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Wind Power

Discussion in 'Earth and Environmental Science' started by amusicsite, 2 Dec 2011.

  1. The video was in an offscreen ad at the bottom right of the page. Apart from it being a damn cheek to inflict sound on someone who has not consented to it, it also made me jump because I had the sound turned up and it took several seconds to start playing. I couldn't see where the sound was coming from so I could not mute it directly.
     
  2. sidevalve

    sidevalve Well-Known Geek

    Apart from the annoying ad it is still a useless idea - wind power will always be at the mercy of the wind and thus too unpredictable for large scale industrial use. Wave and tidal power is the way forward.
     
  3. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    While I agree with you that wave and tidal power is a better long term option. Wind is still a useful part of the grid. It's quite often the case that there is extra demand when it's windy like when it's wet and windy there may be more lights or heating required. So it's a useful addition, especially if they can get them quiet enough to use in city centers. Even if it's only enough power run a few led house lights, most people would be quite happy to have that saving if all it took was a small quiet turbine on the roof.
     
  4. sidevalve

    sidevalve Well-Known Geek

    It is not just a turbine on the roof however it requires maintenance and if it to remain quiet and efficient quite a lot of it. As I have stated before the most efficient way to use wave/tidal power is to use it to work a VERY simple pump, [possibly even a ram pump would do and these have been known to work without attention for decades] to pump seawater up to any convenient storage point [and there are thousands of acres of industrial waste areas around our coast [sad to say] and then release it through turbines whenever a large volume of electricity is required. It requires no 'back up' capacity in case the wind doesn't blow, can produce large amounts of electricity when required and requires very little maintenance. However wind power 'looks good' from the politicians vote catching point of view and until it's overall futility is realized will continue to force all other forms of research into second place.
     
  5. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    While I agree that wave/tidal seems like a good long term goal... There is very little at the moment, the cost of installing them is going to be high and I imagine they will also need regular maintenance like wind does. At least wind power has been proved to work, we know it's limitation and benefits.

    More research in tidal yes, massive roll out now, no...
     
  6. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  7. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  8. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    World's largest wind turbines come online off the UK

    https://www.imeche.org/news/news-ar...-turbines-point-the-way-for-a-wind-powered-uk

    195m-tall 8MW turbines with the blade span larger than the London Eye!

    https://www.theguardian.com/environ...ey-wind-turbines-liverpool-uk-wind-technology
     
    beanz likes this.
  9. classic33

    classic33 Über Geek

    There's nine 120 metre high masts gone up, with the rotor diameter to add on to that near me.
     
  10. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  11. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    I was watching a Shackleton aircraft start its engines on YouTube. Although this one was missing some engines, the Shackleton usually has four sets of contra-rotating propellers. I am fairly sure each contra-rotating propeller had its own engine, so although it only looked like it has four engines, it actually has eight. Fairey Gannets and (I think) Hawker Sea Furys had contra-rotating propellers too. In fact, I believe an Italian entry to the Schneider Sea Plane race had contra-rotating propellers back in the 30s. Everyone seemed to have forgot about the idea in the war.

    I was wondering, as propellers are rather similar to wind turbines, couldn't you have contra-rotating wind turbines? The physics of wind turbines is actually quite difficult to get your head around. It's not string theory, but it's still fairly difficult. I would have thought that air stream was so chopped by the first propeller that it would interfere with the action of the second propeller. I would not have thought the effect was just additive. When I was studying wind power for my MSc, we were told that wind turbines had to be spaced apart so far between each one and so many lengths downwind of each other.
     
  12. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    Yep looks like it can be done to get a bit more power.

    http://iopscience.iop.org/article/10.1088/1742-6596/75/1/012003/meta

    As to why it's not done all the time, considering this paper was back in 2007, seems to be that it's cheaper to build a second tower to get 100% more power than to pay the extra to get 40% more from one tower. My guess is we are in phase one of the renewable energy supply, putting up the first large scale installs of the needed infrastructure which should be good for 25-50 years. By the time these need replacing it will be with the next generation of machines that will squeeze out every last bit of realistically usable energy and probably last 50-200 years. By phase two we should be able to things like this without it being a financial problem and increase the output from the wind farms.

    I've been following some of the developments in vertical wind turbines on YouTube and it's been amazing watching how quickly it's been coming on. They are fairly easy to make, lots of free information and lots of people playing around with them. I think it's a field that will develop very fast and within about five years we will know most of what we need to make the ultimate wind turbines for just about any location. Maybe a few more years to optimise the designs and manufacturing process, then you will have a basic standard wind turbine. Like you have a standard V6 engine, from which most petrol engines are built from, there will be a standard wind turbine tech that all are built from. I think contra-rotating propeller will be part of the blueprint, like a turbo add-on to keep the V6 metaphor.

    At the moment things are moving so fast a lot of wind farms are getting upgraded between the planning and construction phase because the market has moved so much in that time. The more renewables we install, the more we learn. The more we learn, the better we get and that knowledge is rolled out quickly into new projects... That generates more data to learn from.
     
    Yellow Fang likes this.
  13. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    Good find. Interesting that the theoretical efficiency limit for a contra-rotating wind turbine increases from 59.3% to 64%. Also interesting that annual energy production could be increased by over 40%. Those are quite good figures, I would have thought. I see the paper was published in 2007. I've never seen any in operation. Perhaps there were problems in practice, or like you say, the economics is that it is more profitable to install another turbine a bit down stream.

    I think there is a physics reasons for vertical axis wind turbines not being in production much. While the theoretical maximum efficiency for a horizontal axis wind turbine is 59.3%, it is only about 12% for vertical axis. They are supposedly better at coping with turbulent airflow, like you get around buildings, but the wind speed in urban areas is much lower. 12% of the cube of a smaller number is far less power than 59% of the cube of a higher number. Add to that all the buffetting and noise, it is probably not worthwhile. It would be good if it was.
     
  14. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  15. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    Here's an old use of wind power coming back.

    https://phys.org/news/2019-10-shipping-firms-future.html

    The rocket makers Ariane Group have commissioned a sail-equipped cargo ship to transport parts its new Ariane 6 launcher to French Guiana starting in 2022.

    It's going to be one of those price point things. At some point the extra money it cost to add a few sails and maintain them will be a fraction of what you spend on fuel. Then it will be everywhere. A robust computer controlled sail system that can reduce your cost and almost no extra staff needed, got to be a winner. Along with the reduced fuel needs could make it easier to switch to alternative fuels like hydrogen or battery solutions. Will be especially good if you could retrofit them to older ships too but I'd imagine ships with sails that are designed from the ground up to have sails are probably best.