1. Joined
    06 Mar '12
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    25 Oct '13 11:531 edit
    http://phys.org/news/2013-10-iea-ups-power-global-electricity.html

    this happy prediction is made by the International Energy Agency and is partly based on the fact that the cost of wind power has been dropping and is predicted to continually drop.
    In addition, the link says amongst other things:
    “...
    ...Wind power currently generates 2.6% of the world's electricity.

    ...Turbines are higher, stronger and lighter, while masts and blades are growing faster than rated capacity. What's more, turbines are capturing lower-speed winds and producing more regular output. …
    ...”

    It it just my imagination or does there seems to be a lot of good news of renewable energy recently?
  2. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
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    25 Oct '13 12:30
    Originally posted by humy
    http://phys.org/news/2013-10-iea-ups-power-global-electricity.html

    this happy prediction is made by the International Energy Agency and is partly based on the fact that the cost of wind power has been dropping and is predicted to continually drop.
    In addition, the link says amongst other things:
    “...
    ...Wind power currently generates 2.6% of the world's e ...[text shortened]... t just my imagination or does there seems to be a lot of good news of renewable energy recently?
    When the scientific and engineering community get together, things get done.
  3. Joined
    29 Mar '09
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    767
    25 Oct '13 12:58
    Originally posted by humy
    http://phys.org/news/2013-10-iea-ups-power-global-electricity.html

    this happy prediction is made by the International Energy Agency and is partly based on the fact that the cost of wind power has been dropping and is predicted to continually drop.
    In addition, the link says amongst other things:
    “...
    ...Wind power currently generates 2.6% of the world's e ...[text shortened]... t just my imagination or does there seems to be a lot of good news of renewable energy recently?
    Hydro power is producing nearly 20% now. If we had another 20% from wind it would be a huge impact on the use of coal for power. The other thing is that nuclear power may one day not even be a consideration.
  4. Joined
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    25 Oct '13 13:161 edit
    Originally posted by joe beyser
    Hydro power is producing nearly 20% now. If we had another 20% from wind it would be a huge impact on the use of coal for power. The other thing is that nuclear power may one day not even be a consideration.
    The other thing is that nuclear power may one day not even be a consideration.

    I think that is definitely the case. In the very long run, nuclear power can never compete with renewables. I am certain that there would be no nuclear on Earth 300 years from now.
    However, I think having more nuclear power in the more medium run may be a very good idea to buy us more time until the renewables finally completely replace all fossil fuels and then, much less importantly, replace nuclear.
  5. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
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    25 Oct '13 15:26
    Originally posted by humy
    The other thing is that nuclear power may one day not even be a consideration.

    I think that is definitely the case. In the very long run, nuclear power can never compete with renewables. I am certain that there would be no nuclear on Earth 300 years from now.
    However, I think having more nuclear power in the more medium run may be a very ...[text shortened]... es finally completely replace all fossil fuels and then, much less importantly, replace nuclear.
    we may not have fission 300 years from now but fusion is a definite maybe and a lot cleaner than fission. You are right about fission being just a stop gap measure.

    One thing to consider about wind power, there will be climate considerations to take into account when you start getting 20-30% of the entire planet's energy use from wind.

    I think it will alter wind conditions where long time energy producers will find themselves getting less energy because the trade winds have permanently shifted or some such.
  6. Germany
    Joined
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    25 Oct '13 15:33
    Originally posted by sonhouse
    we may not have fission 300 years from now but fusion is a definite maybe and a lot cleaner than fission. You are right about fission being just a stop gap measure.

    One thing to consider about wind power, there will be climate considerations to take into account when you start getting 20-30% of the entire planet's energy use from wind.

    I think it wil ...[text shortened]... nd themselves getting less energy because the trade winds have permanently shifted or some such.
    I find it rather unlikely that it would have a significant impact on global air currents. Did you find any calculations to back this up? (fluid dynamics is not my field)
  7. Joined
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    25 Oct '13 18:01
    Originally posted by KazetNagorra
    I find it rather unlikely that it would have a significant impact on global air currents. Did you find any calculations to back this up? (fluid dynamics is not my field)
    I don't have any calculations specifically for that but note this:

