1.1k likes | 1.11k Views
The Appalachian State University's Small Wind Initiative aims to promote wind energy in Western NC through mapping, wind site assessments, workshops, and presentations. Contact us at wind.appstate.edu or wind@appstate.edu for more information.
E N D
Windin WNC Oct 27, 2007Andrews, NC Brent Summerville, ASU
NC Small Wind Initiative • Appalachian State University Project to promote wind energy in Western NC • Beech Mountain wind site • Anemometer Loan Program • Mapping • Wind Site Assessments • Workshops and Presentations • Ordinance work • Media Outreach • Reach us at: wind.appstate.edu wind@appstate.edu 828-262-7333
Wind Power History 1400 – 1800 years ago,in the Middle East 800 – 900 years ago in Europe 140 years ago,water-pumpingwind mills 70 years ago, electric power
Today: Wind Energy is Reliable and Cost Effective Wind has become the least expensive and fastest growing source of electricity in the world -details at www.gwec.net
Mountain Ridge Protection Act of 1983 Exemptions to Ridge Law “No building, structure or unit shall protrude at its uppermost point above the crest of the ridge by more than 35’ “ Water, radio, telephone or television towers or any equipment for the transmission of electricity or communications or both. Structures of a relatively slender nature and minor vertical projections of a parent building, including chimneys, flagpoles, flues, spires, steeples, belfries, cupolas, antennas, poles, wires, or windmills NC Attorney General’s 2/4/2002 letter to TVA “The Legislature in 1983 had in mind, the traditional, solitary farm windmill which has long been in use in rural communities, not windfarm turbines of the size, type, or certainly number proposed here…”
What causes wind? • Differences in pressure and temperature • Solar Power • Uneven heating of the Earth’s surface • Differences in heating and cooling rates • Earth’s rotation
Location and Percentage of High Quality Wind Resources in the US Class 6 (4.3%) Class 5 (6.3%) Class 4 & above 27.5%
Average Wind Speed is the Key • Most important variable Power ~ V3 • Double speed and power increases 8 times • 73% more power in a 12 mph wind than a 10 mph wind • This is why it is so important to carefully assess
We are not in South DakotaCareful site analysis is important
County Wind Maps for Western NC • True Wind Map Combined With: • Road data • Digital elevation models • Public lands • Appalachian Trail • Town boundaries • Utility grid • Tax parcel maps www.wind.appstate.edu
Wind Monitoring Activities • Actual on-site measurements
Measuring Devices and Parameters Anemometer Best indication of energy production Indicator of turbulence Provide information on wind shear Wind Vane Wind rose Micro siting Temp Sensor Identify icing events Air density Data Loggers
TVA Monitoring Activities 50 meter met tower
Measured vs Truewind Wind Speeds (m/s)(.23 m/s average difference)
Factors Affecting Wind • Elevation • Obstructions • Surface Roughness • Perpendicular Ridges • Time of day • Time of year
Season and Time of Day • Higher winds found late in the evening and early morning • Higher winds seen during the winter
Wind Micrositing Where to put it
Step 2: Resource Assessment • Average annual wind speed at the proposed hub height is critical • Wind maps • Existing data • Extrapolate wind speed from a lower height to hub height • Measure • Anemometer, wind vane, temp, logger • Flagging, interview locals
Rule 1: Minimize TurbulenceRule 2: Minimum Tower Height 30’ above obstructions within 300 – 500’
Rule 3: Stay upwind of obstacles • Know the prevailing wind direction • The turbine would like a clear view in that direction
Annual Frequency and Average Annual Wind Speed in Sixteen Compass Directions Potato Hill, Watauga County, NC N 35 NNW NNE 30 NW NE 25 20 15 WNW ENE 10 5 W 0 E WSW ESE SW SE SSW SSE S Wind Frequency Wind Speed
The wind blows from all directions There may not be the “perfect” spot The goal is to maximize your wind resource Rule 4: Minimize Compromises
Rule 5: Voltage and wire run • Think about the wire run • Higher voltage means smaller wire • Raising the system voltage gives you more flexibility in tower placement
Use a kite or balloon with streamers Visualizing the Turbulence