following figure shows the contributions to the electricity supply in South Australia in the days leading up, and the day after, the blackout:
Three events of interest are marked A, B, C on the figure above, and discussed below:
A: The rise in consumption (black curve) at this time is unusual (at least different to that of the 26th and 27th, a Monday and Tuesday), starting before noon. Note also that the consumption fell shortly after noon, then rose again before the blackout at B. One possible explanation is solar PV rising and falling as the storm on that day came and went, if so then solar PV may have played a part in the blackout via a relatively unpredictable modulation of the demand placed on the other sources of supply.
C: After the blackout the system recovered quickly, thanks to the conventional generators (the mauve curve) being able to respond to demand, peaking at nearly 1500 MW.
The following figure shows the outputs of all the wind farms in the state, grouped into 3 regions:
The strong winds on the blackout day of 28th September had most impact on the wind farms in the hills to the North of Adelaide (the lower set of data), with many of their outputs fluctuating wildly in the last few hours, presumably as their over-speed thresholds were exercised. Note also the feature marked D on the figure above, a short period where the outputs of two separate wind farms (Cathedral Rocks and Mount Millar) varied closely in anti-phase.
The following figure shows the hours before the blackout in more detail, showing only the wind farm outputs North of Adelaide (excluding Hornsdale, which earns a gold star for maintaining a relatively stable output during the storm):
It seems likely that the fluctuations in wind farm output continued during the 5-minute interval containing the blackout, and these fluctuations may have had something to do with it.
Fluctuations in both solar PV and wind power may have been substantial in the minutes leading up to the state-wide blackout of 28th September 2016, and may have had something to do with the blackout. Only the AEMO, with its data at much finer resolution, can settle the issue, but so far they have made no mention of these fluctuations, concentrating instead on wind farm responses to voltage fluctuations.