an evaluation of potential wind farm sites in...
TRANSCRIPT
An evaluation of potential wind farm sites in Vermont
Kate MacfarlaneMiddlebury College, GIS Fall 2010
Rutland
Burlington
Montpelier
Middlebury
Bennington Brattleboro
Saint Albans
Saint Johnsbury
0 50 Km
Manchester
Albany
!
!
N E W Y O R K
M A S S A C H U S E T T S
N E W H A M P S H I R E
Q U E B E C
G
r e
e
n
M
o
u
n t
a
i
n s
Routinely ranked one of the most progressive states in the country, Vermont seems like a natural fit for the development of renewable energy, especially wind. Governor-elect Peter Shumlin has repeatedly voiced his support for large-scale wind energy projects that could help keep Vermont’s energy supply renew-able in the face of nuclear plant Vermont Yankee closing. However, commercial wind development in Vermont faces substantial barriers. Despite their consistently-high public support for clean energy, many Vermonters balk at the idea of wind turbines crown-ing ridgelines. The perfect site would be windy and close to infrastructure, but removed from sensitive habitats and distant to neighbors; no such place exists. Thus, any commercial wind farm development requires balanc-ing a variety of physical, environmental, economic, environmental and social concerns. This project seeks to identify wind farm sites that have the potential to produce at least 45 MW of energy. (Given industry production averages, a wind farm this size would likely to average an output of around 15 MW.) In order to do so, this report identifies ridgelines that are sufficiently windy suitable large-scale wind production. Next, environmental and economic constraints are evaluated separately and then combined to give a holistic view of the advantages and disadvantages of various sites. Finally, I will evaluate viewshed impacts and provide steps for moving forward.
Figure 1. The study site. Vermont’s topography is dominated by the Green Mountains, which divide the state north-south.
Introduction
Where is the wind? Physical constraints
4
5
6
7
Figure 2. Areas of commercially-attractive wind. Commercial wind develop-ments require consistently strong winds. Using the standard industry wind classifica-tion system, we isolate those areas of Vermont that receive enough wind to be suitable. Due to the topography and prevail-ing winds of Vermont, these are primarily located on the high ridges of the Green Mountains. Note that a relatively small amount of land in Vermont receives enough wind to support a commercial wind farm.
Figure 3. Windy ridges: 45MW potential or greater. 1.5 MW turbines are typically placed 200 m apart. Here, contiguous ridge-lines that have room for at least 30 turbines are identified. Water features and wetlands have been excluded—the map shows areas where it is physically possible to build. Before applying further constraints, there are 41 sites that have the potential to produce at least 20 MW of energy. The detail shows the overlay of ridgelines and wind classes.
Wind Class
Environmental Concerns
!
!!
!
!!!
!
!
!!
!
!!
!
!
!
!
!
!!
!!
!!
!!!!!
!
!!
!
!
!
!
! !!
!
!
!!
!
!
!!
!!
!
!!!
!!
!
!!!!!!
!!
!
!!
!
!!
!
!
! !
!
!!!!!
!
!!
!!!!
!!
!
!!
!!!!
!
!!!
!
!!
! !!!
!
!!!
!
!!
!
!
!!
!
!
!!!
!
!
!!! !!!
!
!
!!
!
!
!!
!
!
!
!
!
!! !!!!!!!
!!
!
!
!
!!!!!!
!
!
!
!!!
!
!!
! !!
!!!
!
!
!
!!!
!!!!!!
!
!!!!! !!
!
!
!
!
!
!
!
!
!!!
!!
!!
!!
!
!!
!
!!!
!!!
!
!
!
!!
!!!!!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
! !
!
!
!!
!
!!
!
!
!!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!!
!!!!
!
!
!
!
!
!!!
!
!
!
!
!!
!
!
!
!
!
!
!
!
!!
!
!
!
! Bicknell's thrush nests! Bear mast stands
High wind areas
High wind areas
Deer wintering groundsSignificant natural communities
Figure 4. Species of concern: Bicknell’s thrush and black bear. In many cases, the best spots for wind development overlap with critical habitat for species of special concern. Bicknell’s thrush, which is threat-ened in Vermont, typically nests on ridgelines above 915 m in elevation. The black bear, although not currently endangered, is depen-dent on stands of mast-producing trees for food during the winter and spring.
