1. Oct 27, 2007 Andrews, NC Brent Summerville, ASU
Wind in WNC
Oct 27, 2007 Andrews, NC
Brent Summerville, ASU

2. 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

3. Wind Power History 1400 – 1800 years ago, in the Middle East
800 – 900 years ago in Europe
140 years ago, water-pumping wind mills
70 years ago, electric power
1) Wind power has been an important energy source for at least 1400 years. (Some sources say 3,000 to 4,000 years.)
2) Crusaders brought the concept back to northern Europe where is it evolved into the European or “Dutch” windmill.
3) The American water-pumping windmill was an important innovation. It automatically tracked the changing wind direction and protected itself in high winds... the first wind machines to operate unattended. They were an important contributor to the settlement of the Great Plains. Over 6 million windmills have been sold… and counting!
4) Early in last century, electric utilities served only the cities. Beginning in the 1930’s, thousands of farms in the Great Plains generated their own electricity with small “wind chargers.” Federally-financed rural electric coops brought an end to this industry in the 1950s.

4. 2MW Mod-1 Turbine:

5. 1980s California Wind Rush

6. 1980s Denmark Got it Right

7. 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

8. Mountain Ridge Protection Act of 1983
“No building, structure or unit shall protrude at its uppermost point above the crest of the ridge by more than 35’ “
Exemptions to Ridge Law
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
The Ridge Law was written during the time of the MOD-1experiment on Howard’s Know, a collaborative project by NASA and BREMO, the local electric cooperative. Several of the authors of the Ridge Law were representatives of Watauga County at that time. The meaning of the term “wind mill” has changed today, as the word “wind turbine” was not widely used in 1980.
Developers and landowners in the mountain region have hesitated installing small and large wind due to the ambiguity of this situation.
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…”

9. Our Wind Resource

10. Like most things, wind is powered by the Sun

11. 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

12. Flagging: Deformed Growth from Persistent Winds

13. Extreme Flagging on Grandfather

14. Wind Maps

15. Updated Hi-res Map
One of the powerful features of WinDS is easy access to the best wind resource data via the NREL GIS team and Donna Heimiller
Note that no offshore resources are included for the southeast nor the Gulf of Mexico at this time.
Note that currently WinDS uses annual average wind speed data but is capable of using seasonal/diurnal data

16. Location and Percentage of High Quality Wind Resources in the US
Class 6 (4.3%)
Class 5 (6.3%)
Class 4 & above 27.5%

17. 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

18. Western NC Wind Potential

19. New Hi-Res North Carolina Wind Map

20. We are not in South Dakota Careful site analysis is important
The return button will take you back to the menu slide for this file.

21. North Carolina Coastal Resources

22. 24 County Western NC Wind Map

27. 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

29. What Fir Tree Farm - Watauga

31. Hattie Hill Site - Watauga

33. Wind Monitoring Activities
Actual on-site measurements

34. 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

35. TVA Monitoring Activities
50 meter met tower

36. Anemometer Loan Program

37. Measured vs Truewind Wind Speeds (m/s) (.23 m/s average difference)

38. Factors Affecting Wind
Elevation
Obstructions
Surface Roughness
Perpendicular Ridges
Time of day
Time of year

39. Elevation & Wind Velocity

40. Season and Time of Day
Higher winds found late in the evening and early morning
Higher winds seen during the winter

41. Wind Micrositing
Where to put it

42. Step 1: What do you want to do?

43. 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

44. Rule 1: Minimize Turbulence Rule 2: Minimum Tower Height
“Micro-Siting” refers to how a wind turbine is placed on a given property.
Trees and buildings are significant obstacles to the wind.
We can’t see it, but the region of disturbed flow downwind of an obstacle is twice the height of that obstacle and quite long. For example, a 30-ft tall house creates a region of turbulence that is 60 ft high and 600 ft long (2 football fields!).
This turbulence reduces power output from a wind turbine, and increases the stress and wear on that turbine.
THE SOLUTION  Place the turbine upwind of obstacles (in the prevailing wind direction), or use a tower twice the height of the obstacles, or both.
30’ above obstructions within 300 – 500’

