Posted by admin | Posted in Bird and Wildlife Accessories | Posted on 17-12-1979
Tags: american bird conservancy, american bird songs, american birding association, american birding association sales, american birds, americana, bodypolitic, music, pazzundjop, photography
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Why do irrigation windmills (on farms) have a higher blade surface area than electrical generation turbines?
It seems strange that the rotor chosen for most electrical turbines is a three-blade design. I don’t understand why a much higher surface area design (i.e. the rotor of an irrigation windmill — the ones you see pictured in any Americana photo of a large farm) is not employed to catch a larger amount of wind. Does it have to do with bird mortality? Also, do electrical turbines have any ability to steer directly into the wind, as you see a weather vane do?
Wind turbine generators definitely have the ability to change their direction according to wind conditions. On the very large turbines, there is usually a smaller weather station on the top of the nacelle to measure wind speed and direction. Inside the nacelle (that’s the ‘body’ of the turbine, on top of the tower, to which the blades attach), the turbine control computers direct motors to adjust the turbine into the wind.
The control computers also adjust the pitch of the turbine blades, to catch more or less wind, depending on power output and wind conditions. This is very similar to the propeller technology used on airplanes.
The old-time windmills of the Americana era are simple fixed-blade designs that were intended to be cheap and withstand a large range of wind conditions.
In modern wind turbines, each blade is a highly engineered, carefully controlled, very expensive device. And, each blade is HUGE compared to the little windmill blades. Long-term studies have compared many different blade designs, and found that 3 blades is the most acceptable tradeoff considering cost, performance, reliability, and ability to extract useful energy from the wind.
BIRDS OF AMERICA Trailer
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Prs Private Stock SC 245 Emerald Green Brazilian Fretboard Americana Birds NEW $8,950.00 |
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T. Bird Wall Art Sculpture ONE OF A KIND Roark Gourley Americana $6,300.00 |
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The Birds Xmas Carol 1897 Kate Douglas Wiggin First Edition $1,500.00 |
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ANTIQUE AMERICANA MAN HAT STEIFF BIRD DOORSTOP CAST IRON FOLK ART PRIMITIVE $1,095.00 |
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2007 DONRUSS AMERICANA TIPPI HEDREN AUTO #4/5 HITCHCOCK THE BIRDS $499.00 |
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2007 AMERICANA LEGENDS AUTOGRAPH AUTO: LARRY BIRD #1/1 $384.65 |
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2007 AMERICANA DIRECTORS CUT AUTO: TIPPI HEDREN #5/25 AUTOGRAPH “THE BIRDS” $276.14 |
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BIG! Folk Art painting CA 1900 Hawk/Bird of prey/ hunting/Americana/PrimitiveEXC $225.00 |
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THE FIGHTING CHEYENNES by George Bird Grinnell. 1915 1st edition Signed $260.00 |
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2008 Donurss Americana Celebrity Cuts Century LARRY BIRD Autographed 46/50 HOF $249.99 |
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2007 AMERICANA WORN DRESS AUTO: TIPPI HEDREN #20/25 SWATCH AUTOGRAPH “THE BIRDS” $157.77 |
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2007 AMERICANA WORN DRESS AUTO: TIPPI HEDREN #6/25 SWATCH AUTOGRAPH “THE BIRDS” $157.77 |
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2 BLACK AMERICANA BASEBALL PLAYER FIGURINES,”EARLY BIRD CATCHES THE WORM” ~RARE~ $150.00 |
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Vintage Black Americana PIE AIRE Chef Yellow Pie Bird Funnel Retro Kitchen Man $149.99 |
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2007 DONRUSS AMERICANA AUTO: TIPPI HEDREN #20/25 AUTOGRAPH HITCHCOCK “THE BIRDS” $118.32 |
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2007 AMERICANA AUTO: TIPPI HEDREN #21/25 AUTOGRAPH HITCHCOCK CLASSIC “THE BIRDS” $118.32 |
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Antique Folk Art Wood Bird Carved Americana 16″ # 301-12 $99.00 |
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FENTON QVC AMERICANA COBALT BLUE LADYBUG CANDY BOX & RUBY RED BIRD FIGURINE $88.00 |
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Yellow Bird or American Goldfinch Carduelis Americana 1972 Bird $69.99 |
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RARE VTG Black Americana Yellow Pie-Aire Chef Pie Bird Vent $70.00 |
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Vintage,GARDEN,Wood,BIRD,HOUSE,Cottage,AMERICANA,Farm,Birds,Outdoors,Spring, $68.88 |
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RARE Vintage Black Americana TWO PIE BIRDS CHEF & COOK, Orig. Paint, Great Cond. $79.95 |
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Vtg Yellow Pie Aire Chef Bird Vent Funnel Black Americana James Barry No Tax $74.99 |
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FENTON ROOSTER AMERICANA PATRIOTIC FOLK ART QVC HEN CHICKEN BIRD LIMITED NIB!!!! $49.99 |
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2007 AMERICANA WORN DRESS JUMBO SWATCH: TIPPI HEDREN #7/25 “HITCHCOCK- THE BIRD” $49.27 |
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Black Americana Ashtray The Early Bird Catches The Worm $49.99 |
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Antique HC 1927 Children’s Book Birds Black Americana Mammy 8 Colored Plates $55.00 |
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VTG. BLACK AMERICANA CHALKWARE ASHTRAY & GLASS LINER EARLY BIRD CATCHES WORM $45.00 |
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Antique Early Primitive Metal/Tin Bird with Star Cookie Cutter / True Americana! $49.99 |
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39559 Americana Bird Village Birdhouse (8-family) LAST ONE AVAILABLE $49.95 |
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Butcher Bird (1936) Black Americana $44.99 |
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★antique TIN flatback early ORIG. DOVE BIRD COOKIE CUTTER prim americana $42.50 |
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antique TIN flatback early ORIG. SONG BIRD COOKIE CUTTER prim americana cardinal $42.50 |
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1941 Rare 1st Edition-Bird of the Wilderness-V. Sheean $45.00 |
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Texas In Bloom: Signed by Lady Bird Johnson 1st Ed. D/J $40.00 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Birds and the Bees by Billy Jacobs Primitive Folk Americana House 16×12 Framed $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Patriotic Bird Sampler by Bernadette Deming Country Americana Flag Framed Art $28.95 |
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Wrens On Fence Post Americana Bird Art Print Framed $28.95 |
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Wrens On Fence Post Americana Bird Art Print Framed $28.95 |
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Wrens On Fence Post Americana Bird Art Print Framed $28.95 |
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Wrens On Fence Post Americana Bird Art Print Framed $28.95 |
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Wrens On Fence Post Americana Bird Art Print Framed $28.95 |