Figure 5. Deer wintering grounds and significant natural communities. Although deer are abundant in Vermont, the mainte-nance of a healthy population depends on continued protection ofwinter habitat. ‘Significant natural communities’ are a type of land classification administered by the Vermont Fish and Wildlife Department. They provide important or rare habitat, and have been excluded from analysis.
Environmental Criteria Score
ValueHigh : 100
Low : 0
High wind areas
45 MW (or greater) turbine strings
Figure 6. Environmental weighted score. In order to balance these different habitat needs, the values were classified and weighted accord-ing to their importance and the vulnerability of the resource. The values in the map show the range of acceptability, from 0 (unacceptable habitat conflicts) to 100 (no habitat conflicts). Intermediate values repre-sent varying different degrees of habitat conflict.
Criteria Weight Not acceptable Acceptable IdealDistance from Bicknell's thrush nests
0.4 0 - 200m away 200m - 1000m >1000 m
Distance from bear mast stands
0.3 0 - 200m away 200m - 500m > 500 m
Deer wintering areas 0.3 ----------- -----------Outside
wintering areaSignificant natural communities
Entirely unacceptable: excluded from possible sites
Figure 7. Environmentally viable sites. Once environmental constraints and weights have been applied, there are 20 sites that are a) sufficiently windy and b) do not overlap with critical habitat.
Economic Factors: Infrastructure and Land Acquisition
Transmission lines
Figure 8. Proximity to transmission lines. The best wind development sites are close to existing transmission lines, which minimizes the cost of building new lines.
Figure 9. Proximity to roads. Road access is required to construct and maintain wind farms. According to the VERA, the road construction becomes cost-prohibitive when roads are more than 7 kilometers away.
Private land
Undetermined
Prohibited
Restricted
Potentially compatible
Publ
ic la
nd
Wind Development Compatability
Figure 10. Land use. Public lands, when compatible with wind development, are the cheapest option for development. However, various regulations restrict the availability of public lands.
Worst Worst
Best Best
Economic Criteria Score
ValueHigh : 100
Low : 0
Land classification valuesPublic land - compatible 100Privately owned 50Public land - unknown compatability 50Public land - restricted 30Public land - prohibited 0
Figure 11. Economic weighted score. As in the environmental weighted score, the values range from 100 (best possible economic criteria) to 0 (worse possible).
Figure 12. Economically viable sites. After applying economic weights and constraints, there are 16 sites that meet both economic and physical requirements.
Criteria WeightLand classification 0.6Distance from transmission lines 0.2Distance from roads 0.2
High wind areas
45 MW (or greater) turbine strings
0 50 Kilometers
Integration of economic and environmental concernsFigure 13. Combined sites. Each of these 9 sites has the potential to produce more than 45 MW of energy and fulfills minimum economic, environmental, and physical criteria. Comparing the economic and environ-mental weighted scores allows us to make more nuanced decisions about wind farm siting. In this report, the top five sites are selected on the basis of the lowest economic score within each site. Roughly speaking, this represents the cost of constructing the most inconveniently-placed turbine on the string.
