Wind Energy

Why Renewable Energy?

o Clean, zero emissionsoNOx, SO2, CO, CO2oAir quality, water qualityoClimate Change

oReduce fossil fuel dependenceoEnergy independenceoDomestic energy – national security

oRenewableoNo fuel-price volatility

oDomestic, local power

Renewable Energy: Sources for Electricity

New U.S. Capacity by Energy Source

Total Installed Wind Power Capacity: Top 15 States

Source: GWEC

Utility-Scale Wind Turbine Manufacturing: Investment in New Plants

Annual Installed U.S. Wind Power Capacity

Source: AWEA

Megawatts of Installed Utility-Scale Wind Power as of December 31, 2007

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

Why such growth?…Costs are low!

Need to Change Perceptions…

Modern Wind TurbinesOrientation

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

Vertical Axis Horizontal Axis

Vertical Axis Turbines

Advantages• Omnidirectional

– Accepts wind from any angle

• Components can be mounted at ground level– Ease of service– Lighter weight towers

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

Disadvantages• Rotors generally near ground

where wind poorer• Centrifugal force stresses

blades• Poor self-starting capabilities• Requires support at top of

turbine rotor• Requires entire rotor to be

removed to replace bearings• Overall poor performance and

reliability• Have never been commercially

successful

Horizontal Axis Wind TurbinesTypes of Electricity Generating Wind Turbines

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

pumping, telecom sites, icemaking)

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

Power

Large (250 kW - 2+MW)

•Central Station Wind Farms

•Distributed Power

Net Metering

Large Wind Turbines

• 328’ base to blade• Each blade 112’• Span greater than 747• 163.3 tons total• Foundation 20’ deep• Rated at 1.5 megawatt• Supply at least 350 homes

Off-Shore Windfarms

Middelgrunden

Nacelle56 tons

Tower3 sections

Workers Blade112’ long

Wind Turbine Perspective

Relative height of tall human

structures

B kWh/Yr B kWh/Yr

1. North Dakota 1,210 11.Colorado 4812. Texas 1,190 12.New Mexico 435

3.Kansas 1,070 13.Idaho 734.South Dakota 1,030 14.Michigan 655.Montana 1,020 15.New York 626.Nebraska 868 16.Illinois 617.Wyoming 747 17.California 598.Oklahoma 725 18.Wisconsin 589.Minnesota 657 19.Maine 56

10.Iowa 551 20.Missouri 52

Top Twenty States for Wind Energy Potential

Tax Credits

No Federal Incentives for Small Wind Since 1985 Large Wind Supported with Production Tax Credit –

Recently Passed – 3 Yr. Renewal in the 2005 Energy Policy Act

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

Incentives for Wind Energy

•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

Impacts & Issues

Property Values• In-depth study

– “The Effect of Wind Development on Local Property Values”– 25,000 property transactions

• In view shed of wind projects• Compared to similar sites

– No evidence of reduced value• full report: www.repp.org

• Modern turbines are relatively quiet

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

Impacts of Wind Power: Noise

Net Impacts

Land Use

• Land conservation– Planning: which areas are off-limits to roads/logging/wind turbines

• Primary impact is visual

• Primary impact is visual– Well-sited wind power

All other impacts dwarfed by benefits• Balancing local impacts, global/regional benefits

Resources for this presentation:

American Wind Energy Association www.need.orgKidWind – www.kidwind.orgNational Renewable Energy Laboratory – www.nrel.govEnergy Information Administration – www.eia.doe.gov