Article Date: May, 2000
                  Magazine Volume:104
                  Issue: 5
                  Author(s): *Ann Chambers
           Wind Project Siting Faces Unique
               Despite its Status as the Fastest Growing
               Renewable Energy Source, Wind Power Faces
               Numerous obstacles in siting and permitting.
               This is true for both large projects being built to
               sell power to utilities and small projects being
               built for a single user. Regulations and laws
               governing power project siting are becoming
               ever more complex, and state and federal siting
               agencies are not as likely to approve power
               projects without extensive review. Various
               interest groups have become more involved in
               siting procedures as well.
               Large wind projects raise many of the same
               siting issues as other energy projects. There
               may be concern about truck traffic during
               construction, health effects of electromagnetic
               fields from transmission lines and social issues.
               Wind projects also face some unique challenges
               that require special consideration.
               Unique Considerations
               Visual and noise impacts must be addressed.
               Wind turbines are highly visible structures and
               they often need to be sited in conspicuous
               locations, such as on ridges or hillsides. They
               also generate noise that can be bothersome to
               area residents. Those problems can be
               mitigated through noise abatement, design
               adjustments and other measures. Recent
               design improvements have greatly decreased
               the noise generated by today's wind turbines.
               Impacts on birds and other local wildlife must
               also be considered. In some locations, wind
               turbines and their ancillary equipment have
               killed raptors, such as hawks and eagles. Pre-
               and post-construction studies may be necessary
               to measure the project's impact on wildlife and
               to create strategies for offsetting them. Soil
               erosion is another potential problem that may
               be addressed during the siting process.
               Landowner's rights may also be an issue in wind
               project siting. Wind plants often pay rents or
               royalties for land use, which can be a benefit to
               landowners. But it may also raise concerns. A
               turbine on one resident's land may interfere
               with a neighbor's ability to develop a wind
               The NWCC notes eight key elements for the
               development of a successful process for
               permitting wind energy facilities:
               Principles of Success
                1.Significant public involvement,
                2.Issue-oriented process,
                3.Clear decision criteria,
                4.Coordinated permitting process,
                5.Reasonable time frames,
                6.Advance planning,
                7.Efficient administrative and judicial review
                8.Active compliance monitoring.

