Thread: Big storm and no power in SA

Is that the cost it is sold for, the cost including the infrastructure cost and does it include the hidden costs such as government subsidies and environmental cleanup?

LCOE

Nationalised power was affordable- competition hasn't made ANY power cheaper in Australia - government owned was run for the people - costs covered maintaining the networks.

Another farce played out on the public when pollies sold off assets to clear other debt.

Water, Gas, Telecommunications and power all became more expensive when privatised

Originally Posted by Mick_Marsh

LCOE

So, you have figures for 2006. Has anything happened in the last 10 years, like a massive drop in wind and solar energy costs? Why did a private owner of a coal plant, Alinta, close it down if it was supposedly cheaper? Could the figures be out of date? And how's the black lung disease going?

I don't generally wade into this sort of thing but somehow I feel compelled. I hope this helps.

The National Electricity Market (NEM) connects QLD, NSW (ACT), VIC, TAS and SA, the regions connected by 'interconnectors'.

The market is a pool of energy into which generators supply and from which users demand. Obvious but worth stating, electricity cannot be sent bilaterally from supply to demand. It is supplied to and drawn from the grid at the prevailing price.

Each region (state) has its own price and it is set every five minutes.

The price is set at the point where demand lies in the order of offers to generate, given network 'constraints'.

Constraints are either physical network or plant outages, or theoretical limits that are imposed in order to maintain system stabilty (more on this later).

The 'system' and the market are controlled by a government and privately owned body, AEMO, under legislation.

AEMO forecasts demand, generators submit their offers, and AEMO schedules the generators to run at specific output, generally in price order. Often constraints dictate that generation is scheduled out of price order.

Generation is categorised as 'scheduled' or 'unscheduled', depending on size and whether or not it's synchonous (big, momentous copper wires spinning at grid frequency, or things like wind spinning at varying rates).

Unscheduled generation is fickle and by definition not scheduled by AEMO. You cannot turn it on and off or up and down at will.

AEMO's first priority, by legislation, is system stability, and constraints are one of the tools used to maintain it.

The other major tool is the scheduling of frequency control services (FCAS). Essentially, FCAS is provided by scheduled generators and is also dispatched in price order.

As SA's coal fired plants have shut down over the last few years, FCAS services were increasingly supplied to it via the interconnectors. Further, the proportional increase of wind and solar gave rise to the need for more FCAS.

AEMO have been concerned about a system black event in SA for a few years now. It has been a regular topic of discussion between it and the power industry.

In the last 12 months, AEMO have invoked local SA FCAS constraints when the interconnectors (or parts of) have been out of service. This gave rise to FCAS price events several orders of magnitude higher than in the past and the market has since responded by installing more gas-fired FCAS capacity.

So SA now has sufficient gas-fired FCAS available, but the units are not always running because wind often displaces them in the energy market.

AEMO also uses constraints to manage 'credible contingencies', ie the significant loss of generation, load or transmission equipment.

As an example, if the largest generator supplying SA was a 400MW gas plant, it would likely constrain it to lower output (ie schedule it for fewer MW) in order to induce more energy from elsewhere in the grid and therefore be able to ramp that generator back up should a credible contingency event actually occur.

On the day of the SA storms, ~50% of its energy was supplied by wind, ~30% by the interconnectors and the rest by scheduled SA generators.

Wind turbines are designed to switch off at certain speeds by turning away from the wind.

It seems the same wind event knocked over lines and forced wind generation off. This sudden drop in supply and/or frequency disturbance caused the Heywood interconnector to trip (as it should).

It is academic as to whether the lines or the wind went down first because one did not cause the other.

What nobody has yet asked is why, given a forecast 50 year storm event, the loss of large chunks of wind generation and transmission and therefore the loss of the Heywood interconnector, was not classified as a credible contingency.

It seems to me the Heywood interconnector should have been constrained down in order for it to be able to take the surges to which it was likely to be subjected.

Thanks for that very clear explanation, which seems to me to support the argument that management issues were a big factor in what happened as the system failed to manage the natural disaster.
Now there are two inquiries:
https://www.theguardian.com/environm...-to-close-them


Sent from my GT-P5210 using AULRO mobile app

Originally Posted by DiscoMick

Thanks for that very clear explanation, which seems to me to support the argument that management issues were a big factor in what happened as the system failed to manage the natural disaster.
Now there are two inquiries:
https://www.theguardian.com/environm...-to-close-them


Sent from my GT-P5210 using AULRO mobile app

60% say green energy is the answer.....but no one knows how

Yes...as a SA resident and someone who knows nothing about the complexities of the above....that has been my question all along...WHY weren't backups in place. The forecasters were on TV for a couple of nights prior to this storm, stating categorically that it was going to be a MAJOR storm, possibly one in 50yrs.

On the night, we had power restored about 8pm, obviously once they had fired up the back ups. WHY were the backups not idling along prior, in anticipation.

My cynical and suspicious answer would be...cost. Very poor planning in my uninformed opinion.