The future of energy generation and storage

For reference, list of coal plant in the NEM (in order of age within states):

Qld:

Gladstone - 1680 MW owned primarily by a joint venture of Rio Tinto and NRG Energy and 10% by an assortment of other minor owners. Commissioned 1976.

Tarong - 1400 MW owned by Stanwell Corporation. Commissioned 1984.

Callide B - 700 MW owned by CS Energy. Commissioned 1988.

Stanwell - 1400 MW owned by Stanwell Corporation. Commissioned 1993. Trivia: For a period until 2021 Unit 4 held a world record, 1073 days' continuous uninterrupted operation.

Callide C - 840 MW owned 50 / 50 by CS Energy and Intergen with CS Energy as operator. Commissioned 2001.

Millmerran - 850 MW owned by Intergen. Commissioned 2002.

Tarong North - 443 MW owned 50 / 50 by by Stanwell Corporation and TM Energy with Stanwell as the operator. Commissioned 2003.

Kogan Creek - 750 MW owned by CS Energy. Commissioned 2007. Notable feature is it's air cooled.

Note: Stanwell Corporation and CS Energy are both 100% owned by the Queensland state government.

NSW:

Liddell - 1260 MW owned by AGL. Commissioned in 1971 with one of the original 4 units closed in April 2022.

Vales Point B - 1320 MW owned by Delta Electricity. Commissioned in 1979. Trivia: Vales Point A (now closed) and B power stations feature prominently in a Midnight Oil music video:
Eraring - 2880 MW + 40 MW from a separate diesel-fired gas turbine at the site owned by Origin Energy. Commissioned 1982.

Bayswater - 2740 MW owned by AGL. Commissioned 1985/86.

Mt Piper - 1430 MW owned by Energy Australia. Commissioned 1993 with the recent addition of a separate boiler fuelled by processed refuse, raising capacity of unit 1 by 30 MW.

Redbank - 151 MW owned by Verdant Technologies Australia. Commissioned in 2001 the plant is not presently in operation however there are various plans to resume operations, most likely using biomass rather than coal as the fuel. This facility uses fluidised bed combustion rather than conventional pulverised fuel boilers.

Victoria:

Yallourn (formerly known as Yallourn W) - 1480 MW owned by Energy Australia. Built as two separate projects with commissioning 1973/75 and second stage 1981.

Loy Yang A - 2210 MW owned by AGL. Commissioned 1984.

Loy Yang B - 1160 MW owned by Alinta. Commissioned 1993.

Note that despite separate owners, Loy Yang A & B are at the same site and both exclusively use coal from the Loy Yang mine operated by AGL.

Loy Yang B station was only ever half built and on the unused land sits another power station, Valley Power, a gas turbine plant owned by Snowy Hydro. Its location being due to having been originally built by the former owners of Loy Yang B in 2001/02. As a bit more trivia, Valley Power is actually comprised of 6 generating units, 50 MW each, relocated from the former Stratford and Whirinaki power stations in New Zealand originally built 1976 and 1978 respectively.

To clarify the issues around power generation, without wanting to take the thread too far off the EV topic, the basic issues are in brief:

Coal plant is flexible in operation only up to a point. It varies between facilities but the lower limit is 30 - 55% of maximum output for in service plant in Australia. That is, operation is limited to the 30 - 100% or 55 - 100% range. Etc, the precise figures vary and depend heavily on the coal quality.

Below that four basic options:

1. Dump steam. That comes with issues of using up demineralised water and is also a total waste of fuel burned, it's just a means to keep coal going in and the boiler on without electricity coming out and is not something intended for routine use.

2. Use high grade auxiliary fuel to enable a lower output (but still won't get below 20% of maximum rating). At one facility the oil torches are lit to achieve that and burn about 140 litres per minute. That gets expensive rather quickly.

