Adelaide in for a storm!
Certifs, I take your point about the media. Perhaps the truth will out in the end? Or, perhaps not, if prominent heads are on the chopping block.
I gave the article some credibility because he is highly regarded as being a "real" investigative journalist.
I gave the article some credibility because he is highly regarded as being a "real" investigative journalist.
Last edited by megan; 7th Oct 2016 at 05:10. Reason: journalist
I suggest you google large wind turbines. There are plenty of sites to tell you how they work and life span etc. I think it said 25yrs. Interestingly Australia is about 17th in the world in numbers in use.
Nomorecatering, I was hoping someone else would pad up and answer your questions but I will have a crack at it for you.
Firstly let me tell you I have never worked in a power station but have worked with co generators in Hospitals and the like that work in unison with the grid. I will make this as simple as I can as I have no intension of writing a 100 page thesis or would anyone want to read it.
Imagine you had 2 petrol engines. 1 a v8 running at say 1200rpm and 1 a 4cyl doing 2300rpm but both producing the same hp at those revs. Now say through some clutch mechanism you suddenly joined them together as one. The result would be catastrophic at the very least,with broken crankshafts and bent con rods as a minimum. Now hold that thought. While joining 2 generator outputs together is totally different the end result is similar. For two or more generator supplies to run in unison 4 things have to match up. Voltage magnitude, Phase sequence, Frequency and Phase angle.
Large generators produce 3phase power. In Australia we call these, red phase,white phase and blue phase. All are 120 electrical degrees apart (phase angle). To see this on a scope it looks something like the ABC logo only 3 of them all intermingled but rotating 120deg apart.
The best way to describe how this works is look at the basic 3phase motor.
Around the stator of the motor are sets of winding in groups connected to each phase. Unlike a single phase motor where the current comes in on the active runs around the winding and then out the neutral (return) a 3phase motor has 3 actives but at any given time 1 of those actives is acting as the return.(without a return you would have no flow so no motion)In Australia this changes 50 times/second and is what we call the frequency and measured in Hertz. The rotation direction of that motor is determined by the sequence of each phase supplying the motor and return. eg RWB sequence might result in a clockwise direction. By simply swapping 2 phases at the motor to produce say RBW sequence will cause the motor to rotate counter clockwise.
Now can you imagine the result if we put 2 supplies together that were in opposite sequence or different frequencies ,voltages etc? we are back to our petrol engine senario.Motors would stall,reverse (or try to)burn out, not to mention what it would do to appliances with electronics and also destoy the generators supplying it all. Fortunately this cant happen as there are numerous protection devises installed at different points in the network to monitor and switch off if some event outside the set parameters happen. I use it only as a simple explanation as to why it take such a long time to get it all up and running again once the grid goes off line.
Will continue as time permits with your other questions
Firstly let me tell you I have never worked in a power station but have worked with co generators in Hospitals and the like that work in unison with the grid. I will make this as simple as I can as I have no intension of writing a 100 page thesis or would anyone want to read it.
Imagine you had 2 petrol engines. 1 a v8 running at say 1200rpm and 1 a 4cyl doing 2300rpm but both producing the same hp at those revs. Now say through some clutch mechanism you suddenly joined them together as one. The result would be catastrophic at the very least,with broken crankshafts and bent con rods as a minimum. Now hold that thought. While joining 2 generator outputs together is totally different the end result is similar. For two or more generator supplies to run in unison 4 things have to match up. Voltage magnitude, Phase sequence, Frequency and Phase angle.
Large generators produce 3phase power. In Australia we call these, red phase,white phase and blue phase. All are 120 electrical degrees apart (phase angle). To see this on a scope it looks something like the ABC logo only 3 of them all intermingled but rotating 120deg apart.
The best way to describe how this works is look at the basic 3phase motor.
Around the stator of the motor are sets of winding in groups connected to each phase. Unlike a single phase motor where the current comes in on the active runs around the winding and then out the neutral (return) a 3phase motor has 3 actives but at any given time 1 of those actives is acting as the return.(without a return you would have no flow so no motion)In Australia this changes 50 times/second and is what we call the frequency and measured in Hertz. The rotation direction of that motor is determined by the sequence of each phase supplying the motor and return. eg RWB sequence might result in a clockwise direction. By simply swapping 2 phases at the motor to produce say RBW sequence will cause the motor to rotate counter clockwise.
