I'm sure many of you will approve of this as much as I, but will they get anywhere?
http://www.epaw.org/media.php?lang=en&article=pr45
http://www.epaw.org/media.php?lang=en&article=pr45
Wind Farms
- Thread starter cozycats
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Sadly there are many so called ecology measures which are flawed. Wind farms are just one of them. The materials used against live time of the farm show them as just gaining but what it does not show is the conventional power stations running on standby to fill the gap when the wind farms fail.
The same applies to so called energy saving light bulbs. They only save energy when the heat is not required and since lights are used more in winter and also at a time where more heat is wanted i.e. evening giving the boost to heat required as we sit down likely very little energy is saved. Although since electric costs more then gas likely they do save money.
The energy saving drive has removed all the hot and cold fill washing machines. So even where solar is used to heat the water that hot water can't be used by the washing machine.
The drive for renewable has caused many to install wood burning stoves which unless run at a set heat as a batch burn storing the heat for use latter run at around 30% efficient rather then near 90% for gas.
The list goes on and on. Including discounting the amount of heat the tumble dryer sucks from the home and blows outside.
Interaction is also missed where for example a tumble dryer can suck in flue gases from open flue fires and stoves.
I tried using wind power on a small scale on the Falklands to power electric fences and it was found that solar panels were better than wind generators at providing enough power to keep battery charged even though the wind generator was rated 4 times larger than the solar panel and this is an island named by Argentine as the windy islands.
The same applies to so called energy saving light bulbs. They only save energy when the heat is not required and since lights are used more in winter and also at a time where more heat is wanted i.e. evening giving the boost to heat required as we sit down likely very little energy is saved. Although since electric costs more then gas likely they do save money.
The energy saving drive has removed all the hot and cold fill washing machines. So even where solar is used to heat the water that hot water can't be used by the washing machine.
The drive for renewable has caused many to install wood burning stoves which unless run at a set heat as a batch burn storing the heat for use latter run at around 30% efficient rather then near 90% for gas.
The list goes on and on. Including discounting the amount of heat the tumble dryer sucks from the home and blows outside.
Interaction is also missed where for example a tumble dryer can suck in flue gases from open flue fires and stoves.
I tried using wind power on a small scale on the Falklands to power electric fences and it was found that solar panels were better than wind generators at providing enough power to keep battery charged even though the wind generator was rated 4 times larger than the solar panel and this is an island named by Argentine as the windy islands.
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There's one aspect of all this that I've never seen discussed to much of an extent ... if we ever succeded (presumably/hopefully no chance!) of covering the country with so many of these things that we were extracting an appreciable proportion of the country's (electrical) energy needs from wind, what on earth would be the effect on climate? The weather systems are presumably used to having, if no dependent upon hving, this energy remaining in the winds?
I haven't got a clue as to the answer, but I find it hard to see how large-scale removal of energy from wind could fail to have at least some effect on weather/climate.
Kind Regards, John
I haven't got a clue as to the answer, but I find it hard to see how large-scale removal of energy from wind could fail to have at least some effect on weather/climate.
Kind Regards, John
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As to reducing the speed of wind I don't know but on the Seven there was a trial wave power and the reduction in energy caused it all to silt up.
If one removes energy from wind, it's really inevitable that it will slow. What I don't know is the extent to which thatvwill affect weather and climate, but it surely must have some effect if the amount of energy extracted is large enough.
Kind Regards, John
Well, I'm only surmising but as the wind is not an entity in itself but is caused by pressure differences in the atmosphere I would think that any 'wind' slowed, or removed, by the windmill, if indeed it is, would have to be 'compensated for' in order to continue the process of equalising the pressure between low and high pressure 'areas' (volumes?).
So, It depends where the removed energy originated. I am not sure.
Up there, somewhere.
Is the energy removed so small it is negligible?
Could it have the effect of making it windier - overall or for longer.
Is that why they are called wind generators?
It is similar to water-wheel, isn't it, if there were an endless recirculation of the same water?
Does the wheel slow the flow of the water?
So, It depends where the removed energy originated. I am not sure.
Up there, somewhere.
Is the energy removed so small it is negligible?
Could it have the effect of making it windier - overall or for longer.
Is that why they are called wind generators?
It is similar to water-wheel, isn't it, if there were an endless recirculation of the same water?
Does the wheel slow the flow of the water?
I guess that depends upon what you mean by an entity. Wind has energy since it consists of molecules (which have mass) moving at speed. When one extracts energy with a wind turbine, the mass of the molecules doesn't change, so their velocity must fall. The turbine will also result in the pressure being different on the two sides (think aircraft propeller).
That's the question I'm asking. I know that it will have an effect, I don't know how significant it would be.
It's similar to the 'under' type of waterwheel, but I think they are much less common than 'over' ones
Dramatically so, yes (if it's an 'under' type of wheel' - just as wave generators considerably reduce the waves beyond them. You obvioulsly don't get energy 'for nothing' - you merely shift it from moving molecules in air or water (by slowing down their movement) into electricity. 'Over' waterwheels, or the turbines in hydroelectric plants, are more complicated, since gravity (hence loss of potential energy as the water falls) is a major part of the equation.
