The Forum > Article Comments > The feeble outcomes of Quixotic power crusades > Comments
The feeble outcomes of Quixotic power crusades : Comments
By Mark S. Lawson, published 18/12/2015As the problems of the South Australian electricity market in integrating the state's large supply of wind power show, there is a practical limit to the use of renewables in Australia.
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Posted by Shadow Minister, Tuesday, 29 December 2015 2:41:31 AM
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Shadow -
I am Civil not Electrical. But you're the one with delusions. The statement "because the limiting factor is the peak load not the base load" is far from dumb. It is something I regard as obvious, though clearly it is not obvious to you. "The limiting factor is precisely that the power system has to meet the power demand 24/7 with 100% reliability" No, that's the objective. The limiting factor is the most difficult part of the objective to meet, and that's the peaks not the base. "There again is the issue, you cannot rely on wind and solar to fill the gaps, at least you need large scale gas to do that." That's no excuse for not trying to minimise the amount of gas needed. "Yes there still is a technical reason that renewables cannot meet full capacity, and that is long winter nights with no wind following overcast days" Rather rare meteorological conditions! "where you will need nearly 100% back up from fossil fuels." The gas doesn't have to come from fossil sources - it can come from biological sources and even be synthesised from seawater. "Paying for that massive back up along with the ridiculously expensive renewable generation, it will difficult to ever pay for it." The renewables have very low ongoing costs, so as long as cheap finance is available, they work out cheaper than fossil fuels. And much of the backup is already there so doesn't need paying for again. In sustained overcast conditions, gas can be an alternative source of heat for the solar thermal infrastructure. And one option that's certainly worth investigating is colocation of gas ceramic fuel cells with the solar thermal plants. Posted by Aidan, Tuesday, 29 December 2015 12:06:01 PM
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Aidan,
As I thought, you have no clue. As background, I am an electrical engineer that has spent more than a decade as Group electrical engineer for a large multi site industrial corporation, and have spent years designing and installing generators, co generation, high voltage substations and networks, and integrating with the major power transmission networks, including bidding for power/ generation and demand/peak load control. So when you have finished building roads and culverts, take some time to actually read up on power systems before making such dumb ass comments. The limiting factor in power generation is actually to match supply to demand, especially when the demand is rapidly changing, as supply > demand will mean that voltage and frequency increases and supply < demand means that voltage and frequency decreases, and this happens relatively quickly. So gas systems are used not only to supply peak supply, but to help trim the system. As renewable power supplies are variable, and always put in 100% of the net power they generate, they contribute nothing to load control and are not available to fill the gaps, and only the supremely ignorant would claim that they could. And as above there is no control over the renewable supply, their variability adds to the instability of the network requiring that the remaining supply become more flexible to accommodate the varying renewable supply. Renewables require the back up of expensive gas supplies which adds to the already high costs. At the low cost of government bonds renewables are still far more expensive than coal or nuclear. Similarly while some gas can come from biogas the vast majority comes from fossil fuels Posted by Shadow Minister, Tuesday, 29 December 2015 6:13:33 PM
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We should do what the French did decades ago, and just nationalise electricity and mass produce nuclear power stations. Fast. If we listen to Dr James Hansen diagnose our climate problem, why not the solution? Modern reactors are much better and SAFER than even the French reactors. They *eat* nuclear waste, and convert today's nuclear waste into about 500 years of clean baseload reliable energy! They have passive safety, and require electricity to function, and automatically shut themselves down in a power failure. Dr Hansen recommends the world build out 115 nuclear reactors a year which is slower than the French nuke per GDP rate.
http://www.theguardian.com/environment/2015/dec/03/nuclear-power-paves-the-only-viable-path-forward-on-climate-change We have the advantage of new assembly line reactors like the Integral Fast Reactor and Liquid Fluoride Thorium Reactor, both of which convert nuclear waste into energy. They also have passive safety systems impossible with older water reactors, which have cores well over 100 atmospheres of super-high pressure water. Older cores were like giant pressure-cookers, and when things went wrong, well, Chernobyl! Modern IFR's and LFTR's operate at much lower pressures, and so are cheaper, faster, and SAFER to mass produce! Posted by Max Green, Wednesday, 30 December 2015 6:34:37 PM
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It would be helpful if Hansen et al pointed out that renewables only make sense off-grid.
What is the point of being half pregnant with nuclear supplemented with renewables on grid? Nuclear is ramped up and down with demand while renewables add nothing to reliability, nor to affordability. Is Hansen just throwing a bone to politicians duped by the Green bandwagon to allow them to save face? The sooner Greens come to grips with reality the sooner AGW can be properly addressed. They have to move through questions of genetic effects of radiation, which is seriously under challenge (*), and proliferation. Both have risk/reward aspects. Greens cannot be allowed to keep us fiddling while Rome burns. Hard questions must be asked and good sense must prevail. * The original 1956 paper in the magazine "Science" that gave rise to the panic about radiation and the LNT (linear no-threshold) model for exposure that burdens us today is under challenge. The paper and an appeal to have it retracted, together with the response from "Science", is at https://www.nas.org/images/documents/LNT.pdf Posted by Luciferase, Wednesday, 30 December 2015 10:52:28 PM
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Shadow,
Considering your background, I'm amazed at some of the stupid claims you've posted. It is simply untrue that all renewables contribute nothing to load control – indeed it's one of hydro's greatest strengths. Rather than resorting to dumb generalisations, you should look at each renewable source individually: I accept solar PV supplies what it generates according to how much light it gets. Generally the same is true for wind, though some wind turbines can reduce their output on demand. But what we were discussing was solar thermal. Its output can be controlled. The capabilities obviously depend on the design, but there is no good reason why it can't fill the gaps. I'm saying that's what it should be designed for. But you seem to think the holy grail is to instead put it to the low value use of generating baseload power! And what is your evidence that "At the low cost of government bonds renewables are still far more expensive than coal or nuclear"? Posted by Aidan, Thursday, 31 December 2015 11:26:12 PM
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The reason that I believe that you have no experience in electrical networks and get all your delusions from google is that you make supremely dumb statements like:
"because the limiting factor is the peak load not the base load."
The limiting factor is precisely that the power system has to meet the power demand 24/7 with 100% reliability which wind and solar technically cannot meet yet. Base load supply is renewables greatest weakness.
" it makes much more sense to design it to meet peak demand and fill the gaps in the supply from wind and solar PV."
There again is the issue, you cannot rely on wind and solar to fill the gaps, at least you need large scale gas to do that.
"There is no technical reason why we can't install sufficient renewable energy capacity to meet demand. It would be expensive, but I think it would pay for itself in the long run."
Yes there still is a technical reason that renewables cannot meet full capacity, and that is long winter nights with no wind following overcast days where you will need nearly 100% back up from fossil fuels. Paying for that massive back up along with the ridiculously expensive renewable generation, it will difficult to ever pay for it.