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PRTVR
853 posts
91 months
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HD Adam said: Einion Yrth said: There goes the 2nd law of thermodynamics again. Not really. Having read the article, the inventor claims that the fan helps with the recharging and is not claiming that it's a perpetual motion machine. Yes, the fan will create drag but of you could gear it to drive a big enough alternator, you could probably extend the range of a small electric car quite a lot. It would in effect be "free" energy like regenerative braking. No its nothing like regenerative braking, in normal braking friction is turned to heat, waste energy, with the fan there is no energy to recover.
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jet_noise
1,231 posts
52 months
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Dear P, PRTVR said: No its nothing like regenerative braking, in normal braking friction is turned to heat, waste energy, with the fan there is no energy to recover. It could be (an energy recoverer) if the fan was shielded with shield opening connected to the brake pedal. /branestawm, regards, Jet
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PRTVR
853 posts
91 months
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jet_noise said: Dear P, PRTVR said: No its nothing like regenerative braking, in normal braking friction is turned to heat, waste energy, with the fan there is no energy to recover. It could be (an energy recoverer) if the fan was shielded with shield opening connected to the brake pedal. /branestawm, regards, Jet  ok I Will give you that, but the extra weight would out way any gains plus having to design the shape of the vehicle would not be very aerodynamic.
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HD Adam
1,677 posts
54 months
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PRTVR said: jet_noise said: Dear P, PRTVR said: No its nothing like regenerative braking, in normal braking friction is turned to heat, waste energy, with the fan there is no energy to recover. It could be (an energy recoverer) if the fan was shielded with shield opening connected to the brake pedal. /branestawm, regards, Jet ok I Will give you that, but the extra weight would out way any gains plus having to design the shape of the vehicle would not be very aerodynamic. I meant it as an analogy. Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design. Yes, there's weight and drag to take into account but it could extend the range if done right.
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PRTVR
853 posts
91 months
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HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out
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s2art
13,274 posts
123 months
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PRTVR said: HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out Correct. The only effect would be to reduce the range and top speed of the vehicle.
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LongQ
Original Poster
8,961 posts
103 months
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PRTVR said: HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out It will work fine if the car only travels primarily down hill. Maybe the farmer has enough coolies to drag it back to the top of the hill when required. Or a deal with a haulage company.
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Apache
38,277 posts
154 months
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LongQ said: PRTVR said: HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out It will work fine if the car ony travels primarily down hill. Maybe the farmer has enough coolies to drag it back to the top of the hill when required. Or a deal with a haulage company. You cannot create energy, you can only convert it. There is nothing going to waste, it'll work fine going down hill, but you first need to expend the energy you will recover getting it up the hill in the first place. No free lunch.
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HD Adam
1,677 posts
54 months
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Apache said: LongQ said: PRTVR said: HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out It will work fine if the car ony travels primarily down hill. Maybe the farmer has enough coolies to drag it back to the top of the hill when required. Or a deal with a haulage company. You cannot create energy, you can only convert it. There is nothing going to waste, it'll work fine going down hill, but you first need to expend the energy you will recover getting it up the hill in the first place. No free lunch. Are you lot being deliberately obtuse or just not reading the original post I made? I DID NOT say that it was a perpetual motion machine. Of course you can't create energy by spinning the fan to only drive the wheels. Here's the scenario and I'll keep the maths simple. These figures won't work in real life but it gives you an idea. You (the farmer) has an electric car. It runs off a single 12v battery. The car will do 50mph. It takes 10amps to drive the motor and the battery will last one hour at this rate until it is flat. You can travel 50 miles therefore until you need to recharge. Now you fit a fan on the car. There's extra drag because the fan is turning a generator. The car moving through the air at 50mph moves the fan. The car now takes 20 amps to drive because of the extra drag. The car will only go 25 miles. But, the generator is producing 15 amps. This means that the that the current draw from the battery is only 5amps and therefore at the same speed, it will last twice as long until it goes flat. That means that you could travel 100 miles. You have extended the range. If you could gear the fan and generator so that it's output was greater than the extra current needed to move the fan through the air, then you gain. NB: Apologies for the thread hijack and it's all gone a bit "plane on a conveyor belt". I could also be having an Ambwilans moment 
