The future of energy generation and storage

[Smurf1976]

Update on the situation in NSW and SA.

NSW:

Present load is 13,994 MW with the peak now forecast at about 14,114 so 120 MW above the present level.

Generation in NSW is producing 12,663 MW with a further 374 MW available.

Supply from Qld into NSW is running at 1014 MW with a further 145 MW available for supply to NSW.

Supply from Vic to NSW is running at 298 MW which is the limit under present circumstances.

So overall there's a spare 519 MW and that looks likely to drop to about 400 MW as demand peaks shortly. So long as nothing breaks down the lights will stay on. But it would only take a single generation failure to lead to load shedding straight away - that's definitely possible but the odds are that it won't happen (things break, that's a given, but the odds of it happening in the next hour or two aren't that high).

For the generation running within NSW it's presently 69% from coal, 21% hydro, 6.5% gas, 2.5% wind, 1% large scale solar, 0.1% oil. Most of the unused capacity is gas-fired.

All figures above relate to large scale generation (that is, power stations) only and do not include electricity produced at places where power generation is not the primary activity. Most significantly this is rooftop solar systems on houses plus some minor things like landfill gas, co-generation power + hot water systems in hospitals and so on. Production from small scale solar (households etc) is estimated at 271 MW in NSW presently.

Price is presently $12,915 / MWh in NSW which is extremely high.

SA:

Present load is 2749 MW with the peak forecast at 2790 MW so 41 MW above present demand.

SA generation is running at 2141 MW with a further 388 MW available.

Supply from Vic to SA is running at 622 MW which is the limit of what's available under present circumstances.

So it would need two generation failures, or alternatively a loss of the Vic - SA link, to put the lights out in SA today. Possible but unlikely in practice.

Price is presently $442 / MWh in SA.

Of the generation running in SA it's presently 83% gas, 11% wind, 6% oil.

Not included is small scale generation (household solar etc) which for SA is presently estimated at 231 MW.

A note about price - I've mentioned the current wholesale spot price for both states but it's highly volatile under the present circumstances and jumping around massively.

 

[SirRumpole]

AGL cuts power to aluminium smelter to avoid mass power outages across NSW

http://www.abc.net.au/news/2017-02-10/nsw-aluminium-smelter-power-down-amid-outage-concerns/8260830

 

[Smurf1976]

I take it there would be no barrier to governments either State or Federal building and running power stations to add to the supply and therefore stabilise prices ?

There's no physical or legal barrier, just an ideological one depending on the state in question.

That said, market rules do require that any government owned power station compete on the same basis as anyone else. Using Tasmania (Hydro Tas is 100% government owned), Hydro most certainly isn't protected from competition. Bid too high and we'll have plenty of power flowing from Vic to Tas just like that. Bid lower than those in other states and the reverse will occur. And if someone wants to build a power station down here and compete then Hydro can't stop them.

So government can certainly be in the power industry if they want to under present market rules but they have to compete against everyone else.

The only real advantage government has is that they could, of course, change the rules if they wanted to. But then the private operators do propose rule changes from time to time, some of which have been implemented, but government could of course just ram if through if they really wanted to whereas a private operator can't do that.

 

[Smurf1976]

It seems that we do indeed have load shedding in NSW, AEMO has issued a direction to cut 310 MW.

Tallawarra power station (gas) stopped generating shortly before the situation arose. Was generating 408 MW then went to zero. Reason unknown (to me) at the present time but presumably something broke.

Also one unit has become unavailable at Colongra (gas).

Also Eraring (coal) seems to be struggling a bit in terms of output although everything's running as such.

Good ole Murphy strikes again. If it can go wrong then it will go wrong at precisely the worst time.

 

[Smurf1976]

Not to clarify - in terms of what changed, it was the sudden failure of Tallawarra power station plus one unit at Colongra.

The constraints at Eraring were already accounted for in the figures I posted previously saying that everything would probably be OK.

Tallawarra was running at almost full load when it tripped.

Colongra was not running at the time, itself accounting for much of the spare capacity, but 1 of the 4 units hasn't been able to be started it seems. Was running earlier today, then shut down as not needed, then it seems unable to restart. The other 3 are now running at full capacity. These 4 units are all open cycle gas turbines which can be started quickly, hence didn't need to be kept running all day etc.

Underlying cause is unknown (to me) in both cases. Quite likely those on site haven't worked it out yet either given it just happened (well, not unless the cause is fairly obvious).

 

[Smurf1976]

All back to normal now. Well, AEMO has ended the load shedding direction at least so presumably the smelter is back on (can't confirm if they're actually back on but AEMO doesn't require them to be without power).

Tallawarra power station now restarting and ramping up.

Tomorrow looks much the same as today with only 338 MW to spare in NSW. So if anything breaks, as it did today, then it's load shedding again. No problem if everything works.