45. Tower Height Depends on Terrain

46. Rule 3: Stay upwind of obstacles
Know the prevailing wind direction
The turbine would like a clear view in that direction

47. 5 10 15 20 25 30 35 N
NNE NE
ENE E
ESE SE
SSE S
SSW SW
WSW W
WNW NW
NNW
Wind Frequency
Wind Speed
Annual Frequency and Average Annual Wind Speed in Sixteen Compass Directions
Potato Hill, Watauga County, NC

48. Rule 4: Minimize Compromises
The wind blows from all directions
There may not be the “perfect” spot
The goal is to maximize your wind resource

49. 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

50. Visualizing the Turbulence
Use a kite or balloon with streamers

51. Measuring Heights
Shadow method

52. Measuring Heights
Friend and Pen
Tree Height

53. Micrositing Recap

54. Small Wind Turbine Technology

55. Small Wind Turbine Technology
Horizontal Axis Upwind
Horizontal Axis Downwind
Vertical Axis
Towers
Systems

56. HAWT - Upwind
Configuration: 2 or 3 blades aimed into the wind by the tail
Blades: Fiber-reinforced plastics
Over-Speed Protection: Furling (rotor turns out of the wind)
Generator: Direct-drive, permanent magnet alternator (no brushes), 3-phase AC, variable-speed operation
Bergey EXCEL, 10 kW

57. Southwest Windpower Flagstaff, Arizona www.windenergy.com
Whisper W
AIR 400 W
Whisper W
Whisper kW
(Now with grid-tie)

58. Ned Trivette
Whisper 200
Sugar Grove, NC

59. Beech Mountain Wind Energy Research & Demonstration Site

60. Bergey Windpower Norman, Oklahoma www.bergey.com
BWC XL.1 1 kW
BWC Excel 10 kW

61. Bergey 10kW
Canton, NC

62. Abundant Renewable Energy Newberg, Oregon www.abundantre.com
ARE kW

63. Homebuilt www.otherpower.com www.scoraigwind.com

64. Fuhrländer Lorax Energy Systems, Rhode Island www.lorax-energy.com
FL kW
FL kW
FL kW
Fuhrländer is a German company.
Lorax is the US company importing their products.

65. Over-Speed Protection During High Winds
Furling: The rotor turns up and to one side, or back, or to the side

66. HAWT - Downwind
wind
Configuration: 2 or 3 blades, no tail, blades face downwind
Blades: Fiber-reinforced plastics
Over-Speed Protection: Zebedee Furl (blade coning), tip brakes, stall regulation
Generator: Direct-drive, permanent magnet alternator (no brushes), 3-phase AC, variable-speed operation
Proven WT600

67. Proven Engineering Products, Ltd. Scotland, United Kingdom. www
Proven Engineering Products, Ltd. Scotland, United Kingdom
WT W
WT kW
WT kW
Proven is a Scottish company.
Several U.S. dealers are importing these turbines.

68. Proven Blade Coning Flexible Zebedee hinge
As RPM increases, blades are thrown outwards by centrifugal force
Changes aerodynamic pitch
10-15 year hinge life

69. Southwest Windpower Skystream
70 Foot Guyed Tower
Southwest Windpower Skystream

70. Southwest Windpower Skystream
35 Foot Monopole Tower
Southwest Windpower Skystream

71. VAWT – Drag & Lift Configuration: Lift or Drag
Drag: Anemometer, Savonius
Lift: Darrieus, H-Darrieus
Anemometer
Savonius
Mother Earth News
Darrieus

72. Savonius (S-rotor) Make from buckets, paddles, sails, and oil drums
originated in Finland
tsr ≈ 1
Can be useful for grinding grain, pumping water, and many other tasks
…but are not good for generating electricity (low speed, high torque)

73. Darrieus Lift-Type Vertical-Axis Machines
Darrieus, curved blades
French engineer Georges Darrieus patented the design in 1931
Plus: generator on ground, yawing not required
Minus: low to ground, low efficiency, not self-starting, vibration, high bearing forces
H-Darrieus, straight blades

