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Resisting Climate Hysteria

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So_Cynical said:
A whole week without a red neck denial comment...200 million must have scared them away.
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I am still waiting for an answer from those looney alarmist like Al Gore, Barack Obama, Ban-Ki-moon and Tim Flannery as to why the coral reefs in Moreton Bay died before white man entered the country some 300 years ago.

GLOBAL WARMING!!!!!!!!!!!!! WHAT GLOBAL WARMING?

CLIMATE CHANGE??????????Nothing new......been going on for millions of years.

That Al Gore was hoping to make billions out of ETS....Nothing more a farce and a con job....The alarmist are losing ground fast.

Wrong bait So_Cynical
 

Post of the week right here, I concur with this sensible statement. Pollution of our oceans, ineffectual sewerage programs, water supply filtration to exterminate water borne disease, solar tracking devices to use clean energy are to name but a few ways to reduce our carbon footprint. These are the areas that the $$$$ should be pumped into. Fix the planet with it's river systems which provide nutrients and H2o (deliberate mistake) so that the trees can get back to doing what they do best by providing oxygen by taking out Co2 from the atmosphere.

And yes reduce the amount of elecktrickery we use so the power station is not burning coal
 

I often can't tell if "noco" is a Stephen Colbert style character or not.
 

There's also public resistance.

Taking renewable energy as an example, there's overwhelming public support for it in Tas and quite a lot of support (though it's not unanimous) in SA too. But in Victoria, where the industry is far less significant in broader economic terms, there have actually been protests about wind farms.

So there's a definite degree of wanting to stick to what we've got. In Queensland, coal is the "safe, cheap, reliable" option but mention renewables and you get arguments about dams bursting, turbine blades coming off, being too expensive and only working when it's windy, sunny or raining.

In contrast, big dams and wind turbines are the "safe, cheap, reliable" option in the minds of the public in Tasmania. Mention coal and you'll get a very quick response saying something about coal being unsafe due to mining accidents, too expensive since you have to keep paying for fuel and unreliable since boilers can break and miners can go on strike etc. And that's without mentioning thoughts of belching smokestacks, holes in the ground and piles of ash.

Likewise there was public opposition to a gas-fired plant being built in Melbourne 40 years ago. Never mind that Adelaide already had one that was causing no real problems and that Melbourne itself had two oil and one coal plant operating in the metropolitan area at the time. Coal was familiar, gas was unknown and seemed risky and the plant was only ever half built as a result.

And then I could mention people arguing that cars wouldn't work without lead and that even fuel injection was a bad idea doomed to fail. In reality, it works just fine.

Humans just aren't good at change.
 
noco said:
GLOBAL WARMING!!!!!!!!!!!!! WHAT GLOBAL WARMING?

CLIMATE CHANGE??????????Nothing new......been going on for millions of years.
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Michael Specter: The danger of science denial.
~
[video=youtube_share;7OMLSs8t1ng]http://youtu.be/7OMLSs8t1ng[/video]
 
So_Cynical said:
Michael Specter: The danger of science denial.
~
[video=youtube_share;7OMLSs8t1ng]http://youtu.be/7OMLSs8t1ng[/video]
Click to expand...

Michael Specter is an excellent orator, a superb salesman, a manipulator of rhetoric and has a book to sell.

His main theme revolved around genetically modified food and finding more oil.

I listened through to the end but I could not recall him mention anything about climate change or global warming....I did not hear him mention about droughts or the necessity to build more dams to store water for food crops.


Denialism by Michael Specter
Denialism
Michael Specter
RRP $29.99 Save 28%! ($8.42)
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Details

ISBN
9780715639436 / 0715639439
Title Denialism
Author Michael Specter
Category Popular Science
Impact Of Science & Technology On Society
Format
Paperback
Year 2010
Pages 304
Publisher
Gerald Duckworth & Co Ltd
Imprint Gerald Duckworth & Co Ltd
Language English
Dimensions 232mm x 157mm

Annotation
Presents an examination of the irrationality at the heart of the scare mongering and pseudo-science that stand in the way of progress and argues against modern scepticism of science and for a return to rationality.