Kind Regards, John
So off the coast here is an off shore windfarm.
Whilst building it they damn near sank one of the specialist vessels whilst it was putting the foundations in!
Now the way it works is the foundation is driven in with a pile driver, the rest of the turbine tower is placed over this and the two are stuck together with a special grout!
Now this grout has to be used at a specific temperature, fine, apart from the pile, the sea and the tower all being at different temperatures.
So, guess what, the grout has failed on a number of the towers which I'm told is causing them to lean by a degree or two!
Whilst building it they damn near sank one of the specialist vessels whilst it was putting the foundations in!
Now the way it works is the foundation is driven in with a pile driver, the rest of the turbine tower is placed over this and the two are stuck together with a special grout!
Now this grout has to be used at a specific temperature, fine, apart from the pile, the sea and the tower all being at different temperatures.
So, guess what, the grout has failed on a number of the towers which I'm told is causing them to lean by a degree or two!
I should have added ... have you not come across the phrase "as still as a mill pond"? The water will appoach the watermill's wheel at a fair rate of knots, but once it has passed the wheel (and had the energy extracted), there's often virtually no movement/flow at all.
Kind Regards, John
The wind (air) only has energy because of the high pressure forcing it to the low pressure. After you have extracted the energy with the wind mill there will still be high pressure forcing more air. As this results in low pressure on the leeward side of the blades won't that cause an increase of the wind speed or, at least, a compensatory resumption by the air that missed the blades.
Once the high and low pressure areas are equalised - by atmospheric conditions - the turbine will stop so I suppose the energy extracted must be a negligible amount as no number of turbines could stop the atmospheric low from filling or change the direction from which it is being filled.
An aircraft propeller is the opposite, isn't it and will make wind until the fuel runs out so it's not really comparable?
Were the turbines driven on a calm day at the speed they rotate normally, how windy would it be?
As for the waves, these are just waves, not flow, and are also different in that it is a very small, by volume, movement of the water itself. It would not be hampered by anything man made if it were travelling from one place to another.
A tsunami, being a very large movement is unstoppable and more like the air (wind) though still just a wave.
You say the water mill will slow the rate of flow but surely, whether under or over type, if the gradient were constant it would not as all the water will flow because of gravity.
Were it to slow - overall - then, surely, a backlog would occur so without man-made differences in the gradient - the mill pond - the water, if slowed temporarily by the wheel, must then carry on at the same rate
Once the high and low pressure areas are equalised - by atmospheric conditions - the turbine will stop so I suppose the energy extracted must be a negligible amount as no number of turbines could stop the atmospheric low from filling or change the direction from which it is being filled.
An aircraft propeller is the opposite, isn't it and will make wind until the fuel runs out so it's not really comparable?
Were the turbines driven on a calm day at the speed they rotate normally, how windy would it be?
As for the waves, these are just waves, not flow, and are also different in that it is a very small, by volume, movement of the water itself. It would not be hampered by anything man made if it were travelling from one place to another.
A tsunami, being a very large movement is unstoppable and more like the air (wind) though still just a wave.
You say the water mill will slow the rate of flow but surely, whether under or over type, if the gradient were constant it would not as all the water will flow because of gravity.
Were it to slow - overall - then, surely, a backlog would occur so without man-made differences in the gradient - the mill pond - the water, if slowed temporarily by the wheel, must then carry on at the same rate
I've just done a little Googling of the general topic of the effect of wind turbines on wind, weather and climate. It is clearly a complex and controversial topic, which is currently undergoing consdierable research. Most seem to agree that it has some effect on local weather and that, if wind turbines became far more prevalent, this could have global implications - but most (but not all) seem to feel that the envirronmetal downsides of wind turbines are outweighed by the environmental advantages. It also appears that the mixing (of upper and lower layers of air, with different moisture contents), due to turbulence created by turbines, is a more important reason for weather/climate changes than is the effect on winds.
In terms of what I've been writing, I've just realised that I confused myself (and others, no doubt) by implying that the presence of a tubine (or waterwheel) would result in reduction of wind speed (or water flow) only downstream of the turbine (or wheel). However, one has only got to think of the electrical analogy to see that is wrong. Insert a resistance into a circuit (in order to extract energy, as heat) and the current in the circuit (for a given driving voltage) will fall, but obviously throughout the circuit, not just on one side of the resistor. So it is with wind turbines -they slow the wind (for a given driving pressure difference, c.f. potential difference) on both sides of the turbine. This effect on wind speed is (understandably) apparently important in the positioning of turbines in a 'wind farm' - if one is positioned in the lee of another, it will receive consderably reduced wind (speed) and hence will not function very well.
Kind Regards, John
It's a good weekend to be selling gennies on eBay...
How long before people fetch up here without a clue, no knowledge of changeover switches, DIY'd widowmakers etc?
How long before people fetch up here without a clue, no knowledge of changeover switches, DIY'd widowmakers etc?
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