Wind Energy Kerri Denkenberger Oct. 27, 2006

Typical Wind Turbine Height similar to 20-story building 3 blades: 200 feet across Produces kWh/year (power homes)

Wind Farms  Most wind farms are owned and operated by individuals who sell the electricity to utility companies.  Good sites: –Tops of smooth, rounded hills –Open plains or shorelines –Mountain gaps that produce wind funneling  1% of land used for wind turbines and roads – 99% can be used for crops (assuming 300m diameter and 1 km spacing)  Wind speed varies by season Personal communication. David Denkenberger, CU-Boulder.

Offshore Wind Power 1. Archer, C., Jacobson, M. Journal of Geophysical Research. 110 (2005) D Sahin, A.D. Progress in Energy and Combustion Science 30 (2004) ~90% greater wind speeds offshore compared to over land - Beneficial for small highly populated countries - Cape Cod, 1 st US offshore wind farm (proposed) 6.0 miles offshore simulation 13.8 miles offshore simulation

US Annual Wind Resource Potential

Archer, C. and Jacobson, M. Journal of Geophysical Research. 110 (2005) D12110.

Global Energy Demand Archer, C. and Jacobson, M. Journal of Geophysical Research. 110 (2005) D  Calculations by Archer & Jacobson: –Considering locations (globally) with mean annual wind speeds > 6.9 m/s at 80m –If ~20% of this power were captured, it could satisfy 100% of the world’s energy demand for all purposes and 7x the world’s electricity needs.

Current Use US:  Electricity from wind sources increased by 255% from 1998 to 2003 (fastest growing)  2003: 0.3% of total US electricity generation Globally:  2004: 0.54% of the world’s electric power  2004: 20% of Denmark’s electric power; 6% of Germany’s power F.C. Menz, S. Vachon. Energy Policy 34 (2006) Archer, C. and Jacobson, M. Journal of Geophysical Research. 110 (2005) D12110.

U.S. Electricity Generation by Energy Source,

Global Wind Power Capacity (2004) Sahin, A.D. Progress in Energy and Combustion Science 30 (2004)

Stand-alone Hybrid Systems  Combines wind generator with solar panels and battery or fuel cell  Can also integrate a fossil-fuel-powered generator  Used for off-the-grid electricity needs  Further development is necessary Ntziachristos et al. Renewable Energy 30 (2005) Sahin, A.D. Progress in Energy and Combustion Science 30 (2004)

Application: Seawater desalination  Reverse Osmosis – must also be connected to the grid  Mechanic vapor compression - consumes more energy – however, fewer problems due to fluctuations in energy and fewer skilled workers and chemicals needed  Suitable for remote areas (developing island countries)  Further development is necessary Sahin, A.D. Progress in Energy and Combustion Science 30 (2004)

Wind Power Advantages  Clean fuel – no atmospheric emissions  Sustainable  Benefits the economy in rural areas  Provides energy for locations that are not connected to the grid (i.e. remote locations, developing countries)  Lower delivered cost than any other new non- hydroelectric renewable resource F.C. Menz, S. Vachon. Energy Policy 34 (2006)

Wind Power Disadvantages  Higher initial investment than fossil-fueled generators (75-90% of total long-term cost)  Intermittent source of power (unless batteries or fuel cells are used)  Wind sites are often far from cities  Mortality on wild bird populations  Visual impact on landscape Sahin, A.D. Progress in Energy and Combustion Science 30 (2004)

Overall Cost Comparison  Becoming more affordable: Costs reduced by 20% from  Doesn’t consider ‘social costs’ to human health & environment of nuclear/coal/gas Sahin, A.D. Progress in Energy and Combustion Science 30 (2004)