Publisher Description
science and for a return to rationality.

Review
'Michael Specter has written a lucid and insightful book about a very frightening and irrational phenomenon-the fear and superstition that threaten human science and progress. A superb and convincing work' Malcolm Gladwell, author of “Outliers”, “Blink”, and “The Tipping Point”.

Author Biography
Michael Specter writes about science, technology and global public health for the “New Yorker”. He has twice received the Global Health Council's Excellence in Media Award, as well as the Science Journalism Award from the American Association for the Advancement of Science.
 
Who believes they are saving the planet when they turn off a light?

I used to!

I see the black balloons going up (on Televish).
I realise that CO2 is heavier than air.
I sense the balloons should be falling into valleys!

So they are lying to me!
What else are they lying about?


If I don't put the electricity through a metered device,
someone else must, else it isn't paid for.
Excess production is put through a resistor by the Power Co.

When we turn off our lights that means we reduce our usage.
Popular misconception is that reduces the the power bill.

Truth is, the cost to the Power Co goes up and
comes back to the consumer as increased rates!

Some people believe that there a are fewer black balloons if they do the right thing.
 
Braking resistors do exist, but I can assure you that power stations do increase / reduce output as demand rises / falls during the daily cycle.

For example, the following plants significantly changed output between 6pm last night and 3am this morning.

Note that all data is expressed as a % of available capacity (not total plant capacity). Eg if the plant has 4 machines but only 3 running (maintenance etc) then 100% means 100% of the available 3 machines and ignoring the 4th one.

Osborne (SA, gas) 100% down to 82%
Loy Yang A (Vic, coal) 100% down to 81%
Gladstone (Qld, Coal) 96% down to 80%. Plus a machine taken completely offline.
Loy Yang B (Vic, coal) 100% down to 80%
Northern (SA, coal) 92% down to 75% of available capacity with half the plant taken offline completely.
Poatina (Tas, hydro) 92% down to 74%
Braemar (Qld, gas) 87% down to 71%
Liddell (NSW, coal) 96% down to 71%
Pelican Point (SA, gas) 100% down to 70%
Tarong North (Qld, coal) 83% down to 69%
Bayswater (NSW, coal) 95% down to 66%
Stanwell (Qld, coal) 75% down to 58%
Tallawarra (NSW, gas) 95% down to 43%
Tarong (Qld, coal) 56% down to 43%
Vales Point (NSW, coal) 80% down to 42%
Mount Piper (NSW, coal) 64% down to 40%
Eraring (NSW, coal) 71% down to 38%
Torrens Island B (SA, gas) 80% down to 20%
Kareeya (Qld, hydro) 82% down to 8%
Bairnsdale (Vic, gas) 100% shut down completely.
Barron Gorge (Qld, hydro) 76% shut down completely.
Dartmouth (Vic, hydro) 89% shut down completely.
Eildon (Vic, hydro) 94% shut down completely.
Guthega (NSW, hydro) 82% shut down completely.
Hallet (SA, gas) 5% shut down completely.
Mortlake (Vic, gas) 100% shut down completely.
Murray (Vic electrically (NSW physically)), 12% shut down completely.
Torrens Island A (SA, gas) 83% shut down completely.
West Kiewa (Vic, hydro) 46% shut down completely.

Note that the above is not a full list of operating power stations. It is just those where output decreased by 10% or more of available capacity between 18:00 yesterday and 03:00 today. Note that times are standard time (not daylight savings).

For the record, generation that was running at 100% of available capacity at 3am this morning:

Anglesea (Vic, coal)
Blowering (NSW, hydro)
Callide B (Qld, coal)
Condamine (Qld, gas)
Darling Downs (Qld, gas)
Hazelwood (Vic, coal)
Hume (NSW, hydro)
Kogan Creek (Qld, coal)
Millmerran (Qld, coal)
Quarantine (SA, gas)
Roma (Qld, gas)
Sithe (NSW, gas)
Tarraleah (Tas, hydro)
Yallourn (Vic, coal)

Everything else was either running at partial capacity or was offline altogether.