3. Shutdown and restart. That comes with costs in terms of wasted fuel but more so in that each time plant is pressure and temperature cycled that adds wear. Surest way to know someone's decided to close a coal plant and is just getting the last worthwhile use out of it is if they've started daily or even twice daily cycling of it. That's thrashing the proverbial out of it in terms of wearing it out such that closure becomes inevitable.

4. Remain online at minimum output by offering extremely low prices, negative in practice, to the market. That's paying someone to take the output yes, it's less than giving it away but avoids the need to physically do anything at the plant. The idea being that someone else blinks first and shuts down.

The other side of all this is the economics.

Coal plant is costly to build and has high fixed costs to retain in operational condition but it's relatively cheaper to operate, per unit of output, than other fuel burning plant. That's especially so in the context of coal plant using coal that's below export grade or which has no physical means of being traded (mine next to the power station etc) in which case the cost of operation is extremely low.

In contrast gas turbines are relatively cheap to build, don't cost much to just have sitting there but they're rather more costly to operate, extremely so if we're talking about running on liquid fuels or export parity gas. As the joke goes, may as well blow $100 notes up the stack since that's pretty much what it amounts to.

Where the issue arises with wind and solar is simply that the growth of them is intermittently eating into what would otherwise be a stable, constant load on coal-fired generation. Instead of being able to run constantly, it's now a case of needing to ramp up and down. That brings two problems:

1. Having to do one of the 4 things I mentioned in order to deal with low required output.

2. Fewer MWh sold at a profit from which fixed costs can be recovered.

So costs go up and revenue goes down. Put the two together and that kills the economics in a big way.

As an example of that, in Victoria today prices were generally negative, and coal plant was sitting on its technical minimum output, from around 8am to around 2pm (times rounded for simplicity).

SA also experienced negative pricing during this time with the only fossil fuel generation running being two gas-fired steam units generating at their technical minimum of 40MW each. Those being on as the minimum synchronous generation required under present conditions to maintain system strength (a technical issue I've mentioned previously in this thread but suffice the say the reason is down to engineering considerations not economics, politics or who owns what, it's a strictly technical limit).

The underlying reason reasoning in both states basically being low consumption (Sunday and fairly mild weather in both states) combined with good available output from wind and solar generation.

So what happens?

Transmission flow Vic > NSW and Vic > Tas was at maximum in both cases and that puts some of it to use. At 11am 37% of all consumption in Tasmania was being supplied from Victoria as was 7.7% of consumption in NSW (incl ACT).

But then there's the rest....

At 11am, which I'm referring to simply as being around the middle of the day not literally noon so a representative time not the extreme, available output from wind and solar versus actual production was:

Victoria available = 1833MW
Victoria actual = 1211MW

SA available = 743MW
SA actual = 599MW

Total = 2567MW available of which 1810MW was used and 757MW was curtailed (simply wasted).

Note those figures are for large scale generation only. That is they do not include rooftop solar on houses etc. For reference however output from those at 11am was 1483MW in Victoria and 903MW in SA so 2386MW in total. Those figures are estimates based on scaling up from sample data (since not all systems are directly measured).

So why not just take some of the coal units off completely then? Noting that 9 (of 10) in Victoria were running at the the time. I'll answer that by stating what happened next. All facilities mentioned are in Victoria unless the state is indicated (in brackets).

OCGT = Open Cycle Gas Turbine.

CCGT = Combined Cycle Gas Turbine. More efficient but considerably less flexible.

ICE = Internal Combustion Engine driven plant. They're large ship engines basically just turning an alternator feeding the grid.

13:45 - Coal plant starting to ramp up.

14:25 - Dry Creek unit 3 OCGT (SA) on.

14:35 - Osborne CCGT (SA) on and commenced ramp up.

15:00- Newport, a gas-fired steam plant in Victoria, placed online and starting to ramp up. Gordon hydro (Tas) starting to ramp up.

15:05 - Eildon hydro one unit online.

15:10 - Transmission flow Vic > Tas begins to fall.

15:40 - Poatina hydro (Tas) commences ramping up from very low output to maximum.