 

[SirRumpole]

It seems like breakages are a fairly regular occurrence.

 

[McLovin]

It seems like breakages are a fairly regular occurrence.

Yeah I'm surprised. Smurf how often do these plants go offline? When I fire up the (coal fired) Weber it works every time.

 

[Smurf1976]

The fact that the system works as described in the first paragraph amazes me.

It's easier than it sounds.

In an AC power system (what the grid is) all generators will be at the same frequency. If something drops offline then anything and everything that isn't already maxed out can and will respond as system frequency falls from where it ought to be (ideally 50.00 Hz).

Qld, NSW, Vic, SA are all linked via AC transmission lines so they're effectively the same grid. There's also a DC line between Qld and NSW and between Vic and SA - those transfer additional energy but don't directly do anything with frequency by virtue of being DC (which has on inherent frequency at all).

Vic - Tas link is DC so the Tas system isn't frequency locked to the other states. But the link can certainly transfer the effects of a generation failure, either in Tas or another state, by adjusting energy flow. Eg a generator fails in NSW so that directly affects the Qld, NSW, Vic, SA AC system. Basslink can then send more power north thus dumping some of that load onto the Tas system and bringing about the same response of generators operating below capacity increasing their output so as to maintain system frequency.

It's actually easier than it sounds for the AC system. Where DC links are involved it's more complex but ultimately works since a DC link is still AC at both ends where it interfaces with the rest of the grid. AC in, converted to DC, sent across the link, converted back to AC at the other end. Works in practice although the complexity does mean there's more that can go wrong.

Ofcourse everyone in the industry knows it, but wouldn't large scale storage of electrical energy be awesome, imagine if we could store 3 days of power, and power plants just had to run at their most efficient work / maintenance cycles just to keep the battery topped up.

If anyone can work that out then they'll be the richest person on earth real quick. Either that or someone will buy them out and bury the idea. Or shoot them.

Electricity is very different to any other "commodity" for the simple reason that it cannot at present be stored as such. You can store the means to produce it, eg you can have a stockpile of coal or you can have water in a dam, but you can't store electricity as such. Even a battery is really just a means of production - look inside and you'll see plenty of metal and chemicals but not electricity as such.

Hence there's an immediate problem if the means of production can't keep up with the quantity being consumed in real time.

When AEMO, government or anyone else talks about electricity "reserves" what they really mean is spare capacity to produce it. Power station(s) that aren't needed to be running at full capacity but are ready to ramp up if needed. That's the "reserve" they're talking about - there being no store of electricity as such. Literally it's zero.

 

[Smurf1976]

Yeah I'm surprised. Smurf how often do these plants go offline?

So far as unplanned failures are concerned, well there have been two separate incidents in NSW this week of plant that was running just fine until suddenly it wasn't running at all.

Then we could go for many weeks without a single incident anywhere in Australia.

So it's a bit hard to say when a failure might occur, the one tonight certainly took me by surprise just after I posted that all should be fine, but they do happen.

A related risk is that the "shock" to the rest of the system causes something else to fail immediately (seconds) after the first failure. Something isn't quite right, gets a sudden wobble in system frequency and down it goes.

Standard practice in Australia has always been to keep enough spare plant online ("spinning reserve" in industry speak) to immediately cover the sudden loss of the two largest generating units in service. That's done on a state by state basis given the limited capacity of the interconnectors between states (and the risk that the failure might be the link itself rather than a generator).

Trouble is that NSW, Vic and SA are all in the position at times of simply not having enough capacity to be able to keep some spare whilst still supplying all consumers. Hence the load shedding in NSW today once Tallawarra suddenly shut down.

Other states don't have that problem, they have sufficient capacity, so they do have adequate spinning reserves in case something fails.

In Tas we have a more complex system than elsewhere on account of having a few individual loads and an individual point of supply (Basslink when flow is southbound) which are very large relative to total load on the grid. Worst case, middle of the night with mild weather, we can have 45% of total supply coming from a single source (Basslink) and 30% of total load being used in a single very large factory. Sudden failure of either that supply or load would be a huge "jolt" to the rest of the system so there's some "smarts" to deal with that risk which are in addition to the standard industry approach which is effectively a second line of defence in this case. No such problem in other states since they don't have such individually large loads or sources of supply relative to their total system size.

 

[Smurf1976]

It seems like breakages are a fairly regular occurrence.

Plant outages in the NEM states. This info is from yesterday.

Qld:
Gladstone Unit 3 (coal, 275 MW each unit) out of service.

Swanbank E (gas, 385 MW) withdrawn from the market for economic reasons (nothing wrong with it, just unprofitable to run it).

NSW:
Some reduction in capacity in the Upper Tumut (1 & 2) (hydro) stations but mostly still available.

