WindWindin WNC

Oct 27, 2007Oct 27, 2007Andrews, NCAndrews, 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

800 – 900 years ago in Europe

140 years ago,water-pumpingwind mills

70 years ago, electric power

1400 – 1800 years ago,in the Middle East

2MW Mod-1 Turbine: 1979 - 1983

1980s California Wind Rush

1980s Denmark Got it Right

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

“No building, structure or unit shall protrude at its uppermost point above the crest of the ridge by more than 35’ “

Exemptions to Ridge LawWater, 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 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…”

NC Attorney General’s 2/4/2002 letter to TVA

Our Wind Resource

Like most things, wind is powered by the Sun

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

Flagging: Deformed Growth from Persistent Winds

Extreme Flagging on Grandfather

Wind Maps

Updated Hi-res Map

Class 6 (4.3%) Class 5 (6.3%)

Location and Percentage of High Quality Wind Resources in the US

Class 4 & above 27.5%

Average Wind Speed is the Key

Most important variablePower ~ 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

Western NC Wind Potential

New Hi-Res North Carolina Wind Map

We are not in South DakotaCareful site analysis is important

North Carolina Coastal Resources

24 County Western NC Wind Map

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

What Fir Tree Farm - Watauga

Hattie Hill Site - Watauga

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

Anemometer Loan Program

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

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ards Knob

Hilliards K

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Turkey R

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Wind Springs B

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Cow

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Cham

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Phoenix Mt

Truewind

Anemometer

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

Elevation & Wind Velocity

66.6

7.38.16

6.597.2

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3600'class 2

4000' class 3

4418' class 4

4690' class 5

M/S @ 50 mM/S @ 80

Season and Time of Day Higher winds found late in the evening and early

morning Higher winds seen during the winter

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Wind Micrositing

Where to put it

Step 1: What do you want to do?

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 Turbulence Rule 2: Minimum Tower Height

30’ above obstructions within 300 – 500’

Tower Height Depends on Terrain

Rule 3: Stay upwind of obstacles

Know the prevailing wind direction

The turbine would like a clear view in that direction

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Wind Frequency

Wind Speed

Annual Frequency and Average Annual Wind Speed in Sixteen Compass Directions Potato Hill, Watauga County, NC

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

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

Visualizing the Turbulence

Use a kite or balloon with streamers

Measuring Heights

Shadow method

Measuring Heights

Friend and Pen

Tree Height

Micrositing Recap

Small Wind Turbine

Technology

Small Wind Turbine TechnologySmall Wind Turbine TechnologyHorizontal Axis

UpwindHorizontal Axis

DownwindVertical Axis

SystemsTowers

HAWT - Upwind

Bergey EXCEL, 10 kW

• 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

Southwest WindpowerFlagstaff, Arizona www.windenergy.com

AIR400 W

Whisper 100900 W

Whisper 2001000 W

Whisper 5003 kW

(Now with grid-tie)

Ned Trivette

Whisper 200

Sugar Grove, NC

Beech Mountain Wind Energy Research & Demonstration Site

Bergey WindpowerNorman, Oklahoma www.bergey.com

BWC Excel10 kW

BWC XL.11 kW

Bergey 10kW

Canton, NC

Abundant Renewable EnergyNewberg, Oregon www.abundantre.com

ARE1102.5 kW

Homebuiltwww.otherpower.comwww.scoraigwind.com

FuhrländerLorax Energy Systems, Rhode Island www.lorax-energy.com

FL 3030 kW

FL 100100 kW

FL 250250 kW

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

or to the side

HAWT - Downwind

Proven WT600

• 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

wind

Proven Engineering Products, Ltd.Scotland, United Kingdom www.provenenergy.com

WT600600 W

WT2500 2.5 kW WT6000

6 kW

Proven Blade Coning

Flexible Zebedee hinge As RPM increases,

blades are thrown outwards by centrifugal force

Changes aerodynamic pitch

10-15 year hinge life

Southwest Windpower Skystream

www.skystreamenergy.com

70 Foot Guyed Tower

Southwest Windpower Skystream

www.skystreamenergy.com

35 Foot Monopole Tower

VAWT – Drag & Lift

Darrieus

• Configuration: Lift or Drag

• Drag: Anemometer, Savonius

• Lift: Darrieus, H-Darrieus

SavoniusMother Earth News

Anemometer

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)

