another pie in sky scheme proposed

[slowrotor]

Flyingwindmills.

One bad part and the whole thing could fall apart. It obviously cannot be built as heavy as a land based windmill.

http://www.skywindpower.com/ww/index.htm

[FairWeatherFlyer]

One bad part and the whole thing could fall apart.
There's a concept in engineering called redundancy which is used to alleviate this risk.

[west lakes]

I'm sorry but - thanks for a good laugh on a slow afternoon:}


Until there is a reliable & safe method of transmitting electricity through air sorry it won't fly:ugh:

At 15000ft the lowest practical voltage to transmit power would be in the 33000V region, so add about 1 ton for a transformer & 54tons at least for the power cable

[IFMU]

Hey! It's got lateral symmetry! I bet we can find a buyer for it somewhere around here.

-- IFMU

[arismount]

I think you missed a point, West Lakes. Transmission of generated power could take place through a conducting tether. Also the devices could be tethered from mountainous regions so as to maximize the MSL height and therefore wind speed. A 10,000 ft. tether from the higher regions of the U.S. Rocky Mountains would result in the device being sited approximately at FL 210, assuming a tether angle of 45 degrees to the vertical.

[OneManBand]

Forget your .."how will we make it light enough" ... or ... "how do you pass lots of volts through a thin enough cable" ...

Is it just me that thinks 10,000' ~ 15,000' of "tether" may pose a slight hazard to anyone wanting to use the skies ???? Visions of wartime London and the sky full of barrage balloons springs immediately to mind !!

Durrr !!!!

[NickLappos]

When gas gets to $20 a gallon, we will be driving stakes into our back yards to tether these things, and using the holodeck to hone our flying skills....

[Two's in]

One Man Band,

No, it's not just you...(and it's actually an aerostat, not a blimp)

http://www.aero-news.net/index.cfm?contentBlockId=3b5842a9-a511-43ca-a2f0-ca2332cdc21e

Three Lost When C-182 Hits Blimp Cable Off FL Coast
Sun, 22 Apr '07

Unmanned Airships Provide Radar Coverage, Broadcast Programming To Cuba

Three people are dead after their Cessna 182 crashed off the bay of Cudjoe Key late Friday, local police said.



It appeared the Cessna 182 (file photo of type, above) hit a cable tethering a large government radar surveillance blimp, said police. The cable was not sliced and the blimp does not appear to be damaged, according to Monroe County sheriff's spokeswoman Becky Herrin.

The site has a camera trained on the blimp and the camera captured the crash. The plane reportedly hit the cable about halfway between the ground and the blimp itself, reported the Associated Press.

Investigators on the scene said the aircraft crashed in about two feet of water and appeared to have broken up upon impact.

The plane was believed to have departed from Key West, but its final destination was unknown Saturday.

There are two blimps at Cudjoe Key, one operated by the State Department and the other by the Air Force, according to the Air Force Web site.

The State Department blimp transmits the US government-run station TV Marti into Cuba. One of the uses of the Air Force blimp is to help monitor drug trafficking. It was unclear which blimp was involved in the crash, officials said.

The blimp and blimp site are operated by Lockheed Martin, a contractor for the federal government. The area surrounding the blimps is restricted airspace, said Herrin. (As seen in the chart at right, R-2916 is active in the area, for unmarked tethered balloons up to 14,000' MSL -- Ed.)

A man living in the area reported the crash just before midnight Friday.

Police had not identified the victims Saturday morning.

[Fareastdriver]

Some years ago a South African university researched the efficiency of solar heating panels. What they did was to measure the amount of energy to put it there and then what it produced in a Mediterranean type climate, i.e. sunshine most of the time.
They measured the energy required to dig the raw materials from the ground, then refining them, the whole production process right though to what was required to install and bring it into service. They found that the solar panel would have taken twenty-seven years to repay that. By that time it would have had to have been replaced through general corrosion etc..
Here you have a high tech airborne object which would cost as much as a small airliner. The energy required to build and position it would be horrendous. Also it cannot just sit there, it is a mechanical object and has to be serviced. It does not matter how much monitoring you build into it there comes a day, quite often, where you have to haul it down and look at it. All this totalled together adds up to a massive amount of energy. How long, if ever, does it take to repay that energy.
As with most scientists they gallop along with a theory but no practical comprehension. Effectively it is an autogyro so what happpens if there is no wind, bad weather like cu-nimbs, icing, you name it. Imagine the disc loading when it is being restrained against an 1000 ft/min updraft. Feather them? How fast can you feather them? nature will always find a way of doing it faster. Imagine a down burst faster than than the tether can take it up followed by the inevitable updraft, you would hear the twang for miles.

[Dave_Jackson]

"Hey! It's got lateral symmetry! I bet we can find a buyer for it somewhere around here."
IFMU, Yes!
You have obviously converted to the elevating force of lateral symmetry. :D

Was your conversion due to the book The Equation That Couldn't Be Solved: How Mathematical Genius Discovered the Language of Symmetry (http://www.amazon.com/Equation-That-Couldnt-Solved-Mathematical/dp/0743258207)?

Or, did you attend the Feb 6, 2006 Engineering Colloquium at the Goddard Space Flight Center? It was entitled; "The Equation That Couldn't Be Solved".
This is its abstract; "What do the basic laws of nature, human perception, the music of J.S. Bach, and the selection of mates have in common? They are all characterized by certain symmetries. Symmetry is the concept that bridges the gap between the world of theoretical physics and psychology, between science and art. Yet the "language" of symmetry - group theory - emerged from a most unlikely source: an equation that couldn't be solved. This talk will discuss the story of symmetry, of group theory, and of the mathematical prodigies who opened the door for these concepts."

