Title: Section VI Siting
1Section VISiting
2Wind Farm Turbine Spacing
- As the wind passes though a turbine energy is
extracted causing the wind speed in the wake of
the turbine to decrease. When several turbines
are built near one another, as in a wind farm, it
is important to separate the turbines
appropriately to minimize these array losses.
Spacing turbines too tightly leads to reduced
performance and increased maintenance due to
higher turbulence at the downwind turbines. - Turbine spacing is expressed in terms of the
rotor diameter (RD) of the turbine in
consideration. So, for instance, if a 77 m
diameter rotor is used, then 2 RD means 2 x 77 m
154 m 505 ft. - Typically, turbines are spaced 5 to 10 RD apart
in the prevailing downwind direction and 2 to 5
RD apart in the crosswind direction, when there
is a strongly prevailing direction. - Spacing of 2-3 RD might be used along a ridge
line. - Greater spacing will minimize the losses from
each machine, but will reduce the number of
machines that can be built in a site. - The setback distance from property lines is
determined by local building codes, and typically
takes the height of the structure into
consideration, e.g. 1.5 times the turbine height.
- Additionally, state noise policy will typically
keep wind turbines about 3 times the hub-height
from residences. - Ice throw Ice is likely to accumulate on
ridgemounted wind turbines, just as it
accumulates on trees. The ice sloughs off as the
blade flexes. For public safety, ridge-line
winter trails may need to be moved away from the
base of the tower to a distance of 2-4 times the
blade-tip height, depending on the site. - EX Need 4000 acres (4000 x 43,560 ft2 6.25
mi2) for placement of an 80 MW wind farm (about
30-35 turbines) including a 100 x 100 area
around each turbine.
3Effect of Wake
- Extraction of energy results in an energy and
velocity deficit, compared to prevailing wind, in
the wake of a wind turbine. - Energy loss in the wake will be replenished over
a certain distance by exchange of kinetic energy
with the surrounding wind field. - Higher turbulence in the wind field accelerates
energy and momentum exchange between the wake
and prevailing wind. - Array losses are typically lt 10 for turbines
spaced 8-10 RD apart in prevailing downwind
direction and 5 RD apart in cross-wind direction.
4Off-shore Wind Farms
- Smooth surface of oceans results in low surface
roughness and thus low turbulence intensity and
wind shear. - Higher low-level winds (lower hub heights
acceptable) - Lower fatigue damage and longer turbine life
- Wind velocity measurements at hub heights are not
generally available so good estimates must be
made.
5Siting Considerations
6Wind Turbine Siting
- Siting is at the heart of conflicts regarding
wind turbines - Key issue
- How a turbine interacts with its immediate
natural environment, including living things - What influences siting of wind installations?
- Politics
- Local politics and ad hoc associations have the
greatest effect on the placement of wind energy
installations - Not In My BackYard (NIMBY) opposition
- Noise and shadows created by turbines
- Homeowner opposition
- Often consider the operation of large turbines to
be incompatible with a residential area - Level of controversy depends on context of the
siting - A small wind farm in rural Nebraska
- Little controversy by local residents because the
installation fits into the landscape - A small wind farm near a federal or state park
- Significant level of opposition by local
residents turbines will spoil the pristine
natural surroundings, kill birds, and discourage
tourism
7Wind Turbine Siting
- Survey of opposition to wind energy found a
common set of global issues with minor variation
depending on local conditions - Three key points to remember when considering
siting issues - A limited number of sites exist that are useful
for wind turbines, as opposed to fossil fuel and
nuclear facilities which easily fit into
industrial settings - Wind turbines need high quality wind it blows
fast and often with minimal turbulence created by
the surrounding landscape - Turbines are more effective the higher they are
located above the ground, which further
contributes to one of the biggest issues in
windmill siting disruption of the viewshed - Disruption of the viewshed is cited the most
often by opposition to new wind installations - Local residents may resist the siting anyplace
where turbines will be visible from a distance - Includes offshore development, especially along
the Northeast coast of the United States - Some opponents object to any visible development
of wind energy - Wind power does not suffer as does nuclear
energywhile specific installations are often
opposed, wind energy is generally considered to
be a boon for the environment - (Turbine 50m Observer 1.5m Visual distance
20mi)
8Onshore vs. Offshore Siting
- Both onshore and offshore siting is highly
criticized for its effect on the view-shed - Destruction of pristine natural resources,
reduction in tourism, and reduction in real
estate values (opinions conflict on wind
turbines effect on real estate values) - Onshore concerns
- Wind turbines are assumed to and can create
noise, cast a significant shadow, and create a
