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The future of energy generation and storage

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Meanwhile, getting on with making things happen we now have 4 synchronous condensers operating in the SA transmission network.

Two are located at Robertstown (about 100km north of Adelaide) and the other two are at Davenport (Port Augusta).

In layman's terms a synchronous condenser is a great big motor with a flywheel attached, which weighs about 170 tonnes. It generates no electricity, actually it consumes a small amount, but its purpose is to provide what AEMO generically refers to as system strength (a catch all for a few things technically). Noting that the great problem with wind and solar is they don't do much in that regard but they do generate - put it all together and it works.

The practical effect in a big picture sense is to:

1. Raise the upper limit on wind and large scale solar generation under typical operating conditions, thus reducing the volume that's curtailed (wasted).

2. Lower the number of synchronous generators, that is large conventional plant driven by steam turbines, gas turbines, diesel engines etc. There's some "it depends" detail around the extent of that reduction but for a generic answer, it cuts the minimum from 4 down to 2 under a typical scenario.

So overall it means more wind and solar can be used and, by reducing the minimum level of gas-fired generation, that also frees up space for renewables. Two very similar looking birds killed with one stone.

That doesn't mean SA can go to 100% renewables however but it's a step forward, it'll lead to greater use of renewables and less use of fossil fuels than would otherwise be the case.
 
Thanks Smurf, could you explain how a large motor with a huge flywheel provides the frequency stability?
With an AC generator (steam driven or hydro), the inertia of the turbines allows a fairly stable 50 Hz to be maintained in the network to which everything synchronises to.
How does the large motor with flywheel do the same task if it has no generator attached??
Thanks,
Mick
 

In straightforward terms, in the event of a system disturbance (something fails) the syn con becomes a generator in practice. Not a generator driven by steam or hydro but there's that great big flywheel attached. As system frequency falls following whatever incident, the syn con's frequency will be dragged down with it and in doing so that releases some of the energy stored in its own rotating mass.

So in simple terms the syn con is contributing inertia just as a conventional steam, hydro etc driven generating set contributes inertia. It doesn't have the prime mover, the steam or hydro, but it's a synchronous rotating machine with a flywheel attached so it does contribute inertia. It'll be a generator in practice for a short period if external circumstances cause it to.

A synchronous condenser is ultimately just a generator without the steam turbine, diesel engine etc driving it. It's just sitting there spinning but it can be manipulated (changing the excitation) as required and, since in this case there are flywheels attached, it has that same inherent inertia that a steam or hydro unit does.

 
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What was really funny Rob, was in this article published by the ABC, they initially qouted Albo as saying quote:
"The word plan doesn't constitute a plan, no matter how often [Mr Morrison] said it.

Then that was followed by a statement, that Albo wouldn't be presenting a plan until after the Glasgow meeting, which completely made Albo's statement ludicrous.
Fortunately someone must have twigged and removed the last statement hours later, what a bunch of dicks.
They are obviously worried and rushing to get crap printed.

'Clean' hydrogen and cheap solar power at centre of government's net zero commitment

Australia joins the world in promising to reach net zero on carbon emissions by 2050 — a policy it opposed two years ago — ahead of the upcoming global climate change summit in Scotland.
www.abc.net.au
 
Smurf1976 said:
It'll be a generator in practice for a short period if external circumstances cause it to.
Click to expand...
Adding to that a bit, it may seem counterintuitive but what needs to happen in a fault situation is to keep voltage up and deliver a sufficiently high current (fault current) to operate circuit protection devices.

That basic principle applies everywhere from a large power station right down to a small household switchboard. Fault occurs > high current flow > very rapidly trips the circuit breaker = fault has been isolated. That's the desired outcome.

The basic danger of having an electrically weak system, one that can't deliver those high fault currents, is in the event a significant fault does occur (and sooner or later it will.....) then instead of delivering that high fault current, operating protection and clearing the fault what happens instead is a voltage collapse (and in the context of a major fault in the grid, potentially a frequency collapse as well). Once that occurs, low voltage will limit the fault current, causing protection to not operate as it should and the fault to be not isolated. From there it ends badly.