Now can you imagine the result if we put 2 supplies together that were in opposite sequence or different frequencies ,voltages etc? we are back to our petrol engine senario.Motors would stall,reverse (or try to)burn out, not to mention what it would do to appliances with electronics and also destoy the generators supplying it all. Fortunately this cant happen as there are numerous protection devises installed at different points in the network to monitor and switch off if some event outside the set parameters happen. I use it only as a simple explanation as to why it take such a long time to get it all up and running again once the grid goes off line.
Will continue as time permits with your other questions
Last edited by mostlytossas; 8th Oct 2016 at 04:43.
Cont...
Why do power stations require input power to start generating?
Some can but most can't for variety of reasons. If the place is dead totally there is no power to start anything with,such as open motorized gas valves,run cooling pumps, run or monitor protection devises ,meters etc. excitate the generator field windings it just sits there as one big block of useless concrete and steel.
Why do they take so long to spool up?
They don't really, Torrens Island has I believe 6 generation sets. They would start or stop them as the load demands. While there is some lead in time required to say get them running they can see demand rising on their monitoring load meters etc and so should be ahead of the game for normal increases. I include your eastender effect scenario in this.
During periods of increased demand does this extra load cause the generator rpm to decay? No because it isn't allowed to. If the load became so great and all sets were running at maximum, load shedding would start occuring. Usually by turning off some suburbs for 1 hour each in rotation which has happened before in Adelaide. If load shedding was not carried out the protection devises would start disconnecting as happened with the interconnector.The rest of your question is answered in part 1
Why are the back up service providers secret?
I have no idea either and it is a disgrace!
Hope I have given you some worthwhile info be it in very simple terms.
Why do power stations require input power to start generating?
Some can but most can't for variety of reasons. If the place is dead totally there is no power to start anything with,such as open motorized gas valves,run cooling pumps, run or monitor protection devises ,meters etc. excitate the generator field windings it just sits there as one big block of useless concrete and steel.
Why do they take so long to spool up?
They don't really, Torrens Island has I believe 6 generation sets. They would start or stop them as the load demands. While there is some lead in time required to say get them running they can see demand rising on their monitoring load meters etc and so should be ahead of the game for normal increases. I include your eastender effect scenario in this.
During periods of increased demand does this extra load cause the generator rpm to decay? No because it isn't allowed to. If the load became so great and all sets were running at maximum, load shedding would start occuring. Usually by turning off some suburbs for 1 hour each in rotation which has happened before in Adelaide. If load shedding was not carried out the protection devises would start disconnecting as happened with the interconnector.The rest of your question is answered in part 1
Why are the back up service providers secret?
I have no idea either and it is a disgrace!
Hope I have given you some worthwhile info be it in very simple terms.
Nomorecatering, to answer your question re-individual wind turbines. They are individual alternators turning out AC. This output is rectified to DC and transmitted to the farm substation. In the substation, the load is sensed, from here the power is converted from DC to synchronous AC at the one point for transmission into the grid. It is at this point where the "Software Issue" occurred.
Two lines were subsequently found to be ok and were returned to service without need of repair.
Two lines were subsequently found to be ok and were returned to service without need of repair.
Looks the the system is heading east.
Melbourne to be blown of the map tommorow. 120kh winds.
Melbourne to be blown of the map tommorow. 120kh winds.
Man Bilong Balus long PNG
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Overheard on a talk-back Radio show on Friday morning; Apparently there is an Electrical retail business '..in Adelaide's north...' which specialises in 240V gen sets.
As of around 11.30 am Friday morning, their entire stock on hand had sold out and they have over 300 units on back order!
Here in the Riverland area of SA, the local Honda Dealer has sold 3 Gen Sets (around the 3kva size)in the last four days! And has had several enquiries re larger sets.
As for me; I am making the appropriate enquiries.
As of around 11.30 am Friday morning, their entire stock on hand had sold out and they have over 300 units on back order!
Here in the Riverland area of SA, the local Honda Dealer has sold 3 Gen Sets (around the 3kva size)in the last four days! And has had several enquiries re larger sets.
