Wind Energy

Why Renewable Energy? o Clean, zero emissions o NOx, SO2, CO, CO2 o Air quality, water quality o Climate Change o Reduce fossil fuel dependence o Energy independence o Domestic energy – national security o Renewable o No fuel-price volatility o Domestic, local power

Renewable Energy: Sources for Electricity o Solar: PV and Thermal o Wind o Biomass/Landfill Gas o Hydropower (Rivers) o Geothermal o Hydro/Ocean: o Waves o Ocean Currents o Tides

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: cents/kWh Why such growth?…Costs are low!

Need to Change Perceptions…

Modern Wind Turbines Orientation Turbines can be categorized into two classes based on the orientation of the rotor Vertical AxisHorizontal 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 Turbines Types of Electricity Generating Wind Turbines Small (  10 kW) Homes Farms Remote Applications (e.g. water pumping, telecom sites, icemaking) Intermediate ( 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 tons total Foundation 20’ deep Rated at 1.5 megawatt Supply at least 350 homes

Off-Shore Windfarms Middelgrunden

N acelle 56 tons Tower 3 sections Workers Blade 112’ long Wind Turbine Perspective

Relative height of tall human structures

B kWh/Yr 1. North Dakota1, Colorado Texas1,19012.New Mexico435 3.Kansas1,07013.Idaho73 4.South Dakota1,03014.Michigan65 5.Montana1,02015.New York62 6.Nebraska86816.Illinois61 7.Wyoming74717.California59 8.Oklahoma72518.Wisconsin58 9.Minnesota65719.Maine56 10.Iowa55120.Missouri52 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 support  NY 50%-75% Support  ME 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 Land Use Visual Noise Birds and other wildlife 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:

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 –Well-sited wind power All other impacts dwarfed by benefits Balancing local impacts, global/regional benefits

Resources for this presentation: American Wind Energy Association KidWind – National Renewable Energy Laboratory – Energy Information Administration –