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Turbulent air flow

Turbulent air flow. Typical wind sheer profile. The speed and power available in the wind increases with height Source: Texas State Energy Conservation Office. Source: Wind power layer provided by NC Onemap. Roof top wind energy facility

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Turbulent air flow

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  1. Turbulent air flow

  2. Typical wind sheer profile The speed and power available in the wind increases with height Source: Texas State Energy Conservation Office

  3. Source: Wind power layer provided by NC Onemap

  4. Roof top wind energy facility Rated 10kW or less, one or more roof-mounted systems designed to supplement other electricity sources as an accessory use to existing buildings. Example: 7-foot diameter rated 1.5 kilowatts with 14 mile-per-hour wind Approximately 2,000 kilowatt- hours over a year (U.S. Energy Information Administration states US households typically consume 6,500 to 10,000 kWh per year) Wind turbine at Coquina Beach

  5. Small wind energy facility Single system, rated capacity of 20kW or less, designed as an accessory use to existing buildings where the power generated is used for on-site consumption. Example: Coquina Beach wind turbine Height 65’ Rated at 2.5 kW Will generate approximately 6,000 kWh per year. (U.S. Energy Information Administration states US households typically consume 6,500 to 10,000 kWh per year) Wind turbine at Coquina Beach

  6. Medium wind energy facility Consists of 1 or more wind turbine(s), rated capacity of more than 20kW but not greater than 100kW. Example: Jennette’s Pier wind turbines Height 105’ (above pier deck) Total of 3 turbines Rated at 10kW each Each can generate approximately 15,000 kWh per year. (U.S. Energy Information Administration states US households typically consume 6,500 to 10,000 kWh per year)

  7. Large wind energy facility Consists of 1 or more wind turbine(s), rated capacity of more than 100kW. Example: Utility-scale turbines range in size from 100 kW to as large as several megawatts. grouped together into wind farms, which provide bulk power to the electrical grid. One megawatt wind turbine can produce enough energy for the annual needs of 350 average households

  8. Monopoles with guy wires Advantages: Monopole is slimmer. Less visible at a distance Disadvantages: higher bird mortality rate due to the guy wires. At least 1 acre of land needed to site one. Guy wire Guywire

  9. Lattice work towers Advantages: cost - requires only half as much material as a freely standing monopole tower. Disadvantages: Visual appearance Example – Outer Banks Brewing Station 10kW 92 feet high

  10. Vertical Axis Wind Turbines (VAWTs) A type of wind turbine where the main rotor shaft runs vertically. Advantages: do not have to be pointed into the wind, lower noise, lower rotation speed. Disadvantages: poor performance and reliability.

  11. Horizontal Axis Wind Turbines (HAWTs) The main rotor shaft and electrical generator are at the top of a tower. Advantages: They are reliable. Equipped with shut down features to avoid damage at high wind speeds. Disadvantages: Must be pointed into the wind. Height.

  12. Roof top wind facilitiesnot rated for 130 mph winds Slide courtesy of the Town of Kitty Hawk

  13. Roof top wind facilities rated for 150 mph winds 7-foot diameter 1.5 kilowatts with 14 mile-per-hour wind Approximately 2,000 kilowatt-hours over a year (U.S. Energy Information Administration states US households typically consume 6,500 to 10,000 kWh per year)

  14. Roof top wind facilities “Mounting turbines on rooftops is not recommended. All wind turbines vibrate and transmit the vibration to the structure on which they are mounted. This can lead to noise and structural problems with the building, and the roof top can cause excessive turbulence that can shorten the life of the turbine.” Source: US Dept. of Energy Small WindElectric Systems: a North Carolina consumers guide Roof top turbines

  15. Bird Mortality For every 10,000 birds killed by human activities, less than one death is caused by a wind turbine. Source: Summary of Anthropogenic Causes of Bird Mortality. Erickson et al., 2002

  16. N.C. State Building Code • The code would apply to proposed residential and commercial wind turbines. • No specific design criteria for wind turbines in the State Building Code . • Since wind turbines do not fall under the specific design criteria of the building code they must be designed by a design professional. • Current wind zone in Nags Head is rated at 130 mph. • The seismic rating for Nags Head is the lowest in the state. • All turbines, poles and supports must be rated at least 130 mph as well as meet the seismic rating for the Town.

  17. Permitted Use

  18. Setbacks Setback = required setback number multiplied by the wind turbine height

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