Liddell (coal, 500 MW each) Units 2 & 4 unavailable - that's 1000 MW and highly significant.

Later today (during the peak) problems occurred at Tallawarra (gas, 420 MW) and Unit 1 at Colongra (gas, 181 MW).

Vic:
Loy Yang A (coal, 560 MW for this unit) Unit 4 out of service.

Some reduction in capacty of the Murray (hydro) stations but mostly still available.

Bairnsdale (gas, 42 MW each unit) Unit 2 out of service.

SA:
Torrens Island A (gas, 120 MW each unit) Unit 1 out of service

Port Lincoln (oil, 25 MW each unit) Unit 3 out of service

Snuggery (oil, 21 MW each unit) one unit out of service

Pelican Point (gas, 234 MW for half the station) half capacity withdrawn from the market for economic reasons (nothing wrong with it, just uneconomic to operate although AEMO did order them to run it for a period).

Tas:
Reece (hydro, 119 MW each machine) Unit 2 out of service. Planned major maintenance.

Fisher (hydro, 46 MW) power station out of service (single machine station). Planned major maintenance.

Liapootah (hydro, 29 MW each machine) two (of three) machines out of service. Planned major maintenance.

Wayatinah (hydro, 13 MW each machine) two (of three) machines) out of service. Planned major maintenance.

Tungatinah (hydro, 25 MW each machine) one (of five) machines out of service. Planned as part of major upgrade of the whole station done progressively.

Cluny (hydro, 17 MW) power station out of service. Planned major upgrade.

Wilmot (hydro, 32 MW) power station out of service (single machine station). Planned maintenance.

Poatina (hydro, 57 MW each machine) one (of six) machines out of service. Planned maintenance.

Trevallyn (hydro, 20 MW for this machine, not all are the same size) one (of four) machines out of service. Planned maintenance.

Bell Bay Three (gas, 20 MW per gas turbine / 40 MW each generator) - operating with three (of six) gas turbines which drive 3 actual generators (two turbines per generator). Major overhaul to extend life and improve reliability.

Paloona (hydro, 28 MW) power station out of service (single machine station). Major outage due to problems (will be back in service in due course once fixed).

 

[Value Collector]

Thanks for the info smurf,

So does running the system to its limit such as this create a need for a higher mantenance outages in the coming weeks, I mean is there a limit to how many high demand days we can have before the plants start dropping like flies requiring work.

 

[Smurf1976]

Running a plant flat out generally won't cause it to break but ultimately maintenance has to be done.

The maintenance strategy varies between companies considerably (run it into the ground at one extreme through to keeping it in top condition at the other) and also varies between coal versus gas or hydro.

That said, there would almost certainly be someone deferring maintenance on something right now given the situation. A point comes where either they do it or failure occurs so you're right in thinking that available capacity would drop if it isn't done.

How quickly it would happen is hard to predict since only AGL (for example) really knows what's going on at the generation they own. Same with every other company.

Broadly speaking, planned maintenance of coal and gas plant focuses on autumn and spring when demand is lower and price spikes are less likely.

For hydro plant it's more complex given seasonal inflow variations and in some cases a need to release water for irrigation etc. If the storage capacity is limited then the preferred time for an outage is when it's dry so as to minimise spill and generation loss. If the storage is large and won't spill then it comes down to demand, market prices and the physical availability of generation from other sources.

Likewise if you're burning agricultural waste as the fuel (done on a modest scale in Qld) then you need the plant running when there's a constant stream of truck turning up with the waste.

Likewise if there was a need to take a solar farm offline then winter would make sense simply to minimise the loss of production.

Another factor is managing the workforce or contractors if you've got multiple generating units at the same site or close by. Can't do everything at once even if that makes sense in other ways.

Also portfolio risk is another one. If your plant in Vic breaks down then you wouldn't sensibly choose to shut your plant in NSW at the same time unless you really had to or had covered yourself financially via contracts with someone else in case the spot price spikes. So there's company financial risk in addition to the overall physical supply issues.

 

[Smurf1976]

Additional comment regarding plant outages.

The plant offline in Qld is not limiting Qld's ability to send power to NSW since the constraint is the capacity of the transmission lines. With the present plant availability in Qld, there's enough to run the lines to NSW at full capacity whilst still supplying all load in Qld.

Same in Tasmania but for a different reason, that being that system load in Tas peaks during Winter and is far lower in Summer. Hence having so much plant offline for maintenance at the moment - that's intentional since this is the best time of year to do it. We can still fully load Basslink for supply to Vic during the peaks if required. Worst case, if demand was higher than usual in Tas and there was no wind then we'd have to fire the gas turbines up in order to run Basslink at maximum if Vic needed the power but the capacity to do so is available as such.

It's a different situation for NSW and SA however. Neither state would have had their recent load shedding incidents if all generating plant had been available so there's a direct impact there.

