It got very windy in South Australia this week – in fact, to the point where energy generation from wind farms reached near record levels early on ANZAC Day, with more than 1,500 megawatts of wind coursing through the energy network.
However, with high levels of wind in the generation mix, energy stability became an issue because on the non-synchronous nature of wind generation.
Once again it was gas that rode to the rescue, with the Australian Energy Market Operator issuing a direction to bring stability back to the grid.
The relevant market notice is shown below:
As the ABC reported, the effect of the direction was to order two gas generators to come online and remain available to provide synchronous services to ensure that South Australia did not suffer another ‘system black’ event of the kind that took out the State’s power supplies in September last year.
But there’s more – a review of the AEMO Market Notices shows that the situation on Tuesday got so bad that, in addition to ordering gas generators to provide stability, the market operator also had to direct two generators to constrain their output to ‘minimise the effect on interconnector flows and minimise the number of Affected Participants’.
The relevant Market Notices are shown below:
There’s a third element to what the market operator did on Tuesday to keep the lights on in South Australia.
Under the National Electricity Rules, AEMO can determine an ‘administered price’ during an event that is caused by a market direction.
The practical effect of this is that the market operates under a fixed price for certain services – in this case, for the provision of ancillary services to stabilise the fluctuations caused by the high wind generation.
Once again, to the AEMO market notice:
AEMO’s intervention in South Australia came to an end just after midday on Wednesday.
What this event shows is that, despite the rhetoric of the renewables lobby, there’s always a need to maintain grid stability through synchronous generation – something that gas generators can do that wind simply can’t.