Power shares

[Scrunch]

I don't follow the power market in California, but that article would suggest that it is structured somewhat differently to what we have in New Zealand.

SNOOPY

Quite possibly, but there are the same fundamental issues, if likely peak demand exceeds available capacity there is a problem. The likelihood of demand exceeding supply is low if demand is predictable and reserve is built into the system and lower still if there is demand that can be safely dropped - both of which NZ have. The chances of a problem increase when the levels of reserve in the system are decreased (as happened in California). The chances increase further when there is a surge in demand (as happened in California). The chances increase again when expected generation capacity is not available.

We sometimes reference all these issues coinciding as the perfect storm, but multiple unlikely events can coincide.

[Jantar]

…...

So it looks like hydro is quite capable of providing back ups. It is not just the likes of Huntly and gas.

SNOOPY

Yes, there is less chance of it happening in NZ, although the North Island is more at risk than the South Island. We did see a cascade type failure in the North Island on Waitangi day 1987 that blacked out everything north of Taupo. That was caused by a single fault in the switchyard at Whakamaru. Then there have been single area blackouts from time to time, mainly in the North Island, but one in the central South Island, also due to faults that prevented power being transmitted to areas that needed it.

The market in NZ is similar to California's in that Transpower do hold the dispatch function on behalf of the market, and it is they who issue the warnings about mismatch in offered generation and forecast demand.

It is very common for Transpower to issue reserve shortfall notices that tell generators that if a large unit were to fail, there would be insufficient standby reserve to make up the difference. Less common, but still significant are the energy shortfall notices that tell generators that there is not enough energy being offered to cover a tripping. Then less common still are Grid Emergency notices where there is insufficient energy offered to meet demand.

Transpower get the wind forecasts so wrong that no trader ever takes notice of reserve shortfall notices, but most do react to energy shortfall notices.

Most of the issues we get in NZ is when wind generation is less than forecast, and there are many times that Whirinaki is dispatched to make up part of that shortfall. Whirinaki is NZ's last ditch generation, so once that is running there is almost nothing left.

[kiora]

Not long ago in Australia
https://theconversation.com/why-is-t...why-now-121689

[Snoopy]

Not long ago in Australia
https://theconversation.com/why-is-t...why-now-121689

Interesting article, but I wonder what can be achieved by sending in the legal eagles to chase down wind farmers. A wind farm is entirely dependent on the weather to operate. Battery technology, Tesla style, is I think still too expensive an option to store wind energy, at least in New Zealand. Other participants in the NZ Energy market know that when the wind blows, then the resulting energy must be fed into the grid or it will be wasted. Isn't is up the other non wind farm generators to adjust the ramping up and down of their hydro stations and thermal stations to accommodate the wind farms? Not the other way around?

SNOOPY

[Jantar]

…... Isn't is up the other non wind farm generators to adjust the ramping up and down of their hydro stations and thermal stations to accommodate the wind farms? Not the other way around?

SNOOPY

Yes it is, and that is why wind generation gets priority in the dispatch process. But that is also a large part of the problem. Hydro can ramp fairly quickly, but thermal cannot. A typical hydro generator can ramp at 1 MW per second, or 60 MW per minute, so a station like Arapuni could ramp at 480 MW per minute, if all its generators were running. However if they are all running the Arapuni has a minimum load of around 100 MW and a maximum of 196 MW, giving only 96 MW swing.

If the wind is strong then not many generators would be running, so that would reduce the amount of ramping available even further.

[Snoopy]

Yes it is, and that is why wind generation gets priority in the dispatch process. But that is also a large part of the problem. Hydro can ramp fairly quickly, but thermal cannot. A typical hydro generator can ramp at 1 MW per second, or 60 MW per minute, so a station like Arapuni could ramp at 480 MW per minute, if all its generators were running. However if they are all running the Arapuni has a minimum load of around 100 MW and a maximum of 196 MW, giving only 96 MW swing.

If the wind is strong then not many generators would be running, so that would reduce the amount of ramping available even further.