15:55 - Gordon hydro (Tas) at maximum.

16:00 - Battery discharge commences in Victoria and SA.

16:10 - Repulse hydro (Tas) ramped up. Barker inlet ICE (SA) on with 10 (of 12) engines on and at full load over next 40 minutes. Torrens Island B units 2 & 4 gas-fired steam plant (SA) commences ramp up (has been on minimum load all day).

16:15 - All 9 operating Victorian coal units now at maximum capacity.

16:20 - Tamar Valley Peaking OCGT (Tas) on.

16:30 - Clover and West Kiewa unit 2 hydro both online. Tasmania - Victoria transmission flow now at zero, reversing from Vic > Tas to Tas > Vic.

16:35 - Tungatinah hydro (Tas) on.

16:40 - Fisher hydro (Tas) ramped up. Hallett OCGT (SA) on.

16:50 - Reece hydro unit 2 (Tas) on.

16:55 - Bairnsdale OCGT one unit on. John Butters hydro (Tas) on.

17:10 - Murray (snowy hydro) on. Cethana hydro (Tas) on. Wilmot hydro (Tas) on. Trevallyn hydro (Tas) ramped up.

17:15 - Osborne CCGT (SA) reaches full output.

17:30 - Quarantine unit 3 OCGT (SA) on.

17:35 - Mackintosh hydro (Tas) on. Transmission flow Tas > Vic at maximum capacity.

17:40 - Basytan hydro (Tas) on.

17:45 - Newport at maximum capacity.

18:15 - Dartmouth hydro on.

18:25 - Bairnsdale OCGT second unit on.

So it's a feast to famine thing and today was in no way unremarkable, indeed with mild weather it's a relatively boring one. A lot more plant than that would be brought on, and more quickly, under harsher conditions - today was a casual stroll through the park basically, it wasn't a race by any means.

But if the coal units weren't kept on, well the lights wouldn't have stayed on and there's the problem. They weren't built to do what's now required with intermittent operation and a relatively fast ramp up being required as the sun gets lower meanwhile consumption goes higher.

What all that looks like (transmission flow between states and removed for simplicity)

Yellow = solar
Green = wind
Dark blue = hydro
Light blue = battery
Orange = gas
Red = diesel
Black = coal
Purple = net import from other states

Below the zero line = battery charging, hydro pumping and export to other states

Red line separate at the bottom = spot price





NSW had no surplus supply issues but I'm posting it since the storing of energy, pumped hydro, is clearly visible as load below the zero line during the middle of the day.

As usual a terrific post @Smurf1976 , the problem today is, everyone is an expert, due to the last article they read on the media, it certainly seems pointless discussing it on the forum.
There are only a couple of people on the forum, who have taken anything from the years of discussion and information.

All the media does is undermine the reality of what needs to be done, by replacing it with white noise, to confuse the general population, it puts more pressure on a system that IMO is stretched to the limit. Yet obviously intelligent people believe the only issue is the market price, if only that was the problem, it would be easy.

Time will tell, let's see how Labor manage it, will they be slammed for subsidising coal, or will they allow them to just shut down?
Like you have said many times, politics really needs to butt out of the electrical system especially at this time, the media should take a much more neutral stance on it IMO, they aren't experts yet put their bias on the content of their articles.
Leave it to the technical experts, not the wordsmiths.

More efficient solar PVT cells.

sptrawler said:

All the media does is undermine the reality of what needs to be done, by replacing it with white noise, to confuse the general population, it puts more pressure on a system that IMO is stretched to the limit.

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I think the point the politicians and media miss is that it will do nobody any favours to have the lights go out.

Labor, Liberal, Greens, National or anyone else, having people sitting in the dark etc or ordered to not use heating when it's cold or to not watch TV is not a vote winner.

My personal view is there'll be a crisis but it probably won't be a purely technical one. Rather, it'll be a financial one and by that I mean either the operators of coal plant simply walk away and government ends up an owner of last resort, being faced with either that or the lights going out, with the other risk being the rising price of trade exposed fuels leads to an electricity price shock to consumers.