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s2art
13,274 posts
123 months
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HD Adam said: Apache said: LongQ said: PRTVR said: HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out It will work fine if the car ony travels primarily down hill. Maybe the farmer has enough coolies to drag it back to the top of the hill when required. Or a deal with a haulage company. You cannot create energy, you can only convert it. There is nothing going to waste, it'll work fine going down hill, but you first need to expend the energy you will recover getting it up the hill in the first place. No free lunch. Are you lot being deliberately obtuse or just not reading the original post I made? I DID NOT say that it was a perpetual motion machine. Of course you can't create energy by spinning the fan to only drive the wheels. Here's the scenario and I'll keep the maths simple. These figures won't work in real life but it gives you an idea. You (the farmer) has an electric car. It runs off a single 12v battery. The car will do 50mph. It takes 10amps to drive the motor and the battery will last one hour at this rate until it is flat. You can travel 50 miles therefore until you need to recharge. Now you fit a fan on the car. There's extra drag because the fan is turning a generator. The car moving through the air at 50mph moves the fan. The car now takes 20 amps to drive because of the extra drag. The car will only go 25 miles. But, the generator is producing 15 amps. This means that the that the current draw from the battery is only 5amps and therefore at the same speed, it will last twice as long until it goes flat. That means that you could travel 100 miles. You have extended the range. If you could gear the fan and generator so that it's output was greater than the extra current needed to move the fan through the air, then you gain. NB: Apologies for the thread hijack and it's all gone a bit "plane on a conveyor belt". I could also be having an Ambwilans moment If the fan is producing 15 amps then the draw on the battery (the only power source) will be an additional 15 amps divided by the conversion efficiency of the fan. This is at best 50% judged by the windfarm figures. So to draw 15 amps from the fan will require the battery to provide 30 amps just to drive the fan through the air. Thus the range is reduced by a factor of 3 (at least).
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HD Adam
1,677 posts
54 months
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s2art said: HD Adam said: Apache said: LongQ said: PRTVR said: HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out It will work fine if the car ony travels primarily down hill. Maybe the farmer has enough coolies to drag it back to the top of the hill when required. Or a deal with a haulage company. You cannot create energy, you can only convert it. There is nothing going to waste, it'll work fine going down hill, but you first need to expend the energy you will recover getting it up the hill in the first place. No free lunch. Are you lot being deliberately obtuse or just not reading the original post I made? I DID NOT say that it was a perpetual motion machine. Of course you can't create energy by spinning the fan to only drive the wheels. Here's the scenario and I'll keep the maths simple. These figures won't work in real life but it gives you an idea. You (the farmer) has an electric car. It runs off a single 12v battery. The car will do 50mph. It takes 10amps to drive the motor and the battery will last one hour at this rate until it is flat. You can travel 50 miles therefore until you need to recharge. Now you fit a fan on the car. There's extra drag because the fan is turning a generator. The car moving through the air at 50mph moves the fan. The car now takes 20 amps to drive because of the extra drag. The car will only go 25 miles. But, the generator is producing 15 amps. This means that the that the current draw from the battery is only 5amps and therefore at the same speed, it will last twice as long until it goes flat. That means that you could travel 100 miles. You have extended the range. If you could gear the fan and generator so that it's output was greater than the extra current needed to move the fan through the air, then you gain. NB: Apologies for the thread hijack and it's all gone a bit "plane on a conveyor belt". I could also be having an Ambwilans moment If the fan is producing 15 amps then the draw on the battery (the only power source) will be an additional 15 amps divided by the conversion efficiency of the fan. This is at best 50% judged by the windfarm figures. So to draw 15 amps from the fan will require the battery to provide 30 amps just to drive the fan through the air. Thus the range is reduced by a factor of 3 (at least). No, you are looking at this the wrong way. The battery is not driving the fan. The air passing over the fan from the vehicle doing 50mph is driving the fan. Stick your hand out of the window at 50mph and you feel pressure on it. That moves the fan. The pressure drives the fan. The fan turns a generator. The generator charges the battery. Imagine it like a turbo. The exhaust flow would otherwise be wasted. In my scenario, the air flowing over (or into) the frontal area of the car would be wasted too but you could drive a generator from it.