74. The main issue with VAWT: Availability on the Market

75. Small Wind Turbine Towers
Fixed Guyed Tower
Tilt-Up Tower
Self-Supporting Tower

76. (3) guy wire anchors, climbing, crane
Fixed Guyed Tower
Build on ground
Tilt-Up with crane
(3) guy wire anchors, climbing, crane

79. Tilt-Up Guyed Tower Build on ground Tilt-Up with winch or grip-hoist
(4) guys wire anchors, maintenance on ground, economical

80. Self Supporting Towers
Build on ground
Raise with crane
No guy wires, requires climbing or crane

82. On-Grid Wind System without Storage
Meter AC
Inverter
Wind turbine
This simple schematic shows how a wind turbine is connected to the utility grid in a residential application.
When wind-generated power exceeds the power consumption of the home, the excess power flows back to the utility. At other times, power flows from the utility to supplement the wind-generated power.
The inverter delivers electricity at the same voltage and frequency as the utility grid. It also must turn off automatically if the utility grid goes down. When that happens, the home is without power.
Load

83. On-Grid Wind System with Storage
Meter
Regulation and conversion AC
Inverter
Wind turbine
In order to have backup power when the utility grid goes down, batteries must be used with the wind turbine. Energy previously stored in the batteries can be used to “ride through” a utility outage.
(The inverter and home must disconnect from the utility grid during the outage. Some inverters can do this automatically.)
This system has storage which provides backup power.
Load

84. The Effect of Seasons on Hybrid Power Systems
Summer
PV modules and wind turbine
Battery
Loads
(active generation)
(storage)
(utilization)
(building on the previous slide:)
The seasonal complimentarity of solar and wind resources provides a more continuous year-round energy supply in a hybrid system.
Winter
PV modules and wind turbine
Battery
Loads
(no generation)
(storage)
(utilization)

85. Hours of sunshine or average wind power (Watts/m2)
Solar and Wind Resources are Complimentary
400
Data from SE Iowa
350
Hours of sunshine/month
Hours of Sunshine
300
Hours of sunshine or average wind power (Watts/m2)
250
It very important to understand how solar and wind resources vary during the seasons of the year. The trends shown in this chart of data from Iowa are representative of all the continental U.S.. The solar resource reaches a peak during the sunny summer months while the wind resource is highest in late winter to early spring. These resources are complimentary to one another during the year. (see following slide also)
200
Average wind power
150
100
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

86. PV/Wind Hybrid Project Installed on Beech

87. Energy

88. Power Power: Rate at which energy is delivered Power = Energy Time
Measured in Watts (W), kilowatts (kW), or horsepower
Power is an instantaneous quantity
Power does not accumulate
Think gallons per minute

89. Energy Energy: Ability to do something
Measured in kilowatt  Hours (kWhrs)
Why?
Since Power = Energy/Time,
then Power  Time = Energy
Energy does accumulates over time
Think gallons
Gallons = (gallons/min)  minutes

90. Swept Area
The single most important parameter of a wind turbine is its rotor’s swept area A

91. Power of a Wind Turbine The power of a wind turbine is
P = ½  v3 A CP
A: swept area of rotor
CP: rotor efficiency
Example: A 2.5 m diameter turbine with a 25% efficient rotor in our 8.0 m/s wind will have
P = ½ (1.0 kg/m3)(8.0 m/s)3 [ (2.5 m/2)2](0.25)
= 314 W

92. Method of Bins There are limitations to this method…
Wind speed is not constant!
Rotor efficiency depends on wind speed!
Small turbines furl in high winds
Here’s a better method: Method of Bins
Need to know (or approximate) your wind distribution
Power Curve of turbine

