Using liquid natural gas powerships for emergency power is a mistake - Chris Yelland

Cosmik Debris

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I think Eskom, with all their incompetence, perceived or real, are still way more knowledgeable about their infrastructure that you will ever be.

How do you know he didn't work for Eskom or in power generation like I did at one time? So far, his answers definitely indicate a background in power generation. Yours indicate no such background nor any background requiring STEM subjects at all.
 

TheChamp

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How do you know he didn't work for Eskom or in power generation like I did at one time? So far, his answers definitely indicate a background in power generation. Yours indicate no such background nor any background requiring STEM subjects at all.
I would be pleasantly surprised if there's anything you have never been, Engineer, military expert, scientist, philosopher, doctor, lawyer, advisor to the Zulu Royal House, cultural expert and pretty much anything one can think of.

At least Swa doesn't pretend to be an expert in everything.
 

Cosmik Debris

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In my little experience this is the key. Assuming cable size etc is ok, once the load factors have been determined it can work fine, well up to a point. With sophisticated grid connections it may be possible to (automatically?) adjust the load factors to meet power demand if say, it drops at night and demand is further from the generation source, up to a point. If not, power output could be reduced; again, up to a point as the real wizardry (for me) is that reciprocating generators have to stay at constant revolutions to match grid frequency (50Hz?). Very tricky (to me) to keep constant rpm but reduce power output seamlessly. Again, my little experience is that this can only be done to maybe 60% of maximum power, not less and the generator becomes less fuel efficient (obviously). I would guess you do not want to turn the generators off unless it is for planned (or unplanned (aka breakdowns) ha ha) maintenance as re-starting is (or was) not just at the press of a button. Quite big machines these (tiny compared to power stations though).

It's called synchronisation. You can only switch a unit onto an active grid once it is running at the same speed with all three phases synchronised. Once switched on, all units will cause each other to remain synchronised unless one loses it's power source. If that happens and it slows, safety devices will trip it from the grid. In the old days or in emergencies where the units are manually synchronised, it was possible to cause major damage. A unit switched on 180 degrees out of phase could cause the entire unit to leave the building via the roof.

Power output is determined by the excitement voltage supplied to the unit. The speed has to always remain constant to provide a frequency of 50 Hz. That speed is dependant on the number of pairs of poles inside the unit and is determined by the design of the generating unit which is adapted to the motive power source. Slowing a unit down causes brownouts and your fridges and clocks run slower. Fridges hate this and can be damaged. To reduce power on a unit, the speed is kept constant but the excitement voltage to the unit is reduced causing a reduction in the power produced. The voltage and frequency are kept constant automatically.
 

Cosmik Debris

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I would be pleasantly surprised if there's anything you have never been, Engineer, military expert, scientist, philosopher, doctor, lawyer, advisor to the Zulu Royal House, cultural expert and pretty much anything one can think of.

At least Swa doesn't pretend to be an expert in everything.

I have never been a philosopher, doctor, lawyer nor adviser to the royal Zulu house. I am a registered advanced life support paramedic, robotics engineer and served the military in operations in the Mozambican and Angolan theatre from 1978 to 1988. I did once run a plant using a SCADA system with over 6000 points controlled and/or monitored by PLC's that had it's own emergency generation. And all platforms in the maritime and offshore oil industry use their own generation. I have been on a platform off Angola that used gas turbines for generation.

Are you telling me people like myself don't exist? I can show you several people that have achieved far more than I have. Just because you have achieved nothing doesn't mean others will also achieve nothing.

Now, what is your claim to fame? You seem to be an expert in absolutely nothing except trolling. Care to share?
 

Happy Days

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Am I the only one that read the following lines in the article? :unsure:
The plan is to significantly overbuild on wind and solar power plants and back this up with large battery energy storage facilities.

This approach, Mallinson said, allows for 30TWh per year to be procured at an estimated tariff of R0.61 per kWh.

This is 39% of the weighted average tariff of R1.58 per kWh of the winning bids in the RMIPPPP.

He added that his solution guarantees a dispatchable supply of 2,000MW from 05h00 to 21h30 every day of the year.
 

itareanlnotani

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It's called synchronisation. You can only switch a unit onto an active grid once it is running at the same speed with all three phases synchronised. Once switched on, all units will cause each other to remain synchronised unless one loses it's power source. If that happens and it slows, safety devices will trip it from the grid. In the old days or in emergencies where the units are manually synchronised, it was possible to cause major damage. A unit switched on 180 degrees out of phase could cause the entire unit to leave the building via the roof.

Power output is determined by the excitement voltage supplied to the unit. The speed has to always remain constant to provide a frequency of 50 Hz. That speed is dependant on the number of pairs of poles inside the unit and is determined by the design of the generating unit which is adapted to the motive power source. Slowing a unit down causes brownouts and your fridges and clocks run slower. Fridges hate this and can be damaged. To reduce power on a unit, the speed is kept constant but the excitement voltage to the unit is reduced causing a reduction in the power produced. The voltage and frequency are kept constant automatically.
I would argue that frequency response is less important in a modern grid*

Solar doesn't need frequency response, nor does wind. Long distance transmission is overwhelmingly DC nowadays, and also doesn't need frequency response.


*Our grid is currently overwhelmingly coal generation, so the majority of our generation does need to be sync'd up.