flicker effect when the sun shines through the
turbine blades - These issues are easily avoided through careful
planning and engineering. - Three dimensional modeling accurately simulates
viewshed concerns, turbine shadow, and flicker - Turbine design and placement can ensure local
residents are not disturbed by excessive noise - Offshore concerns
- Commercial fishermen fear that turbine
installation will interfere with the operation of
commercial fishing nets and drags - In Danish offshore installations, drags are not
allowed in the turbine area - In the proposed Cape Wind site off of Cape Cod,
lines would be buried deep enough to allow them - Sport fisherman and whale watching operations
fear the effects on marine life - The Danish installation (by far the most
complete) has demonstrated - Fish exist as they did previous to the turbine
installations - The turbine installations create reefs, which add
to the diversity and health of ocean life (takes
time) - Once installation is complete, maintenance trips
and any noise from the turbine operations disturb
marine life no more than already present shipping
operations - Concerns over coolant oil leaks into the
surrounding ocean have also been addressed by
some groups who plan to use a nontoxic gaseous
replacement
9Assessing a Wind Resource
- Must have enough wind with the right
characteristics - Identify a wind energy site (typically through
wind resource maps) - Measure winds at the site for at least a year
through all seasons (anecdotal information about
a wind resource is insufficient) and make a
long-term estimate - Shorter measurement periods may be adequate for
site screening if sufficient data is available
for correlation - For small wind must have enough open space to
reduce wind turbulence from nearby trees and
buildings - For larger, multiple-turbine projects, a more
extensive wind resource assessment using wind
resource analysis and digital terrain models is
necessary - Multiple measurement locations and heights
- Wind direction
- Shear and terrain roughness
- Turbulence and turbine wake
- For example New England sites on ridgelines
with tree cover introduce more complex terrain
characteristics and require a wind resource
assessment
10Wind Turbine Siting
- No simple answer to the question of where wind
turbines will be welcome - Whether onshore or offshore, someone or something
that somebody cares about will be affected - For example opposition to drilling for oil in
the Arctic National Wildlife Refuge - Only a small impact on humans but expected to
disrupt a pristine natural area - Which uncertainties and social costs will people
be comfortable accepting? - Who will be willing to accept these burdens in
place of the status quo? - Who will receive the benefit?
11Siting Considerations
- Choosing a proper site for a wind turbine or farm
is critical to a successful project - While the most important factors may vary from
site to site, in any given instance a single
factor can undermine the success of an otherwise
superlative project - On the other hand, a site may be weak in one area
but so strong in another area that it is viable,
such as a site with very strong winds that is
farther than normal from a transmission line - A viable wind energy site generally includes the
following key factors - Attractive wind resource
- Landowner and community support
- Feasible permitting
- Compatible land use
- Nearby access to an appropriate electrical
interconnect point - Appropriate site conditions for access during
construction and operations - Aviation compatibility
- Favorable electricity market
12Landowner and Community Support
- Landowner support
- After a prospective wind site is identified, the
project developer contacts landowners to discuss
their interest in hosting one or more wind
turbines - Most developers enter into a land lease
arrangement with the landowner - Landowner grants the developer the right to
access the property for studies related to
permits, installing a meteorological tower to
measure the winds, and ultimately to construct
and operate a wind project in exchange for a
payment to the landowner - For a multiple-turbine project where a large site
is necessary to capture economies of scale,
neighboring landowners are contacted to ensure
that contiguous roads and electrical lines can be
located between turbines - Community support
- Critical to the success of a wind energy project,
whether a large, multiple-turbine project or a
single residential small wind turbine - Build support by helping the community to
understanding and appreciate the environmental
benefits and, for larger projects, tax revenue
benefits and employment benefits during
construction - Objections to the visibility of turbines
represents the majority of objections from the
local community - For smaller, community-scale projects advocated
or sponsored by the community (a city or town) or
hosted by a part of the community (a school or
other commercial or industrial end user),
community support may be the driving force for
the project - For example, the Hull, MA, turbines and many of
the other community-scaled wind developments
throughout New England
13Issues Affecting Public Acceptance of Wind Energy
- Wind farm developers seek locations with the
greatest wind resource and the smallest
