Wind Energy in Vermont:
A Meteorologist’s Perspective
NVDA Wind Study Committee
Barton, VT
9/25/13
Dr. Jason Shafer
Associate Professor of Atmospheric Sciences
Lyndon State College
Jason.Shafer@lyndonstate.edu
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Annual Wind Resource
Climatology
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http://www.windpoweringamerica.gov/images/windmaps/us_windmap_80meters.jpg
http://www.windpoweringamerica.gov/images/windmaps/vt_80m.jpg
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http://www.northeastwind.com/resources/wind-resource-maps
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http://www.northeastwind.com/resources/wind-resource-maps
http://www.northeastwind.com/resources/wind-resource-maps
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http://www.northeastwind.com/resources/wind-resource-maps
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Seasonal and Diurnal Climatology
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Newport
Island Pond
Lyndonville
~15 Stations in the NEK
10 with wind data
All below 1400’ elevation
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Average Annual Wind Speed (2012)
45.0
39.3
40.0
35.0
Speed (MPH)
30.0
25.0
20.0
15.0
10.0
8.1
6.7
5.0
5.2
4.8
Lyndonville
Island Pond
0.0
Burlington
Newport
Mt. Washington
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Mt. Washington, NH: Average Monthly Wind Speed (1982-2011)
55.0
52.0
51.0
50.2
50.0
45.9
45.8
45.0
39.7
39.4
MPH
40.0
35.0
32.9
32.4
31.3
29.4
30.0
27.3
25.0
20.0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
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Newport, VT (KEFK), 2012 Average Seasonal Wind
8.00
7.57
Wind Speed (MPH)
7.00
6.96
6.23
6.00
5.89
5.00
4.00
Winter
Spring
Summer
Fall
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Newport, VT (KEFK), Avg 2012 Diurnal Wind Speed
10.00
9.00
Speed (MPH)
8.00
7.00
6.00
5.00
4.00
1:00 AM 4:00 AM 7:00 AM 10:00 AM 1:00 PM 4:00 PM 7:00 PM 10:00 PM
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Wind Rose climatology for Lyndonville, VT
Source: AWS True Wind
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Burlington, VT Wind Direction Frequency
Carrera et al. 2009
Similar to Lyndonville, the two dominant wind directions are from the south and
northwest.
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Localized Effects
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Wind Energy Production
Pe 
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2
C p  V   AV
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Wind energy production is very sensitive to small changes in wind speed,
to the cube of the wind speed.
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IPCC 2012
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Fig. 2. Hourly vertical profiles of horizontal wind speed from HRD conical scans showing evening development of the LLJ
near Lamar, CO, on 15 Sep 2003. Wind speed (m s−1) on horizontal axis, and height (m) on vertical axis. Profiles are color
coded by time (UTC), which is 7 h ahead of local (mountain) standard time, so that 0100 UTC about sunset and 0700 UTC is
midnight. Vertical resolution is 5 m. Turbine-rotor layer is indicated by horizontal dotted lines. (Figure courtesy of the
American Meteorological Society.)
Banta et al. 2013
One of the biggest challenges for producing accurate projections of wind resources
is the assumptions made with the vertical profile with height in the lowest layer of
the atmosphere; depends on the local terrain features and land-surface environment.
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This is an example of a localized terrain effect, with the wind flow accelerating
through Willoughby Gap; these nuances are impossible to know without collecting data.
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Percentage of Time Wind Speed Greater Than or Equal to 10 knots (11.4 MPH)
(Data from 2012)
Mt. Washington
91.2
Island Pond
9.7
Lyndonville
13.6
Newport
17.4
Burlington
29.3
0
10
20
30
40
50
Percent (%)
60
70
80
90
100
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Climate Change and
Local Wind Resources
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Cold Season Jet Stream Climatology
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Barnes and Polvani, 2013
Literature supports a shift of the midlatitude jet stream north, in this paper
showing the largest migration of the Atlantic jet in Fall and least in Winter.
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Mt. Washington, NH Average Annual Wind Speed (1970-2011)
50.0
Wind Speed (MPH)
45.0
40.0
35.0
30.0
Average: 39.5 MPH
25.0
Data courtesy Mt. Washington Observatory and Plymouth State University
1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
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Mt. Washingon Yearly Wind Speed Variability (1970-2011)
15.0%
12.1%
11.8%
10.0%
9.3%
9.2%
6.6%
6.2%
5.6%
5.0%
10.6%
9.8%
4.3%
3.9%
5.0% 5.3%
4.3%
2.7%
2.1%
1.9%
0.4%
0.0%
0.0%
-0.2%
-5.0%
-2.6%
-3.1% -2.9% -3.2%
-2.3%
-0.1%
-0.7%
-2.4%
-2.0%
-2.5%
-3.4%
-3.6%
-1.4%
-3.4%
-4.5%
-6.3%
-10.0%
-9.6%
-10.0%
Average: 5%
-15.0%
-12.4%
-9.5%
-12.3%
-13.0%
1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Data courtesy Mt. Washington Observatory and Plymouth State University
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Climate Change and Wind Resources
• Observations:
– We don’t know the answer, developing field,
Global Climate Models need to be downscaled for
this application
– There will probably be some seasonal shift to
wind resources
– Year-to-year variability is larger than the long-term
climate signal
– There do not appear to be any long-term changes
atop Mt. Washington
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References
•
Banta, Robert M., Yelena L. Pichugina, Neil D. Kelley, R. Michael Hardesty, W. Alan Brewer, 2013: Wind
Energy Meteorology: Insight into Wind Properties in the Turbine-Rotor Layer of the Atmosphere from
High-Resolution Doppler Lidar. Bull. Amer. Meteor. Soc., 94, 883–902.
•
Barnes, Elizabeth A. and Lorenzo Polvani, 2013: Response of the Midlatitude Jets, and of Their Variability,
to Increased Greenhouse Gases in the CMIP5 Models. J. Climate, 26, 7117-7135.
•
Carrera, Marco L., John R. Gyakum, Charles A. Lin, 2009: Observational Study of Wind Channeling within
the St. Lawrence River Valley. J. Appl. Meteor. Climatol., 48, 2341–2361.
•
DOE, 2013: Energy Sector Vulnerabilities to Climate Change and Extreme Weather:
http://energy.gov/sites/prod/files/2013/07/f2/20130716Energy%20Sector%20Vulnerabilities%20Report.pdf
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IPCC, 2012: Renewable Energy Sources and Climate Change Mitigation: Special Report of the IPCC.
Cambridge University Press. 1088 p. Available: www.ipcc.ch/pdf/specialreports/srren/SRREN_Full_Report.pdf
•
NOAA ESRL Web Plotting Analysis Tools: http://www.esrl.noaa.gov/psd/cgibin/data/composites/printpage.pl
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