As an analogy, if we consider that a fault is represented by a cow on the tracks and that an electrically strong grid is a freight train well then the cow gets obliterated and the train just carries on. Unfortunate for the cow but for the overall system that's the desired outcome, it carries on.

Now if you run into a cow whilst riding a bicycle..... That would be the equivalent of an electrically weak grid that can't deliver sufficient fault current. It comes to a spectacular halt meanwhile the cow remains.

That's trying to be very layman's terms on a stock market forum not an engineering one but in short that's what it's about. Big heavy rotating machines to add inertia which was traditionally supplied "free" as part of the inherent characteristics of steam, hydro etc. Even though they're not actual generators, they'll do the job of holding voltage and frequency up long enough in a fault situation for the fault to be isolated and balance restored. Plus they can be intentionally manipulated under normal circumstances when required.

Which brings me to "System Strength". Not a real technical term and one that nobody used until AEMO came up with it in an effort to capture the range of issues regarding reactive power, frequency rate of change, voltage stability, fault currents and so on in a way that could be communicated to the media, public, politicians and so on. The term has been pretty widely adopted in Australia following that - two words and it does capture it sufficiently.
 
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thanks for that great explanation.
Wish I had not thrown away my old Uni power tech bibles, or I might have been able to relearn about reactive power, and the inductive currents caused by power surges etc. Maybe its time to go back to uni.
One of the things that attracted me to engineering in the first place was that it was such a practical useful occupation.
Making things, designing things, fixing things seemed so much more useful than writing fiction novels, painting pictures, or goung to the bar (the legal one, not the one in the pub.).
Mick
 
Adding more to what @Smurf posted, this has some good diagrams and pictures showing the full context of SCs role in the grid.
 
SirRumpole said:
Sorry about that, will continue the politics in an appropriate thread.
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I was having a go at government more than anyone here....

No matter how much they talk, a project like that is ultimately delivered by all sorts of people - investors (since virtually all electrical infrastructure in SA is privately owned), managers, engineers, electricians, fitters and various other trades, truck drivers and so on.

We need action not words. Doubly so when the words aren't helpful anyway.
 
Smurf1976 said:
We need action not words. Doubly so when the words aren't helpful anyway.
Click to expand...
That is the crux of the matter, the media aren't going to stump up any money, just a load of garbage that hopefully gets the muppets buying more media.
What is more important, is what the Governments want to do and how much that is going to cost the taxpayer and or business.
Both the taxpayer and business will benefit from a reduction in emissions, how the cost of that is apportioned is the key part IMO.
We can have tax payer subsidies on the EV car makers, but that in reality just makes it cheaper for rich people to buy them, as ICE cars are still a lot cheaper.
We can give a lot of taxpayers money to any business that says it will make cheap energy, that just encourages profiteering and usually a huge mess that the taxpayer has to fix up, in reality IMO that is the situation S.A got itself into a few years ago.
It really is about time, that everyone took a deep breath and assessed everything on its merits, rather than its advertising expenditure IMO.
Or indeed its media ramping, if some of this media nonsense was listed, it would have already been under investigation. ?

Weigh what all the political parties have to say about zero emissions, on their technical merit and social cost IMO.
The taxpayer shouldn't have to wear the brunt and industry shouldn't be made unprofitable, that is the balance that's required.
 

I agree with much of what your saying but there is a fair bit of blue sky thinking in that quick movement to a carbon neutral economy and coping with CC is somehow not going to financially impact tax payers and industry.

Because we have left this far too late there will be a series of stranded assets. If this process had begin 30 years there could have been a more orderly move to new industries/processes and, in theory, much of this could have been avoided. Simply speaking, the world won't survive CC if we don't massively reduce fossil fuel use quickly. That isn't part of this Government future intentions.