93. Wind Distribution Wind is known to follow a distribution pattern
Credit: Paul Gipe

94. Power Curve
The turbine’s manufacturer will provide you with its power curve
Bergey XL.1

95. Method of Bins Calculate Energy = Power  Time for each wind speed bin
Sum ‘um up!

96. Method of Bins Power Curve Wind Distribution (data)
Annual Energy Output

97. Power Curve Southwest Windpower Whisper 100 and Whisper 200
Similar rated power
Difference in energy

98. Charts from Manufacturer

99. Incentives

100. North Carolina Incentive Programs
TVA Green Power Switch
NC GreenPower
NC Personal Renewable Energy Tax Credit
NC Corporate Renewable Energy Tax Credit
Green tags
Renewable Energy Equipment Manufacturers Incentive
Energy Improvement Loan Program
USDA Farm Bill

101. Green Tags

102. TVA Green Power Switch Generation Partners Program
Details
Wind or PV
(.5 – 50 KW)
Residential or small commercial
$.15/kWh credit
Energy used on site is billed at standard rate

103. NC GreenPower Program www.ncgreenpower.org
To improve the quality of the environment by encouraging the development of renewable energy resources through consumers’ voluntary purchase of green power.
RFP process for green power
No wind producers yet
Green Power program initially quoted an estimate of .06/kwh

104. NC Net Metering
Credited to a customer's next monthly bill, but reset to zero at the beginning of each summer (June 1) and winter (October 1) billing season. Any renewable-energy credits associated with net excess is granted to the utility when the balance is zeroed out.
20 kW for residential systems; 100 kW for non-residential systems
Investor-owned utilities (Progress Energy, Duke Power, Dominion North Carolina Power)
Photovoltaics, Landfill Gas, Wind, Biomass, Anaerobic Digestion

105. NC Renewable Energy Tax Credits
35% for all technologies
Can take tax credit over 5 years
No more than half of tax liability
No refund based on tax credit
To simplify and modernize the North Carolina tax credits for solar and other renewable energy sources, new legislation was enacted in the 1999 legislative session. Fourteen different credits were eliminated and replaced by one general credit that covered residential and non-residential solar and other renewable energy property. A credit of 35% was established for all renewable energy sources, with the maximum limits varying by renewable energy resource or technology, and by residential or non-residential sectors.

106. Wind Turbine Installed Cost Example
This table is a summary of installed cost for a Bergey 10 kW turbine. The columns on the right show how costs can vary. Tower cost varies widely depending on the tower type and its height. Installation costs may be low for a do-it-yourself installation, or higher for a professional installation. Permits/Fees and Sales Tax can also vary over a large range.
Notice that the costs can range from $30,000 to $60,000 (unit costs of $3,000 to $6,000/kW).
Tax Credit
$2, $3,511 $1,790
Final Cost $ $6, $3,325

107. USDA Farm Bill Section 9006
Farmers and Rural Small Business Owners Can Apply for:
25% from $2,500 to $500,000
Or up to $10 million in guaranteed loans
Contact
H. Rossie Bullock
Business Programs Specialist
440C Caton Rd.
P.O. Box 7426
Lumberton, NC
Phone: (910) ext. 4
Fax: (910)

108. Wind Turbine Installed Cost
This table is a summary of installed cost for a Bergey 10 kW turbine. The columns on the right show how costs can vary. Tower cost varies widely depending on the tower type and its height. Installation costs may be low for a do-it-yourself installation, or higher for a professional installation. Permits/Fees and Sales Tax can also vary over a large range.
Notice that the costs can range from $30,000 to $60,000 (unit costs of $3,000 to $6,000/kW).
USDA Grant $11, $18,068 $8,702
Adjusted Total $34, $54,204 $26,108

109. This chart shows simple payback for a small wind turbine, that is how many years of utility bill savings are needed to recover the initial cost. Payback varies with many factors including wind speed, tower height, utility rates, turbine cost, and financial incentives.
In particular, this chart illustrates how a 50% buydown incentive can significantly reduce wind system payback.

110. Questions? Thanks Brent Summerville Call or email me for more info
wind.appstate.edu
My presentations will be available at wind.appstate.edu
Click on REPORTS….CONFERENCE PRESENTATIONS