Note that intermittent generation, primarily wind, is excluded from the above since in practice it always runs at 100% of whatever capacity it has available at the time (use it or lose it).
 
Smurf1976 said:
Braking resistors do exist, but I can assure you that power stations do increase / reduce output as demand rises / falls during the daily cycle ...
Click to expand...

I stand corrected!

But I do not understand the how of it.
After all the turbines need to spin at the correct rotational speed to produce the right CPS .
I had assumed that would create a certain amount of push or EMF.

Maybe I should google!
 
burglar said:
I stand corrected!

But I do not understand the how of it.
Click to expand...

In "layman's terms" it comes down to energy / power as distinct from speed.

For example, ramp a turbine up to speed and apply no load. With no load on it, it will keep spinning for quite a long time as it very gradually slows down due to friction etc. But put a load on it and it will stop rather quickly.

So you need energy input to match (slightly exceed after friction etc) energy output from the turbine + alternator at any given time. You put more energy in, that effectively "pushes" it along and results in energy going into the grid. Take that energy input away but leave it connected electrically and it keeps spinning, it's just that it is no longer adding power to the grid as such.

If you've got a bench grinder at home then turn it on until it reaches full speed then turn it off. It takes a long time to stop spinning. Now repeat that but start grinding something as soon as you turn the power off. Now it stops quickly since you're taking energy out of what is effectively a flywheel (ie the grinding wheels) but putting nothing back in.

Or like how a car will roll quite some distance on a flat road if you simply turn the engine off and put it in neutral. Apply the brakes (taking energy out in the form of heat) or if the road is going up hill then it will stop a lot quicker.

So you have x number of turbines spinning at 50Hz in the grid at any one time. The total energy input to those turbines needs to match that being drawn from the grid as electricity. If too much energy input then speed of ALL the turbines will increase, likewise they'll ALL slow down if energy input is insufficient.

Energy input - that's water through a hydro turbine, steam into a steam turbine, gas or oil as fuel into a gas turbine, etc. Related to that is of course the operation of the water infrastructure (some of which is a lot more complex than most would realise) or the boiler in a steam plant but it's what actually goes into the turbine that counts in this context.

It's all automated now, but back in ye olde days it was done manually. Operator sits there watching speed (frequency) and accumulated time error and manually adjusts the energy input to one or more turbines in order to keep the entire grid where it ought to be. Automated now, but it's been done manually in the past.

A point to note is that all machines will be at the same frequency in an AC grid. Not necessarily the same turbine speed, hydro turbines run at a lower speed than steam turbines for example, but they'll be at the same electrical frequency whether it's in Adelaide or somewhere in North Qld since it's all the same AC grid. That being so, it's entirely possible that a change in load in Sydney is met entirely by changing the output of power stations in another state. The link to Tas is DC such that Tas is not synchronised to the mainland as such, but the inverter at the receiving end is certainly synchronised to the mainland or Tas grid as appropriate.

Something I should add, is that the efficiency of converting primary energy (coal, water, gas etc) into electricity is not constant for any given generating unit (turbine + alternator and associated equipment) but varies considerably.

Eg the machines at Reece power station run optimally at about 85% of capacity. Above that there's a greater increase in water discharge than there is in power output, and below that efficiency also falls. Note that the optimum figure varies from plant to plant according to various factors (steam pressure and temperature in the case of thermal, head and turbine type in the case of hydro). Broadly speaking, thermal plants achieve optimum efficiency at high loads whereas for hydro it's typically at partial load but it does vary. Gas turbines in particular, suffer a massive efficiency loss below a certain point. They're quick to start and stop, but best run hard once they're going.