population - Mitigates human interaction and impact whenever
possible - Uninhabited areas are scarce, such as in the New
England states, for example - Many of the windy locations (including coastal
areas and high elevations) are prized for their
natural beauty and/or recreational value and are
within sight of nearby communities, making
community acceptance and support even more
critical - Local impact vs. societal benefits
- All forms of energy impact their surroundings,
but society demands that its need for electric
power plants be met - The benefits of wind power, on a regional and
broader scale, are widely accepted and the
population, as a whole, supports wind power when
compared to the alternatives - After weighing the local impact versus the
societal benefits, most communities embrace wind
power proposals
14Issues Affecting Public Acceptance of Wind Energy
- Where local concern or opposition to wind energy
exists, several factors may be in play - The idea of wind power is new to the local
community - Misinformation about wind projects and their
impact on local communities may be circulating,
initiated by proponents and/or opponents - Without wind project experience, it is difficult
for community members to know what to believe - As noted earlier, disruption of the viewshed is
the complaint most often cited by local
opposition to new wind installations - The American Wind Energy Association addresses
most of these issues and others in "Wind Power
Myths vs. Facts"
15Cumulative Role of Wind Power
- In addition to local concerns is concern over the
broader context or cumulative role of wind power - If wind power currently comprises less than 1
percent of a region's electricity supply
portfolio, it is too small to be significant and
the local community questions why it should host
a facility - To other opponents, their concern is just the
opposite if one wind project is permitted on
one scenic ridgeline, will all of the region's
ridgelines and scenic vistas be open to wind farm
development? - The reality lies somewhere between these two
extremes - For example
- New Englands power supply mix consists of a
range of sources, powered by natural gas, oil,
coal, nuclear, hydroelectric, waste-to-energy,
and biomass sources - The contribution of each of these to the whole
has, at one point in time, been negligible - Having only recently reached the point of
commercial viability and reliability, wind power
is now the nation's (and the world's)
fastest-growing power source - In the near future, wind power will play an
important role in New Englands electricity
portfolio, perhaps similar to the 6 share now
supplied by hydroelectricity (although it is not
expected to contribute more than 10-15 of New
England's portfolio)
16Feasible Permitting
- The permitting process for wind energy
installations is unique to the permitting
jurisdiction, the characteristics and location of
the site, and technical details of the project - Studies that may be required to obtain permits
may include, but are not limited to - Avian and bat interaction
- Wildlife
- Plants
- Wetlands
- Archaeological and historical review
- Stream crossing and soil disturbance
- Aviation interaction
- Local zoning
- The permitting process typically has a public
component where local residents have the
opportunity to learn and comment about the project
17Compatible Land Use
- A viable wind project must be compatible with the
site, the surrounding area, humans, and wildlife - Nearby residential development may make it
difficult to maintain appropriate setbacks for
zoning, sound, and public safety during
construction and operation - Property value may diminish if converting it to
host wind turbines is not its highest value use - Projects at higher elevations that are prone to
icing must consider the proximity to the public
during winter to ensure public safety - Compatibility with wildlife is typically
addressed as part of permitting - Developers looking at prospective sites avoid
major bird flyways and areas with known
sensitive, threatened, or endangered species - Many land uses are fully compatible with wind
energy - Farmland
- Land parcels are large and sparsely populated
- The amount of land taken out of production for
the footprint of the wind turbines and ancillary
roads is small when compared to the added revenue
the landowner receives - For example
- Many of the higher elevation sites in New England
that are ideal for wind energy projects are under
conservation easements or are located on state or
federally owned land not open to wind development - Other windy sites on mountain ridges or
shorelines are highly valued for
recreational/scenic purposes - Opportunities do exist where land use and wind
projects can be compatible, e.g., farming, timber
harvesting, ridgelines with little public use or
not under conservation easements, and industrial
or commercial properties
18Proximity to a Nearby Transmission Interconnection
- An optimal wind site may not be viable due to the
cost and/or difficulty of interconnecting to the
power grid - For small wind installations, proximity to the
electrical interconnection point (the home or
business electric meter) will minimize
construction and wiring costs - For large projects, a nearby transmission line