The rush to look at new investment opportunities always looks exciting and profitable. On paper there will be excellent returns for new investments and ASF and the Government and industry want to focus on that part of picture. But CC is not just about new investment opportunities. The impact of rising temperatures, rising sea levels , more violent weather patterns on homes, shorelines, property and infrastructure is quite clear. Just speak to the thousands of people who have lost homes to bushfres and still living in caravans. Or beachside properties being washed away rising seas. Or thousands of people waking up to cars and homes damaged by freak hailstorms that are now commonplace.

The Shovel makes this point with a smile .

Man announces he will quit drinking by 2050





A Sydney man has set an ambitious target to phase out his alcohol consumption within the next 29 years, as part of an impressive plan to improve his health.

The program will see Greg Taylor, 73, continue to drink as normal for the foreseeable future, before reducing consumption in 2049 when he turns 101. He has assured friends it will not affect his drinking plans in the short or medium term.

Taylor said it was important not to rush the switch to non-alcoholic beverages. “It’s not realistic to transition to zero alcohol overnight. This requires a steady, phased approach where nothing changes for at least two decades,” he said, adding that he may need to make additional investments in beer consumption in the short term, to make sure no night out is worse off.

Taylor will also be able to bring forward drinking credits earned from the days he hasn’t drunk over the past forty years, meaning the actual end date for consumption may actually be 2060.

To assist with the transition, Taylor has bought a second beer fridge which he describes as the ‘capture and storage’ method.
 
Unlike @basilio I don't agree with much of what you said.
Snowy 2 is an example of how poorly thought through projects impact consumers when quicker and better alternatives were not only available, they were getting cheaper.
And Snowy 2 was only ever on the table because the Coalition has was unable to develop an energy policy that gave the private sector confidence to invest at the necessary scale. That's not my opinion, but is expressed in the many submissions to AEMO from operators over the past 6-7 years.
In terms of action, the federal government has a number of financing options available to get projects of national importance off the ground. It could do a Snowy job and own the project. It could incentivise States to enter into Public Private Partnerships (PPP). It could create novel arrangements whereby interest free loans were available along with tax concessions and deferred payback (think of HECs). Or it could enter into arrangements with industry super funds who would finance major projects and receive annual dividends rom the federal government equal to the rate of earnings that ordinarily received from their investments. Any of the foregoing could be financed by diverting the billions of dollars each year that are wasted on the diesel fuel rebate.

I know none of this is likely to happen, but my point is that @sptrawler thinks there is a balancing act that needs to occur, when in fact there is a rebalancing that is future looking that should instead be acted on.
 
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rederob said:
Snowy 2 is an example of how poorly thought through projects impact consumers when quicker and better alternatives were not only available, they were getting cheaper.
Click to expand...

What is wrong with Snowy 2 ? Don't we need more storage ?


Definitely.
 
SirRumpole said:
What is wrong with Snowy 2 ? Don't we need more storage ?
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Yes, but it could have been achieved at half the price and be spread across the eastern seaboard, rather than in one spot.
Just remember that about +30% more energy is needed to refill the emptying dam, and that much of this is going to come from intermittent renewables. All the government needed to do was say years back that all new intermittent supply had to have some form of backup. Problem solved!
 
There's over 20,000 identified pumped hydro sites nationally. Sounds good but the big problem isn't peak power by total energy stored. I say that since it's readily apparent that private enterprise is willing to invest in short duration (1 - 4 hours) to meet the peaks (that is, batteries) such that it's bulk energy which becomes the issue.

Take out all the sites which are in the middle of nowhere and that culls a decent percentage but still leaves more than enough.

Now to the hard bit, duration. Take out all the ones that store only a few hours worth and we're left with a much shorter list.

Now here's a chart showing wind and solar (only) generation in Victoria on a daily basis for the past 12 months:



Look carefully at the end of April, the middle of June and early July.

They all have the same problem - multiple consecutive days of consistently low yields from wind and solar.

