Poor Mountain Wind Analysis

8/6/2019 Poor Mountain Wind Analysis

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Creating a venue for a

Wind Analysis Study for a site on

Poor Mountain in Roanoke County, Virginia


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This image describes a 650 ft x 650 ft pixel size

overlay of a Wind Density Analysis extrapolated

from data from sites, nationwide, on a vertical

elevation above sea level basis to assess electrical

energy production for a site on Poor Mountain in

Roanoke County, VA


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Understanding the

Wind Developers

Wind Analysis Study

for a site on

Poor Mountain in

Roanoke County,

Virginia


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Is this site on

Poor Mountain in

Roanoke County,Virginia a key

to accessing

additional energy

resources from the

abundant wind power

bands near a little

model city in the

southern Appalachians?
http://upload.wikimedia.org/wikipedia/commons/9/96/Diagrama_de_formacion_de_la_brisa-breeze.png


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A: Sea breeze (occurs at daytime)

B: Land breeze (occurs at night)

Mountain wave schematic. Th

towards a mountain and prod

oscillation (A). A second wave

away and higher. The lenticula

the peak of the waves
http://upload.wikimedia.org/wikipedia/commons/9/96/Diagrama_de_formacion_de_la_brisa-breeze.png


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Wind Flow Visualization over Appalachian Mountain Terrain

Poor Mountain Wind Reaping - Roanoke County - Virginia


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The wind profile power law relationship is:

u/ur = (z/zr)

where u is the wind speed (in meters per second) at height z (in m

known wind speed at a reference height zr. The exponent () is an

coefficient that varies dependent upon the stability of the atmosp

stability conditions, is approximately 1/7, or 0.143.In order to estimate the wind speed at a certain heightx, the rela

rearranged to:

ux = ur(zx/zr)

The value of 1/7 for is commonly assumed to be constant in win

assessments, because the differences between the two levels are

as to introduce substantial errors into the estimates (usually < 50

a constant exponent is used, it does not account for the roughnes

displacement of calm winds from the surface due to the presencezero-plane displacement), or the stability of the atmosphere. In p

structures impede the near-surface wind, the use of a constant 1/

yield quite erroneous estimates, and the log wind profile is prefer

neutral stability conditions, an exponent of 0.11 is more appropria

(e.g., for offshore wind farms), than 0.143, which is more applica

surfaces.


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Rayleigh Distribution - Wind Speed

The purpose of this page is to illustrate the use of the Rayleigh distribution to

energy recovered by a medium sized wind turbine. The parameters are illust

important to obtain site specific parameters for a project evaluation.

Basic Equation

The equation for energy recovery from the wind is as follows:


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Coefficient of Performance

Not all the energy can be recovered from a

wind stream. The theoretical maximum value

for the coefficient of performance is 0.593. An

"ideal" wind turbine with this maximum value

is known as a Rayleigh-Betz machine.In practice the value of the maximum values of

coefficient is in the range 0.25 to 0.45.

In general, the larger the machine the higher

the value. Also the use of variable pitch rotors

can optimize the coefficient of performance

for a range of wind speeds. The curve used in

the example is shown below.

The maximum value of the coefficient has

been set close to the modal wind speed for

Rayleigh averages in the range 5 - 7 m/sec. The

rotor design should be optimized for the site.


11/15From GE Wind (2.5xl Power curve speculation NOT fro


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Poor Mountain PThe Nature Conse

Globally Rare PiratBottom CreekHeadwaters

Big Laurel Creek

Headwaters

Bottom Creek Gorge

PreserveThe Nature Conservancy

EPA/DEQ Tier III Stream

Poor Mountain Wind Analysis

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