Further complicating all that, is "no go" areas at which wear on the machinery is disproportionately high. Eg the turbine can operate above or below that area nicely, but will suffer excessive wear in a certain output range. Generally speaking, you want to through that range as quickly as possible and not spend too much time there.

Then there's the absolute limits on minimum loads. Hydro plant can run down to incredibly low output, it can basically go down to almost zero and still remain operating, but there's lots of issues doing that with gas and especially coal in a boiler. In short, if you try and run a coal-fired boiler at 10% of capacity then that's not going to work since combustion becomes unstable. Minimum loading varies between plants, but it's around 20% for a gas steam plant and for coal it tends to be 30% or higher for good quality coal. If you've got coal that's full of water then it can be even higher - 50% of capacity or more as the lower limit to keep running. And you generally want to keep running since, apart from hydro, stopping and starting costs big $ for start-up fuel (oil, gas), lost efficiency and wear on equipment.

As for which plants run and when, apart from issues with transmission constraints that's basically a commercial decision for the owners. When demand is highest, everyone needs to be running, but when demand is low it comes down to price as to who runs and who doesn't.
 
Smurf1976 said:
In "layman's terms" it comes down to energy / power as distinct from speed ...
Click to expand...

Thanks Smurf!

Ok. I'll leave it to the guys who know.

Meanwhile, I will leave some lights on and pay a few cents extra.
At my age, I don't bounce if I trip over furniture!!



 

7:46AM today in Tasmania.

All was going fine then *FLASH* - a lightning strike tripped both transmission circuits from Gordon power station.

The line auto-reclosed (put itself back into service) straight away but the overall "wobble" to the grid tripped the Basslink inverter off completely.

Basslink was supplying (from Vic) 39% of the entire load in Tas at the time (wind 12%, hydro 49%).

The result was the automatic (instant) dumping of major industrial load (smelters) equivalent to 33% of total system (Tas) load at the time. That's an automated system (only one of its' type in the world so far as we know) not your regular under frequency load shedding that every grid has. So, lightning strikes, Gordon off, Basslink dead and industrial load instantly dumped, Gordon straight back on again. Someone sitting at home might have noticed the lights get dimmer for half a second but that's it, all regular consumers retained full supply.

Key point there is that Gordon, a conventional hydro station and the immediate "victim" of the lightning strike which briefly isolated it from the rest of the grid, was straight back up and running without incident. Likewise every other hydro unit online at the time worked flawlessly and stabilised the system amidst the chaos. It was the inverter at the other end of the state which shut down.

What next? It takes a bit of time for the smelters to ramp up again after a major trip, but an hour later they were back to full power. And it was good old hydro power that got everything running again, wind output dropped 22% amidst all this (due to natural wind variation) and Basslink was still down. That said, at least the wind farms do keep operating as such.

Rotating machines, particularly those driven by stable means such as hydro or steam, work in a crisis during which inverters give up. Quite a lot of household solar inverters would also have tripped at the time, they're also no help in a crisis, although due to the weather and time they wouldn't have been generating that much power anyway.

If we're going to have inverters, particularly small decentralised ones, supplying a large portion of total generation at some future time then there's a lot of system stability issues associated with that. It's difficult enough having one large inverter, it's an order of magnitude more difficult trying to control a million of them.

For the record, at one point today we had literally every transmission line in the state subject to lightning nearby although nothing drastic actually happened apart from a major hail storm around Hobart (definitely the largest hail I've ever seen in Tas, would be roughly 15mm diameter so almost big enough to start causing damage).
 
Smurph, you need to get into the training field, your wasted in power system control, or generation.
 
Smurf I really appreciate your detailed explanations of how our power systems operate. It adds so much practicality to what are often simplistic and inevitably incomplete discussions.

Cheers
 
Gee whiz Smurf, now you're answering my questions before I even ask them. How engineers think about distributed generation (i.e. micro-grids down to domestic) in relation to the big grid was going to be my next request, after I finished responding to Smurf, IFocus, and orr, who answered my questions of last month. I've written at least five versions of that response as I kept exploring the issues you all raised. They all started with thanks to the three of you for your disconcertingly quick replies to my questions about synchronous rotary machines, so please consider yourselves thanked five times.

