The future of energy generation and storage

[Smurf1976]

For those who want the details:

Solar curtailment for minimum system demand events - SA Power Networks

www.sapowernetworks.com.au

In order, the steps we take as the grid operator in these events are:

1. Turn off large-scale solar and wind farms.
2. Turn off large-scale solar systems such as shopping centres and factories.
3. Turn off the exporting of rooftop solar using the regulated Relevant Agent and Dynamic Export functions.
4. Turn off any remaining exporting rooftop solar using our Emergency Voltage Management (EVM) function.

Step 4 is relevant to all older solar systems, which are still the majority of residential installations, and is quite literally just pushing up the distribution voltage so as to shed enough rooftop solar generation which will trip or at least curtail output.

 

[sptrawler]

For those who want the details:

Solar curtailment for minimum system demand events - SA Power Networks

www.sapowernetworks.com.au

Step 4 is relevant to all older solar systems, which are still the majority of residential installations, and is quite literally just pushing up the distribution voltage so as to shed enough rooftop solar generation which will trip or at least curtail output.

It is only a matter of time before old style inverters have to be replaced, they will just make it like smoke detectors and Earth leakage cct breakers, while the requirement is to put more in, they don't advertise bad news.

Stick with the narrative, the more the better, until it isn't, nothing changes.
Except when they legislate the non wifi, non CT monitoring inverters have to be replaced, will be just after the rebate on inverters ceases.

 

[sptrawler]

What you don't want is the situation that actually exists in SA.

It was left too late and the workaround is simply to crank up the distribution voltage until sufficient solar generation trips off.

Needless to say, intentionally sending overvoltage into every home and small business isn't ideal and brings about "the law of unintended consequences" one of which is reports that as well as shutting down solar, it also shuts down at least some EV chargers. That's not a good outcome obviously, cutting load is the opposite of what's required.

Remotely curtailing inverters via commanding them to do so is theoretically a far nicer way but not without problems as well with the implementation. It's all well and good until someone who's lost grid supply completely, and has an inverter with battery operating in backup mode as an islanded power system, has it remotely shut down. Since the loss of power means the house also loses internet, there's no way to send it a command to restart it.

Consumers who've got $10k+ systems providing backup power, and who've had that system disabled during an actual power failure, tend to get extremely angry....

The real problem is that most people think it is all fine, but when you think that I'm putting is a brand new 5kW system, that is throttled to 3kW when in reality we need as much as possible and somehow this is magically going to be sorted in 6 years, yeh right.
The more we move toward the pointy end, the more precarious it becomes.

 

[Smurf1976]

In answer to a question and keeping this in layman's terms:

Key concept - all generating plant in an AC power system ("grid") is in parallel and so is all load.

In other words, each generating unit is generating into a single AC power system. Everything from the 750MW, that's 750,000,000 Watts, steam driven unit at Kogan Creek (Qld) which is the largest single generating unit in Australia down to someone's little 1.1kW (1100 Watts) Sunny Boy solar system installed 15 years ago in the early days of rooftop solar are all in parallel, they're all ultimately supplying into that same AC power system. There's a lot of circuit breakers, distribution and transmission lines, transformers and so on between them yes but it's a single system as such.

Likewise all load is drawing from that same system. Everything from your table lamp to an aluminium smelter, they're all just loads in parallel albeit some much larger than others and some supplied directly from the transmission system (smelters etc) and the rest supplied via the distribution network.

System frequency in Australia is nominally 50Hz and so long as total generation matches total load, including losses, it'll remain stable.

More generation than load and frequency will rise.

Less generation than load and frequency will fall.

Same concept as a car speeding up or slowing down if the mechanical power from the engine doesn't match the load placed upon it. That there's some lag, that frequency will rise or fall gradually rather than abruptly changing to a new value, largely coming down to physical inertia. The many tonnes of rotating machinery does take some energy to speed up or slow down (and that's a good thing not a bad thing).

For the main grid in Australia, the NEM (National Electricity Market) mainland power system (covering most of Qld and effectively all of NSW, ACT, Vic and SA apart from isolated remote towns etc) the frequency standard is:

Nominal = 50.00 Hz

Under normal operating conditions in the range 49.75 - 50.25Hz, with at least 99% of the time in the range 49.85 - 50.15Hz.

