Free flying wind power assemblies

[nexium]

I made some changes and many additions, but I don't think it changes any of the excellent analysis by igoresboss. Many of the ideas from the windpower at 35,000 feet thread apply, but no tether to the ground, which reduces NIMBY = not in my back yard and the hazard to low flying airplanes. Two of the wind power assemblies are connected by a long tether. Electricity is produced using the vector difference in the wind speed at the two ends of the tether. I think this will often exceed 100 MPH. Near the center is a parabolic mirror which can reflect sunlight through holes in the clouds to existing solar energy sites on the surface. The same mirror beams laser energy to the existing solar sites, when one or both of the wind power assemblies are producing enough power, but the sun angle is not favorable. The same center assembly will have some batteries to allow the electronics and rotor pitch motors to operate uninterrupted while the assemblies are maneuvered or the wind fails. Wind failures are rare and typically brief above 30,000 feet, but both ends of the tether will rarely be that high. It takes about a minute for stretch transients produced at the ends to reach the center assembly, so there is plenty of time to prepare for the arrival of a transient. The three computers are in constant radio contact with each other and the nearest control station on the ground. The tether can typically fly higher, lower and cross wind, but likely not up wind. Back up laser power for a minute or two is often stored mechanically in the tether. The center assembly should have a smaller wind power assembly to keep the mirror pointing at the solar site below. When no solar site is practical, the narrow beam can be aimed upward to assist in finding space junk and small meteors that pass close to Earth. 35 foot mirrors were built in the 1980s for battle laser research which can possibly be rented or purchased. If the mirror illuminates 1000 square feet at the solar site, the light lev

 

[igorsboss]

So many details! I'll only think about this much:<br /><br /><font color="yellow">Many of the ideas from the windpower at 35,000 feet thread apply, but no tether to the ground. Two of the wind power assemblies are connected by a long tether. Electricity is produced using the vector difference in the wind speed at the two ends of the tether. I think this will often exceed 100 MPH. Please comment, refute and/or analyze details.</font><br /><br />Given:<br />Two aircraft, tethered, fly in formation so that the top aircraft flies in the jet stream, while the bottom aircraft flies outside the jet stream. Power is generated using the difference in wind speed.<br /><br />Implications:<br />1) From the previous thread, generated power implies tether tension. Tether tension means that the tether's shape and orientation will resemble that of a kite's string.<br /><br />2) Both aircraft will tend to have very large drag. The top kite must generate lift.<br /><br />3) The aircraft which generates electrical power must have at least one moving part. (the "turbine")<br /><br />4) Both aircraft will need to vary their lift and drag characteristics to account for variable power generation and wind conditions.<br /><br />What this might look like:<br />Visualize two kites, connected with a fixed length tether. The top kite must generate lift. The bottom kite must generate enough drag to keep the top kite aloft, and have enough weight to keep it in a different fluid environment. The bottom kite flies upside down and backwards.<br /><br />The simplest situation would be a parasail-like kite on top, tether-connected to a matched pair of counter-rotating turbines at the bottom, connected by a rigid bar. The bar between the two turbines gives the generator something to torque against.<br /><br />I would keep the upper kite very light weight and simple. Put the turbine and all the complexity in the lower kite. Keep the weight in the lower craft.<br /><br />Could this fly at all?<br />I th

 

[nexium]

I agree connected by a riged bar makes analysis less complex, but a very long rigid bar seems unlikely even with CNT. Would a winch to shorten or lengthen the tether occasionally be helpful? Neil

 

[igorsboss]

<font color="yellow">I agree connected by a riged bar makes analysis less complex, but a very long rigid bar seems unlikely even with CNT. Would a winch to shorten or lengthen the tether occasionally be helpful? Neil</font><br /><br />Sorry for the misunderstanding. I didn't explain myself well enough previously. I am NOT suggesting that a rigid bar be connected between the upper and lower kites. The bar is part of the lower kite only.<br /><br />A suggested design:<br />The upper kite consists of a parafoil.<br />The upper kite is connected to the lower kite by a strong (flexible!) rope.<br />The lower kite constsis of: two counter-rotating wind turbines, connected to each other by a rigid bar.<br /><br />If there was only one wind turbine, and you attached a big generator to it, the torque would twist the rope. The turbine woud eventually try to winch itself right up the long rope, and the whole thing would crash.<br /><br />Instead, you need to construct two turbines, one turning clockwise and the other conterclockwise, so they can develop torque against each other, thereby allowing power generation.<br /><br />You could also develop concentric counter-rotating turbines...

 

[nexium]

I agree on the construction of the windpower assembly, except 4 rotors give better failure performance and reduced parts ware. Here is a paste from another forum: Mensa at compuserve <br /> Science/technology Free flying wind power assemblies<br /> <br /> It is a *lot* more trouble to set up lots of photovoltaic collectors across the continent than to have one ground end for the tether within a few 100 km of one market for the power. <br /><br />The problem is multiple.<br /><br />Problem one, we have a limited amount of energy and we need more<br /><br />Solutions abound, wind power, water, solar, nucular, and more however<br /><br />Wind: Danger to the birds, so bird lovers don't like it, noisy so quiet lovers don't like it and, well, "it don't look pertty" so home owners don't like it. Result, we can't use a lot of wind power<br /><br />Water: Danger to the fish, if you dam a stream you bury land and houses and other issues. So we can't make more water power<br /><br />Nucular, Chernobyl, Two Mile Island (From "Robots and Foundation" we know it as Three mile island Nuff said.<br /><br />Your teatherd windpower array device is very likely a good idea, but sure as I'm typing this some bleeding heart is going to worry about some bird which has 10x the brains of said bleeding heart flying into the teather line and injuring itself. And then someone is going to note the damage done when a cable snaps (trust me you do not want to be there when that happens) and... Well, let' just say I don't think it's going to happen.<br /><br />Far too many people think "Better the devil you know" as it were.<br /> <br />There already are millions of photovoltaic collectors and other kinds of solar collectors across the continent and more will be built if the free beam of light is available. I suggest a $99 beacon which tells the mirror computer that the beam is not wanted when the beacon is turned off. The beam switches to a different solar site when it finds a beacon the mirror computer thinks is at