The other risk is of old plant suffering a major failure and being uneconomic to repair. Plenty of examples of that worldwide with one that comes to mind being Ironbridge B in the UK, a site somewhat well known due to its very close proximity to a World Heritage site and the power station itself with its distinctive pink cooling towers. Long story short unit 1 suffered a major fire in 2014, it was decided to not repair the 45 year old plant and the rest of the station was closed in 2015.

The risk of that can't be ruled out in the Australian context in my view. Eg Origin have announced the intention to close Eraring and logically there'd be a limit to how much they'd be willing to spend on repairs if anything happened in the meantime given that its fate is already sealed. Not that I'm predicting a major failure there but it can't be ruled out, it's 40 year old plant after all.

Smurf,

Are you aware of any serious proposals to join WA to the east coast grid? This would have to improve the flexibility and resilience of the grid.

I appreciate that the great distances involved would mean very high capital costs, but perhaps this is the sort of nation building project that a federal government should be backing.

Ferret said:

Are you aware of any serious proposals to join WA to the east coast grid?

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The idea's around and proposals have been put forward but at this point in time the big problem is economic.

The shortest possible route between the systems is about 1450km but that results in connection to Kalgoorlie at the WA end and that's an already extremely constrained, far edge of the WA grid situation. Capacity to transmit power from WA to SA would be essentially zero, indeed the ability to simply supply existing load at Kalgoorlie and surrounds does rely on some local generation being in operation, it can't run solely on the single 220kV transmission line connecting it to the rest of the system.


Image source = AEMO and the map is publicly available to anyone. Note the map shows main transmission lines only and does not show the local distribution network fed from it.

To get to a strong point from which to connect with serious capacity requires going most of the way to Perth or alternatively to Muja power station, south of Perth and the point where the blue 220kV line originates from.

That ends up at about 2000km and the problem is simply one of economics versus benefits.

Traditionally south-west WA and SA have both had pretty similar economics for power generation with the use of low grade coal and high reliance on natural gas (and previously oil). There hasn't been a major difference there, it's not as though either state has a great big hydro scheme or something like that.

My personal view is it'll probably happen someday but not for quite a while, it's not the lowest hanging fruit on the tree in terms of cost / benefit ratio. To happen in the short term it would need someone (a politician) to grab hold of it from the "nation building" perspective.

Easier things in the short to medium term in terms of cost / benefit:

SA - NSW interconnection which is actually being built.

Upgrades NSW - Vic and Vic - Tas associated with wind, solar and hydro developments as well as transmission within the states.

Queensland grid to Mt Isa is proposed and that would remove Mt Isa (and surrounds) present reliance on its isolated standalone power system.

Another possibility is the Lake Argyle hydro in WA is now very much underutilised due to closure of the Argyle diamond mine which used the majority of its output. There have been various thoughts and proposals regarding it and it's not something I've really followed given its location but I do note that it's "only" 400km from the existing Darwin-Katherine system, the main power grid in the NT.

Given it's an effectively free power source, since it's already built and costs very little to maintain, it might be worth the cost of the line to use it to replace a portion of the (increasingly expensive) gas used for generation in the NT. Combined with other potential hydro sites in the NT (several have previously been identified) + solar that could effectively replace gas completely.

A substantial presentation likely to interest those following this subject:


It's 80 minutes long and covers a range of topics specifically focused on the NEM although the same concepts do apply to other states especially south-west WA.

The first 10 minutes is a just "this is who we are and here's some advertising from our sponsors" but it gets more serious after that.

Note that the GenInsights21 report referred to is not freely available. Well, it's available as such but it'll cost you $3000 + GST if you want to read it.....

The presentation in the video is free however

There is a good two page article on Snowy 2.0 in todays Financial Review, if anyone is interested. If people took the time to read the article, it would save a lot of baseless arguments in this thread IMO.