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Blib
20,884 posts
67 months
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This is so off topic. Can you not take it somewhere else? 
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s2art
13,274 posts
123 months
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HD Adam said: s2art said: HD Adam said: Apache said: LongQ said: PRTVR said: HD Adam said: I meant it as an analogy.
Of course the fan does not recover energy like a braking system but something going to waste normally, in this case a fan being driven by air passing over it, may be of help depending on the design.
Yes, there's weight and drag to take into account but it could extend the range if done right. And I will say again it will not work,there is no waste energy, the fan turning will only work if you put more energy in via the wheels or accept the power loss in reduced speed and distance traveled. Come on somebody help me out It will work fine if the car ony travels primarily down hill. Maybe the farmer has enough coolies to drag it back to the top of the hill when required. Or a deal with a haulage company. You cannot create energy, you can only convert it. There is nothing going to waste, it'll work fine going down hill, but you first need to expend the energy you will recover getting it up the hill in the first place. No free lunch. Are you lot being deliberately obtuse or just not reading the original post I made? I DID NOT say that it was a perpetual motion machine. Of course you can't create energy by spinning the fan to only drive the wheels. Here's the scenario and I'll keep the maths simple. These figures won't work in real life but it gives you an idea. You (the farmer) has an electric car. It runs off a single 12v battery. The car will do 50mph. It takes 10amps to drive the motor and the battery will last one hour at this rate until it is flat. You can travel 50 miles therefore until you need to recharge. Now you fit a fan on the car. There's extra drag because the fan is turning a generator. The car moving through the air at 50mph moves the fan. The car now takes 20 amps to drive because of the extra drag. The car will only go 25 miles. But, the generator is producing 15 amps. This means that the that the current draw from the battery is only 5amps and therefore at the same speed, it will last twice as long until it goes flat. That means that you could travel 100 miles. You have extended the range. If you could gear the fan and generator so that it's output was greater than the extra current needed to move the fan through the air, then you gain. NB: Apologies for the thread hijack and it's all gone a bit "plane on a conveyor belt". I could also be having an Ambwilans moment If the fan is producing 15 amps then the draw on the battery (the only power source) will be an additional 15 amps divided by the conversion efficiency of the fan. This is at best 50% judged by the windfarm figures. So to draw 15 amps from the fan will require the battery to provide 30 amps just to drive the fan through the air. Thus the range is reduced by a factor of 3 (at least). No, you are looking at this the wrong way. The battery is not driving the fan. The air passing over the fan from the vehicle doing 50mph is driving the fan. Stick your hand out of the window at 50mph and you feel pressure on it. That moves the fan. The pressure drives the fan. The fan turns a generator. The generator charges the battery. Imagine it like a turbo. The exhaust flow would otherwise be wasted. In my scenario, the air flowing over (or into) the frontal area of the car would be wasted too but you could drive a generator from it. One last try. The only thing that drives the fan is the electric motor pushing the vehicle through the air. That takes energy. If the fan is extracting energy it can only come from the work being done to push the fan trough the air; the battery and electric motor.
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Globs
11,968 posts
101 months
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Sorry HD Adam, 2sart is correct, and you and the chinaman with the fan is wrong.
There is no free lunch, the fan is in the way of the air, and slows the car down. The amount a turbine can extract from the wind is rather limited to about 1/3rd of the power IIRC, then you have conversion losses.
So you slow the car down by the air drag (sapping power P), and may put back into the battery power P/4. So in fact you have a reduced drag of 3/4P - instead (best case) which would be better achieved by making the nose more pointy in the first place.
At best it's a bizarre interpretation of streamlining, which could be done considerably better by an aircraft designer. Which has happened a fair few times anyway...
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turbobloke
55,678 posts
130 months
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Only Global Poverty Can Save The Planet, Green Extremists Insist
Extremist green campaigning group WWF - endorsed by no less a body than the European Space Agency - has stated that economic growth should be abandoned, that citizens of the world's wealthy nations should prepare for poverty and that all the human race's energy should be produced as renewable electricity within 38 years from now. Most astonishingly of all, the green hardliners demand that the enormous numbers of wind farms, tidal barriers and solar power plants required under their plans should somehow be built while at the same time severely rationing supplies of concrete, steel, copper and glass.