As for me; I am making the appropriate enquiries.
You will see comments that wind farms can't provide support to the grid (ie frequency and voltage support). This is certainly true of type 1 and 2, but the other types can (I think type 4 can actually be used as a stand alone generator, without being part of a wind farm bus).
I believe SA farms are mostly type 2 with some type 3. I would expect that future wind farms will only be allowed if they are the higher type numbers.
Which will then make some peoples heads explode as it seems one possible solution to make the SA system "more secure" is to build ... more wind farms!
(Of a suitable type, see, nothing is simple)
Yes, steam generation is reduced at times of lower load. As a basic relationship, power out exactly equals steam in and power out is exactly needed to match the load on the system.
During periods of increasing demand from consumers, does this extra load cause the generator rpm to decay, reducing the frequency, if so why would damage occur if the frequency output of the generators falls below 47 Hz.
How does the system cope with instant demand increases when hundreds of thousands of people put the kettle on at the same time during a commercial break on a popular TV show. I think they call it the East-Enders effect. A TV show in the UK that was massively popular and they could predict the spikes in electricity demand from the Ad breaks.
How does the system cope with instant demand increases when hundreds of thousands of people put the kettle on at the same time during a commercial break on a popular TV show. I think they call it the East-Enders effect. A TV show in the UK that was massively popular and they could predict the spikes in electricity demand from the Ad breaks.
The 47Hz thing is not the problem as such (although there are problems because of it) Rather it is an indicator that other bad things are about to happen(like alternators leaving the floor). In a normally functioning system the turbines wont (cant) slow down as they cant change speeds due to being synchronised. If they have, then something is bad wrong with the whole system.
Note that .
As an aside the NEM pays power stations to be able to quickly pick up this transient load. These are some of the ancillary services that generators can bid and contract for in the electrical market (like the SRAS mentioned by gerry111 earlier). It isn't just about MegaWatts. The boiler of the power station in Port Augusta is (was?) a "once through" design (Benson boiler) so actually was worse than normal for being able to cope with rapid load changes consequently they couldn't provide this support and so couldn't get money in this part of the market.
No (good faith) questions are dumb. Some answers may be.
Certifs
.....Meanwhile, in the time this thread has been running, China has opened up another new coal fired power station. In less then two weeks China will open up another new coal fired power station, and a couple more weeks after that another, and so on...
It were interesting looking through the auction catalogue for the equipment of the recently closed South Australian power plant. A lot of the equipment had Made in Australia on it. ...And down the hole we go thanks to idiotic green hysteria..
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It were interesting looking through the auction catalogue for the equipment of the recently closed South Australian power plant. A lot of the equipment had Made in Australia on it. ...And down the hole we go thanks to idiotic green hysteria..
.
Last edited by Flying Binghi; 9th Oct 2016 at 00:22.
From Wikipedia:
In early 2016 the building of new coal capacity continued at a significant pace with 406 GW proposed.[8] However, the central government issued directions in April 2016 curbing construction of new coal fired plants throughout the country.[9] This is in line with a moratorium issued by the National Energy Agency in 2015 banning new coal mines in China for a period of three years and closure of thousands of small coal mines.[10]
Can you explain what you men by this? What exactly is hysterical? How,specifically, are the Greens responsible for us going down the hole? They have never been in government so I don't really understand how they can be responsible for anything?
I look forward to a detailed explanation of your argument
I look forward to a detailed explanation of your argument
Via certifs:
Meanwhile in the real world China is closing old power stations, banning new ones and closing down mines.
From Wikipedia:
In early 2016 the building of new coal capacity continued at a significant pace with 406 GW proposed.[8] However, the central government issued directions in April 2016 curbing construction of new coal fired plants throughout the country.[9] This is in line with a moratorium issued by the National Energy Agency in 2015 banning new coal mines in China for a period of three years and closure of thousands of small coal mines.[10]
Meanwhile in the real world China is closing old power stations, banning new ones and closing down mines.