    http://phys.org/news/2013-02-real-world-capacity-farms-large-scales.html
    "...
    Each wind turbine creates behind it a "wind shadow" in which the air has been slowed down by drag on the turbine's blades...
    ...
    ...as wind farms grow larger, they start to interact, and the regional-scale wind patterns matter more.
    ....
    ...Keith's research has shown that the generating capacity of very large wind power installations (larger than 100 square kilometers) may peak at between 0.5 and 1 watts per square meter. Previous estimates, which ignored the turbines' slowing effect on the wind, had put that figure at between 2 and 7 watts per square meter.
    ...
    If we were to cover the entire Earth with wind farms, he notes, "the system could potentially generate enormous amounts of power, well in excess of 100 terawatts, but at that point my guess, based on our climate modeling, is that the effect of that on global winds, and therefore on climate, would be severe—perhaps bigger than the impact of doubling CO2
    ...
    ...
    The whole earth receives about 100 000 TW of solar energy, using about 0.25% or 250 TW of it to move the air about.
    ..."
  8. Cape Town
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    25 Oct '13 18:40
    Originally posted by humy
    Each wind turbine creates behind it a "wind shadow" in which the air has been slowed down by drag on the turbine's blades...
    But even the largest turbines are under hundred metres (I believe). Most of the worlds winds are kilometers above the earths surface.
    Here in Cape Town we have rows of mountains 1km high.
  9. Joined
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    25 Oct '13 19:23
    Originally posted by twhitehead
    But even the largest turbines are under hundred metres (I believe). Most of the worlds winds are kilometers above the earths surface.
    Here in Cape Town we have rows of mountains 1km high.
    Most of the worlds winds are kilometers above the earths surface.

    yes, and those winds will still blow. But the turbines don't only slow wind up to their own high but well above that hight due to the well-known phenomenon of wind turbines dragging the wind momentum well above them down to close to ground level. This effect would mean, if you had enough wind turbines world wide, the winds up to perhaps about 1km high could be severely slowed and that would have a drastic effects on world climate.
  10. Cape Town
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    25 Oct '13 20:38
    Originally posted by humy
    This effect would mean, if you had enough wind turbines world wide, the winds up to perhaps about 1km high could be severely slowed and that would have a drastic effects on world climate.
    Maybe a positive effect? I believe many farmers plant wind breaks to slow down wind.
    I suspect that deforestation and man made forests covers far more land and affects far more wind than wind turbines ever will.
    Do you have any stats on the increase of wind speed over the Amazon due to deforestation?
  11. Joined
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    26 Oct '13 02:02
    Originally posted by KazetNagorra
    I find it rather unlikely that it would have a significant impact on global air currents. Did you find any calculations to back this up? (fluid dynamics is not my field)
    Does extracting wind energy have a cooling effect on the atmosphere?
  12. Joined
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    26 Oct '13 02:102 edits
    Originally posted by twhitehead
    But even the largest turbines are under hundred metres (I believe). Most of the worlds winds are kilometers above the earths surface.
    Now and then I'll read about somebody proposing a kite-like device having a turbine that sends electric current down the tether to the ground. I can't remember what sort of altitude they are considering for this.

    Pie in the sky? 😕
  13. Cape Town
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    26 Oct '13 08:59
    Originally posted by Paul Dirac II
    Now and then I'll read about somebody proposing a kite-like device having a turbine that sends electric current down the tether to the ground. I can't remember what sort of altitude they are considering for this.

    Pie in the sky? 😕
    http://www.makanipower.com/home/

    They were bought by Google.
  14. Joined
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    26 Oct '13 09:022 edits
    Originally posted by twhitehead
    Maybe a positive effect? I believe many farmers plant wind breaks to slow down wind.
    I suspect that deforestation and man made forests covers far more land and affects far more wind than wind turbines ever will.
    Do you have any stats on the increase of wind speed over the Amazon due to deforestation?
    Sorry, don't have any stats on that. But I think you must be right about trees having much more effect (at least currently ) on the wind than wind turbines. I predict that will one day change.

    Maybe a positive effect?

    Arr yes. Just because it changes something natural doesn't mean it is bad. I have predicted that wind turbine farms built over vast areas of sea and land in the far future would be carefully arranged to give a double purpose; both generate electricity and partially control climate esp to reduce wind speeds generated from storms and hurricanes to reduce the damage from them.
  15. Joined
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    26 Oct '13 09:071 edit
    Originally posted by joe beyser
    Does extracting wind energy have a cooling effect on the atmosphere?
    I don't think so. But it may indirectly reduce the rate of heat transfer from where the climate is hottest on Earth to where the climate is coldest on Earth. I have speculated that this could be used to help stop ice caps melting from global warming but obviously you would have to have one hell of a lot of wind turbines to have any measurable effect that way.
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