Tree Wind Generator
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From: Dirk Bruere at NeoPax on 18 Apr 2010 10:23 On 18/04/2010 07:03, Paul Keinanen wrote: > On Sat, 17 Apr 2010 15:17:39 +0100, Dirk Bruere at NeoPax > <dirk.bruere(a)gmail.com> wrote: > >> On 17/04/2010 11:22, Paul Keinanen wrote: >>> On Sat, 17 Apr 2010 01:42:01 -0700 (PDT), TerryKing >>> <terry(a)terryking.us> wrote: >>> >>>>> I have wire antennas hanging from pine trees and if the movement and forces would be as large as stated, the antennas would have snapped a long time ago. >>>> >>>> I've had long wire antennas in trees in New England for 50 years. >>>> The wind motion WILL snap even strong wires, so there has to be >>>> hundreds of pounds of force, at least some of the time. >>> >>> The question is, how much sag do you accept in calm warm environment ? >>> With sufficient sag, the wire will not snap. >>> >>> I have a multiband inverted-V dipole hanging from the tallest pine >>> tree with the ends of the element suspension wires suspended via other >>> pine tree branches "pulleys" into small trees acting as "springs". >>> >>> Anyway, most of the dipole radiation is created close to the high >>> current point, i.e. close to the dipole feed-point, so the wire >>> sagging does not drop the radiated power in a significant way. >>> >>>> The typical "Solution" is to have one end supported by synthetic rope >>>> going through a pulley attached near the top of the tree, and routed >>>> down to the ground. A weight of 20 to 50 pounds (Typically a concrete >>>> block or two) is attached to the lower end, keeping constant tension >>>> on the antenna wire. >>>> >>>> I've been out in a high wind, checking antennas, and seen those >>>> weights move 2 or 3 FEET up and down. So the energy is there. I >>>> never tried to USE it :-) >>> >>> Thus 10 .. 25 kg and 0.7 .. 1 m with unspecified cycle. >>> >>> The original poster claimed >>> >>>> Simple idea - capture the energy of a tall tree swaying in the wind. >>>> Rough numbers: 200kg force (2kN) through 0.3m every 2 seconds is >>>> potentially around 330W. >>> >>> Thus up to an order of magnitude less and then only during a storm. >> >> Just because the stroke is moving 25kg does not mean that it could not >> move something 10x heavier. >> After all, the above poster was adding weight merely to tension his lines. > > Do you expect that the amplitude of the tree oscillation will remain > the same, when you put say, 250 kg hanging from the line ? No, I assume it will probably be in line with my example ie around 30cm stroke in moderate wind. That's what I observe. -- Dirk http://www.transcendence.me.uk/ - Transcendence UK http://www.blogtalkradio.com/onetribe - Occult Talk Show
From: Kevin McMurtrie on 18 Apr 2010 23:15
In article <hqalgf$qt5$1(a)news.eternal-september.org>, "Tim Williams" <tmoranwms(a)charter.net> wrote: > It would be pretty cool if you put the trees on a merry-go-round. Put up > some sort of wind screen so they only sway on the windward side. Instead of > 200kg through 0.3m, you get maybe 100kg through 20m/s! > > Moving/living sculpture projects aside, sway has the advantage of working in > place. Can't say I've heard of it before though. > > Invent it, then market it to nut orchards -- turn the generator around and > it doubles as a tree shaker for harvest. :-) > > Tim I've seen cylindrical turbines placed at the edges of buildings where bad aerodynamics causes extreme winds. I found this for the turbines on Park Ave. in San Jose, CA: http://www.mercurynews.com/breaking-news/ci_14191622 -- I won't see Google Groups replies because I must filter them as spam |