Bonneville Environmental Bonneville Environmental FoundationFoundation

Wind Energy WorkshopWind Energy Workshop

Why Wind?Why Wind?

Wind Energy is the Fastest Growing Energy Wind Energy is the Fastest Growing Energy Source in the WorldSource in the World

1979: 40 cents/kWh

• Increased Turbine Size

• R&D Advances

• Manufacturing Improvements

NSP 107 MW Lake Benton wind farm

4 cents/kWh (unsubsidized)

2004: 3 – 4.5 cents/kWh

2000:4 - 6 cents/kWh

Wind PowerWind Power

Early “WINDMILL” in Afghanistan Early “WINDMILL” in Afghanistan (900AD)(900AD)

Jacobs Turbine – 1920 - 1960Jacobs Turbine – 1920 - 1960

Smith-Putnam Turbine

Vermont, 1940's

Modern WindmillsModern Windmills

OrientationOrientationTurbines can be categorized into two overarching Turbines can be categorized into two overarching classes based on the orientation of the rotorclasses based on the orientation of the rotor

Vertical AxisVertical Axis Horizontal AxisHorizontal Axis

Vertical Axis Vertical Axis TurbinesTurbines

AdvantagesAdvantages• OmnidirectionalOmnidirectional

– Accepts wind from Accepts wind from any angleany angle

• Components can be Components can be mounted at ground mounted at ground levellevel– Ease of serviceEase of service– Lighter weight towersLighter weight towers

• Can theoretically use Can theoretically use less materials to less materials to capture the same capture the same amount of windamount of wind

DisadvantagesDisadvantages• Rotors generally near Rotors generally near

ground where wind poorerground where wind poorer• Centrifugal force stresses Centrifugal force stresses

bladesblades• Poor self-starting Poor self-starting

capabilitiescapabilities• Requires support at top of Requires support at top of

turbine rotorturbine rotor• Requires entire rotor to be Requires entire rotor to be

removed to replace removed to replace bearingsbearings

• Overall poor performance Overall poor performance and reliabilityand reliability

• Have never been Have never been commercially successfulcommercially successful

Lift vs Drag Lift vs Drag VAWTsVAWTs

Lift Device Lift Device ““DarrieusDarrieus””– Low solidity, Low solidity,

aerofoil bladesaerofoil blades– More efficient More efficient

than drag devicethan drag device

Drag Device Drag Device ““SavoniusSavonius””– High solidity, cup High solidity, cup

shapes are shapes are pushed by the pushed by the windwind

– At best can At best can capture only capture only 15% of wind 15% of wind energyenergy

VAWT’s have not been VAWT’s have not been commercially successful, commercially successful, yet…yet…Every few years a new Every few years a new company comes along company comes along promising a promising a revolutionary revolutionary breakthrough in wind breakthrough in wind turbine design that is low turbine design that is low cost, outperforms cost, outperforms anything else on the anything else on the market, and overcomes market, and overcomes all of the previous all of the previous problems with VAWT’s. problems with VAWT’s. They can also usually be They can also usually be installed on a roof or in a installed on a roof or in a city where wind is poor.city where wind is poor.

WindStorMag-Wind

WindTree Wind Wandler

Horizontal Axis Horizontal Axis Wind TurbinesWind Turbines

• Rotors are Rotors are usually Up-wind usually Up-wind of towerof tower

• Some machines Some machines have down-wind have down-wind rotors, but only rotors, but only commercially commercially available ones available ones are small are small turbinesturbines

Types of Electricity Generating WindmillsTypes of Electricity Generating Windmills

Small (10 kW)•Homes•Farms•Remote Applications (e.g. water

pumping, telecom sites, icemaking)

Large (250 kW - 2+MW)

•Central Station Wind Farms

•Distributed Power

Intermediate (10-250 kW)•Village Power•Hybrid Systems•Distributed

Power

Modern Small Wind Turbines:Modern Small Wind Turbines:High Tech, High Reliability, Low MaintenanceHigh Tech, High Reliability, Low Maintenance

• Technically AdvancedTechnically Advanced• Only 2-3 Moving PartsOnly 2-3 Moving Parts• Very Low Maintenance Very Low Maintenance

RequirementsRequirements• Proven: ~ 5,000 On-Proven: ~ 5,000 On-

Grid Grid • American Companies American Companies

are the Market and are the Market and Technology LeadersTechnology Leaders

10 kW50 kW

400 W

900 W(Not to scale)

SouthWest WindPower Sky SouthWest WindPower Sky StreamStream

Rated Capacity:Rated Capacity: 1.8 KW 1.8 KW

Rotor:Rotor: 12 feet (3.72 m); 50-325 12 feet (3.72 m); 50-325 RPMRPM

Estimated Energy Estimated Energy Production:Production: 400 KWh/month 400 KWh/month at 12 MPH at 12 MPH

Tower:Tower: Towers from 34-70 feet Towers from 34-70 feet

COST:COST: 8 - 12K Installed 8 - 12K Installed

Net MeteringNet Metering

10 kW Wind Turbine

24 m (80 ft) GuyedTower

Safety Switch

Power Processing

Unit (Inverter)