It's not just resources that are limited, in the WWF's view: human potential itself is up against a hard limit beyond which the race cannot ever advance. Even progress thus far, as seen in the wealthy nations, has been achieved only by an unfair and wasteful over-use of precious resources: we rich Westerners are already beyond the practical limits that humans should ever aspire to achieve in terms of health, wealth - and even of education. That's not economics - that's religion. And not very nice religion either.
Lewis Page, The Register, 18 May 2012
At Rio+20 next month, the world’s elites will meet in Brazil with the aim of holding back human progress. Forty years ago, two ideas about humanity’s relationship with the natural world caught the imagination of the richest and most influential people. The first was that the demands of a growing population were taking more from the planet than could be replaced by natural processes. The second, related idea was that there exist natural ‘limits to growth’. These two reinventions of Malthusianism became the basis of a new form of global politics, which has sought to contain human industrial and economic development ever since.
Ben Pile, Spiked, 17 May 2012
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LongQ
Original Poster
8,961 posts
103 months
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turbobloke said: Only Global Poverty Can Save The Planet, Green Extremists Insist
Extremist green campaigning group WWF - endorsed by no less a body than the European Space Agency - has stated that economic growth should be abandoned, that citizens of the world's wealthy nations should prepare for poverty and that all the human race's energy should be produced as renewable electricity within 38 years from now. Most astonishingly of all, the green hardliners demand that the enormous numbers of wind farms, tidal barriers and solar power plants required under their plans should somehow be built while at the same time severely rationing supplies of concrete, steel, copper and glass.
It's not just resources that are limited, in the WWF's view: human potential itself is up against a hard limit beyond which the race cannot ever advance. Even progress thus far, as seen in the wealthy nations, has been achieved only by an unfair and wasteful over-use of precious resources: we rich Westerners are already beyond the practical limits that humans should ever aspire to achieve in terms of health, wealth - and even of education. That's not economics - that's religion. And not very nice religion either.
Lewis Page, The Register, 18 May 2012
At Rio+20 next month, the world’s elites will meet in Brazil with the aim of holding back human progress. Forty years ago, two ideas about humanity’s relationship with the natural world caught the imagination of the richest and most influential people. The first was that the demands of a growing population were taking more from the planet than could be replaced by natural processes. The second, related idea was that there exist natural ‘limits to growth’. These two reinventions of Malthusianism became the basis of a new form of global politics, which has sought to contain human industrial and economic development ever since.
Ben Pile, Spiked, 17 May 2012 One strange aspect to preserving 'resources' by not using them is that they then stop being resources. At least in theory. However since most of the 7 billion or so have at least some idea of what, locally to them, is a useful resource that helps them survive in some way the message to abandon such benefits would seem doomed no matter how loudly one shouts it. Why is WWF still thought of as a charity? Why do large multinationals still pump money into it when its policies appear to be designed to cripple their markets?
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turbobloke
55,678 posts
130 months
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Agreed about WWF.
In terms of consumption exceeding biosphere limits, those calculations are bogus.
For starters there is an assumption that global warming is a problem and that it's manmade and that we must fix it and can fix it.
No need to go any further.
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LongQ
Original Poster
8,961 posts
103 months
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I rather suspect that the 'limits to growth' in terms of resources are a lot more likely to come from the use of certain materials required for electricity generation and consumption by modern technologies than they are with more traditional sources like oil and especially coal.
Either way I will be dead before anyone has to grapple with the nasty issues so I'm not too bothered and it's really up to the younger generations to decide their own fate - if only they knew they had one.
It is rather depressing watching them being herded to the edge of the cliff when there are other directions they could take.
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mybrainhurts
71,767 posts
125 months
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Has Guam fallen asleep, or is he trapped in the bog..?
Just wondered...
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LongQ
Original Poster
8,961 posts
103 months
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It's interesting to note that the disturbine industry seems to have the support of senior Judges for its operations. Nothing like a nice disturbine development to enhance the scenery in the Peak District. http://www.bbc.co.uk/news/uk-england-derbyshire-18...I wonder where these judges live and what sort of investments they may have for their retirement?
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