 

[nexium]

I just realized that the long electrically conducting tethers will gather electric energy from the atmosphere and Earth's magnetic field. If a DC = direct current system is used this will typically add to the voltage produced by the wind generators. At times the tethers will be self propelled by Earth's magnetic field, not necessarilly in the desired direction. This will at times be excessive and damaging = lightning, but it may considerably enhace the amount of power available for the laser and for communications. Please embellish. Neil

 

[igorsboss]

<font color="yellow">So we can't make more water power</font><br /><br />I don't agree. We haven't tapped the ocean currents or tides for power yet.

 

[igorsboss]

<font color="yellow">Your teatherd windpower array device is very likely a good idea</font><br /><br />Although it would work, I think it would be rather lame, actually.<br /><br />I think it might make for an interesting long-duration flight platform, though.

 

[nexium]

Apparently all alternative energy methods are lame. We might need to fly millions (thousands is an optimistic projection) of these freeflying tethers to produce 1% of the world's energy needs. Every little bit helps. There will be tangling if there are a million free fling and a million attached to the ground. The attached type may be necessary to get large free flying types up to altitude.<br /> Please find the thread that talks about 100 alternate energy methods or start a new one to analyze tide and ocean current power. I found the thread in Free Space and bumped it to page one with two new posts, one about water power, sort of. Neil

 

[nexium]

"Keep the upper kite very light and simple" The tether can be non-conducting electrically. That solves a bunch of problems. Are the new problems easy to solve? Reduced flight control of the upper kite/a solar panel could increase the airfoil of the kite, while providing telemetering and.....? Closer to the ground is likely best most of the time for the mirror as the illuminated area can be smaller for small solar sites. Will it be difficult to keep the upper kite in the jet stream? Previous thinking was we would not try to use the jet steam as 100 MPH differences are sufficient. Neil

 

[igorsboss]

<font color="yellow">"Keep the upper kite very light and simple" The tether can be non-conducting electrically. That solves a bunch of problems. Are the new problems easy to solve? Reduced flight control of the upper kite/a solar panel could increase the airfoil of the kite, while providing telemetering and.....? Closer to the ground is likely best most of the time for the mirror as the illuminated area can be smaller for small solar sites. Will it be difficult to keep the upper kite in the jet stream? Previous thinking was we would not try to use the jet steam as 100 MPH differences are sufficient. Neil</font><br /><br />I'm restricting my discussion to just the kites. I'm not discussing the mirror or solar panel ideas (because I think they are a dead end.)<br /><br />I don't know where else you're going to find 100 mph wind differences (in close vertical proximity) except in the jet stream.<br /><br />I envision 3 ropes going to the upper kite. The central rope would be very strong, connected at the center of lift of the upper kite. The two other ropes would be lightweight control lines. Pulling the left(right) control line increases lift and drag on the left(right), turning the kite left(right). Pulling both control lines increases lift and drag for the whole kite, which is needed during power generation.<br /><br />The main problem with staying in the jet stream is figuring out where the jet stream is. Turning the kite is not the problem.<br /><br />Initial deployment of the whole contraption would be by balloon, to lift the top kite into the jet stream.

 

[nexium]

Hi igorsboss: You seem to have believable answers. With 1000 of these in the jet steam; we should know very precisely where the jet steam is. Do you by any chance have a million dollars for a proto type laying around? Neil

 

[igorsboss]

Show me how to recoup my investment. I don't see it yet.<br /><br />It might be intersting to set a new a new distance record for unpowered heavier-than-air flight...<br /><br />As for a prototype, give me a couple of weeks.

 

[nexium]

The first two or three all but surely operate at a loss, but that is usual for new technology. If it flies a month, it might deliver $1000 worth of energy mostly to private parties who would pay little for high priority. It might be worth $10,000 per month as a cell phone tower, as it would provide service briefly in thinly populated and mountanous locals presently without service. This gives it some emergency value, but likely no one will pay you except with thanks. A government grant is probable. Someone might offer to buy you out for a million dollars. Like most alternative energy, losses are more likely than profits, even after years of making improvements and scaling up. If you persist long enough, someone may buy you out for a billion dollars. Neil

 

[spacester]

um, can i ask a stupid question? What keeps the kites from circling the globe at the whim of the wind? If there's no tether to the ground, how do you prevent the kite pair from leaving your operational area? <div class="Discussion_UserSignature"> </div>

 

[igorsboss]

<font color="yellow">um, can i ask a stupid question? What keeps the kites from circling the globe at the whim of the wind? If there's no tether to the ground, how do you prevent the kite pair from leaving your operational area?</font><br /><br />Why, nothing at all! That's why this isn't going to be very attractive as an energy source. ...well, one of several reasons, actually...<br /><br />I can see some use as a communications platform, or as a weather monitor, but not as a power station. It might be able to set a world record for flight duration by an unpowered heavier-than-air craft.<br /><br />What was that word I used earlier? Oh, yeah: Lame. Fun, but lame.