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Turn off all wind and solar at 6pm peak time — makes no difference

All those billions we spent and yet at 6pm, many days coal, gas and hydro provide 98% of the power Australia needs. Wind and solar are our spare bikes, the third ski, the Banana-Slicers of the National Grid (read those reviews). Just what would we do if wind and solar were all we had? — Jo

At peak time intermittent renewables often make less than 2% of total Australian electricity

Guest Post by Anton Lang (TonyFromOz)

h/t to Rafe Campion at Catalaxy

When power is required the most, wind and solar are missing almost entirely. This isn’t cherry picking of one time — peak time is the most important time on the grid, when the most power is required.  The almost non-existent contribution from renewables is so common it has occurred now for seven days out of the last 14 days.

I’ve been doing a series on the Australian generation and demand curves on a daily basis for seven weeks, the totals are settling down, so that now the percentage changes are only in tenths of a percent, and consider that when it comes to total power and coal fired power, a tenth of one percent is 600MegaWattHours, so at that end of the scale, small is actually large, if you can see that.

At the moment, after 10 weeks, coal fired power is delivering 72.37% of all power, and wind is delivering only 6.16% of all generated power. I have all the percentages, but those two are the ones of most importance. Wind power has just had a very good week (for wind), but in the end, coal fired power is still delivering more than 3 times the total for every renewable power source in the country.

You might wonder why I haven’t mentioned solar power here, because ALL the solar plants, (not rooftop solar) only generate 0.38% of the required power, so just a tick above nothing at all.

Wind, solar, peak time, Australian NEM.


The main evening peak occurs at 5.30 to 6PM, when power consumption is always at its greatest when people come home, cook dinner, throw on the washing and have showers. (Note here the time, 5.30/6PM, so the Sun has set and there is ZERO power from any solar power plant, and also ZERO power from any rooftop solar installation as well). It’s that one point in time when a large supply of power is at its most critical, so now look at this data for seven days of 14 days in the middle of winter. Wind has had a poor time of it lately, due to those High Pressure weather systems hovering over the area where there is the largest concentration of wind plants, hence very little pressure gradients for wind, and they are in South Australia and Victoria.

Here’s a sample of seven of those 14 midwinter days at 6pm peak power time:

There were three other days when it was between 2% and 3%, but these are the seven lowest. This is all wind, as the Sun has set and in winter, solar is useless at 6pm.

So, when power is required the most, wind and solar are missing almost entirely. The point here is that even though the country is consuming the most electricity it actually can consume, on those 14 days, almost ALL OF IT was actually being delivered from coal fired power, natural gas fired power, and hydro power.

From the low point of 0.3% (100MW of that Peak) to the high point of 2%, (600MW) is between one and three units at a gas plant just waiting for the call already to ‘fire up’. The fact that those three main sources have already proved they can handle it is an indictment on the total and utter uselessness of wind power, solar power, and rooftop solar power.

Coal power just keeps going, while hydro and gas are volatile depending on wind generation

There was something I noticed after a week or two of doing it, and that was that whatever wind power did, up, or down, it had no effect at all on what coal fired power was supplying. At first I thought it may have been an anomaly or a short term thing, but after seven weeks now, it is in fact the case.

Wind power varies wildly on a daily basis, but coal fired power just kept delivering within its close range of power generation, no matter what.

What they were using as an ‘adjustment’ factor was natural gas fired power, and also hydro power as well. So, if wind power was up, then those other two were down, and when wind power was down, then those other two were up. And coal fired power stayed (virtually) the same. You might think that (keeping in mind that I said earlier that with coal fired power, big can ‘look’ small) any change would be subject to ‘scale’, but here I’m talking of wind varying by sometimes hundreds and more MW, and the other two the same also, but coal fired power only changed by perhaps one hundred MW up or down, so nothing really. The confirmation came on two days last week, the Thursday and Friday, and look at these figures, and these are the average power delivery per hour across the day.

Thursday coal fired power – 18600MW and wind power – 710MW

Friday coal fired power – 18500MW and wind power 2450MW, and overall power generation was 300MW lower at an average of 25200MW per hour.

So, while overall power consumption was ever so slightly lower, wind power was up by 1740MW , and coal fired power only changed by 100MW, and while this one is the most obvious, all the other changes also reflect very little change for coal fired power when wind power varies so wildly on that daily basis.

TonyFromOz series on daily Australian power supply and demand. The Latest week results, (week 10) and there will be a new one next Monday


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