OPINION: The canary on the turbine - Part I
THERE are gales of self-interest or self-protection blowing from every direction about the SA power catastrophe. It was a big storm but not cyclonic. Will it happen again? Does the sun rise in the east?
The 22 towers which collapsed came down because they were a shonky design and 40 years old, were rusty and had not been properly maintained. They were not the cause of the system failure as most collapsed after the blackout occurred.
On 28/09 the fluctuations in wind power generation had reached a level where a stable 230V/50Hz output, could not be maintained so the system closed itself down, dropping from 900MW to zero in "seconds". This would be like jumbo jet at full throttle, touching down and stopping in 100m.
Two interconnectors from Victoria supply 60% of SA power from the soon-to-be-closed Hazelwood power station. When they "noticed" this huge drop they automatically disconnected. If they hadn't the problems could have cascaded into the east coast system, with disastrous results.
(What if there was an interconnector from NSW? It would cost $5000 per family in SA to build and increase their electricity rates, already the world's highest. And on 28/09 it too would have closed down.)
SA had two coal fired plants in Port Augusta but they had been closed down and dismantled. They could have saved the steel mill, but no power for days was probably the final blow. So much for submarine steel from SA.
SA also has two gas-fired plants near Adelaide. Half of the Torrens Island plant still operates but it automatically shut down to protect itself. The Pelican Point plant had been mothballed and took time to un-mothball.
The result: SA suddenly had zero power.
So why didn't they just restart the windmills? To start, they need electric power, just like our cars need a battery-starter motor combination. Catch 22. No power, no wind generators. So why doesn't each windfarm have its own restart diesel generator?
Based on lessons learnt, can SA continue building more green power? No.
Why not? One engineering rule ignored by governments, Jay Weatherill and his supporters, is that once green exceeds "30%" of base load power, it is very difficult to maintain the required 230V/50Hz power supply. Hopefully Part II will explain why.
On a light note, the above lets me write one of my favourite, slightly modified conundrums, which asks: Do you "Wonder whether the "Wether-ill" will whether the weather?"
John Ibbotson, Gulmarrad