From Wikipedia:
In early 2016 the building of new coal capacity continued at a significant pace with 406 GW proposed.[8] However, the central government issued directions in April 2016 curbing construction of new coal fired plants throughout the country.[9] This is in line with a moratorium issued by the National Energy Agency in 2015 banning new coal mines in China for a period of three years and closure of thousands of small coal mines.[10]
Your new to this aren't yer certifs.."China is closing old power stations" Considering China has a large number of old power plants it is no surprise that they is closing old power plants. Its like a car, it gets old and uneconomic to repair and gets traded in on the shiny new one with three times the horse power and full of bright new computer screens..
"banning new ones and closing down mining" certifs, you do understand that China is a command economy. All sectors of the Chinese economy 'suffer' constraints from time to time as the government 'adjusts' things. Power stations and coal mining is no different. I see they want more thermal coal mining now to act as a price 'adjustment'... amongst other things... NDRC loosens coal production restrictions - Global Times.
certifs, So, if as yer say it takes ten years to get things done in the coal station building game do that mean it will be ten years before they slow down the 'two a month' new station opening regime ? ...
certifs, the Chinese are fairly astute. Something tells me that their concerns of a slowing world economy, i.e., a slow down of world demand for Chinese goods, is likely the reason for their looking to slow the break-neck domestic development of the manufacturing sectors power supplies rather then the thinking of those afflicted with climate hysteria wishing it were something else..
.
Certifs, that's how they run in Tassie. Methinks the alternators are multiphase...but they definitely feed into the substation as DC...can you imagine phasing more than 10 individual alternators spinning in marginally different wind conditions? ...my info is second hand, the brother does the contract work for comms for TasHydro.
That comment re 47hz...imagine turbine and alternator weigh in about 800tonne of inertia spinning at 3000 rpm...imagine that slows..or wants to slow by 6%. That alternator becomes a motor and the grid wants to drive it back to 50hz...800t spinning and the grid wants to drive it? ...but it only slowed by 180rpm? It may as well be 1800rpm out!
Re Eastenders, that excess load is normally taken up by hydro. Quick start...very much unlike random wind.
Seriously, if there was no interconnector and no wind generation, SA would have only suffered local load shedding! The great social experiment is a bust!
That comment re 47hz...imagine turbine and alternator weigh in about 800tonne of inertia spinning at 3000 rpm...imagine that slows..or wants to slow by 6%. That alternator becomes a motor and the grid wants to drive it back to 50hz...800t spinning and the grid wants to drive it? ...but it only slowed by 180rpm? It may as well be 1800rpm out!
Re Eastenders, that excess load is normally taken up by hydro. Quick start...very much unlike random wind.
Seriously, if there was no interconnector and no wind generation, SA would have only suffered local load shedding! The great social experiment is a bust!
The climate wars....King Canute had the right idea.
Sentient beings living in the intertidal zone with a life span of six hours and no history would come up with a similar theory about weather and statistics.
Sentient beings living in the intertidal zone with a life span of six hours and no history would come up with a similar theory about weather and statistics.
Latest update
https://www.aemo.com.au/Media-Centre...49F38A36D.ashx
Seems the cause of failure lies in
20MW was off line due to high winds >90kph. Thermal power remained connected unit the interconnector blew.
Still not known at what point the towers collapsed. Seems the "Australian" might not be so far off the mark after all certifs
https://www.aemo.com.au/Media-Centre...49F38A36D.ashx
Seems the cause of failure lies in
All SA wind turbines have a control system that takes action if the number of ride through events in a specific period exceeds a preset limit
Still not known at what point the towers collapsed. Seems the "Australian" might not be so far off the mark after all certifs
Although not confirmed information, AEMO notes there have been anecdotal references made to tornado weather conditions in reports relating to the SA events. It is not yet clear whether those conditions potentially contributed to the line faults or whether the transmission towers collapsed after the Black System.
When you live....
Megan, unfortunately what the AEMO media release says contradicts what the report actually says.
The 'failure' of the wind turbines to 'ride through' faults has nothing to do with the fact that they were wind turbines - the issue is that their protection settings were set to trip after a set number of ride through events. In most cases, this setting was 2 and so event 3 tripped them out. Why was it set to 2? Most likely the manufacturers settings and nobody ever asked them to be set differently (makes intuitive sense - 3 phase failures likely = transmission line failure). A massive failure of the regulator and operator (AEMO) to understand how their network worked and what would happen if a total transmission line failure occurred.
