Industry sources, not authorised to speak publicly about internal discussions, confirmed meetings were held last week about the severity of the situation and there was now a “consensus” that at least one coal plant was likely to close its doors in response to unsustainable prices and spiralling losses.
For those not familiar with the technical aspects I'll add that a closure doesn't have to be absolute.
Most thermal (fuel burning) power stations are comprised of multiple complete sets of generating equipment (in industry terminology simply "units") which operate independently of each other.
It's not out of the question to close some units at a power station and not others, thus retaining it as a working site just with a lesser workforce and other costs.
Also it's not impossible to mothball plant rather than outright closing, thus retaining the option to resume operations if required.
Another variant on that is seasonal operation. In practice that means simply shutting down at the end of the highest demand period and simply not intending to run again until some later time.
Another variant is to take a 4 unit station (most large thermal power stations are 2 or 4 units in practice although other numbers do exist) and deliberately run it as a "firm" 2 units. That is, keep them all able to operate but only run two at a time - if one breaks down or needs to be taken off for maintenance then put another one on. That effectively means you've got a 2 unit station but it's 100% reliable - which then means you don't need to financially take risk or hedge against failure when you've got your own backup sitting there.
So there's quite a few options available apart from the obvious one of outright total closure.
Some past examples:
Hazelwood (Vic, closed 2017) comprised 8 separate generating units. During the 1990's one was left unrepaired following a major failure, two others were mothballed and another was used only as backup to the 4 that were being run. So a combination of deferring maintenance, mothballing and deliberately running only 4 of the available 5 units. When demand and prices picked up, all were progressively put back into full operation. Capacity was 200 MW per unit, coal-fired steam.
Newport D (Vic, still operational) is a single unit station with gas-fired boiler. It was mothballed completely for a couple of years ~ 20 years ago. Capacity is 500 MW, gas-fired steam (oil-fired backup).
Munmorah (NSW, closed) originally comprised 4 units. Two were shut circa 1990, the other two were run until mothballing in 2010 and final closure in 2012. Units were 350 MW each, coal-fired steam.
Bell Bay (Tas, closed 2009) had both units mothballed in 1991, returned both to operational status in 1998 without any real operation apart from a test run, then operated intermittently from 1999 through to closure of unit 1 in 2008 and unit 2 in 2009. Units were 120 MW each, gas-fired steam plant (oil-fired prior to conversion 2002 and 2003).
At present, Torrens Island A (SA, owned by AGL) has units 2 & 4 mothballed and units 1 & 3 still in operation, with plans to mothball unit 1 later this year and to mothball unit 3 and thus the entire station in 2022. That's mothballing not outright closure though, a return to operation at a future time would need staff and a thorough inspection of the plant but as with Bell Bay it could be done.
Also at present AETV (a subsidiary of Hydro Tasmania) has mothballed the Tamar Valley CCGT plant, last operation being May 2019, but continues to operate other gas-fired generation at the same site. Mothballed plant is a 208 MW CCGT (gas-fired only). Operating plant is 1 x 58 MW and 3 x 40 MW open cycle (gas / diesel fired) although in practice they're really only used as backup anyway.
Swanbank E (Qld, still operational) was mothballed in 2014 and resumed operation late 2017. Capacity 385 MW (gas-fired CCGT) although for the record the current owners have recently written it's value down to zero.
So quite a few precedents there for temporary or partial closures.
In all of that, I'll draw particular attention to the idea of mothballing or closing part of a facility but keeping part of it open or alternatively shifting to intermittent operation. Those ideas are certainly around at the moment.
Another one to mention is that the commissioning of 4 large synchronous condensers in SA soon will reduce the amount of gas-fired generation required on at a minimum. Economically that becomes simply supply and demand with a reduction in "forced" supply. Eg right now that is the case, there's 255 MW of gas running in SA at a market price that wouldn't cover even a third of the gas cost to run it. Technically essential at present but financially a dead loss.
Also I'll mention that there's the already announced Liddell closure (NSW, AGL, 2022 and 2023), the mothballing of the remaining two units at Torrens Island A (SA, AGL, 2021 and 22) and the closure of Osborne (SA, Origin, end of 2023). They could plausibly be brought forward as a relatively easy option.
On the other side of all that, there's the very real problem that NSW and Vic simply don't have adequate peak generating capacity without the coal plants. All good when it's windy or sunny, but when it isn't? There's simply no way that existing non-coal facilities could cope, not even close.
Something new could be built sure, hydro, gas or batteries, but right now that something hasn't actually been built and does not exist. That reality creates quite a problem for government if a coal plant owner does pull the pin since blackouts don't help a government get re-elected.
Solar owners in SA could be in for a shock too since on a rolling 12 month basis the average spot market value of their output has now dropped below $10 / MWh (one cent per kilowatt hour). That could get "interesting" to say the least.....
Ultimately though the electricity industry isn't going out of business, just through a massive shakeup in how business is done.
SA with 61% from wind and solar over the past 12 months is, so far as I'm aware, the actual world leader so far as any major power system in a developed country being run from wind and solar is concerned. I'll stand corrected if that's not the case, but it's definitely what many do understand to be true.
61% from wind and solar but just one point - more than 90% of all electricity consumed is still purchased from an electricity company. The vast majority of wind and solar production is ultimately put into the grid and sold to someone via the likes of Alinta, AGL, Energy Australia, Engie, Origin and so on.
Individual companies might fail and in due course the coal power stations will close one by one but the electricity industry as a whole isn't going away, indeed with the likely transition to electric transport the future is ultimately one of growth not shrinkage.