Cummulative Production

Meter

AC Load Center

Large Wind TurbinesLarge Wind Turbines

• 328’ base to blade328’ base to blade

• Each blade 112’Each blade 112’

• Span greater than 747Span greater than 747

• 163.3 tons total163.3 tons total

• Foundation 20’ deepFoundation 20’ deep

• Rated at 1.5 megawattRated at 1.5 megawatt

• Supply at least 350 Supply at least 350 homeshomes

Wind Power Today: Wind Power Today: RelativeRelative HeightHeight

Empire Eiffel Umass 1.5 MW Medium Farm State Tower Library Turbine Turbine Turbine1250’ 986’ 297’ 356’ 212’ 142’ 381 m 301 m 90 m 109 m 65 m 43 m

28 stories --------------examples -------------------

Relative height of tall human

structures

Wind FarmsWind Farms

Windfarm 2Windfarm 2

Off-Shore WindfarmsOff-Shore Windfarms

Middelgrunden Middelgrunden

Wind Turbine PerspectiveWind Turbine Perspective

Nacelle56 tons

Tower3 sections

Workers Blade112’ long

Calculation of Wind PowerCalculation of Wind Power

•Power in the wind Power in the wind Effect of air density, Effect of air density,

– Effect of swept area, AEffect of swept area, A

– Effect of wind speed, VEffect of wind speed, VR

Swept Area: A = πR2 Area of the circle swept by the rotor (m2).

Power in the Wind = ½ρAV3

Why do windmills need to be high in the Why do windmills need to be high in the sky??sky??

North Wind HR3rating: 3 kWrotor: 5 m hub height: 15 m

North Wind 100rating 100 kWrotor: 19.1 mhub height: 25 m

Lagerwey LW58 rating: 750 kWrotor: 58 mhub height: 65 m

Enercon E-66rating: 1800 kW rotor: 70 mhub height: 85 m

Boeing 747wing span: 69.8mlength: 73.5 m

Enercon E-112rating: 4000 kWrotor: 112 mhub height: 100 m

Comparative Scale for a Range of Wind Turbines

Wind Turbine Technology

Potential of Wind Potential of Wind EnergyEnergy

Importance of Wind SpeedImportance of Wind Speed• No other factor is more No other factor is more

important to the important to the amount of power amount of power available in the wind available in the wind than the speed of the than the speed of the windwind

• Power is a cubic Power is a cubic function of wind speedfunction of wind speed– VV X X VV X X VV

• 20% increase in wind 20% increase in wind speed means 73% speed means 73% more powermore power

• Doubling wind speed Doubling wind speed means 8 times more means 8 times more powerpower

Source: U.S. DOE

Wind Potential

Key Issues facing Key Issues facing Wind PowerWind Power

Tax CreditsTax Credits No Federal Incentives for Small Wind Since No Federal Incentives for Small Wind Since

19851985 Large Wind Supported with Production Tax Large Wind Supported with Production Tax

Credit – Recently Passed – 3 Yr. Renewal Credit – Recently Passed – 3 Yr. Renewal in the latest Energy Bill (Summer 05)in the latest Energy Bill (Summer 05)

State have varying levels of supportState have varying levels of supportNY 50%-75% SupportNY 50%-75% SupportME 0%ME 0%MA 20%-50%MA 20%-50%

May 1, 2002

Tax Incentives & Buydown

Local Option Tax Incentives**

Net Metering & Local Option Tax Incentives**

Tax Incentives & Net Metering

Tax Incentives, Net Metering & Buydown

Net Metering & Buydown

*Contact your utility to see if you qualify for the Renewable Energy Resources Program.

** Contact your city or county to see if they offer tax incentives for small wind systems.

Tax Incentives Net Metering Only

Buydown*

Residential Small Wind IncentivesResidential Small Wind Incentives

•6.5 million customers

• 330+ generating units

• Over 8,000 miles of transmission lines

• 11 Interconnections

• 28,100 MW of capacity

• Peak demand: 22,544MW

Transmission Problems

Northeast – Siting!Northeast – Siting!

Photosimulationof Wind Plant

ActualWind Plant

Impacts of Wind Power:Impacts of Wind Power:NoiseNoise

• Modern turbines are Modern turbines are relatively quietrelatively quiet

• Rule of thumb – stay Rule of thumb – stay about 3x hub-height about 3x hub-height away from housesaway from houses

Go to Hull or Searsburg & listen!

Note: Searsburg turbines are older & a bit louder than many modern turbines

Predicting Power OutputPredicting Power Output

What does it take to install a What does it take to install a Turbine?Turbine?

• Utility EngineersUtility Engineers

• Geophysical EngineersGeophysical Engineers

• Concrete/Structural EngineeringConcrete/Structural Engineering

• Turbine Engineering (ME/EE/Aerospace)Turbine Engineering (ME/EE/Aerospace)

• Site/Civil EngineeringSite/Civil Engineering

• Microelectronic/Computer ProgrammingMicroelectronic/Computer Programming

• Business Expertise (Financial)Business Expertise (Financial)

• Legal ExpertiseLegal Expertise

• MeteorologistsMeteorologists

The Future?The Future?