Under fault conditions, the sudden unexpected failure of generation, transmission or disconnection of major load, the most extreme acceptable limits are 47.00 to 52.00 Hz. Noting those are extreme values that would never be done intentionally and ideally should never occur.

Tasmania has a variation in that the upper extreme limit in the event of major faults is 55.00 Hz. Otherwise it's the same standard as the mainland NEM states including the aim to contain frequency to 52Hz under any "normal" fault scenario. Noting that the physical connection between the mainland and Tasmania is DC such that whilst energy transfer can and does occur routinely, the mainland and Tasmanian systems aren't synchronised as such, frequency can vary between the two.

Places not part of the NEM have different standards, due to technical factors, but they're not much different in practice, they all aim to keep system frequency within a few % of 50.00 Hz under all circumstances.

The reason for such precision being once it's outside that range the chance that it ends badly becomes rapidly greater, especially for under frequency, because generating units will themselves trip due to low frequency and it doesn't need much below the lower bound, 47Hz, to see that happen. So a lack of generation causes a further lack of generation and from there it's an extremely rapid slide into the abyss.

In theory Under Frequency Load Shedding (UFLS), which is the automatic disconnection of loads in a pre-determined order, should arrest any major fall in frequency. However it does so by the brutal method of leaving consumers without power so is never a preferred occurrence and could be likened to the air bag deploying in a car. Beats being killed but definitely not good as such, it's a last line of defence and, crucially, there's no guarantee it'll be sufficient - plenty of incidents around the world where it wasn't.

In the Australian context under normal circumstances the preferred means of maintaining system frequency is ultimately market driven. FCAS (Frequency Control Ancillary Services) is the official term and in short that's market driven in that any generating plant with the technical capability can offer a price for the service, and it's the cheapest that'll be picked subject to satisfying technical requirements. There's no bias toward any particular technology there - it's simply technical ability and whatever price the owner (well, the traders they employ) offer.

That results in there being no generating plant specifically dedicated to that function. Yes in practice some will tend to offer the best price, and that'll be influenced by technology (the big batteries have a definite advantage there), but under varying conditions which facilities are being used for that purpose will vary. Noting that due to the scale of requirements multiple units will be used in practice.

For the third quarter of 2023, batteries provided 40% of FCAS, coal 25%, hydro 15%, 13% demand response (heavy industry mostly) and the remaining 6% was split between gas, diesel, wind, solar. Figures don't add to 100% due to rounding.

Contrary to popular belief, wind and solar can do it under the right circumstances. Eg they can't offer an increase in output if they're already fully utilising the wind or sun, but they certainly can offer a decrease in output as a contingency measure. etc. Likewise a battery that's fully charged can't do the decrease but it can do the increase. Put them together and it works and AEMO's system can easily cope with sending different instructions to different units.

If all that fails though, well there's always primary frequency control at the machine level which is just the generating unit itself responding to frequency deviations without any external direction to do so. In very simple terms that's speed governors on generating plant, albeit rather complex ones, and it's the natural response of loads to any deviation in frequency. That's raw engineering stuff - it's at odds with the modern era thinking that says someone ought offer a price and be paid to do it, it's just the machine doing it itself.

Which brings up the point that the idea of having a market for FCAS is a completely human construct, it's not something fundamental to power systems. Go back 30 years and there was no such concept, it's just something that was an inherent feature of generating plant and running a power system. That it's viewed differently today being a political and economic construct not an engineering one - it stems from having multiple owners of generation in the same power system and the ideological view that they ought be competing against each other on price not only for energy but for FCAS as well.

There was quite a battle over that one, engineers versus politics and economics, and it's a case where the engineers did ultimately succeed in making the point that primary frequency control is a necessity. If there's also some other system then OK, we can live with that even though it seems overly complex (a market for the sake of a market), but primary control must always be there - that it doesn't fit with the market idea doesn't change that need, political or economic ideas don't overcome physics. Suffice to say there was quite a battle over that one, mostly out of public view.

