Vibration resonance?

[terry]

Current construction activity for a new school about 200 yards away has caused a vibration or resonance in this single story 38 year old wood frame house, from a diesel powered excavator. It's not that bothersome or annoying just puzzling and it will cease it's present 8 hours, sometimes 6 days per week, when construction carries on to the next stage. Ultimately the new school replacing the old 1950s one will again be a quiet area, especially at night.

But it got me wondering; about wind farms and some of the objections to them that have been raised?

New technologies, it seems, are always initially objected to. When (steam) railways were first built, some towns, to their later cost, objected to their smoke and noise coming anywhere near. When motor cars were first introduced regulations were imposed that required a man carrying a red flag at no more than three miles per hour to precede them; might scare the horses! Also initially steam driven ships carried masts and sails, etc. etc.

All part of an attitude of; "It's new, therefore it can't be any good it!" or the NIMBY (Not in my backyard) syndrome!

One of the objections to wind farms has apparently been noise?

To date I have, mentally pooh-pooed the idea that a gentle 'whooshing' noise could be objectionable!

But maybe one will have to build to reduce the 'Wind noise'. This house btw, being low to the ground, ain't too bad even in 66 mph winter storm gusts.

Maybe not wrong? Maybe there are noise concerns? While not objecting at all to 'alternative energy' in all it's forms, from photo voltaic, heat pumps and wind energy, just curious.

If noise were/is a consideration then one design parameter, to avoid nuisance to humans and other creatures, would be to minimise it, both at the wind turbines and one's home?

Of course some local development committee will be bound to find some hare brained other means of objection. According to some housing associations we should all live underground and have no effect on anything or any neighbours above ground?

Typically 'No drying of clothes on outside line'. DURING AN ENERGY COST CRUNCH, no less!

Consistently drying clothes outside, whenever possible, makes a lot more sense and saves more energy than not idling your car in a drive through line-up for several minutes!

But as Shakespeare observed "Lord, what fools these mortals be".

Comments, ideas, criticism, flaming, suggestions etc. invited.

[dpb]

terry wrote: ...

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Some early demonstration facilities were quite noisy and bothersome -- the one near Boone, NC, was particularly notable in that regard early on. It had both an audible "whoosh" at 3X the rotor as each blade passed the support tower plus a sub-audible reverberation that was felt rather than heard. Owing to it's location, both echoed in the surrounding mountain area if wind conditions were right (which was frequent). I don't know status of that project any longer -- at one time it was closed owing to the complaints; whether modifications were made and it was ever operated any significant amount I've not investigated.

The larger current towers in the area (typical would be Gray County

are not particularly noticeable for noise but they're built in the open. Standing at the base of the tower nearest the kiosk, I've not felt any ground vibration or the sub-audible shock wave mentioned about the NC demo facility. It was on a much lower tower, however.

The biggest complaint I have w/ wind is the fickle nature of the power source (even in W KS, notorious for being windy, the highest monthly capacity factor attained in the seven years of operation has been barely over 50% and there are months in midwinter and late summer the seven-year monthly average has only been in the low-20% range) and although they're not terribly ugly, it would be nice if we didn't have stuff just built all over everywhere. The output of this facility is only 112 MWe at 100% capacity and its spread out over 12,000 A (roughly a 20-sq mile area) and can be seen from nearly 20 miles away. That capacity is only a tenth of the output of a single large scale generating station that would have a land footprint of perhaps 1/4-sq mile and be visible from only a few miles at most even on the flat KS prairie. Plus, it would have an average availability of something like

80% or so on demand.

Wind, solar, geothermal, tides, etc., have a place but they're not the panacea many wish for.

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[Boden]

The most annoying are those which locate the blade down wind of the support. Instead of allowing the blade to see a fairly uniform wind "field" the pole creates a wind free zone and the resulting noise is quite audible. Most of the newer systems have corrected this.

[Joe]

Here in Central Illinois we have several hundred turbines operating (with more on the way) and the noise level is all but inaudible. There is that gentle 'whoosh' about as loud as Aunt Mable clearing her throat. Some neighbors in the small town where the facility is headquartered are somewhat grumpy about the red warning lights flashing at night, but since it keeps AirTran from making a surprise landing in their back yard, they have accepted that. The crop dusters do have a legitimate gripe, though, threading their way among the towers to go after Japanese beetles intent on gobbling up all the soybeans in sight. If the wind farm builders have one thing on their side, it is the quick, competent and tidy way they do their work. Promises to restore land used for construction access are kept, County blacktops are improved better then new, and taxing bodies have a revenue source as do the property owners. Even transmission towers are a new modern design, not at all unattractive. A biofuels plant can't help being a blot on some landscapes, with associated traffic, odors and the like. A pity, really, as the need is there, too. Now if we could only make solar arrays look better,,,

Joe

[dpb]

Joe wrote: ...

Well, best be careful w/ recent/new lease deals if trends in the SW KS, OK and TX panhandles are any indication... :(

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