From the article:
The article takes the politics out of it and explains the rational behind it, the concept was originally concept started in 1980 and built on since then.
Another interesting quote, "The AEMO estimates that by 2050 without coal fired plant, the national grid will need 45GW and 620GWhs of storage", to keep the grid stable.
Also since the original costing the assumption of a pumping cost of $40/MWHr has dropped to $10-$15 due to the amount of renewables that has since been installed on the system.
When commissioned Snowy 2.0 will be able to inject power into the grid in 90 seconds, currently Tumut takes about 3-3.5 minutes, gas plant takes about 15 minutes.

Smurf1976 said:

A substantial presentation likely to interest those following this subject:


It's 80 minutes long and covers a range of topics specifically focused on the NEM although the same concepts do apply to other states especially south-west WA.

The first 10 minutes is a just "this is who we are and here's some advertising from our sponsors" but it gets more serious after that.

Note that the GenInsights21 report referred to is not freely available. Well, it's available as such but it'll cost you $3000 + GST if you want to read it.....

The presentation in the video is free however

Click to expand...

I certainly hope @SirRumpole @Value Collector , @basilio and @rederob watch that clip from the 10 minute mark, it is a brilliant explanation and thanks @Smurf1976 for posting it.
I see they call plant "scheduled" and "semi scheduled", scheduled being what we on here have been calling "at call" generation and semi scheduled being what we refer to as "renewables". Also remembering coal generators aren't designed to have their load constantly swung around, GT's and batteries are much more suited to that function.
Magic clip smurf.

sptrawler said:

I see they call plant "scheduled" and "semi scheduled"

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For clarification those are AEMO terms.

Scheduled = conventional plant which, unless something fails unexpectedly, has a known definite output it can be dispatched to achieve. So coal, gas, hydro etc.

Semi-scheduled = plant where there's uncertainty and the limit of capacity is a forecast only subject to change beyond the control of any human. Wind and solar in practice.

Non-scheduled = small generating units not centrally dispatched. Mostly rooftop solar and minor sources such as landfill gas but a few others also exist - eg smaller hydro or internal combustion units up to 30 MW each.

Some non-scheduled generators are intentionally aggregated and scheduled. For example the 6 x 15MW hydro machines at Tarraleah power station in Tasmania are dispatched by AEMO as a single 90MW unit as are the 12 x 17.5MW internal combustion engines at Barker Inlet in SA. AEMO dispatches the station as a single generator, Hydro Tas and AGL respectively resolve that in terms of what happens physically with the machines on site.

Someone (not me) has filmed a walk through of Tarraleah PS during a public open day by the looks of it. It's rather noisy yes......


84 years of operation this year, the first 3 machines were commissioned in 1938 (the others being 1943, 1945 and 1951). A check online finds it's running at 74MW right now.

sptrawler said:

I certainly hope @SirRumpole @Value Collector , @basilio and @rederob watch that clip from the 10 minute mark, it is a brilliant explanation and thanks @Smurf1976 for posting it.
I see they call plant "scheduled" and "semi scheduled", scheduled being what we on here have been calling "at call" generation and semi scheduled being what we refer to as "renewables". Also remembering coal generators aren't designed to have their load constantly swung around, GT's and batteries are much more suited to that function.
Magic clip smurf.

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Are you suggesting I've been spreading misinformation ?

SirRumpole said:

Are you suggesting I've been spreading misinformation ?

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No, in your case, I actually did think you would find it interesting. You've always shown an interest in the subject and had an open mind about it.

SirRumpole said:

Are you suggesting I've been spreading misinformation ?

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Not you no.

There's a lot of it around in the general community however and it really frustrates those involved.

The main ones being the two extremes.

One is the claim that solar and wind can do the lot and it's all dead easy but which fails to mention any of the real world complexity and requirements to making it work. There's some very real challenges to it all - it seems doable but it's not as simple as just installing wind and solar farms and that's it.