As an example of modern "excellence" - I think one generator went kablooie when they didn't sync it... at Duvha?


As for all those people talking about infrastructure at Richard's Bay.

IT ALREADY EXISTS

There were Aluminium smelters in the vicinity, so heavy infrastructure is in place. The government has also been planning to stick gas generation in there for at least a decade too. Aramco is building a refinery there.

They're adding more to supplement, as detailed here -

 

eg2505

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His point being this is obviously yet another corrupt BEE deal, forced into place so the beneficiaries (ANC) make money, fück the rest of SA.
this,
nothing surprises me anymore, par for the course really these days,
the ANC know they will never get voted out, and this is the end result,
 

Cosmik Debris

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I would argue that frequency response is less important in a modern grid*

Solar doesn't need frequency response, nor does wind. Long distance transmission is overwhelmingly DC nowadays, and also doesn't need frequency response.


*Our grid is currently overwhelmingly coal generation, so the majority of our generation does need to be sync'd up.


As an example of modern "excellence" - I think one generator went kablooie when they didn't sync it... at Duvha?

All generators have to be synched. Solar and wind generate DC current that has to be converted to AC either by rotary converters (DC motors driving AC alternators - The correct term for the generators used at Eskom) or electronic solid state full sine wave static convertors (Incorrectly called inverters in the renewable energy game) Anything switched onto the grid has to be synchronised or it goes kablooie as you put it.

The kablooie you refer to was apparently caused by a PLC technician using the Force function on his laptop to force the PLC to order the close command to the generator breaker. The PLC would not normally order that command until the generator was in synch.
 

itareanlnotani

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Oh look, more corruption related to this deal.
 

TheChamp

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Oh look, more corruption related to this deal.
Corruption or not, someone was bound to cry foul, that's the very nature of tenders, the only difference here is most probably that the aggrieved party did not have enough resources to sway things in their favour.

I honestly don't believe a clean tender is possible, the one who got the tender will always be connected to someone in a position of power in one way or another. At the end of the day the one who is preferred to the powers that be will.get the tender, what we can only hope for is that they are competent enough to deliver.
 

Gordon_R

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Corruption or not, someone was bound to cry foul, that's the very nature of tenders, the only difference here is most probably that the aggrieved party did not have enough resources to sway things in their favour.

I honestly don't believe a clean tender is possible, the one who got the tender will always be connected to someone in a position of power in one way or another. At the end of the day the one who is preferred to the powers that be will.get the tender, what we can only hope for is that they are competent enough to deliver.

I half agree with you. The basic problem is that the tender process is inappropriate in this case, at multiple different levels. The artificial date deadlines, single gate-keeper, and conflict between regulation and decision making, turn this into a complete fiasco. The distorted outcome is almost inevitable.

Removing arbitrary barriers to IPPs would produce a level playing field, where all bidders could construct their own power plants, and let natural competition sort out the winners and losers. Of course this is a complete anathema to central planners (such as Mantashe), both politically and self-interestedly.
 

Cosmik Debris

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Corruption or not, someone was bound to cry foul, that's the very nature of tenders, the only difference here is most probably that the aggrieved party did not have enough resources to sway things in their favour.

I honestly don't believe a clean tender is possible, the one who got the tender will always be connected to someone in a position of power in one way or another. At the end of the day the one who is preferred to the powers that be will.get the tender, what we can only hope for is that they are competent enough to deliver.

No it's not. If the tender is in sealed envelopes and awarded on defined criteria related to ability to deliver on time and on cost only with penalty clauses included, the best tender will be awarded. Like pre 94 and Solidarity's college completed recently.
 

Oldfut

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It's called synchronisation. You can only switch a unit onto an active grid once it is running at the same speed with all three phases synchronised. Once switched on, all units will cause each other to remain synchronised unless one loses it's power source. If that happens and it slows, safety devices will trip it from the grid. In the old days or in emergencies where the units are manually synchronised, it was possible to cause major damage. A unit switched on 180 degrees out of phase could cause the entire unit to leave the building via the roof.

Power output is determined by the excitement voltage supplied to the unit. The speed has to always remain constant to provide a frequency of 50 Hz. That speed is dependant on the number of pairs of poles inside the unit and is determined by the design of the generating unit which is adapted to the motive power source. Slowing a unit down causes brownouts and your fridges and clocks run slower. Fridges hate this and can be damaged. To reduce power on a unit, the speed is kept constant but the excitement voltage to the unit is reduced causing a reduction in the power produced. The voltage and frequency are kept constant automatically.

Synchronisation is pretty automated; once the rpm speed is stable the gs switchgear will close BUT what isn't is reducing power at constant speed; done by automatically controlling turbo boost on the gas powered engines I have been involved with.
 

Cosmik Debris

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Synchronisation is pretty automated; once the rpm speed is stable the gs switchgear will close BUT what isn't is reducing power at constant speed; done by automatically controlling turbo boost on the gas powered engines I have been involved with.

Correct, synchronisation is automated but can be done manually and I have done it manually many times.. On gas turbines it's done by altering the boost, on diesel engines by altering the fuel rack setting and on steam turbines by altering the steam feed. This is done automatically to maintain the synchronous speed in auto control once connected to the grid and power demand varies.
 
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