Pylons carrying electricity at $0.005 per kWh. Last Saturday.
I was at home on a cloudy Saturday morning in Adelaide last week, performing some much needed repairs on my puppets in between refreshing my knowledge of chemistry. (Apparently everything is still made of atoms.) Then I noticed through a crack in the wall that the sun had come out and I opened the electrically operated steel shutters to see that, although there were still patches of cloud around, most of Adelaide was bathed in glorious noon sunshine.
On a whim I decided to check what effect this break in the weather had on grid demand and so I went to the Australian Electricity Market Operator’s site. Fortunately I could do this via internet and so didn’t have far to walk. I saw there had been quite a steep decline in demand which apparently had gone hand in hand with the clearing skies.
What was interesting was demand had dropped to just under 900 megawatts, which was the lowest point so far that day. It was the same as grid demand had been at the traditional “off peak” period – around three or four o’clock in the morning.
What was also fascinating was the wholesale electricity price for the state (technically the Regional Reference Price) dropped to half a cent a kilowatt-hour at about 12:30pm, which is roughly 10 minutes after solar meridian.
[Note from Finn: That means that in dollar terms, the coal and gas fired power stations are technically getting “two fifths of rock all” for burning all that coal and gas for that time which used to be one of their most profitable periods . No wonder their owners are lobbying to scrap the Renewable Energy Target!]
I can’t recall it ever being that low in the middle of the day before, and to the best of my knowledge it has never been that low, but I can’t be certain for while I try to obsessively stare at the little graph of South Australian electricity prices, I find I keep getting distracted by other activities such as watching paint dry or using glacier cam to watch glaciers melt.
I don’t want to speculate on exactly why the wholesale electricity price was so low at that point, as it depends on all kinds of factors such as how much the wind was blowing, what particular games dispatchable generators were playing with each other at the time, and what was going on in Mordor. Sorry, I mean Victoria. However, what is clear is that as rooftop solar capacity continues to expand in South Australia it will become common for grid demand during the day to fall below the night time minimum.
Currently South Australia has roughly 530 megawatts of rooftop solar capacity and on a cloudless day, which happens a lot around here, is capable of providing over 400 megawatts of power around noon. As the installed capacity exceeds one gigawatt, which it will, our new off peak period of lowest grid demand will consist of the majority of sunlit hours around noon in autumn, spring, and winter.
This will have many interesting consequences for electricity generation in Australia, which I will go into in future articles. But I am not going to tell you when I will write these articles on account of how I am notoriously unreliable.
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“But I am not going to tell you when I will write these articles on account of how I am notoriously unreliable…”
But extremely well-informed and interesting, nonetheless…! 🙂
Must be extremely worrying for the power distributors and retailers.
I’m in Melbourne and during June and July, 2 of the worst solar output months of the year, my 5kW system on some days produced some perfectly bell shaped output curves (SMA data) peaking at 4.8 kw output at 12.30pm. These last 2 days of spring sunshine ditto with the system producing 28.5 kW and 25.8 kw daily totals on two consecutive days and I’m sure this is going to be a 30/7 day event in the peak of autumn and summer.
The trouble though I think the power distributor’s are rigging the smart meter programs to make up for their 12md peak losses. I’m developing a sneaky but unfounded suspicion that my smart meter is outsmarting my system and as programmed by the power distributor is somehow beating me.
For some reason or other try as hard as I want too I can’t absorb all the power output by my 5kw system. I’ve turned on everything at the same time, washing machine, cook top, heater fan, oven, lights, and the best I’ve been able to achieve is 8kwh PVS output usage with 20kW still going into the grid for a miserable 8c/kWh return. I did manage on 1 occasion to utilize 17kW and feed in 5kW into the grid. The strange thing is that even though I’m using solar output, my flexible TOU usage remains relatively the same even though I’m trying hard as I could to absorb all the output from the PV system to lower these figures.
I must admit though that my daily average electricity usage (kWh) has dropped by 60% and my electricity cost by 29% both compared to the same no of days and to the same period last year when I did not have solar. (Also bear in mind last year was charged at lower rates per kWh and this years usage was charged out at much higher cost per kWh due to price increases making the 29% cost saving conservative).
So the question is, has the power distributor who has programmed the meter, programmed it in favor of themselves, so that only a % of what is produced by the PV system is allowed through to the end user? (although I am of the belief that this a function of the inverter), and if they have are, are they doing that to all other PV smart meter grid connected electricity users to offset their losses when the PV systems peak so beautifully at 12md. If they are not, I sincerely hope they don’t cotton on to this idea.
However another thought, something I think Finn Peacock could possibly shed some light on, is it possible that at the times when Solar system outputs are peaking, that is around 12.30 pm, all the power distributor has to do is raise the line voltages to maximum allowable levels to counteract the Solar PV systems from maximising their grid feed in, but my problem is my system is feeding too much into the grid.
I have kept meticulous PV system output records (SMA inverter data) and rigorously recorded smart meter register figures and compared this to the Jemena Outlook database data fed to my retailer and on my electricity bill relating to the period since I installed my PV system, and the figures correspond very closely to my manual computer analysed records, both as to electricity used from the grid and PVS output fed into the grid.
But this does not explain why most of my PV system output is managing to find its way into to the grid rather than being absorbed by my utilities in my home, bearing in mind the power companies are losing 8c on one hand for every kWh fed into the grid but gaining either 24c or 34c on the other hand for every kWh not used from my PV system but instead requiring me to draw from the grid instead. So no matter how much PV output generated they still win.
Hi Byron,
Do you have a 3 phase supply?
(and I’m not sure the networks can do what you say to limit feed-in, but in Queensland, they can certainly do it with the new export-limiting inverters that are now mandatory)
Finn