with the capacity to handle the power output of
the wind installation is required - Power lines and substations can be costly and
time consuming to permit and build - Costs depend on the area through which the line
will run and the size of the line - The project developer will work with the local
utility and/or the region's power pool operator
to determine the feasibility of connecting to the
nearest transmission line - The interconnection study will assess the impact
of the wind energy generated and its electrical
characteristics on the regional power grid - If modifications are necessary, the study will
identify the technical and financial requirements - This rigorous and highly technical study is
necessary to ensure continued reliability of the
power grid as directed by the regional system
operator (for Nebraska and the southern plains
area this is the Southwest Power Pool, SPP)
19Appropriate Site Conditionsfor Access During
Construction and Operations
- Ridgelines are attractive sites for larger wind
energy installations to capture the more
attractive wind resource at higher elevations - Roads to these sites can be marginal or
nonexistent - Developers look for sites with existing adequate
roads that can handle, or be modified to handle,
the construction equipment needed to deliver the
large turbine and tower components and the
specialized crane to erect the turbine - If no roads exist, the economic impact of
constructing a new road must be considered
20Aviation Compatibility
- Usually the highest objects in their area, wind
turbines must be sited to avoid potential hazards
to aviation - The Federal Aviation Administration (FAA) has
established regulations applicable to large
structures such as wind towers - Tower heights more than 200 feet, which includes
most utility-scale wind turbines, require Federal
Aviation Lighting and the filing of the FAA form
7460-1 Notice of Proposed Construction or
Alteration - Each FAA region works with wind developers to
design lighting requirements specific to that
region and the site - The FAA is currently working to create a national
standard for wind turbine lighting - Each FAA region would have the option to adopt
these recommendations
21Favorable Electricity Market
- The economics of small wind projects, under a net
metering configuration, are primarily based on
the retail electricity rate that the wind energy
displaces - In areas with high retail rates, the appropriate
net metering legislation in place, and the right
site, small wind can be a cost-effective
supplement to a home or business's electricity
supply - A large wind project's revenue (and, hence, its
economic viability) depends on the region's
wholesale electricity market - Attractive market prices and the ability to
secure power purchase contracts for the energy
from the wind project largely depend on the costs
of the existing mix of electric supply sources in
the market and the ability of this supply mix to
meet the demand - For example, in New England, the supply mix is
predominantly natural gas and nuclear, with
lesser amounts of coal, oil, and hydroelectric - Wind will typically compete with supply sources
that are more expensive and are used more
immediately to meet the hourly fluctuations in
demand currently this tends to be natural gas - As natural gas prices continue to climb, the
energy from wind will become more attractive from
a cost perspective
22Favorable Electricity Market
- Different locations within the region's power
pool command different wholesale prices for
electrical energy - Due to certain locations' higher demand, a lack
of sufficient generation capacity in that
location, and constraints in the transmission
system that limit the import of less expensive
power from outside that location - For example, within the New England Power Pool,
energy is most valuable in southwest Connecticut
(not a good location for wind) and the greater
Boston area (where small wind projects along the
coast may be viable) and less valuable in
locations such as Maine (which has ample wind
energy potential) - Favorable wholesale market rules are critically
important to the viability of a wind project - Rules for physical interconnection to the power
grid and how the wind project works in concert
with the power requirements of the grid (i.e.,
integration, balancing and scheduling, etc.)
influence the value of the wind energy directly,
and in some cases the cost or financial risk
associated with operating the plant - The specific electric characteristics of a wind
project and its ability to satisfy the local
regions' power quality requirements (such as
through voltage support and other ancillary
services) are also important
23Exercise 11
- 1). Typically, turbines are spaced how far apart
in the prevailing wind direction? - 2 to 5 rotor diameters
- 100 feet
- 50 rotor diameters
- 5 to 10 rotor diameters
24Exercise 11
- 2). Typically, turbines are spaced how far apart
in the cross-wind direction. - 2 to 5 rotor diameters
- 100 feet
- 50 rotor diameters
- 5 to 10 rotor diameters
25Exercise 11
- 3). A typical setback distance of a turbine from
property lines or other structures is - half the turbine height.
- 1.5 times the turbine hub height.
- 5 to 10 times the turbine hub height.