So in short, there's no single answer. There's no generating unit specifically tasked with maintaining a stable frequency but rather, there's a procurement of FCAS for every dispatch interval and who does it comes down to the price offered. Politics and economics prefers that approach whilst engineers aren't keen, generally seeing it a an unnecessarily complex process.

 

[Smurf1976]

Battery operation in Victoria over the past 24 hours.

They're mostly operating in one direction at any given time, either charge or discharge, but there's a lot of volatility there, their output or load is rapidly fluctuating.

Above the zero line is generation into the grid, below the line is charging from it.

 

[sptrawler]

Court rejects solar farm for wrecking a town's view, poor consultation | RenewEconomy

NSW court rules the solar project didn't take into account its impact on the landscape's character and fell short on community consultation.

reneweconomy.com.au

 

[mullokintyre]

Battery operation in Victoria over the past 24 hours.

They're mostly operating in one direction at any given time, either charge or discharge, but there's a lot of volatility there, their output or load is rapidly fluctuating.

Above the zero line is generation into the grid, below the line is charging from it.

View attachment 168768

That is some volatility!
I wonder if there has been any research done on how this sort of volatility affects battery life over the medium to long term.
It would be interesting to have a look at the software that controls which bank of cells discharges and when.
There would be some fancy balancing in those large scale battery backup units.
Mick

 

[Smurf1976]

I wonder if there has been any research done on how this sort of volatility affects battery life over the medium to long term.

A good question that I haven't seen an detailed information about.

What I can say is the different owners of the large batteries have quite different expectations as to their lifespan. For those built and under construction thus far it ranges from 15 to 40 years.

Only the owners know the basis for those life projections, the inputs to that conclusion aren't publicly disclosed (and that includes not being disclosed to others within the industry), only the answers are disclosed. So it's not clear what reflects differences in assumed usage versus what reflects assumed differences in the lifespan of large batteries as such. Another factor may simply be risk tolerance which is a "human" factor.

One thing that is clear is that different operators are adopting very different approaches. Eg AGL have very clear "preferred" levels of output for the Torrens Island battery with a chart over time looking like a series of steps up and down, they're trying to operate close to those preferred points where possible (noting it's not always possible but most of the time it is). In contrast Neoen aren't doing that with the Hornsdale battery, they're far happier with erratic operation providing FCAS.

 

[mullokintyre]

One thing that is clear is that different operators are adopting very different approaches. Eg AGL have very clear "preferred" levels of output for the Torrens Island battery with a chart over time looking like a series of steps up and down, they're trying to operate close to those preferred points where possible (noting it's not always possible but most of the time it is). In contrast Neoen aren't doing that with the Hornsdale battery, they're far happier with erratic operation providing FCAS.

Is there possibly a different pricing structure depending on whether its a stepped usage versus FCAS? Maybe the Horsdale suppliers are happy taking a higher price for more erratic usage?
Mick

 

[sptrawler]

The penny is definitely dropping, as I said a while ago, a lot of companies will be working out if it makes sense to decarbonise, or close.

It's an industrial precinct that contributes $15 billion into WA's economy, but what lies in store for Kwinana?

The chief executive of a peak body says the Kwinana industrial area in Perth's south must undergo drastic change if it is to meet state government emissions targets.

www.abc.net.au

 

[sptrawler]

41degrees C, the last thing you need is an extended power outage, been there done that.
Spare a thought for those in Kalgoorlie, Kambalda 60km away has its own backup power, the daughter in law is there working ATM, says it is mayhem 30,000 people from Kalgoorlie trying to fit in the shop and petrol station.
Welcome to a World without power, for some it will be the first taste, Kal has been pretty good since the 220kv line and the gas pipeline have been installed.

No power, no fuel, no alcohol as DFES warns regional WA blackouts could last up to a week

The Department of Fire and Emergency services has warned residents across the Goldfields and Wheatbelt to prepare for ongoing blackouts over the next seven days.

www.abc.net.au

Thousands of residents who have spent the day sweltering in 41C temperatures now have no access to fuel, following a huge power outage across Western Australia's Goldfields and Wheatbelt.
This afternoon, Main Roads said there was no fuel available in Kalgoorlie or Coolgardie because of the power outage.