Now consider that electricity consumption in Victoria will, if we're going fully renewable, increase very substantially and this is where the real pain arises.

Highest consumption week for the past year in Victoria was 5 - 11 July with an average load, over the full 7 days, of 6143 MW.

If that week sounds familiar well it's the same week which had the lowest wind and solar output.

Ahh.....

Now consider that most space heating in Victoria is presently not electric since gas is extremely dominant. Now how much heat does that supply? Well on a typical non-extreme day in June or July the gas consumption over 24 hours averages just on 10,000 MW.

That's the gas consumption for space heating only to be clear. That doesn't include gas used for hot water, cooking, in industry or for power generation. It's just what's being burned to heat buildings and is simply the difference in consumption between a mild day and a typical winter one (since space heating would account for almost all the difference in practice)

Now if we replace that gas with electricity via heat pumps well there's another ~2000 MW of electrical load during winter (allowing for efficiency differences), with the nasty characteristic that it's inverse to wind and solar yield.

Now add in electrification of other gas uses (hot water, cooking, industry) and things like electric cars and all up we're looking at total electricity use in Victoria during winter, averaged over 24 hours / 7 days, being roughly double the present value or to be more specific 12,000 MW.

12,000 MW.

12,000,000 kilowatts.

On average. 24 hours per day, 7 days per week. Peak demand somewhat higher than that.

Now back to those gaps. Here's the same chart again, this time displayed on a weekly basis:



Ignore the last week since that's the incomplete present one and the problem's rather obvious. The worst wind and solar yields occur at the very same time we're going to see the highest consumption and there's a direct inverse correlation there - less sunlight directly pushes up heating use.

How to fix that is the big question. Victoria's the most problematic state but the same underlying issue does exist in other states to a lesser degree.

One solution is to massively overbuild wind and solar such that the worst week's production does in fact yield sufficient energy and only short duration storage is needed.

Another solution is seriously large hydro storage on a scale that can discharge constantly for a week not just a few hours.

Another solution is we keep burning something which can itself be easily stockpiled for use when required either to generate electricity or used directly as the means of heating buildings.

Or we stick with fossil fuel / nuclear power generation and build enough of it to support the future load.

That's the elephant in the room however that you won't find too many people willing to discuss, usually because they either don't have an answer or they do have an answer but don't wish to be flamed for saying it due to the politics of the whole situation.

Just in case anyone thinks I cherry picked Victoria, well it's the most problematic state so I did pick it for that reason but the basic problem exists across the entire National Electricity Market:



How to deal with that low production in winter, when we're going to see consumption during winter greatly increase with a shift to electricity for heat, is the big problem really.

Noting there that wind and solar "droughts" lasting a week or more aren't something that's only happened once or twice, it's happened literally every single year since they've been in the grid at significant scale. So the data says it's real, multiple consecutive days of poor wind and solar yield will occur, and those are the very same days when consumption goes up.
 

A knotty problem indeed.

I can see more enlargement of existing dams (like that proposed for Wyangala NSW) and expansion of existing hydropower works or construction of new ones at those sites.
 
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SirRumpole said:
I can see more enlargement of existing dams (like that proposed for Wyangala NSW) and expansion of existing hydropower works or construction of new ones.
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That's essentially where the real debate, at the technical and economic level as distinct from party politics, lies.

How best to deal with those runs of multiple consecutive days of poor wind and solar yield which just happen to mostly occur at the same time load's going to increase with a shift to electricity for heat.

At present hydro, gas and diesel fill the gap plus of course a large proportion of buildings, in Victoria especially, are burning gas directly.

Hydro:


Gas-fired electricity:


Diesel / kerosene:


Even coal has its maximum output in the middle of Winter:


Whilst peak demand as such occurs during hot weather in summer (except Tasmania), total energy volume is greatest during winter and that's also where the greatest increase will occur with a shift to electricity replacing other fuels at the point of use.

A key point in all this is that distinction - peak power demand versus total energy volume.
 

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