- not needed.
26Exercise 11
- 4). The top reason that wind turbine
installations are opposed is generally in regard
to - noise produced.
- disruption of the viewshed.
- micro-weather concerns.
- cost of operation.
27Exercise 11
- 5). A viable wind energy site generally includes
the following key factors (list all that may
apply). - Access to an electrical interconnect point
- Landowner and community support
- Attractive wind resource
- Feasible permitting
- Site access during construction and operations
28Exercise 11
- 6). Permitting for an installation may involve
environmental or ecological impact estimates on - Wetlands
- Birds
- Plants
- Bats
- B. and D.
- All the above
29Exercise 11
- 7). Federal Aviation Lighting and the filing of
the FAA form 7460-1 Notice of Proposed
Construction or Alteration are necessary for
turbines extending to or above - 200 m
- an elevation of 1,500 feet above sea level
- 200 ft.
- only near airports
30Exercise 11
- 8). The study done to determine the feasibility
of connecting to the nearest transmission line,
and assess the impact of the wind energy
generated and its electrical characteristics on
the regional power grid is called - an interconnection study
- a power transfer study
- a funding study
- a line routing study
31Exercise 11
- 9). The regional transmission authority that all
Nebraska utilities are part of is - National Renewable Energy Laboratory, NREL
- Midwest Independent Transmission System Operator,
MISO - Federal Energy Regulatory Commission, FERC
- Southwest Power Pool, SPP
32Exercise 11
- 10). A large wind project's revenue, and hence
its economic viability, depends on the region's
wholesale electricity market. - True
- False
33Impacts on the Human Environment
- Visual
- The primary impact of wind power is visual as
wind turbines must be exposed to the wind in
prominent locations - It is impossible to quantify esthetic
considerations - Public policy and planning governs whether a
community is willing to accept a visual impact in
return for clean power - FAA lighting
- The FAA requires objects over 200 feet tall
i.e., all commercialscale wind turbines to be
lit - Specific lighting requirements vary from site to
site lights may be red or white, constant or
flashing - Property values and tourism
- The Renewable Energy Policy project studied
25,000 property transactions in the viewshed of
wind projects, compared them to similar sites and
found no evidence of reduced property values - Noise
- Wind turbines are relatively quiet however, how
sound carries depends on terrain and wind
patterns - Wind turbines should be about three times the hub
height or more from residences - The sound generated from wind turbines can be
compared to the sound level of a refrigerator
from about 300 ft - TV interference
- Todays fiberglass composite wind turbine blades
are unlikely to cause any interference with
broadcast signals unlike the former metal blades
which caused ghosting - Compatibility with other human land uses
- Wind turbines can be found around the world
safely coexisting with many land uses, including
schools, highways, hiking trails, and farms
34Sound
- The majority of wind installations are in quiet
rural areas - Receptors may be sheltered from the wind
- Topography may amplify sound
- Sound perception is highly subjective
- An acoustical consultant may be helpful
35Comparative Noise Level
Equipment Noise Level in deciBels (dB)
Jet Airplane 140-150
Pneumatic Drill 120
Industrial Noise 100
Stereo Music 90
Inside Car 80
Office Noise 60
Home 50
Wind Turbine 45
Bedroom 30
Whispering 20
Falling Leaves 10
- Rotor three-bladed
- Smoother flow
- Configuration upwind
- Tower shadowing reduced
- Blades redesigned
- Less vibration
- Gearbox nacelle soundproofing
How loud is the sound from a utility-scale
turbine? 45 decibels at 350 meters
36- Wind turbine noise (at 200 m) is as loud as your
refrigerator heard from the living room
37Shadow Flicker (Visual Pollution)
- Occurs when the sun is low in the sky and the
sunlight is interrupted by a rotating turbine
blade - Flicker is a function of season, latitude, and
time of day - It is a temporary phenomenon as the sun moves
across sky - Flicker can be minimized by proper setbacks
- The developer may negotiate a sight easement
38Ice Shedding
- Small pieces of ice may be thrown
- Larger pieces of ice usually drop within a
blades length from the towerthey are not thrown - Recommended setback is 1.5 x total height
- Tens of thousands of turbines are installed
worldwide, and there has been no reported case of
injury
39Safety
- Turbines have tubular towers with locked doors
the exterior cannot be climbed - Blade throw is extremely rare today, even in a
catastrophic failure - Setbacks of 3-5 rotor diameters are common
- A turbine failed at Weatherford, OK, May 7, 2005
- Winds were light at the time
- The tower snapped
- No injuries occurred
- The cause is under investigation
- The turbine was engineered to international
safety standards (Germanischer Lloyd, Det Norske
Veritas) - This was an isolated incident
40Property Values
- Phoenix Economic Development Group study, October
2002 - Views of wind turbines will not negatively
impact property values. Based on a nation-wide
survey conducted of tax assessors in areas with
wind power projects, we found no evidence
supporting the claim that views of wind farms
decrease property values. - Renewable Energy Policy Project (REPP) study, May
2003 - The statistical analysis of all property sales
in the view shed and the comparable community
provides no evidence that wind development has
harmed property values within the view shed.