I think I should explain why I'm tackling this crash course in grid management. I run the website for a regional climate action group which currently has one group working actively to implement solar generation (probably in a micro-grid for an industrial area) and another group studying nuclear generation. I’m trying to understand the issues at least well enough to be sure that the website gives them a fair, full, and accurate discussion at a popular level. Not easy.

Nuclear generation is a very tough issue for many people, myself included. I can see its attraction as a substitute for fossil fuel generators that can more or less be dropped into place and hooked up to the existing distribution system. On the other hand, distributed generation, like distributed computing, seems inherently more robust than big generation, however it's powered. At least it does to an old software bunny who has trouble remembering that power networks are subject to physical forces.

I've got many more problems with nuclear power but for the moment I'd love to understand inverters and why they are so sensitive to wobbles in the grid.

This seems to me to be one aspect of the general subject of how to handle the interface between power generation and distribution. I wonder how much of the present system is historical accident and how much is physical necessity. Following from that, how hard is it to get from where we are to, say, a different kind of grid that doesn't rely on the inertia of synchronous rotary machines to recover from the wobbles.

Can't you tell I have no engineering background? Thanks very much to those who do and who are so quick to share it.
 
basilio said:
Smurf I really appreciate your detailed explanations of how our power systems operate. It adds so much practicality to what are often simplistic and inevitably incomplete discussions.

Cheers
Click to expand...


Simplistic and inevitably incomplete discussions are my way of asking Smurf to elaborate.

And yes, he does it extremely well!!
 
ghotib said:
Gee whiz Smurf, now you're answering my questions before I even ask them.
Click to expand...

I always try to put things in "layman's terms".

Same thing happens at a public open day at a power station (at least it does in Tas) by the way. Put things in terms that are understandable and most people can grasp the concepts quite well especially when they're standing inside a real power station looking at the equipment right in front of them. Once you relate it to things like driving a car or emptying a bath then it all makes sense.


Nuclear - essentially a "drop in" replacement that from a grid perspective is no different to any other large generating unit regardless of how it's powered. It's controllable and predictable within reason. Same as coal, gas, hydro etc.

Distributed - in principle, 100,000 x 3kW inverters are far less likely to all break down at once than a single 300MW machine. Same with anything really, if you've got a fleet of 100 cars then the won't all break at once unless some common element (eg fuel) causes them to all fail. Much the same with having lots of inverters. It's highly unlikely that my inverter at home would break as such at the same time as thousands of others but they can certainly fail all at once if a common element (the grid) causes them to trip offline.

Controlling it is where things get difficult. A few big power stations are a lot easier to control in terms of output than trying to do the same with a million or more inverters and especially when those inverters have a variable input (solar) versus the far more reliable energy input to a large power station.

Distributed generation at present (without any form of central control) basically leads to a situation where the load on the grid seems smaller than it is. Eg if the "real" load is 1000 MW but half that is distributed, then the centralised power stations only "see" a 500MW load and they only produce to meet that 500MW. If something goes wrong and all those inverters suddenly trip offline, well now you've suddenly got the full 1000MW load being placed on the remaining centralised generation. End result = widespread blackouts at best, system black (complete grid collapse) at worst if the load isn't dumped quickly enough to avoid overload and frequency collapse.

Theoretically it would be blackouts not an actual collapse, but things don't always work as you'd expect them to in an extreme situation. There was one such "not as expected" situation a few years ago in NSW with a transmission fault north of Sydney. That ended up dumping load as far away as Hobart. There's also been plenty of incidents in all states where something tripped due to a problem and then something unrelated suffered as a result - that's in the "law of unintended consequences" category really.
 
http://www.businessspectator.com.au...&utm_content=1053453&utm_campaign=kgb&modapt=



 
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