So what is the way to go for the North Island Jantar? I see the Rankine Units at Huntly have previously been used for peaking in the past, but are you saying they are really too slow to ramp up? How long beyond their design life can we reasonably expect the Rankines to keep going anyway? Do we need to fast track the geothermal projects, like the one that Contact has put on ice, so that hydro in the North Island shifts from providing base load to being the peaker of choice? And what would that strategy mean for the mighty Waikato and Mercury Energy?

Using MCY as an example a 3 odd % return is far better than a 1% in term deposits most likely sometime next year. overseas experience from very low rates shows people will pay up for stocks when the return is higher and stable.

I pinched the above quote from the 'Black Market' thread. Bull wouldn't be the only one singing the praises of Mercury Energy. But I wonder if too much emphasis has been put on how relatively unaffected Mercury would be with a Tiwai shut down, while ignoring how developments in the electricity sector in the North Island could significantly disrupt their future?

SNOOPY

[gains]

I don't have extensive understand of the Welsh power network. However, I believe they adopted a large base load and use a pumped hydro scheme (Electric Mountain) as their peaker plant. Then refilling the upper reservoir, with the over-supply from base load, over night.

You can read or watch about it here:
https://www.thecivilengineer.org/news-center/latest-news/item/1606-one-of-the-largest-pumped-hydro-plants-in-europe-is-only-accessible-through-a-network-of-underground-tunnels
Video:
https://www.youtube.com/watch?v=d-Gbs_kXK8Q

Why I bring it up is NZ could adopt a similar scheme with Onslow and primarily use it to smooth future wind generation. But as you mention snoopy, we would need to have some instantaneous reserves closer to Auckland, unless the HVDC could handle variability (I don't recall that it can..)? which puts MCY at potentially a loose as they'd be required to repurpose their hydro..? Or could an Onslow scheme to do something similar to Electric Mountain and transmit over HVDC?

I say NZ is going to face issues with wind in the future because there's some 2000MW worth of consented wind projects at the moment which means the majority of NZ new generation for the next while is going to be wind.. This COULD (not would) put us in a similar situation to what California found themselves in by removing their extra gas plants. Instead for NZ, it's the wind that stopped blowing.

Either way, NZ will face issues in the future as demand increased and wind's variability will highten the need for reserves. A pumped-hydro scheme is attractive to me as been a much cheaper battery-style storage and longer term solution. If it is Onslow, could Waikato hydro schemes become peakers or FIR/SIR? I think it's possible

[Jantar]

So what is the way to go for the North Island Jantar? I see the Rankine Units at Huntly have previously been used for peaking in the past, but are you saying they are really too slow to ramp up? How long beyond their design life can we reasonably expect the Rankines to keep going anyway? …...

SNOOPY

Some interesting questions here Snoopy. Pumped storage is the ideal solution, and it can be based in the South Island while still buffering North island ramping. The risk is that it may be the HVDC link that faults, and that reserve cover still needs to be met from the North Island. There is sufficient fast ramping in the North to meet that contingency (the risk is one pole of the HVDC tripping off, not both).

The Rankine units are already 5 years past their design life, and Genesis are doing really great work in keeping them running. I would suspect another 3 years would be about the limit before the next one is shut down. Geothermal is great for base load, but does nothing for managing peaks or unexpected outages. Fast start GT peaking plant, like at Stratford, is probably still going to be needed for North Island security.

[peat]

Not much mention of Trustpower here.
I've been taking a little more interest in the power companies recetnly for obvious reasons. I'm not in agreement with using equity as a bond but they are discounted currently so worth casting an eye...

I was looking at Trustpower's assets and note how diverse they are all over the country small hydro stations. Seems useful as a risk spreading strategy although generation may not always be transferable around the network I guess. Also they have a peaker in Whangarei. Their forecast is ok and so does yield. ANy reasons against them particularly? Yes Infratil have a big stake so maybe no t/o interest but Govt owns majority stakes in others so same deal there.

GNE are going to be impacted when the MEL power comes north ?
MCY subject to dry year risks.
TPW boxed up by IFT and TECT?

[bull....]

Rio Tinto confirms it is continuing to seek help for smelter from Government


https://www.stuff.co.nz/business/122...rom-government