There is no valid empirical support for claims
that wind development will harm property values.
41Wildlife Impacts
42What Kills Birds? Human Causes
- Glass Windows Bird Deaths a year more than 100
million - Dr. Daniel Klem of Muhlenberg College, studied
bird collisions with windows over 20 yr., His
conclusion glass kills more birds than any other
human-related factor - House Cats Bird Deaths a year 100 Million
- The National Audubon Society says 100 million
birds a year fall prey to cats. Dr. Stan Temple
of the University of Wisconsin estimates that in
Wisconsin alone, about 7 million birds a year are
killed by cats - Automobiles/Trucks Bird Deaths a year 50 to 100
Million - Birds killed by cars and trucks on the nation's
highways is 50-100 million a yr., National
Institute for Urban Wildlife and U.S. Fish and
Wildlife Service - Electric Transmission Line Collisions Bird Deaths
a year up to 174 million - U.S. Fish and Wildlife Service estimates millions
of birds die each year as a result of colliding
with transmission lines - Agriculture Bird Deaths a year 67 million
- Pesticides likely poison an estimated 67 million
birds per yr., Smithsonian Institution. Cutting
hay may kill up to a million more birds a year. - Land Development Bird Deaths a year unknown
- Suburban sprawl is a silent but deadly killer.
The National Audubon Society says loss of bird
habitat is the greatest threat to bird
populations. - Communication Towers Bird Deaths a year 4 to 10
million - U.S. Fish and Wildlife Service estimates that
bird collisions with tall, lighted communications
towers and their guy wires results in 4-10
million bird deaths a yr. - Stock Tank Drowning Bird Deaths a year unknown
- U.S. Fish and Wildlife Service biologists and
other conservationists believe that large numbers
of birds inadvertently drown in livestock water
tanks. - Oil and Gas Extraction Bird Deaths a year 1 to 2
million - The U.S. Fish and Wildlife Service reports that
up to 2 million birds died landing in oil pits to
bathe and drink in 1997. Netting has improved
that situation somewhat. There are no overall
estimates for the number of birds affected by oil
and gas spills and oil and gas extractions (and
transport) - Logging and Strip Mining Bird Deaths a year
unknown
Curry Kerlinger, LLC has compiled the following
information from environmental organizations and
government agencies. info_at_currykerlinger.com
Dick Curry, 1734 Susquehannock Drive, Mc Lean,
VA 22101, (703) 821-1404, rca1817_at_aol.com Paul
Kerlinger, P.O. Box 453, Cape May Point, New
Jersey 08212, (609) 884-2842
43Wind Turbine Effect on WildlifeFluffy is
Dangerous!
