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Post by Deleted on Oct 10, 2019 20:14:40 GMT
I was told that for every photovoltaic module (solar panel) produced there was a proportional reduction in the sun's light output because the PV "suck it up".
Could be a made up story but at the end of the day nothing lasts forever does it.
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Post by Telemachus on Oct 10, 2019 22:06:35 GMT
So where does the energy come from then? Is it created out of nothing? (Probably not, if Mr Newton was right). it isn't important to ask where the energy comes from. it is important to understand that wind energy is absorbed by friction, mainly associated with contact with land structures; these could be mountains, high rise buildings, trees or wind turbines. it doesn't make any difference to the wind energy how it is absorbed - but it does make a difference to us if we can harness it instead of allowing it to be wasted in locations where it is of no benefit to us; harnessing it does not reduce the constant creation of new wind energy from sources like the sun's heat. Some wind energy is absorbed by friction. Not all of it though - otherwise there would be any wind left! More is absorbed by turbine blades with are cleverly designed to extract the maximum amount of energy. Unlike rough structures like trees and mountains. If you have ever compared the glide performance of a light aircraft with the engine dead but prop still windmilling, vs engine /prop stationary, you would know that the latter creates far less drag. Yes of course the amount of energy (and hence planetary rotation speed) extracted by wind turbines is small compared to the general loss of rotational energy, but it isn’t zero. As a clue, look at how the moon and other satellites (as in moons) present only one face to the planet they orbit. This is caused by tidal locking, an effect whereby the energy dissipated in tidal forces (of perhaps solid, not necessarily liquid) on the moon is dissipated as friction over millennia until the moon rotates at the exact speed to keep a specific face presented to the planet.
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Post by naughtyfox on Oct 10, 2019 22:29:31 GMT
I was told that for every photovoltaic module (solar panel) produced there was a proportional reduction in the sun's light output because the PV "suck it up". I'd fancy a spaceship whose motors suck in photons and convert them into bosons and quarks for the drive for hyperspace.
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Post by naughtyfox on Oct 10, 2019 22:34:16 GMT
Spaceships that get a slingshot boost from going close to a planet get this at the expense of the planet, by slowing it down, I think. That energy has to come from somewhere. I am rather concerned at the climate change of Neptune caused by Voyager 1 passing it. It's all messed up now. Thanks for nothing, NASA!
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Post by bodger on Oct 11, 2019 7:02:45 GMT
Some wind energy is absorbed by friction. Not all of it though - otherwise there would be any wind left! More is absorbed by turbine blades with are cleverly designed to extract the maximum amount of energy. Unlike rough structures like trees and mountains. Yes of course the amount of energy (and hence planetary rotation speed) extracted by wind turbines is small compared to the general loss of rotational energy, but it isn’t zero. you may have a blind spot in this regard. there is no finite amount of wind - it is constantly being created. where do you get the concept that the planet's rotation is related to wind energy? it is utter nonsense. energy is dissipated by turbines, trees, or whatever. I suppose if we cut down all the forests the planet would spin faster? no, I don't think so either. ................... perhaps you are just being mischievous.
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Post by Deleted on Oct 11, 2019 7:15:19 GMT
I assumed he was having a little giggle.
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Post by JohnV on Oct 11, 2019 7:23:53 GMT
So where does the energy come from then? Is it created out of nothing? (Probably not, if Mr Newton was right). but it does make a difference to us if we can harness it instead of allowing it to be wasted in locations where it is of no benefit to us; harnessing it does not reduce the constant creation of new wind energy from sources like the sun's heat. but it will sure annoy the rag and stick merchants www.yachtingmonthly.com/news/sailor-prosecuted-for-wind-farm-sabotage-30393
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Post by Deleted on Oct 11, 2019 7:48:11 GMT
"...and it is hard to see how a leisure activity such as sailing should be allowed to damage livelihoods to this extent."
That implies that windfarms are little independent businesses where Mr Bloggs and Mrs Bloggs work hard and rely on the income from it.
I really don't think that's the case. I think wind farms are probably operated by huge multinationals and the profits are fed to shareholders.
