Time to give electricity the flick?

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Ultimate Geek
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#1617347 25-Aug-2016 13:09

Is there even such a thing as official provisional prices? Interim and final, but not sure if provisional is a real pricing? Maybe what some people refer to interim prices as? Pretty sure there is a deadline for interms to be published? Maybe 1300 the day after.

In regards to yesterday, it seems it was a pretty complicated sequence of events that lead to it. In the north island there was what looks like a problem with a generator in Taranaki (McKee) at 7:30 which combined with a high demand peak meant there was not enough generation in the north island. Coincidentally, a South Island generator removed a significant amount of spinning reserve from the market at around just before 6am yesterday morning. That meant that there was not enough reserve in the South Island to cover the amount required for network security requirements. That through some convoluted calculations in regards to reserve and HVDC transfer between the islands meant the price went 'infeasible' which is a hard coded to cap any prices at $100k. So the ~$88k 5 min price was derived from the infeasible South Island reserve less the HVDC losses which is usually in the 10-15% region. Sorry if this explanation doesn't make much sense, it is such a complicated system when things like this occur and very difficult to explain in text! I am pretty sure the final price for that period will resolve down to around $500 to $5k....maybe...

voy1d

178 posts

Master Geek
+1 received by user: 35

#1617365 25-Aug-2016 13:48

Rappelle:

AFAIK the half hourly forecast prices are locked in as provisional 2 hours before the half hour to which they pertain (and then go through the interim/final process)

Sort of but not quite.

There are eight schedules, 5 of which are ex-ante and 3 of which are ex-post.

Ex-ante Schedules

WDS (Weekly Dispatch Schedule)

This is done for trading periods 72 through 336 (i.e. next seven days) and is run at 0130 every morning.

NRSL & PRSL

These are run every two hours and cover trading periods 9 through till 72 and are run at 10 minutes past the even hour. These are known as the "long schedules" of which there are two types. The first NRS (Non Responsive Schedule) where demand is considered inelastic. The second is PRS (Price Responsive Schedule) and customers are demand responsive (e.g. large industrial may submit a difference bid to shut down at a certain price point).

NRSS & PRSS

These are run for every trading period and are for trading periods 1 (current TP) through till 8 and are run at 3 minutes past the half hour. These are the last itertion of the schedule.

Ex-Post Schedules

Provisional Prices

These are run traditionally around 6am on the first trading day following the day they are solving. This takes the finalised datasets (metering, demand, transmission availability etc) and is purely an error check. If there are no errors, then they are transformed into Interim Prices. If there is a data error, then a "Provisional Pricing Situation" may occur.

Interim Prices

These are produced the same day as provisional prices (unless a provisional pricing situation exists) and must be published by midday the trading day following the trading day they are solving for. They are made available for participants to claim pricing errors and vet.

Final Prices

These are what you are billed on and essentially if there are no issues (or the issues solved) with the provisional and interim schedules and are published before midday on the first business day following the publication of interim prices.

In addition there are also two "5 minute schedules" however these are unlikely to reach the pricing run.

As to yesterdays, I'm looking at the interims right now, and the morning had Benmore prices reach $265, Haywards reach $288 and Otahuhu $328 through the evening yesterday. I expect these will be turned into final prices before midday tomorrow.

timmmay

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#1617456 25-Aug-2016 16:14

The spikes have started again, already, it's only 4:15pm. There's plenty of generation capacity, no idea about NI/SI cable capacity. It's just annoying really. Seems like a technical problem with the market, ie human error, not with supply.

k14

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Ultimate Geek
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#1617504 25-Aug-2016 17:50

timmmay:
The spikes have started again, already, it's only 4:15pm. There's plenty of generation capacity, no idea about NI/SI cable capacity. It's just annoying really. Seems like a technical problem with the market, ie human error, not with supply.

What makes you say there is plenty of capacity? I can guarantee there is no technical problems with the market. Just because there is spare capacity doesn't mean there is capacity available. Thermal stations need 24 hours plus notice to start, hydro stations can only run if there is water available..... The joys of an open market :)

timmmay

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#1617708 26-Aug-2016 09:36

k14:
timmmay:

The spikes have started again, already, it's only 4:15pm. There's plenty of generation capacity, no idea about NI/SI cable capacity. It's just annoying really. Seems like a technical problem with the market, ie human error, not with supply.

What makes you say there is plenty of capacity? I can guarantee there is no technical problems with the market. Just because there is spare capacity doesn't mean there is capacity available. Thermal stations need 24 hours plus notice to start, hydro stations can only run if there is water available..... The joys of an open market :)

The little graphs on EM6 suggested spare capacity, including hydro. Given Wed and Thu both had spikes I hope someone has worked out they need more supply.

By problems with the market I meant more like the model isn't encouraging sufficient generation, or is increasing prices because of an algorithm issue.

Wills1

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Ultimate Geek
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#1617720 26-Aug-2016 10:02

The spikes this week have been huge. We've had plenty of rain, plenty of wind. Its not overly cold around the country for this time of year. Can anyone offer a simple explanation as to whats happening with the prices? Thank you

droopanu

168 posts

Master Geek
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#1617746 26-Aug-2016 10:55

Wills1:

The spikes this week have been huge. We've had plenty of rain, plenty of wind. Its not overly cold around the country for this time of year. Can anyone offer a simple explanation as to whats happening with the prices? Thank you

I agree with plenty of rain, but there was barely any wind ...

k14

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Ultimate Geek
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#1618487 27-Aug-2016 20:52

timmmay:
k14:
timmmay:

The spikes have started again, already, it's only 4:15pm. There's plenty of generation capacity, no idea about NI/SI cable capacity. It's just annoying really. Seems like a technical problem with the market, ie human error, not with supply.

What makes you say there is plenty of capacity? I can guarantee there is no technical problems with the market. Just because there is spare capacity doesn't mean there is capacity available. Thermal stations need 24 hours plus notice to start, hydro stations can only run if there is water available..... The joys of an open market :)

The little graphs on EM6 suggested spare capacity, including hydro. Given Wed and Thu both had spikes I hope someone has worked out they need more supply.

By problems with the market I meant more like the model isn't encouraging sufficient generation, or is increasing prices because of an algorithm issue.

If all the generators are immune to the wholesale market then they may not care. They may have enough generation to cover their retail customers so aren't worried about high prices.

The EM6 capacity graphs aren't very useful in real world scenarios. As I said, just because there is only 70% of hydro generating doesn't mean there is any more available at that point in time. There could be planned maintenance, resource consent limitations, or fuel constraints. I wouldn't make any assumptions on those graphs.

Probably the best graph on EM6 to look at is cleared vs offered reserves. If the cleared line is getting close to the offered line then things are tight.

Rest assured, the upcoming week is looking a lot friendlier. I'd hazard a guess that prices will stay under $80 ;)

timmmay

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#1618492 27-Aug-2016 21:11

Not sure where to find cleared vs offered reserves, any hint?

voy1d

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Master Geek
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#1618497 27-Aug-2016 21:24

http://www.em6live.co.nz/PriceImpact.aspx

It's on the price impact page.

EM6 doesn't use the data around outages and availability of equipment. I know for a fact that whilst there is c. 3500 MW of installed capacity of hydro in the South Island, I believe there are a number of unit outages active in the south island.

Fun fact, if you want to look at the outages, you can visit http://pocp.redspider.co.nz