Meanwhile, queues for fuel at Kambalda, 60 kilometres south of Kalgoorlie, are huge.
Western Power's executive manager of asset operations Zane Christmas said the Kalgoorlie outage was caused yesterday when lightning struck a critical communications tower near Merredin and a network that fed the Goldfields town tripped.

He said Synergy then started generators which restored power to about 7,000 of the 23,000 customers cut off last night.

But some of the generators had now suffered technical challenges, he said.
"So we are relying on Synergy technicians to address those as quickly as we can."

Mr Christmas said he did not know when power would be restored.

Ralph English said he had never experienced such a long outage during his 68 years in Mukinbudin in the eastern Wheatbelt.

"All day Sunday we had no power, [it was] on and off for the most of Monday and then Tuesday about 1:30 it went off," he said.

"And it's been off ever since."

Mr English drove about 40 kilometres to get phone service and said his local petrol station and supermarket could not open due to the internet being down.

He said he was worried about elderly residents and people who could not drive to leave the region, given yesterday's 46C heat.

"I don't really know how they're coping. It's been so hot."

 

[macca]

41degrees C, the last thing you need is an extended power outage, been there done that.
Spare a thought for those in Kalgoorlie, Kambalda 60km away has its own backup power, the daughter in law is there working ATM, says it is mayhem 30,000 people from Kalgoorlie trying to fit in the shop and petrol station.
Welcome to a World without power, for some it will be the first taste, Kal has been pretty good since the 220kv line and the gas pipeline have been installed.

No power, no fuel, no alcohol as DFES warns regional WA blackouts could last up to a week

The Department of Fire and Emergency services has warned residents across the Goldfields and Wheatbelt to prepare for ongoing blackouts over the next seven days.

www.abc.net.au

Thousands of residents who have spent the day sweltering in 41C temperatures now have no access to fuel, following a huge power outage across Western Australia's Goldfields and Wheatbelt.
This afternoon, Main Roads said there was no fuel available in Kalgoorlie or Coolgardie because of the power outage.

Meanwhile, queues for fuel at Kambalda, 60 kilometres south of Kalgoorlie, are huge.
Western Power's executive manager of asset operations Zane Christmas said the Kalgoorlie outage was caused yesterday when lightning struck a critical communications tower near Merredin and a network that fed the Goldfields town tripped.

He said Synergy then started generators which restored power to about 7,000 of the 23,000 customers cut off last night.

But some of the generators had now suffered technical challenges, he said.
"So we are relying on Synergy technicians to address those as quickly as we can."

Mr Christmas said he did not know when power would be restored.

Ralph English said he had never experienced such a long outage during his 68 years in Mukinbudin in the eastern Wheatbelt.

"All day Sunday we had no power, [it was] on and off for the most of Monday and then Tuesday about 1:30 it went off," he said.

"And it's been off ever since."

Mr English drove about 40 kilometres to get phone service and said his local petrol station and supermarket could not open due to the internet being down.

He said he was worried about elderly residents and people who could not drive to leave the region, given yesterday's 46C heat.

"I don't really know how they're coping. It's been so hot."

Might be few businesses putting in big solar panels soon after 4 days of no power

 

[sptrawler]

Might be few businesses putting in big solar panels soon after 4 days of no power

So true, it has been a long time, since an outage like this.

People automatically think, i'll just fuel up the car and head off to Perth, no they wont if there isn't any power the fuel pumps don't work.
That's why years ago, when I was installing gen sets, I always had a wind up alarm clock.
You couldn't rely on the diesel power station always running through the night, but you had to be at work on time.

 

[Smurf1976]

You couldn't rely on the diesel power station always running through the night, but you had to be at work on time.

Love that confidence there....

 

[sptrawler]

Love that confidence there....

Yep I've had some weird $hit happen in my time, I remember once we had finished work for the day in very touristy town in the NW of WA.
They had a blackout and found that the DC control system was dead, so they had no control cct supply to start anything.
Well long story short the town had built up and built up, the power station had grown as it does, no one had really thought about the control system drain on the black start batteries.
Well that was a cracker.
Even now where ever I go I take a wind up clock, an interesting thing I found on my last cruise was, how useless these smart watches are.
My kids all put in and bought me one, well the problem is it locks in with your phone, but if you have no service and the ship goes through a time change you don't.
Absolutely useless in that scenario.
So it has become another piece of useless trash on my bedside table, give me my classic analogue watches any day, I don't care if I'm a dinosaur.