Site ID Min Mean Min Mean8 68.7 87.1 67.5 96.5 42 63 Private / Public1 52.5 61.8 60.5 95.5 73 109.5 Private9 52.2 63.9 100 100 32 48 Private / Public2 51.7 58.7 87.3 99.1 59 88.5 Private6 49.7 51.1 60.6 95.5 50 75 Private7 49 52.1 62.8 98.5 88 132 Private / Public3 47.5 81.3 61.5 91.2 58 87 Private / Public4 37.9 53.3 60.8 91.2 64 96 Private / Public5 37.9 47.2 100 100 36 54 Private / Public
Environmental ScoreEconomic Score Number of turbines Land ownership
Energy Potential (MW)
1
2
3
5
6
8
7
9
4
High wind areas
45 MW (or greater) turbine strings
Lowell
BartonAlbany
Newport
Orleans
Johnson
Richford
Cambridge
North Troy
Enosburg FallsLowell
BartonAlbany
Newport
Orleans
Johnson
Richford
Hyde Park
Derby LineNorth Troy
Morrisville
North Wolcott
Enosburg Falls
Jeffersonville
Barre
Bethel
Bristol
Chelsea
Hancock
Brandon
Randolph
Northfield
East Middlebury
Pownal
GraftonJamaica
Newfane
Stamford
Arlington
Manchester
Shaftsbury
West Dover
Bennington Wilmington
Jacksonville
Old Bennington
North Bennington
Pownal
Jamaica
Newfane
Stamford
Arlington
Shaftsbury
West Dover
Bennington Wilmington
Jacksonville
Old Bennington
North Bennington
0 10 km
0 10 km
0 10 km
0 10 km0 10 km
Figure 14. Top five sites. Viewsheds from the top of the turbines show the areas that can see each proposed site. This help planners judge where local opposition is likely to be the strongers. Color saturation signifies the number of turbines visible from a given location.
Conclusion
This report identifies five possible sites for large-scale commercial wind farms in Vermont. However, further analysis is needed into the socio-economic and political impacts of the proposed sites. The weights and constraints included are not intended to be definitive or exhaustive – rather, they are proposed as a starting point for a discussion about the priorities of Vermont as a state. The model presented here should be considered as way to think about balancing environmental and economic criteria when evaluating wind project sites.
It is important to note potential sources of error. This entire analysis is based upon the assumption that commercial wind projects in Vermont build turbines in linear strings along ridgelines, which may not always reflect reality. Distances were calculated as-the-crow-flies, rather than taking into account differences in land cover, steepness, and ownership. The accu-racy of the wind speed data cannot be assured. Furthermore, land suitability classifications require further investigation and analysis. While some private owners may be amenable or even enthusiastic to leasing or selling land for private development, others will not be. This report does not attempt to take statewide variability in habitat quality, local preferences, or property values into account. Modeling smaller potential wind farms is another possible area for investi-gation and would provide further opportunities to deepen understanding of the geography of wind development in Vermont.
Bibliography
Atwood, Jonathan L. et al. “Distribution of Bicknell's Thrush in New England and New York.” The Wilson Bulletin 108.4 (1996): 650-661..
Baban, Serwan M. J., and Tim Parry. “Developing and applying a GIS-assisted approach to locating wind farms in the UK.” Renewable Energy 24.1 (2001): 59-71. Web.
Vermont Fish and Wildlife. “Black Bear Fact Sheet.” http://www.vtfishandwildlife.com/library/Factsheets/Hunting_and_trapping/Big_Game/black_bear_fact_sheet.pdf
General Electric. “GE Wind.” http://www.gepower.com/businesses/ge_wind_energy/en/downloads/wind_energy_basics.pdf
Hammond, Forrest. “Bear responses to human activity.” 2002. http://www.vtfishandwildlife.com/books/Stratton_Mountain_Black_Bear_Study_-_Final_Report/__Chapt6.pdf
Hansen, Henning Sten. “GIS-based multi-criteria analyis of wind farm development.” National Environmental Research Institute, Denmark :
Janke, Jason R. “Multicriteria GIS modeling of wind and solar farms in Colorado.” Renewable Energy 35.10 (2010): 2228-2234. Web.
Rimmer, Christopher C., J. Daniel Lambert, and Kent P. McFarland. “Bicknell's Thrush (Catharus bicknelli) Conservation Strategy for the Green Mountain National Forest.” 2005: n. pag. Print.
Vermont Environmental Research Associates. “Estimating the Hypothetical Wind power potential on Public Lands in Vermont.” 2003. Vermont Department of Public Service.
Vermont Fish & Wildlife. “Deer Wintering Area.” 3 Dec. 2010.
“Wind Powering America: Vermont 50-Meter Wind Resource Map.” Web. 6 Dec. 2010. http://www.windpoweringamerica.gov/maps_template.asp?stateab=vt