:ok:
Dave

[Agaricus bisporus]

What a load of cobblers! When will we learn that the only practical long term way to generate electricity without hydro is nuclear? One nuke plant will do the job of 200 of these toys, and reliably, 24/7, not dependant on the wind blowing, or not blowing.

Sad we can't concentrate on the all-important primary sources instead of footling around with pointless peripheral political 1% part time distractions like this - and all other wind machines. They are the equivalent of the city buying rickshaws to make public transport "greener", (saves diesel, "obviously") but neglecting to provide the buses that are needed to carry the 100,000 pax who want to travel every day.

If this sort of idiotic "logic" continues I'm starting a candle factory, cos demand is going to be insatiable...


Ridiculous.

[Graviman]

I gather that Fusion will be with us within 4 decades (no idea how the figure of 37 years was estimated), so windmill project would have to pay back within that lifetime:
http://en.wikipedia.org/wiki/Fusion_power

Seems a shame if we can't tap into the jet stream, but it is not an easy challenge to solve. Ocean currents offer similar benefits, and look to be more practical in the short term.

[Two's in]

The USA's will to succeed with Nuclear Power stopped in 1979 when they put the real life Homer Simpson in charge of Three-Mile Island. Rather than learn to avoid a repeat incident, the Nuclear industry has allowed the anti-nuclear lobby to go from strength to strength with its scare tactics. Nuclear waste will be a fascinating subject for discussion while we sit around one of Agaricus' Candles discussing how boring life is without electricity.

[Graviman]

Well, we've had our share of things that go bang in the night: Dounreay, Windscale, and even Chernobyl had us holding our breaths...

[IFMU]

Maybe if we could just tether it to the space elevator cable it would be more practical:

http://www.aero-news.net/news/aerospace.cfm?ContentBlockID=c912f436-6ffd-4a76-a8ae-31a38e5a05cb&Dynamic=1

-- IFMU

PS Dave, I said someone, not me!

[Gomer Pylot]

Once the scientific possibility has been demonstrated, and there is an economic need, then the rest is just engineering. It hasn't been that long ago since the idea of having personal computers was almost universally pooh-poohed. Cost is relative, and always goes down with volume. I remember the first electronic calculator I ever saw, purchased by the university's chemistry department. It was the size of a PC a few generations old, and did basic adding machine stuff, and cost $5000 in 1965ish dollars. Several years ago I bought a pack of two, the size of a credit card and perhaps twice as thick, that did everything that one did and more, and runs almost forever on solar power and a small lithium battery, total price for two was ~$5. Getting technology to work cheaply is mostly a matter of putting talented engineers on the job, with adequate startup funding. I can't say that this particular scheme will be used, but something certainly will be used. Oil will eventually become too expensive to be used for much of anything, and nuclear waste is already causing major problems. The sun, the wind, and the tides are here forever, and free. The only expense is in extracting and distributing the energy, and will decrease as the extraction rate rises. We had better start being serious about alternate sources of energy very soon.

[slowrotor]

Nuclear waste is not really a problem. It can be put back underground with all the radiactive elements that have been underground for millions of years before man invented nuclear power.

The anti-nuke people forced us to use coal.

Read about the radioactive elements in coal that are being pumped into the atmosphere from coal power plants here: http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html

[Dave_Jackson]

IFMU, you said; "Hey! It's got lateral symmetry! I bet we can find a buyer for it somewhere around here."
Then you say "I said someone, not me! "

OK you don't buy into symmetry, however an old friend does. He is currently reading the book and while discussing it he mentioned a very interesting conclusion. He said that the 'language' of symmetry mathematically explains that it is impossible for an unsymmetrical form of life to exist in the universe.

His interest in the book is due to the fact that he is a professor of Mathematics.


Maybe the tail-rotor is rotorcraft's 'pie in the sky'.:eek:
You can force just about anything to work, but that doesn't mean that it's efficient.

Dave

[IFMU]

....He said that the 'language' of symmetry mathematically explains that it is impossible for an unsymmetrical form of life to exist in the universe.
I also remember reading articles about how the most attractive, most beautiful people had more perfect symmetry than the rest of us. As a normal ugly person perhaps I've developed an adversion to symmetry!

-- IFMU

[Graviman]

Guys, this is all wrong! The need is to get energy from the jet stream and into the helicopter, right? The solution - wonderfully simple:

The wind-up helicopter. :}

Now who wants first go at clipping on the tether to wind up the spring?

[biggles99]

Is the end of the wind itself the the logical conclusion of all this harnessing of wind-power?

If you extract the energy from the air using wind turbines the wind will subside and the turbines will slow down, in line with the diminishing amount of energy stored in the atmosphere.

It's like perpetual motion, but in reverse.......

[Dave_Jackson]

How about fuel efficient vehicles?

. . . ` ` `. . http://www.Unicopter.com/Bicycle.gif

[Gomer Pylot]

Somehow I don't think a few turbines is going to bring the jetstreams to a standstill.

[riff_raff]

Until you start accepting both the immutable laws of physics and economics, you'll never get anywhere with these "green" power schemes. If you can't generate electricity cheaper than the guys burning coal, then you got NOTHING.

Cost is king.