Then there's the other extreme, those who say it can't be done. Had they been alive at the time those same people would probably have ridiculed the idea of aircraft, sound recording and even the bicycle too.

The mainstream media and politics has done much to unnecessarily confuse the population about all this in my view.

Would you say that in Europe where, unlike Australia, the ability of renewables to provide power is quite constrained (less solar radiation, higher density of people so wind power incapable of providing load) that Nuclear power will likely be necessary if a low carbon power system is to be reality by their timelines of 2030?

Knobby22 said:

Would you say that in Europe where, unlike Australia, the ability of renewables to provide power is quite constrained (less solar radiation, higher density of people so wind power incapable of providing load) that Nuclear power will likely be necessary if a low carbon power system is to be reality by their timelines of 2030?

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My guess, absolutely, we have a tiny grid compared to Europe.
Also they are already heavily dependent on Frances nuclear and Russia's gas, yet have a huge amount of renewables already installed.
The amount of pumped hydro required would be huge and would take a considerable amount of time to build. But in the next few years we will know, because Germany has to lower its dependence on Russia's gas, how they do that will paint the picture.
From google:
With a population of around 740 million inhabitants, or roughly ten percent of the global population, Europe is one of the world's largest electricity consumers. In 2018, Europeans consumed approximately four petawatt hours, roughly the same consumption of Africa, Eurasia, the Middle East, and Latin America combined.
Total installed European wind capacity stood at 219.5 GW at the end of 2020, of which 179 GW was in EU27 states.

Interesting article on ENGIES transition to renewables, there seems to be a lot of 'fluff' about batterie, but this statement I found really interesting. As we have said in this thread earlier these coal power station sites have a huge amount of critical infrastructure already existing, also they are usually situated in strategic positions.

From the article:
Hazelwood, shut down in 2017 in a portent of what was to come for other ageing coal plants, is taking on new life as home to a battery that will make use of existing transmission connections.

ENGIE, which is aiming to pioneer vertically integrated utilities of the future in Australia, owns 70 per cent of the initial stage of the Hazelwood battery. The remaining 30 per cent rests in the hands of Macquarie’s Green Investment Group.

ENGIE’s Andrew Hyland says the 150MW battery is just the start of Hazelwood’s evolution and is excited to think about the legacy 1600MW of transition capacity associated with plant.

Knobby22 said:

Would you say that in Europe where, unlike Australia, the ability of renewables to provide power is quite constrained (less solar radiation, higher density of people so wind power incapable of providing load) that Nuclear power will likely be necessary if a low carbon power system is to be reality by their timelines of 2030?

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Theoretically nuclear isn't essential and it would be possible to do it with renewables instead.

In practice though I really can't see that happening. Europe will certainly deploy renewables but they're not done with nuclear and for that matter fossil fuels will be around for a while yet too.

Smurf1976 said:

Theoretically nuclear isn't essential and it would be possible to do it with renewables instead.

In practice though I really can't see that happening. Europe will certainly deploy renewables but they're not done with nuclear and for that matter fossil fuels will be around for a while yet too.

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The issue as you know surf, isn't whether it can be done with renewables and storage,but the time it would take to do it with renewables and storage and at the same time maintain living standards and industrial production.

The other thing that is interesting is, if it is so easy to do it with renewables and storage, why haven't can't we do it with most of our central Australian Towns? They are endowed with terrific amounts of sun radiance and wind, why not make Alice Springs fully renewables?
They are a relatively small population in a perfect location, why not try and make it a renewable centre piece?

sptrawler said:

The issue as you know surf, isn't whether it can be done with renewables and storage,but the time it would take to do it with renewables and storage and at the same time maintain living standards and industrial production.

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If a "wartime" approach, of the kind we've actually seen with the pandemic, were adopted then I've no doubt it would be possible to do it.

In practice however there's very little chance of that happening so it's going to take far longer and in that means there's a place for nuclear and fossils for a while yet too.

In Australia though the only reason we'll build a nuclear power station is if someone just wants one for some reasons other than simply generating electricity.