So, yes, the tripping of all the wind farms was an issue but there could just have easily been gas generators supplying via those protection settings and the same result would have occurred. Of course there is no guarantee that if the setting had been higher that the event wouldn't have caused more ride through events and the settings tripped anyway - although AEMO have even suggested that wind farms should just keep on trying to ride through events - and bad luck if these events are destroying your turbines......
AEMO also have to answer as to why, with such a storm bearing down on them, did they have the Heywood inter-connector running at such high capacity and all the spare gas generation shut down? The answer appears to be price - it was cheaper to get power from Vic than start up more local gas generation (wind was already doing it's bit and operating in the 90km/h winds). So when the transmission lines all bent over (and it's still not clear if it was this that actually tripped out heywood or the loss of the wind farms - it was the frequency not the voltage that went haywire first) then there was no capacity in the network to step up supply to try and cope with the problems - thus Heywood went down and dark she went. A market operator paying attention to security of supply and not just price would have fired up the rest of the gas plants, scaled back Heywood and when it all turned to poo might have been able to recover. But it didn't - and surprisingly doesn't mention this in the report....?
Finally, the state having gone black, the wind turbines were still there and ready to generate (albeit possibly not for long as the wind speed was increasing) but with the state gone black, ALL of the contracted black start operators (those paid large sums of money by AMEO to be ready for this situation) failed to do so. Wind turbines are not paid to be black start capable (I suspect they may not be capable of doing so) and so they couldn't come back on line until AEMO managed to organise power back from Heywood gradually across the state to the turbines and allow them to sync and start supplying. Funnily enough, AEMO won't say who their contracted black start providers are......
So whatever AEMO are saying, an alternate story might be:
1. It's not clear what caused the massive frequency variation - was it the farms going off line or the towers going down (i bet it was the towers) that took out Heywood
2. The wind farms shut down as they were designed to but in a way AEMO hadn't considered due to their failure to understand the network
3. The loss of the transmission lines/wind farms guaranteed a dark state because of the %load Heywood was running at and the lack of contingency planning by AEMO who were too busy worrying about the price of bringing on (expensive) gas alternatives
4. Total failure by the operators contracted by AEMO to provide black start capacity
All of which doomed the state to blackout as soon as transmission lines started to bite the dust and ensured that getting the power back on was a long and complicated process. The role of windfarms/renewables was incidental but nice and easy for AEMO to blame when the alternative is to investigate and admit to your own failures.
The 'failure' of the wind turbines to 'ride through' faults has nothing to do with the fact that they were wind turbines - the issue is that their protection settings were set to trip after a set number of ride through events. In most cases, this setting was 2 and so event 3 tripped them out. Why was it set to 2? Most likely the manufacturers settings and nobody ever asked them to be set differently (makes intuitive sense - 3 phase failures likely = transmission line failure). A massive failure of the regulator and operator (AEMO) to understand how their network worked and what would happen if a total transmission line failure occurred.
So, yes, the tripping of all the wind farms was an issue but there could just have easily been gas generators supplying via those protection settings and the same result would have occurred. Of course there is no guarantee that if the setting had been higher that the event wouldn't have caused more ride through events and the settings tripped anyway - although AEMO have even suggested that wind farms should just keep on trying to ride through events - and bad luck if these events are destroying your turbines......
AEMO also have to answer as to why, with such a storm bearing down on them, did they have the Heywood inter-connector running at such high capacity and all the spare gas generation shut down? The answer appears to be price - it was cheaper to get power from Vic than start up more local gas generation (wind was already doing it's bit and operating in the 90km/h winds). So when the transmission lines all bent over (and it's still not clear if it was this that actually tripped out heywood or the loss of the wind farms - it was the frequency not the voltage that went haywire first) then there was no capacity in the network to step up supply to try and cope with the problems - thus Heywood went down and dark she went. A market operator paying attention to security of supply and not just price would have fired up the rest of the gas plants, scaled back Heywood and when it all turned to poo might have been able to recover. But it didn't - and surprisingly doesn't mention this in the report....?