 

[Smurf1976]

Mr English drove about 40 kilometres to get phone service and said his local petrol station and supermarket could not open due to the internet being down.

This is a problem in itself.

The idea that the internet is required in order for someone to buy something that's sitting on a shelf right in front of them is really quite ridiculous.

As for the power, I know that 5 towers are damaged on the 220kV line (for others that's the only transmission between the rest of the system and Kalgoorlie) and apparently there's a problem at West Kalgoorlie with the gas turbines (2 x 25MW), they did have them running then something failed.

Haven't heard anything about Parkeston PS (total capacity 110MW) though and what's stopping that being used to put the lights on. Physically it's on the outskirts of Kalgoorlie and has three open cycle gas turbines. Even if it can't meet all load, limited supply is better than no supply if they could get that running.

 

[sptrawler]

This is a problem in itself.

The idea that the internet is required in order for someone to buy something that's sitting on a shelf right in front of them is really quite ridiculous.

As for Kalgoorlie well there's 5 gas turbines total 160MW there to my understanding, 2 at West Kalgoorlie (50MWl) and 3 at Parkeston power station (110MW) , as well as the 220kV line to the SWIS and also 132kV transmission south to Kambalda with its 42MW generating capacity. Must be quite a bit of damage if they can't get anything at all running in or into Kalgoorlie.

My guess a lightning strike, but it shows how fragile it is, there is a 220kv line and a gas line, plus diesel backup on the GT's.

This is one of the down side issues with the NBN, the old Telstra system from what I remember was an isolated 50vDC system through PABX exchanges and actually generally stayed up during bushfires.
The NBN is a cluster flck of taxpayer funded optical upgrade, so that the telecommunication companies can charge more, for what most don't need.
Just a humoguos brain fart, that we are still seeing the financial and social loses unfold from, the NBN has already written off $30b that the telcos owed for the install. Now the basic plan is $60 whereas ADSL2 was $30. Eventually everyone will want internet and phone on the go, blind Freddy could see that.
All the NBN will be is cable TV for tenants and secure data transfer for commerce.

Now Telstra has signed up to Starlink for regional coverage, it is just another slow moving train wreck, as was the education revolution, as was the NBN, as will be the next brain fart which is shaping up to be superannuation IMO.

That's the downside of growing old, history repeats and you see the same train wreck in slow motion all over again.

 

[Smurf1976]

Haven't heard anything about Parkeston PS (total capacity 110MW) though and what's stopping that being used to put the lights on. Physically it's on the outskirts of Kalgoorlie and has three open cycle gas turbines. Even if it can't meet all load, limited supply is better than no supply if they could get that running.

There's another 42MW gas turbine at the nickel smelter too that I failed to mention previously.

 

[sptrawler]

Water, is now the problem in Kal, welcolme to life without power. Don't shower, don't flush the toilet, live they did when Kal was started, oh what a mess.

 

[sptrawler]

As I said earlier where has all the talk of building a battery manufacturing plant here gone? Just give Samsung. LG or Tesla a tax incentive to process here we have the ingredients just need the tech and Govt support.
Let's be honest the last Govt got CSL to build a vaccine manufacturing plant in Victoria, it's about time we moved on with secondary manufacturing and using our materials.
Why can't we supply our own grid batteries, we are going to need plenty of them.

Taxpayers, CSL to build vaccine manufacturing plant​

The Morrison government will spend $1 billion over a decade to underwrite the construction of a new vaccine production facility to guarantee the nation continues to have its own supply of flu shots, antivenins and, if another pandemic occurs, the sovereign capability to look after its own...

www.afr.com
The Morrison government will spend $1 billion over a decade to underwrite the construction of a new vaccine production facility to guarantee the nation continues to have its own supply of flu shots, antivenins and, if another pandemic occurs, the sovereign capability to look after its own citizens first.

Under the deal, CSL subsidiary Seqirus will spend $800 million to build a new state-of-the-art facility at Melbourne's Tullamarine airport.