Geographic Analysis of Optimal Wind Farm Locations and Related Demand Sources in Montana

Cully Cavness GEOG 320: Geographic Information Systems

Professor Jeff Howarth December 7, 2009

Word Count: 1,080

Introduction

Montana is ranked fifth in the nation for wind power potential, but it is 16th in the nation

for wind energy production. That discrepancy highlights the opportunity to develop Montana’s

prime wind resources. This report presents a GIS based geographic analysis of the five cities in

Montana most amenable to wind power consumption, and the nearby wind power production

areas. The analysis considers physical, economic, political, and aesthetic variables, and weighs

those elements to generate a map of the best wind power locations.

Methods

This analysis is broken into three major sections: (1) physical criteria, (2) economic and

political criteria, and (3) aesthetic impacts of windmills. In each section, multiple layers are used

to analyze different pieces of the broader issue. For example, the physical analysis consists of

four maps that asses wind power potential, land cover, slope, and transmission line proximity.

The multiple layers are then weighted according to priority and combined into an

aggregate analytical map for that section. As a final step, each of the three sections was then

weighted and combined into an aggregate analytical map.

The remainder of this report will discuss the details and processes of each section, then

discuss the final synthesis, site locations, and recommendations for next steps.

[

[

Havre

Butte

Laurel

Sidney

Helena

Bozeman

Missoula

Anaconda

Lewistown

Kalispell

Livingston

Miles City

Great Falls

[

0 200 km

Introduction to Montana'sEnvironmental and Man-Made Considerations

[ Capital - Helena

Population > 5000

Existing Transmision Lines

Native American Reservations

Lakes and Major Rivers

Wildlife Management Areas and Refuges

Coincident Priority Conservation Areas

State and National Parks

National Forests

0 2,000 km

The decision of where to develop wind power in Montana will need toweigh a host of economic, political, environmental, and aesthetic factors.These maps show the locations of major population centers, transmission

lines, land ownership, and key environmental zones. The followinganalysis will balance these variables and others including viewshedimpacts on historic hiking trails and important recreation zones.

Physical Analysis

The physical analysis considers four criteria: wind power potential, land cover analysis,

surface slope, and transmission line proximity. These variables are considered due to their

impact on the feasibility and economics of windmill construction and the functionality of built

windmills. Each variable is mapped on a scale of 0 – 10, then combined into an aggregate map

ranking all physical constraints from 0 (least amenable) to 10 (most amenable).

Wind Power Potential: Wind power potential is a major consideration for any wind farm

development, and the distribution of ideal wind resources is not uniform in Montana. Montana’s

most ideal wind conditions generally lie in the plains and foothills on the east side of

mountainous areas. The wind analysis linearly ranks wind potential in megawatts per square

meter. Montana has a range of values from 1 to 7 MW/m2, so wind potential values were

multiplied by 1.42 to normalize the data to a scale of ten (7MW/m2 gets a value of 10 and

1MW/m2 gets a rank of 1.42).

Land Cover: Land cover is another economic and logistical constraint. The land cover layer is

weighted on a ten point scale as follows:

Open Water = 0 Perennial Ice or Snow (glaciers) = 0 Developed Land (urban) = 0 Wetlands = 2 Forests = 5 Cultivated Crops = 7 Barren Land = 10 Pasture / Hay = 10 Grasslands = 10 Shrub / Scrub = 10

Surface Slope: Steep gradients increase the cost of construction and extremely steep gradients

will prevent the windmills blades from turning. Slopes are ranked on a ten point scale as follows:

0 – 5% (slope) = 10 5 – 10% = 7 10-20% = 5 20 – 30% = 2 >30% = 1

Transmission Line Proximity: Existing transmission lines represent the most economic way to

transport power to consumers. However, many of Montana’s grids are at or near capacity.

Existing grids still provide an economic advantage because many grids maintain a right of way

margin, which can be leased or bought to build new grids to cities in the most affordable way

possible (this is one reason why many railroads, telephone lines, and power lines parallel each

other in close proximity). Proximity is ranked linearly on a ten point scale with a minimum

distance of zero meters to the grid equaling ten points and a maximum distance of 152 km from

the grid equaling zero points.

Havre

Butte

Laurel

Sidney

Helena

Bozeman

Missoula

Anaconda

Lewistown

Kalispell

Livingston

Miles City

Great FallsMalmstrom AFB

Physical Considerations:Where Can Functioning and Useful Windmills Be Built?

Land Cover Analysis Wind Power Potential Analysis

Aggregate Physical Analysis

This aggregate physical analysis combines analyses of slope, wind power, land cover, and proximity to existing transmission lines. A ranking of amenability for each of these four considerations was prepared, then those four maps were synthesized into the aggregate map with equal weighting for each of the four parts. The slope of building sites is important because turbine building expenses rise dramatically for slopes beyond 25% due to access and construction difficulties. Land cover also impacts building costs because more extensive (expensive) foundations are required for unstable

soils or wetlands as compared to exposed bedrock or dry pastures. The amount of wind is obviously a major consideration, and is critical for the economic analysis of wind turbines. Proximity to existing power lines is also important; existing power lines may provide transmission of wind power or a right of way to build new lines (if existing lines are at maximum capacity). When compared to the very high costs of building new high tension power lines, existing transmission lines represent the most economic mode of transporting any power generated by wind.

0 200 km

Transmission Line Proximity

Population > 5000

transmission_lines

Transmission Lines

Least Amenable to Wind Power

Moderately Amenable to Wind Power

Most Amenable to Wind Power

Slope Analysis

0 200 km

Economic and Political Analysis

The economic and political analysis uses multiple layers to consider proximity to major

population centers, land ownership, and protected areas. Again, layers rank the land in Montana

on a scale of 1 -10. The layers are combined into an aggregate map which is then normalized to a

ten point scale – this map reflects the economic and political amenability to turbine construction.