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Post by bills on Oct 11, 2019 8:20:18 GMT
My boat definately moves faster when my Ecofan is on and facing backwards, so I think that wind turbines slowing the planet's rotation could well be a real thing.
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Post by JohnV on Oct 11, 2019 8:26:51 GMT
"...and it is hard to see how a leisure activity such as sailing should be allowed to damage livelihoods to this extent." That implies that windfarms are little independent businesses where Mr Bloggs and Mrs Bloggs work hard and rely on the income from it. I really don't think that's the case. I think wind farms are probably operated by huge multinationals and the profits are fed to shareholders. (article date)
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Post by naughtyfox on Oct 11, 2019 9:04:38 GMT
My boat definately moves faster when my Ecofan is on and facing backwards, so I think that wind turbines slowing the planet's rotation could well be a real thing. Yes but the ecofan making your boat go faster is saving propulsion fuel and thus you are doing your bit to save the planet. More coal in the stove!
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Post by thebfg on Oct 11, 2019 11:15:16 GMT
"...and it is hard to see how a leisure activity such as sailing should be allowed to damage livelihoods to this extent." That implies that windfarms are little independent businesses where Mr Bloggs and Mrs Bloggs work hard and rely on the income from it. I really don't think that's the case. I think wind farms are probably operated by huge multinationals and the profits are fed to shareholders. My sister and her husband don't work with wind farms.
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Post by Telemachus on Oct 11, 2019 11:45:05 GMT
Some wind energy is absorbed by friction. Not all of it though - otherwise there would be any wind left! More is absorbed by turbine blades with are cleverly designed to extract the maximum amount of energy. Unlike rough structures like trees and mountains. Yes of course the amount of energy (and hence planetary rotation speed) extracted by wind turbines is small compared to the general loss of rotational energy, but it isn’t zero. you may have a blind spot in this regard. there is no finite amount of wind - it is constantly being created. where do you get the concept that the planet's rotation is related to wind energy? it is utter nonsense. energy is dissipated by turbines, trees, or whatever. I suppose if we cut down all the forests the planet would spin faster? no, I don't think so either. ................... perhaps you are just being mischievous. No I am not being mischievous. Why is it that when ever anyone has a different view, it must be for “mischievous” purposes? Can you not comprehend that you might not always be right and or that on occasion, people have genuinely held different views from you? No, i guess not. Obviously wind is constantly being created. And the planet’s rotation is a significant factor in it. Without the rotation there would be no weather patterns, no highs and lows etc. Have a look at how low and high pressure regions are created and don’t just fill in (ie why high pressure air doesn’t just flow in to fill a low pressure as one might expect). It is all because the planet is a rotating sphere. Take out the rotation and the effect doesn’t exist - high pressure and low pressure areas would just equalise and the only wind remaining would be the very sluggish circulation cause by convective circulation as alluded to earlier. With mechanical systems you don’t get something for nothing, and there is a reversibility concept. ie if the rotation of the planet is a significant factor in the creation of wind, and some of that wind has extra energy extracted, it follows that that extraction of energy has an impact on the planet’s rotational speed. Of course that effect is tiny. But it is non-zero, hence my beef about the term “renewable energy”. Tidal energy extraction of course translates more directly into an alteration of planetary orbit and rotational speed (again, the effect is tiny but non-zero). No if you cut down the trees and flattened the mountains, the planet wouldn’t spin any faster (conservation of angular momentum considerations aside). But it would slow down less quickly.
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Post by Deleted on Oct 11, 2019 11:55:36 GMT
Did anybody notice the date of the article? I suspect John is taking the piss a tad.
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Post by thebfg on Oct 11, 2019 12:26:07 GMT
Tides are causing the earth to slow down, apparently, but this is causing the moon to pull away 3cms per year.
I wonder if it will get to a point where the moon stops causing tides, and the planet then equalises at that speed.
What is intresting is the planet is slowing down causing a day to be about 2 milliseconds longer over a century. With the earth spinning at 1000mph how long will it take to stop?
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