Darrieus Lift-Type Vertical-Axis Machines

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

Darrieus, curved blades

H-Darrieus, straight blades

The main issue with VAWT: Availability on the Market

Small Wind Turbine Towers

Fixed Guyed Tower

Tilt-Up Tower Self-Supporting Tower

Fixed Guyed Tower

Build on ground

Tilt-Up with crane (3) guy wire

anchors, climbing, crane

Tilt-Up Guyed Tower

Build on ground

Tilt-Up with winch or grip-

hoist

(4) guys wire anchors, maintenance on

ground, economical

Self Supporting Towers

Build on ground

Raise with crane

No guy wires, requires climbing

or crane

02770329

Load

Meter

InverterAC

Windturbine

On-Grid Wind System without Storage

02770330

Inverter

Regulationand

conversion

Windturbine

AC

Load

Meter

This system has storagewhich provides backup

power.

On-Grid Wind System with Storage

The Effect of Seasons onHybrid Power Systems

02770322

PV modules and wind turbine(no generation)

Battery(storage)

Loads(utilization)

PV modules and wind turbine(active generation)

Summer

Winter

Battery(storage)

Loads(utilization)

Solar and Wind Resourcesare Complimentary

Hours of sunshine/month

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Average wind power

Data from SE Iowa

02770324

Hours of Sunshine

PV/Wind Hybrid Project Installed

on Beech

Energy

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

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

Swept Area The single most important parameter of a

wind turbine is its rotor’s swept area

A

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

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

Wind Distribution Wind is known to follow a distribution

pattern

Credit: Paul Gipe

Power Curve The turbine’s manufacturer will provide you

with its power curve

Bergey XL.1

Method of Bins Calculate Energy = Power Time for each

wind speed bin Sum ‘um up!

Method of Bins

Power Curve

Wind Distribution (data)

Annual Energy Output

Power Curve Southwest Windpower Whisper 100 and

Whisper 200 Similar rated power Difference in energy

Charts from Manufacturer

Incentives

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

www.dsireusa.org

Green Tags

TVA Green Power Switch Generation Partners Program

www.tva.com/greenpowerswitch/partners/index.htm

Details Wind or PV (.5 – 50 KW) Residential or small

commercial $.15/kWh credit Energy used on site

is billed at standard rate

NC GreenPower Programwww.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

NC Net MeteringCredited 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

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

Wind Turbine Installed CostExample

Updated: Oct04

High Cost Low Cost

Wind turbine & Controller $2,045 $2,045 $2,045

Tower (80 guyed) $2,220 $690 $2,220

Inverter $1,000 $2,500 $500

Battery and Containment $300 $800 $200

Shipping $200 $400 $150

Installation $1,200 $2,500 $0

Permits/Fees $200 $500 $0

Sales Tax, 5% $358 9% 0%

Total $7,523 $10,033 $5,115

Southwest WindpowerWhisper H40

$2,633 $3,511 $1,790Tax Credit

Final Cost $4890 $6,522 $3,325

USDA Farm Bill Section 9006

ContactH. Rossie BullockBusiness Programs Specialist440C Caton Rd.P.O. Box 7426Lumberton, NC 28359-7426Phone: (910) 739-3349 ext. 4Fax: (910) 618-9444 email: rossie.bullock@nc.usda.gov

Farmers and Rural Farmers and Rural Small Business Owners Small Business Owners Can Apply for:Can Apply for:•25% from $2,500 to 25% from $2,500 to $500,000$500,000•Or up to $10 million in Or up to $10 million in guaranteed loansguaranteed loans

Wind Turbine Installed CostUpdated: 11-Oct-04

High Cost Low Cost

Wind turbine & inverter $24,750 $24,750 $24,750

Tower (100 ft guyed) $7,800 $25,100 $6,200

Tower Wiring Kit $860 $1,070 $860

Shipping $1,500 $2,000 $1,000

Installation $8,000 $10,000 $2,000

Permits/Fees $500 $3,500 $0

Sales Tax, 5% $2,146 9.3% none

Total $45,556 $72,272 $34,810

Bergey Excel-S (10 kW)

USDA Grant $11,389 $18,068$8,702Adjusted Total $34,167 $54,204$26,108

Small Wind Economics in North Carolina35% State Income Tax Credit & 25% USDA Grant

(wind speed at 10 m)

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Electric Rate, ¢/kWh

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16.3 mph (Class 7)

Residential Electric Rates for North Carolina Utilities

Questions? Thanks Brent Summerville Call or email me

for more info 828-262-7333 wind@appstate.edu wind.appstate.edu

My presentations will be available at wind.appstate.edu

Click on REPORTS….CONFERENCE PRESENTATIONS