NSW grid struggles as coal goes missing after bad trips

The bad week for coal power in the eastern states continued on Friday, with the multiple trips of coal generators earlier in the week extending to an absence of more than 4,700MW of coal units in NSW grid, sending wholesale prices soaring.

The Australian Energy Market Operator issued a “lack of reserve” forecast for NSW on Friday for the fifth consecutive day. On two of those days – Tuesday and Thursday – the AEMO declared “actual LOR2” conditions, which means if one more big coal unit was to trip, then load shedding would be likely.

LOR2 conditions are also normally a trigger for the Murdoch media and conservative commentators to go into melt-down over the perilous state of the grid.

And in doing so they rarely fail to mention the insidious dangers of the left-wing greenie plot/scam/hoax/conspiracy to impose wind and solar on an unwilling population, in the name of doing something on climate change that is not happening/not our fault/can’t be stopped/not worth worrying about.But the events in NSW and elsewhere on the east coast this week are all about coal. The first LOR2 appears to have followed trips from two units at Liddell, the ageing clunker of a coal-fired generator that the federal government demands to be kept running in the interest of grid reliability.

On Wednesday, there was a spectacular cascade of unit trips from coal and gas generators in Queensland and Victoria (top graph – courtesy of Climate and Energy College) that took out 1,400MW of capacity without notice.

And on Friday, there were coal units down all over the place in NSW as AEMO issued another LOR2 warning for the most coal dependent grid in the world, and later relaxed that to a possible LOR1 as Snowy and gas generators fired up.

According to Fairfax Media, the Tomago aluminium smelter said it had been forced to halt each of three potlines this week – one on Tuesday and two on Thursday – because of a lack of reserve across the grid serving eastern states.

Matt Howell, Tomago’s chief executive, told Fairfax Media on Friday lunchtime, the company was concerned it may face another curtailment of operations later in the day.  Tomago accounts for about a tenth of the state’s electricity use.

The nearby Bayswater coal generator had three units out, the Liddell coal generator had one unit out and another struggling to reach full capacity, the Mt Piper coal generator had one of its two units out, and the Vales Point coal generator also had one of its two units out.

In all, there was approximately 4700MW of coal units in NSW that were not generating as prices soared to the market cap on Thursday and remained around $300/MWh for much of Friday. That’s out of a total registered capacity of 10,240MW, and demand of under 10GW.

AGL Energy had more than 1000MW missing from Liddell at one stage, and just over 2000MW missing from Bayswater.

That must have seemed like a lost opportunity for the country’s biggest coal generator given that wholesale prices were averaging around $300/MWh in the middle of the day, after spiking to the market cap of $14,200/MWh twice on Thursday evening.