- Bird mortality due to wind turbines became an
environmental concern with an abnormally high
number of bird fatalities at the Altamont Pass
Wind Resource Area (ARWRA) in Northern California - The 5,400-turbine project in Altamont killed at
estimated 800 to 1,300 birds a year - Prompted many studies on avian mortality due to
wind turbines - Studies have since revealed that the bird
mortality rate seen at Altamont is unusual and
can be attributed to technology used during
construction and poor site selection - It lies along the path of a major migration route
where many raptors nest and hunt - For all combined species, data collected in the
U.S. outside of California revealed an average
1.83 avian fatalities and 0.006 raptor fatalities
per year - This compares favorably with mortality rates
caused by window strikes and domesticated cats - A less understood phenomenon is bat fatalities
due to tower and turbine blade strikes - In 2003, more than 2,000 bats were killed at a
44-turbine project in Thomas, West Virginia - Biologists have theories but no consensus on what
causes bats to fly into towers and turbine blades
- While wildlife interacting with wind turbines is
an important issue, it is manageable through
siting and technologythe key is to make sure it
is managed - The argument against wind energy due to avian
mortality is put into context by the Audubon
Society, which states that global warming and its
concurrent loss of habitat is the greatest threat
to wildlife today - Wind energy generations potential in displacing
greenhouse gas emissions makes it acceptable in
this context
44Avian Impact (no pun intended)
No. Known or Suspected Risk Factors for Avian Collision Altamont Pass, CA Typical Modern Wind Installation in New England
1 Large concentrations of turbines 5,400 (in 2001) 1-40
2 Lattice towers allow raptors to perch Lattice Tubular towers do not attract perching
3 Fast rotating turbine blades 50-72 rpm Slow rotating blades 12-18 rpm
4 Closely spaced turbines 80-100 ft. (lt30M) Widely spaced turbines gt650 ft. (gt200M)
5 Turbines in steep valleys or canyons Steep valleys and canyons Turbines on flat terrain, rolling hills, or ridge tops (no steep hills except sides of ridges)
6 Prey base to attract raptors Large
7 Raptor and susceptible species Present
8 FAA lighting attracting night-migrating birds Often unlit Risk is present and may account for the majority of night-time avian collisions with modern turbines
The magnitude of these risks at a particular
site would be addressed in a Phase 1 Avian Risk
study.
Modern wind turbines kill on average one to two
birds per turbine, per year.
45Bats and Wind Power
- Bat fatalities have recently become an issue in
the wind power industry because fatalities have
been documented at wind power sites where
post-construction bird studies have been
conducted - Because of these fatalities, various wildlife
agencies and environmental organizations have
become interested in determining whether a
problem exists - Bat fatalities have been studied at nearly the
same number of wind power facilities as have bird
fatalities - Data are now available from more than a dozen
wind plants across the U.S. - Here's what we know about this issue
- The numbers of bats involved are small at most
wind plants, although in Minnesota and Wyoming
moderate numbers have been found - Many of the bats involved in collisions with wind
turbines were apparently migrating - About seven species of bats have been documented
to collide with wind turbines - Bats involved are primarily common, tree-dwelling
bats with widespread geographic distributions - Endangered or threatened species have not been
involved - Population impacts seem unlikely
- Bat fatalities have not emerged as a significant
issue at wind plants in Europe - Migrating bats may turn off their sonar causing
them to fly into towers - Small numbers of bats also collide with
communication towers
46Project Overview
47Finding Suitable Sites
- 3. Sufficient Landowner Interest
- Meet with landowners to gauge interest
- Will the project be supported by the community?
- Enough land to develop a project (approx 4000
acres for an 80 MW project) - Approx. 100 acres per turbine (1 acre 43,560
ft.2 4,047 m2)
Photo Credit Alice Buschkamp
48Moving Forward
- Sites that meet the previous criteria now need
- A project company and funding
- Cooperation Agreements with Landowners (initial
land rights) - On-site wind data
- Initiate fatal flaw review
- Begin transition from prospecting into
development
Photo Credit Alice Buschkamp
49Turbine Layout Plan
- What factors into a Turbine Layout Plan?
- Setbacks applied to project acreage to obtain
buildable area. - Within buildable area, wind resource and
constructability used to determine turbine sites.
- Landowners approve locations of turbines and
access roads. - Other factors include microwave beam paths,
environmental issues, pipelines, etc. - Final plan used to submit for permits.
50Center Pivot Irrigators
- You Cant Always Avoid Center Pivots
- Nebraska has more sprinkler irrigated land than
any other state 72 - Look to avoid pivots where economically feasible.