The plant offline in Vic has had no impact in practice, it hasn't limited the ability to send power to SA or NSW since the transmission lines are the constraint, but it would have an impact if demand in Victoria had been higher than it has been.

Update on present situation in NSW is that it's almost exactly comparable to yesterday. There's sufficient supply provided that nothing goes wrong. Probably it won't go wrong but as happened yesterday the risk is definitely there between about 16:00 and 19:30 today (Sydney time).

After today, no problems currently expected in any state for at least the next week.

 

[noco]

Additional comment regarding plant outages.

The plant offline in Qld is not limiting Qld's ability to send power to NSW since the constraint is the capacity of the transmission lines. With the present plant availability in Qld, there's enough to run the lines to NSW at full capacity whilst still supplying all load in Qld.

Same in Tasmania but for a different reason, that being that system load in Tas peaks during Winter and is far lower in Summer. Hence having so much plant offline for maintenance at the moment - that's intentional since this is the best time of year to do it. We can still fully load Basslink for supply to Vic during the peaks if required. Worst case, if demand was higher than usual in Tas and there was no wind then we'd have to fire the gas turbines up in order to run Basslink at maximum if Vic needed the power but the capacity to do so is available as such.

It's a different situation for NSW and SA however. Neither state would have had their recent load shedding incidents if all generating plant had been available so there's a direct impact there.

The plant offline in Vic has had no impact in practice, it hasn't limited the ability to send power to SA or NSW since the transmission lines are the constraint, but it would have an impact if demand in Victoria had been higher than it has been.

Update on present situation in NSW is that it's almost exactly comparable to yesterday. There's sufficient supply provided that nothing goes wrong. Probably it won't go wrong but as happened yesterday the risk is definitely there between about 16:00 and 19:30 today (Sydney time).

After today, no problems currently expected in any state for at least the next week.

Smurf, you have written some great article on the subject of power production and can always speak with authority that most of us appreciate.

I would like to know your opinion on renewable energy, whether it should be increased of should we be considering more oil or coal fired base load power stations to be able to always meet demand in hot weather conditions currently being experienced

 

[Tisme]

I don't know why there is any notion that coal fired stations will continue into the future: the current owners are shutting down the ones that exist and there is no financial incentive to build privately owned new ones.

It's pretty much flogging a dead horse to death. NEMMCO and it's successor AEMO have failed their duty and allowed financial gain to override best practice.

 

[SirRumpole]

and there is no financial incentive to build privately owned new ones.

There will be a financial incentive after Turnbull and Morrison raid the Clean Energy Fund.

 

[Tisme]

There will be a financial incentive after Turnbull and Morrison raid the Clean Energy Fund.

All those voters who cheered on the sale of state essential services are probably the ones who are now throwing tanties at the SA govt or cheering on Malcolm or both. If the LNP had a second term in QLD we'd all be in worse shape, because Campbell Newman wanted to 99 year lease the whole shop to multinationals. QLD has 1000 megawatt buffer/reserve.

SA's power generation is wholly privatised so why is the govt to blame for price gouging and idle generators ... because family indoctrinated dumb voters are too busy adulating their political champions instead of holding the real culpable leaders and our **** stirring PM to account for the outrageous claims.

The Senate inquiry two days ago found and laid the blame at the feet of the grid operators. Whose jursidiction is grid operator, being a cross border agency?

 

[SirRumpole]

All those voters who cheered on the sale of state essential services are probably the ones who are now throwing tanties at the SA govt or cheering on Malcolm or both. If the LNP had a second term in QLD we'd all be in worse shape, because Campbell Newman wanted to 99 year lease the whole shop to multinationals. QLD has 1000 megawatt buffer/reserve.

SA's power generation is wholly privatised so why is the govt to blame for price gouging and idle generators ... because family indoctrinated dumb voters are too busy adulating their political champions instead of holding the real culpable leaders and our **** stirring PM to account for the outrageous claims.

The Senate inquiry two days ago found and laid the blame at the feet of the grid operators. Whose jursidiction is grid operator, being a cross border agency?

I couldn't agree more. I shuddered when the NSW Labor government under Morris Iemma and Treasurer Michael Costa first mooted selling off public electricity assets, and now the Baird government has finished it off. AS electricity consumers we are worse off, but I put most of the blame on Abbott/Hockey/Morrison for insisting on "asset recycling" before the States get any more Federal money for infrastructure.

 

[noco]

I couldn't agree more. I shuddered when the NSW Labor government under Morris Iemma and Treasurer Michael Costa first mooted selling off public electricity assets, and now the Baird government has finished it off. AS electricity consumers we are worse off, but I put most of the blame on Abbott/Hockey/Morrison for insisting on "asset recycling" before the States get any more Federal money for infrastructure.

And the South Australians are worse off again due to the poor policies of Wetherill..