Results 556 to 570 of 2079
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11th May 2022, 05:23 PM #556
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11th May 2022, 05:25 PM #557
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11th May 2022, 06:00 PM #558.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 1,174
This morning as part of the dogs walk we walked for about 1km alongside the main southern freeway immediately south of the Narrows bridge. I haven't walked this path at commuter time for 4-5 years, anyway I counted 22 pedal bikes, 3 e-bikes and 7 e-scooters heading north into the city, and 3 pedal bikes heading south.
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12th May 2022, 12:23 AM #559GOLD MEMBER
- Join Date
- Apr 2019
- Location
- NSW
- Age
- 38
- Posts
- 313
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12th May 2022, 10:39 PM #560
Not quite as dire as the spot market indicates. Base load power (c.80%) is bought on contracts which are far less volatile. Here's a source of spot prices:
AEMO | NEM data dashboard
As you can see, the spot price in NSW today fluctuated between $250.84 and $503.59 per mwh.
For Tasmania, today's spot price fluctuated between $225.42 and $995.94 per mwh. It can be very volatile!
... time to vote in/out the policy makers ...
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12th May 2022, 11:26 PM #561
Fuel to Make Electricity
While looking at the spot prices above, I stumbled on this calculation of the sources of power for the elctricity generated in each state. Note - these figures are for a single day - today. Source is: AEMO | NEM data dashboard
Electricity Sources.jpg
I was surprised by the diversity of figures.
- Only Tasmania was totally green,
- NSW generated 81% from fossil fuels,
- Queensland generated 92% from fossil fuels,
- South Australia generated 83% from gas, and
- No state produced statistically significant solar electricity, today; the sun didn't shine!
AGAIN, emhasise figures are for one day only.
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13th May 2022, 01:13 AM #562
Graeme,
I can't find a copy of the data you displayed.
However, I can find the data for the 24 hour ending at 4 AM on May 11.
Are you sure that the data you presented represents the full 24 hours through to midnight on May 12, and not a fuel snap snap shot as say 11 PM on May 12?
In particular I find it very difficult to believe that for all of SA, TAS, VIC, NSW, QLD the sun didn't shine at all during the whole day.
following is the satellite cloud image for 11:30 AM, AEST on May 12
regards from Alberta, Canada
ian
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13th May 2022, 03:00 AM #563
Green power
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13th May 2022, 11:18 AM #564
I gave the source in the above post, Ian; here it is again: AEMO | NEM data dashboard
When you get to that "dashboard" just hit the Price & Demand button. I just re-tested it and got immediate access.
It gives a rolling graph showing showing demand and price in 5-minute segments over the previous 24 hours and projections over the next 24 hours.
My post covered the period up to about 10pm, and I just ignore the initial two hours data before midnight yesterday.
... In particular I find it very difficult to believe that for all of SA, TAS, VIC, NSW, QLD the sun didn't shine at all during the whole day. ...
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13th May 2022, 12:55 PM #565
Over the last few days Solar generation has been low. Yesterday in QLD was one of the greyest days I have seen in a long time. So there was very little solar generation. The spot market price does distort the overall average price as much is under contract. However I can't find out how much of our own generation is under contract so perhaps (Graeme) you could link to where you are getting that information, which I guess is overall thus not giving away confidential information.
The spot price is sufficiently import that traders at each power station seek to maximise their return.
Just on generation in Tasmania, There is a DC connector under Bass Strait to the mainland. Most people assume it was installed so Tassie could send power to the mainland. Actually the primary reason was the other way around. Tassie's power is all in one basket: Hydro. If they have a drought, they are in trouble. In fact they had been exporting power to Victoria, arguably because they saw a way to make some extra money, when the DC link broke a few years back. They had depleted their dams and had to rely on diesel generators, which had to be shipped.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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13th May 2022, 01:41 PM #566
Hi Paul
You are right in that the details are shrouded in "commercial-in-confidence" but I vaguely remember the figure of 80% being mentuioned in a "usually reliable source" - otherwise I would have dismissed it. Also it is in the right ball park from any sort of monte carlo or pareto simulation. That's why I qualified it as c.80%.
Bass-link cable was sold to the public as a combination of drought-proofing (as you mention) and as an arbitrage opportunity.
Coal fired powerstations take time to fire up and down, so they cannot react quickly to changes in demand. Hydro can be switched on and off almost instantly. Power is sold to the mainland grid in those hours when prices are high and then bought back when prices are low. Power flows both ways virtually every day, and often does not flow.
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13th May 2022, 03:17 PM #567
Contracts are a double edged sword from the generator's viewpoint. On the positive side you are getting a guaranteed price, which is often required by the financial institutions. The down side is that you are obligated to meet those contracts under all circumstances. If you cannot provide that generation you have to buy it back from the market and assuming that one of your units was no longer able to provide, the market price has very likely escalated. Consequently it is unwise to contract too much if you have a limited number of units: I should qualify that by saying the government stations that have multiple units, not all in the same location necessarily, are much better placed to absorb an unscheduled outage.
For example, Gladstone has six units and could probably contract 80%, but a station with only two units would be foolhardy to contract 80% of their available generation for the reason I have outlined above and their contracts would be closer to 50%. Millmerran has two units but I and indeed anybody on the operations side has no knowledge of how much of our power is under contact as this is confidential and a closely guarded secret. Consequently I would be surprised if the overall contract are up at 80%, but I could believe that some stations are around there. The four unit stations would likely be in the region of 75%.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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13th May 2022, 03:36 PM #568
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13th May 2022, 04:45 PM #569
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14th May 2022, 03:35 AM #570
Graeme
I copied and pasted your link to NEM's dashboard (thank you for providing the link) and then clicked on the Fuel Mix tab.
What I'm trying to convey is that your data seems to represent a snap shot as at 10 PM AEST on May 12, not the fuel mix over the whole of May 12.
Below is screen shot for SA of the 48 hour period up to 4 AM AEST on May 13. The 48 hour period covers both May 11 and May 12.
The yellow shading represents the periods during which the sun was shining and providing solar power to the SA grid.
(In the main, roof top solar is not included in NEM data as the roof top systems are too small a scale to be registered in the market.)regards from Alberta, Canada
ian
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