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The Forum > Article Comments > Electricity price increases: gold plating or carbon dating? > Comments

Electricity price increases: gold plating or carbon dating? : Comments

By Anthony Cox, published 16/8/2012

Is Julia Gillard trying to wedge Tony Abbott on electricity prices.

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Is not part of the build up of the transmission system because of the need to handle the massive unregulated and irratic inflows of energy that Solar and Wind will be injecting into the system from virtually anywhere. By Government fiat, these sources of energy are required to increase hugely. A cloud covers the sun and all the solar panels in Sydney suddenly stop generating power and then clears so (in time) mega-watts surge back into the system just in time for gas turbine generators to have cut in.
Posted by McCackie, Friday, 17 August 2012 7:57:29 AM
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Wind does not work, not only for reasons to do with capacity factor but also because of the minute to minute unreliability which I also spoke of. Wind farm performance is measured in Australia here:

http://windfarmperformance.info/?date=2012-08-15

As I say, even when the wind is blowing, the output is so unreliable that it strains the capacity of the grid to maintain constant VA flow. This has been the universal experience of grid operaters all over the world. Backup plants — most often gas — have to be kept constantly spun up on warm standby ready to fill in on a minute’s notice.

Compounding this unreliability, turbine output varies as the cube of the wind speed. This means that a breeze gusting from 20 to 30 mph — a 50% variation, not at all uncommon — produces output that momentarily triples, then drops back unpredictably. There is no power grid in the world that could withstand this vacilation by even 25% of its generating units, let alone what that would do to the air conditioners, stoves, factories, and televisions of the end users.

This means special grid construction to handle these surges has to be undertaken which explains a lot of the new "poles and wires" infrastructure expense. And the cost of wind energy is frightful.

The incredible cost per MW of these towers is around $1 million US per MW to erect. The decommissioning cost per tower (regardless of capacity, at present) is also estimated at about $1 millon per MW. Apologists for wind have pointed out that these are of the same magnitude as nukes; which is true of the older-generation plants in the US and UK, but not of the newer designs common in France and planned for India. But this overlooks two points:

Firstly, at the end of their life, the nukes, like coal and gas plants, will have been producing at around 90% capacity for the entire period. Wind won’t even come close; as I say CF is about 20%.

And secondly the environmental damage of windfarms which is just starting to be appreciated.
Posted by cohenite, Friday, 17 August 2012 9:24:20 AM
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Roses1 - your point "the AEMO has set capacity factors for wind at 3-7%' is nonsense".. sorry I didn't realise that you were not with this stuff..

Capacity factor in this case is simply the amount of the installed capacity which the AEMO will count towards the generating capacity they need to keep on hand at any time. Note, that's CAPACITY not the actual supply. The figure has nothing to do with the overall contribution of wind power to the power supply.

But as AEMO will only count 3-7 per cent of installed wind power towards the capacity they need (for fossil fuel plants the capacity factor is around 85 per cent), the figure means that wind farms supplying 20 per cent of power will replace only a tiny fraction of conventional capacity, although the conventional capacity MAY be used less at varuious points duing the typical day.. in other words, they are a straight additional cost. .

Cohenite - good stuff, but if I may take it one step further. One megawatt hour from a wind power will NOMINALLY replace one MWhr from a conventional plant, so the legislative requirements may be met, but with changes in the network, the need to run the existing plants less efficiently and increased spinnng capacity, ther is a real question in my mind as to whether they save much carbon at all..
Posted by Curmudgeon, Friday, 17 August 2012 1:47:06 PM
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OK Curm; can you give me a link to AEMO paper describing their 3-7% capacity factor.

Regardless of the AEMO's figure, the fact remains that wind did in fact produce >20% of SA's electricity consumption in 2011-12. That's a lot of fuel saved and a lot of greenhouse gas reduction.

One reason the AEMO sees a need to have more fossil fuel capacity reserve is that we still have the old style centralized grid. If it were a dispersed state of the art 'smart' grid this would not be needed.

Also having fossil capacity is a lot different from actual spinning reserve. Coal fired units can be powered down or switched off most of the time. For example one of the large old SA coal plants is going to be turned off for more than half the year; it's still there as capacity but it's not working for most of the time. I've got nothing against keeping old coal plants in mothballs for this purpose until the grid is modernized (not repaired/ enlarged as is currently being done but really modernized).

So I don't dispute your figures, just your extrapolation of what they mean. You've got to be joking to imply that 20% renewable energy generation requires fossil plants powering away in the background churning out as much carbon as if there were no renewable generation.
Posted by Roses1, Friday, 17 August 2012 2:25:02 PM
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Roses just googling greenie sights doesn't give you much true information it would seem.

Fossil fuel plants are not all the same. Coal can not be spun up to suit the variability of wind, or cloud cover for that matter. If coal is the back up for fairy floss power, it must be kept spinning.

Gas can be fired up more quickly, but not as quickly as wind goes up or down, so much of that must be on standby.

Interesting suggesting that a coal fired plant will be shut down. Please advise us when it has been, & for how long. If that requires power from Victorian brown coal generation to be imported, you won't forget to mention that now, will you.

Have you noticed that one of the prime movers in solar cell development, Germany, is building no less than 8 new coal fired plants, to meet their requirements. They said they were going to get rid of coal completely, so it's what is done, not said that matters. It is often much more interesting to look at actions, rather than listen to talk. As we now know, with our Julia, talks cheep.

If you are going to regale us with the production of your Google finger, I suggest you do a bit more study in less green areas first, so you have some understanding of the subject. That way you could avoid the worst, & most laughable assertions of the green movement.
Posted by Hasbeen, Friday, 17 August 2012 2:59:28 PM
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Wind has a capacity factor of between 20-38% but, as I have said, that average output is unreliable from minute to minute; the unreliability factor of wind is between 2-6%; see Table 1 here:

http://aefweb.info/data/Wind%20farming%20in%20SE%20Australia.pdf

That unreliability is why wind can NEVER supply base load, and why money spent on wind is wasted.
Posted by cohenite, Friday, 17 August 2012 4:50:30 PM
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