Distance to Towns: Urban centers with populations greater than 5,000 were selected as priorities

due to their larger electricity markets. Distances to the nearest city were broken into ten

categories at equal intervals, then ranked from 1 – 10 such that 1 – 30km is a value of ten and

anything over 225km is a value of one.

Land Ownership: Federal lands are given a value of ten. Indian reservations received a value of

seven. Private land received a value of five. Protected land (state parks, national parks,

coincidental interest zones, sensitive habitats, etc.) received a value of one. See the layout for

more information on land ownership ranking rationale.

Economics and Politics:Where Can Windmills Be Built Legally and Profitably?

Population > 5,000

Protected Areas

Federal Lands

Native American Reservations

Least Amenable to Wind Power

Most Amenable to Wind Power

0 200 km

0 200 km

Proximity to Major Population Centers Land Ownership

Aggregate Political and Economic Analysis

Political and Economic Analysis of Land Ownership

This analysis combines political and economicconsiderations for wind farm construction. Federal land ispotentially the cheapest option for construction because

federal leases are typically cheaper than private leases.Native American reservations are also a viable option; many tribes already have arrangements with transmissionline companies, mining operations, oil producers, and other natural resource companies. Typically, a use of reservation lands will require a royalty to be paid to the tribe, so reservation lands are weighted as 30% less desirable than federal lands. Protected lands represent a huge economic

and political hurdle for development, and the resultantdamage to delicate or unique ecosystems presents an ethicalroadblock. Privately held lands are weighted neutrally in this analysis. Proximity to major population centers(electricity demand centers) is a major economic consideration because closer demand means less newtransmission line construction and less electricity lost in

transmission.

Aesthetic Analysis

Some people perceive windmills as unattractive and noisy, so it is important to consider

the aesthetic impact of wind power. Special attention is given to areas of historic significance

and popular recreation destinations. The aesthetic analysis includes a view shed analysis from

BLM recreation sites, the Louis and Clarke Trail, and the Continental Divide Trail.

Areas not visible from these sites received a score of ten. Areas visible from either trails

or recreation sites received a score of 2.5. Areas visible from both trails and recreation sites

received a score of three.

Final Synthesis

The physical, economic and political, and aesthetic maps were combined into one

aggregate map. The physical and econo-political maps were weighted equally, and the aesthetic

map was weighted as 70% less important than either of the other two maps. While aesthetics are

important, they factor relatively lightly into the logistical and economic constraints to a wind

project. Further, many people admire and enjoy the sight of domestic, clean, sustainable energy

production. The final map ranks areas on a 0 – 10 scale for aggregate amenability to wind

production.

Continental Divide Trail

Lewis and Clark Trail

BLM Recreation Sites

Not Visible

Visible from either trails OR recreation sites

Visible from trails AND recreation Sites

Aesthetic Considerations:Where Will Windmills Not Impact Historic or Scenic Views?

0 200 km

This analysis highlights the impact of windmill construction on important view sheds. The Lewis and Clark Trail is a major tourist destination for hikers and American history buffs alike. The Continental Divide Trail is another legendary hiking trail; it is considered to be one of the great north-south traverse trails in the United

States. This analysis also considers the impact of windmill construction on Bureau of Land Management (BLM) recreations sites. Those sites include ecological reserves, trail heads, parks, boat launches, and other scenic outdoor sites. The view sheds from important trails and BLM recreation sites are combined with equal weight. Sites visible from both BLM sites and trails are given an additional 50% weighting to reflect their impact on multiple types of recreation areas. In general, aesthetic impacts are weighted lightly compared to economic, physical, and political variables (see the final aggregate analysis).

Aggregate Aesthetic Analysis

View Shed for BLM Recreation Sites View Shed for Important Trails

0 200 km

[

[

[

[

[Laurel

Missoula

Billings

Kalispell

Miles City

Political and Economic Analysis (Proximity, Protected Lands, Land Ownership)

Combined Analysis

0 100 km

Kalispel Missoula

Laurel & Billings Miles City

This analysis combines the three previous weighted analyses into one comprehensive map. Equal weighting is given to physical criteria andpolitical and economic criteria. Aesthetic criteria are given 30% of the weighting that the other two maps are given. The result is a mapshowing the areas most amenable to the construction and transmission of wind power (largest amenity scores highlighted in green). Theincorporated towns closest to these areas have been selected with preference for larger populations, proximity to high wind amenity areas, and

size of high wind amenity areas.

[Kalispell

All Things Considered:Which Five Cities Are Most Amenable to Wind Power Construction?

[Missoula

[[Laurel

Billings[

Miles City

0 200 km

0 200 km

[ Selected Towns

Less Amenable to Wind Power

More Amenable to Wind Power

Best Wind Power Areas

Aesthetic Analysis (Viewsheds and Town Proximity)

Physical Analysis (Wind, Land Cover, Slope)

Conclusion

The analysis concludes by identifying Kalispel, Missoula, Laurel, Billings, and Miles

City as the five best incorporated cities for wind power development. These cities were selected

with preference for larger populations and proximity to large patches of prime wind resources.

Logical next steps (in chronological order) include due diligence research for each site

(foundation assessment, detailed wind pattern tests, lease chain history, ecological research), site

specific project planning, transmission line planning, power sale arrangements, leasing of lands,

and ultimately construction.

The most immediate next step, due diligence, should be an exhaustive and fine-scale

version of this broad analysis. Fine grained local data and ground truthing will be helpful to

confirm this analysis’ results and check against error.