Finally, the state having gone black, the wind turbines were still there and ready to generate (albeit possibly not for long as the wind speed was increasing) but with the state gone black, ALL of the contracted black start operators (those paid large sums of money by AMEO to be ready for this situation) failed to do so. Wind turbines are not paid to be black start capable (I suspect they may not be capable of doing so) and so they couldn't come back on line until AEMO managed to organise power back from Heywood gradually across the state to the turbines and allow them to sync and start supplying. Funnily enough, AEMO won't say who their contracted black start providers are......
So whatever AEMO are saying, an alternate story might be:
1. It's not clear what caused the massive frequency variation - was it the farms going off line or the towers going down (i bet it was the towers) that took out Heywood
2. The wind farms shut down as they were designed to but in a way AEMO hadn't considered due to their failure to understand the network
3. The loss of the transmission lines/wind farms guaranteed a dark state because of the %load Heywood was running at and the lack of contingency planning by AEMO who were too busy worrying about the price of bringing on (expensive) gas alternatives
4. Total failure by the operators contracted by AEMO to provide black start capacity
All of which doomed the state to blackout as soon as transmission lines started to bite the dust and ensured that getting the power back on was a long and complicated process. The role of windfarms/renewables was incidental but nice and easy for AEMO to blame when the alternative is to investigate and admit to your own failures.
Waffle; verb (talk)
Meanwhile...
"...China is investing massively in fossil fuel energy – not just at home but across the world, such as this project in the former Yugoslavia...": Shock: 'Green' China Investing Massively in Fossil Fuel Power
.
Meanwhile...
"...China is investing massively in fossil fuel energy – not just at home but across the world, such as this project in the former Yugoslavia...": Shock: 'Green' China Investing Massively in Fossil Fuel Power
.
"banning new ones and closing down mining" certifs, you do understand that China is a command economy. All sectors of the Chinese economy 'suffer' constraints from time to time as the government 'adjusts' things. Power stations and coal mining is no different. I see they want more thermal coal mining now to act as a price 'adjustment'... amongst other things... NDRC loosens coal production restrictions - Global Times.
.
.
Meanwhile, the Chinese thermal coal consumption fell about 3% in 2014 and then again in 2015 (no data yet for 2016) while their economy continued to grow at more than 6%. Binghi, the word you need to edumacate yourself on is decoupling.
For those interested, the process in Australia and other similar western economies (ie non command economies) goes like this:
Finance
A prospective builder has to think that the idea of building a new power station is a good one. They then have to do some basic market research to confirm they aren't mistaken, then they have to convince some financer that its a good idea and get them to promise to stump up a big wad of money when needed. You'll need a good part of a year to do this.
Environmental approvals
Since no one can plonk this stuff down any old place, there's a whole lot of federal, state and local government approvals to get done. This costs money and takes time. Never less than a couple of years. I notice the Carmichael coal mine is in its sixth year of this process and still not finished.
Ordering
No one in the world (even the Chinese) keeps major power station components on the shelf on spec in case someone wants to buy them. You will have at least 2 years lead time for major parts like turbines and step up transformers. If the boiler is coal its design will need to be optimised to burn that particular grade, so lead times might even be a bit longer for that.
Detail design
Once you know your major parts, from all the different suppliers, then all the bits, down to the simplest valve, pipe and motor must be designed to work together. 100s of thousands of hours of design work here. Probably a year or two in design work.
Now some of these things can overlap a bit, but if you can get all of that done in less than 5 years you will be lucky.
And then you can start clearing the site. The actual build time 2-3 years. Add on 6 months to a year for every additional unit in your power station because you need to stagger the work force you have you wont have enough skilled worked to build two, three or four unit simultaneously.
So, a single unit power station with a bit of luck about 7 years. Something with more than one unit 8+ years. Issues with approvals or long lead time equipment not being ready can blow this out past 10 years easily.
Australia was locked into this situation by the creation of the national electricity market nearly twenty years ago, long before renewables were even a remote thought.
A thermal power station is enormously expensive with no return on investment for the best part of a decade. And you can howl at the moon as much as you like but that is why no private entity will ever build another meaningful coal station in Australia and they will be few and far between in the rest of the western world. Gas fuelled boilers (not combined cycle) will follow the same pattern in years to come.
Certifs