               Source: NWCC
               Successful wind project siting depends on
               negotiation to balance concerns and benefits.
               Details vary widely from site to site, but the
               National Wind Coordinating Committee (NWCC)
               recommends a few guidelines, including
               significant public involvement, reasonable time
               frames, clear decision criteria, coordinated
               siting processes, expedited judicial review and
               advance site planning.
               Early public involvement allows the public to
               have its interests factored in early in the siting
               process. Without this, there is a much greater
               likelihood of later opposition and costly
               litigation. The public, particularly residents
               living near a proposed site, should be notified
               of the siting application, and the siting agency
               should hold public meetings and accept public
               Open siting processes with long delays are a
               legitimate concern for wind developments.
               Establishing reasonable time frames for review
               of applications, hearings and a final decision
               from the siting agency is one way to avoid
               unnecessary delays.
               The siting agency should make the criteria for
               its decisions clear at the beginning. The agency
               should list all the factors to be considered,
               specify how the factors are weighed against
               each other, and set minimum requirements to
               be met by the project. The factors will vary
               depending on the circumstances.
               Land Use
               Unlike most power plants, wind generation
               projects are not land intensive. On a MW output
               basis, the land required for a wind project
               exceeds the amount of land required for most
               other energy technology, but the physical
               project footprint covers only a small portion of
               that land. For example, a 50 MW wind facility
               may occupy a 1,500-acre site, but it will only
               use three to five percent of the total acreage,
               leaving the remainder available for other uses.
               Because wind generation is limited to areas
               with strong and fairly consistent wind
               resources, most wind generation is sited in rural
               and relatively open areas that are often already
               used for agriculture, grazing, recreation, forest
               management or seasonal flood storage.
               To ensure that a wind project is compatible
               with existing land uses, the layout and design
               of the wind project can be adjusted in a variety
               of ways, including:
                   selecting equipment with minimal guy
                   placing electrical collection lines
                   placing maintenance facilities off site,
                   consolidating equipment on the turbine
                   tower or foundation,
                   consolidating structures within a selected
                   using the most efficient or largest turbines
                   to minimize the number of turbines
                   increasing turbine spacing to reduce
                   density of machines,
                   using roadless construction and
                   maintenance techniques, or
                   using existing access roads.
               Other land use strategies include buffer zones
               and setbacks to separate wind projects from
               sensitive or incompatible land uses. Land use
               agencies in California have established
               setbacks ranging from two to four times the
               height of a turbine or a minimum of 500 to
               1,200 feet from any residential area. Minnesota
               has established minimum setbacks of 500 feet
               from occupied dwellings.
               For the Birds
               The problem of birds, especially raptors, flying
               into wind turbines has been the most
               controversial biological consideration affecting
               wind siting. Wind developments have produced
               enough bird collisions and deaths to raise
               concern from wildlife agencies and conservation
               groups. On the other hand, some large wind
               facilities have been operating for years with
               only minor impacts on birds. Smokestacks and
               radio and television towers have actually been
               associated with much larger numbers of bird
               deaths than wind facilities have, and highways
               and pollution account for a great many as well.
               Whether or not this becomes a serious sighting
               issue tends to depend on the protective status
               or number of bird species involved. Most raptors
               are protected by state and federal laws and any
               threat to them may cause siting concerns.
               Both the wind industry and government
               agencies are sponsoring or conducting research
               into this problem. Studies are under way
               comparing mortality at lattice and tubular
               towers and investigating birds' sensory
               physiology and how it affects their ability to
               detect components of wind turbines. One study
               is painting colors on turbine blades to observe
               birds' reactions.
               Wind farms are thought to affect wildlife in
               several other ways, including:
                   direct loss of habitat,
                   indirect habitat loss from increased human
                   presence, noise or motion of operating
                   habitat alteration resulting from soil
                   erosion or construction of obstacles to
                   collision with structures, turbine blades or
                   wires, and
                   electrocution from contact with live
                   electrical wires.
               The NWCC recommends several strategies for
               dealing with biological resource siting issues
               Planning and coordination with permitting
               agencies can reduce the chances of project
               delays. Most permitting agencies recommend
               wind developers consult with them and
               appropriate natural resource protection agencies
               early in the site selection process to determine
               the potential for conflicts. It is important to
               find out whether protected plants and animals
               inhabit, use or migrate through the area.
               Unique or rare habitat types, such as savannas,
               can raise interest and alternative sites may be
                Biological surveys can be helpful, but the timing is important.
                Some necessary information can only be obtained at a certain time
                of the year.  Protected plants may only bloom for a few weeks or
                months at a time and bird use or migration patterns may need to be
                studied over several seasons or years.
               Equipment selection can reduce the risk of high
               bird mortality, but the best plan is to avoid
               sites near major bird feeding, roosting or
               resting areas. Research is ongoing, but to date
               there are no designs or modifications that have
               been statistically proven to significantly reduce
               the risk of bird collisions. Unless protected
               plants or animals are involved, most permitting
               agencies tend to find the non-collision effects
               of wind development on wildlife to be
               Visionary Planning
               Visual or aesthetic concerns are also a common
               issue in wind siting. Wind projects tend to be
               located in rural or remote areas with few area
               residential developments. Potential for visual
               impact is sometimes considered as part of the
               evaluation of land use, and the degree to which
               the visual quality of a project is addressed will
               vary. Elements that can influence the visual
               impact of a wind project include spacing, design
               and uniformity of the turbines, markings on
               turbines and other structures, spacing of
               turbines, design and uniformity of the turbines,
               roads built on slopes, and service buildings.
               There is considerable motion in turbine blades
               and this motion is intensified when the turbines
               are placed close together, are of different
               designs or rotate in different directions.
               Adequate spacing between turbines and
               between rows or tiers of turbines mitigates
               visual impact.
               When turbines are sited on ridgelines, the units
               are visible for greater distances. Against the
               sloping terrain, surfaces exposed by
               construction of access roads and turbine pads
               may contrast with existing soils and vegetation.
               From a distance, the visual impact of the roads
               may be greater than that of the turbines.
               Constructing roads on ridges also may increase
               It is generally recommended that developers
               contact any agencies with jurisdiction for any
               maps, plans, guidelines or design standards in
               that particular area. Design strategies can be
               used to reduce the visual impact, including:
                   using the local landscape to minimize
                   visibility of access and service roads and to
                   protect soils from erosion,
                   consolidation of roads or use of grating
                   over vegetation for temporary access
                   without road construction,
                   use of low-profile building designs,
                   use of uniform color, structure types, and
                   surface finishes,
                   consolidating electrical lines and roads into
                   a single right of way or corridor,
                   limiting the size, color and number of
                   labels on turbines,
                   limiting size and number of advertising
                   signs on fences and facilities, and
                   using air lift for transport of turbine
                   components and installation.
               Calculating the Wind's Power
               Because air has mass moving to form wind, it
               has kinetic energy, calculated as:

               Kinetic energy (joules) = 0.5 x M x V2
               M = mass (kg)
               V = velocity (meters/second)
               To calculate power, which changes moment to
               moment, calculate energy to equal power times
               the time and density. The kinetic energy
               equations can be converted to a flow equation
               showing the power in the area swept by the
               wind turbine rotor.

               P = 0.5 x rho x A x V3
               P = power in watts
               Rho = air density
               A = rotor swept area exposed to the wind (m2)
               V = wind speed in meters/sec
               This yields the power in a free flowing stream
               of wind. It is impossible to extract all the power
               from the wind because some flow must be
               maintained through the rotor. More terms need
               to be included in the equation to get a practical
               equation for a wind turbine

               P = 0.5 x rho x A x Cp x V3 x Ng x Nb
               P = power in watts
               Rho = air density
               A = rotor swept area exposed to the wind (m2)
               Cp = Coefficient of performance (0.59 is the
               maximum theoretically possible and 0.35 is a
               good design)
               V = wind speed in meters/sec
               Ng = generator efficiency (80 percent or more
               for a permanent magnet generator or
               grid-connected induction generator)
               Nb = gearbox/bearings efficiency (up to 95
               Source: Eric Eggleston and AWEA
               Top 10 Permitting Issues
                1.Land use
                3.Birds and other biological resources
                4.Visual resources
                5.Soil erosion and water quality
                6.Public health and safety
                7.Cultural and paleontological resources
                8.Socioeconomics, public services and
                9.Solid and hazardous wastes
               10.Air quality and climate

               Source: NWCC
               "Wind Energy Issue Brief No. 3,"National Wind
               Coordinating Committee,
               "Permitting of Wind Energy Facilities," National
               Wind Coordinating Committee
               "How Can I Calculate the Amount of Power
               Available at a given Wind Speed?" Eric