|Fig. 1 Power production at Snowtown Sept 28,2016|
It looks like a natural disaster but brought on by the fragility of the South Australian power system caused by the size of the variations in wind power.The lesson is not necessarily that wind power is bad power; it can be a useful form of power production if you take measures to address its inherent weakness. Since wind power is intermittent and variable, and power storage on a mass scale is not practical in most cases, an adequate back up of some form of easily ramped up power must be available on short notice. Natural gas from fracking is the obvious choice in most cases.
The failure is most likely to have been triggered by the violent fluctuations from the Snowtown wind farms (Figure 1 and 5). Shortly after 3 pm there was a loss of 200MW with a partial recovery some twenty minutes later of 100MW. The total wind farm supply for South Australia also shows these variations (Figure 2).
This would have put a shock to the system for frequency stability at 50 cycles per second. For most of the day the local gas fired generators were only supplying 100 MW (Figure 3) with the balance to match demand with supply coming from Victoria. But the local generators started to increase and vary their output with first a 150 MW loss at Snowtown just before mid-day and then 50 MW variations that followed. Shortly before 3 pm the Hallett wind farms lost and then recovered 70 MW in a 20 minute interval (Figure 4 and 6). This added to the final Snowtown wind farm 200 MW loss. This detail is shown in Figure 5.
So the system instability could trigger Victoria shutting off the link to South Australia and the blackout followed.
The primary requirements for an energy network like, say, South Australia, or the the US Eastern Seaboard are two, 1) Production needs to be adequate for the service area and 2) The sources must be reliable, which implies planning for failures, and having the infrastructure to support it.
If you advocate for more "renewables," notably wind and solar, these factors must be considered. It's no good to have adequate power on sunny, windy days, with no ability to bridge the gaps. Opposing fossil fuel backup power, and the infrastructure to support them (power lines) out of NIMBYism is not a path to a sustainable future.