Power shares

[Dassets]

What do we pay high electricity prices for... :\

Maybe trim the 10% gross dividend yields slightly.

Ah, not sure where 10% comes from. Div yields for gentailers for coming year forecast to be between 3-5%.

[GTM 3442]

The demand today is just not there. Starting those large coal units isn't as simple as pushing a button. The boiler has to be warmed up slowly, and once steam is bening generated then the temperatures and pressures have to be brought up in a controlled manner. Once there is sufficient steam pressure, then the turbine has to brought up to speed very slowly to allow the blades and casings to warm and expand at the same rate. It is a 12 hour process and cost as much as runnning the plant for 12 hours. Imagine doing all that and then finding that it was only needed for 3 hours.

Maybe there has been political pressure from their major shareholder. We will find out in the next few hours.

Out of idle curiosity, how long does it take to start up a hydro unit?

To an ignorant layman like me it seems simply a matter of letting gravity pull water downhill into a turbine, thus turning a generator. Gravity puls water downhill quite quickly if I remember secondary school General Science.

But it's bound to a bit more complicated than that. So what are the timeframes and constraints?

[kiora]

Longer than you may think if its full of weed
https://www.stuff.co.nz/national/pol...blackout-event

[Jantar]

Out of idle curiosity, how long does it take to start up a hydro unit?....

Generally around 2 to 5 minutes. When at Clyde I used to hit the start button around 2 mins before I expected to get dispatched on, and most times the circuit breaker to connect the unit to the grid would close a few seconds before the dispatch instruction to increase load came through. The unit would then load up at 1 MW per second. At Roxburgh (much smaller units) it normally took a little longer to start, but not by much.

In my early days operating at Ohakuri power station where everything was manual (No computers in 1979) it was normally around 3 minutes. There was however on memorable occassion when there was a grid emergency and we managed to start 4 units from shut down to full load in 4 minutes.

What usually takes the time in starting a hydro unit is getting the speed stabilised and then sychronising to the grid. If the circuit breaker is closed unsynchronised it could destroy the generator.

[peat]

its easy to think this Govt is going to use this as an excuse to rark the system up a bit. Not that they seem to need one these days.

I perceive some risk here however also see a final diagonal in GNE falling share price


why are they not focussing on the Cook Strait Line not being used to the max? I heard it was only 50% utilised

[Jantar]

its easy to think this Govt is going to use this as an excuse to rark the system up a bit. Not that they seem to need one these days.

I perceive some risk here however also see a final diagonal in GNE falling share price


why are they not focussing on the Cook Strait Line not being used to the max? I heard it was only 50% utilised

All available South Island generation was already flat out. There was simply no more power available to send across. This is a good example of where the Onslow scheme could have helped. It could have boosted the power flow across the cable by around 300 MW.

[peat]

All available South Island generation was already flat out. There was simply no more power available to send across. This is a good example of where the Onslow scheme could have helped. It could have boosted the power flow across the cable by around 300 MW.

thanks for advising that Sth. Is. was maxxed.

But I dont see how a 'battery' could have increased transmission capability?

[peat]

Bernard Hickeys writings on this topical subject also agree that there is risk
identifying (and my twitter feed agrees) that the power companies have now lost their social license.

Market reform, including the potential break-up of the three state-controlled gentailers Meridian, Mercury and Genesis, is now much more likely, although still dependent on the Government’s appetite to overcome the industry’s until-now fortress-like status quo bias and the Cabinet’s ability to execute.
https://thekaka.substack.com/p/dawn-...Published=true

[GTM 3442]

Generally around 2 to 5 minutes.

<snip>

What usually takes the time in starting a hydro unit is getting the speed stabilised and then sychronising to the grid. If the circuit breaker is closed unsynchronised it could destroy the generator.

Thank you Jantar, much appreciated.

[Jantar]

thanks for advising that Sth. Is. was maxxed.

But I dont see how a 'battery' could have increased transmission capability?

There was nothing affecting the capability. The HVDC was fully available and capable of passing 1240 MW if the power was available. It was only passing around 600 MW as that was all the spare power in the South Island. The limiting factor would have been the amount of reserve in the North Island, that would have limited the total transfer to between 800 and 900 MW. That extra 200 - 300 MW could have come from a battery.