Transcript Wind Energy - Environmental Science and Policy at SIO

Wind Energy
Kerri Denkenberger
Oct. 27, 2006
Typical Wind Turbine
• Height similar to 20-story
building
• 3 blades: 200 feet across
• Produces 1.4-4.0
kWh/year (power 150-400
homes)
http://www.eia.doe.gov/kids/energyfacts/sources/renewable/wind.html
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
http://www.eia.doe.gov/kids/energyfacts/sources/renewable/wind.html
Personal communication. David Denkenberger, CU-Boulder.
Offshore Wind Power
- ~90% greater wind speeds offshore compared to over
land
- Beneficial for small highly populated countries
- Cape Cod, 1st US offshore wind farm (proposed)
6.0 miles offshore simulation
13.8 miles offshore simulation
1. Archer, C., Jacobson, M. Journal of Geophysical Research. 110
(2005) D12110. 2. Sahin, A.D. Progress in Energy and Combustion
Science 30 (2004) 501-543. 3. www.capewind.org
US Annual Wind Resource Potential
http://www1.eere.energy.gov/windandhydro/wind_potential.html
Archer, C. and Jacobson, M.
Journal of Geophysical Research.
110 (2005) D12110.
Global Energy Demand
 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.
Archer, C. and Jacobson, M. Journal of Geophysical Research. 110 (2005) D12110.
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) 1786-1796.
Archer, C. and Jacobson, M. Journal of Geophysical Research. 110 (2005) D12110.
U.S. Electricity Generation by Energy Source,
2004
http://www.eia.doe.gov/neic/brochure/renew05/renewable.html
Global Wind Power Capacity (2004)
Sahin, A.D. Progress in Energy and Combustion Science 30 (2004) 501-543.
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) 1471-1587.
Sahin, A.D. Progress in Energy and Combustion Science 30 (2004) 501-543.
http://www1.eere.energy.gov/windandhydro/wind_consumer_faqs.html
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) 501-543.
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 nonhydroelectric renewable resource
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http://www1.eere.energy.gov/windandhydro/wind_ad.html
http://www1.eere.energy.gov/windandhydro/wind_consumer_faqs.html
F.C. Menz, S. Vachon. Energy Policy 34 (2006) 1786-1796.
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) 501-543.
http://www1.eere.energy.gov/windandhydro/wind_ad.html
Overall Cost Comparison
 Becoming more
affordable: Costs
reduced by 20%
from 1999-2004.
 Doesn’t consider
‘social costs’ to
human health &
environment of
nuclear/coal/gas
Sahin, A.D. Progress in Energy and Combustion Science 30 (2004) 501-543.