- Laredo Ridge had a handful of parcels where
turbines ended up inside pivot. - Source http//cropwatch.unl.edu/web/cropswater
/stategraph
Photo Credit Mark Grundmayer
51Energy Production Estimate
- Used to determine how much power a given wind
turbine or farm will produce in a year - Most important value is the Net Capacity Factor
or the of power produced versus maximum rating - Individual turbine NCF and rankings used to make
adjustments to increase production - Also estimate losses due to wake effect and line
loss
52Wind Turbine Lease
- 20-25 year land lease for each turbine site and
associated access roads and underground cables - 100 x 100 square centered on turbine base plus
16 gravel access road is the only ground taken
out of production - Rent paid annually per turbine either by MW or
of revenue of entire farm - All commercial terms mirror any power purchase
agreement that is obtained - Contains provisions for crop damages,
decommissioning, repowering, etc
Photo Credit Alice Buschkamp
53Obtaining Permits
- Obtaining all permits is the critical path for
a project and can take two years or longer - Begin interaction with Federal and State agencies
as soon as possible - Environmental protection is an important focus
(Army Corps, USFWS, NGPC) - Local zoning process is the main forum for
communities to discuss wind development - Also need approvals from the FAA, FCC and other
agencies
Photo Credit Mark Grundmayer
54Interconnection and PPAs
- Interconnection process is another critical path
issue taking at least a year - Involves working with transmission owner (NPPD),
regional transmission operator (SPP) and power
purchaser through complicated regulatory process - Available capacity dictates project size
- Could add to the project depending on
upgrades needed to the system
55Finishing Up
- Finalize turbine layout plan
- Obtain final FAA approvals
- Finish entitlements (leases, easements, local
permits, etc) - Finalize energy production estimate
- Execute Power Purchase Agreement
- Execute Interconnection Agreement
- Commence construction
Photo Credit Alice Buschkamp
56Construction
- Construction takes about a year
- It takes 2500 person-hours to construct each
turbine or approx 1.25 full-time jobs for one
year - The crawler crane takes 18 semi-truckloads to
deliver to the site - Each foundation is a continuous pour needing
60-80 cement truck loads - One full-time job created for every 10 MWs
- A typical 80 MW windfarm generates enough power
for 24,000 houses
Photo Credit Mark Grundmayer
57Exercise 12
- 1). Some impacts that wind turbines have on
humans are - Noise and the viewshed.
- Possible electromagnetic interference with radios
and television. - Interference with other land uses.
- A. and C.
- All the above
58Exercise 12
- 2). Compared to sitting inside a moving car,
large wind turbines are - much louder
- louder
- quieter
- about the same loudness
59Exercise 12
- 3). Based on studies done in 2002 and 2003, wind
turbines within sight of residential areas caused
property values to - increase considerably
- decrease
- slightly increase
- be unaffected
60Exercise 12
- 4). Glass windows in buildings and predators,
such as domestic cats, kill many more birds each
year than wind turbines. - true
- Not clear from the statistics
- false
61Exercise 12
- 5). For initial project planning, how much land
should be allowed for proper spacing of large
turbines (1 to 2 MW each) in a wind farm? - 100 acres per turbine
- 100 sq. ft. per turbine
- ΒΌ section per turbine
- Determined by local zoning restrictions
62Exercise 12
- 6). Land leases are typically contracted for
- 1 year at a time
- rolling 50 year window
- 20-25 years
- 10 years
63Exercise 12
- 7). The Capacity Factor (sometimes called Net
Capacity Factor) refers to the - ratio of the footprint of a wind farm compared to
the total land leased. - ratio of the average power produced over a year
compared to the nameplate (maximum) power rating - ratio of hours each turbine is in operation
compared to hours under maintenance - number of hours each month that a turbine
produces its nameplate power.
64Exercise 12
- 8). The footprint of a large turbine occupies
approximately - all the land except as used by a pivot irrigation
system - 100 ft. x 100 ft. plus the access road to it
- 10 ft. x 10 ft. plus the access road to it
- 10 acres
65Exercise 12
- 9). There are at least two contracts that must be
negotiated between a developer and the local
utility. One is to be able to connect the wind
farm to the local transmission system and the
other is to determine the price of kWh sold to
the utility. These are typically called - CBED agreement and green tag purchase contract.
- A net metering agreement and a regional
transmission study - investment tax credit application and avoided
cost contract. - An interconnection agreement and a power purchase
agreement.
66Exercise 12
- 10). During construction of a large wind farm, a
turbines concrete foundation is poured - Using 60 to 80 truck-loads of concrete
- continuously
- In 2 ft. layers and allowed to dry between the
pouring of each layer - A. and C.
- A. and B.
- B. and C.
- All the above