Title Page
URBAN WIND TURBINE SENIOR DESIGN PROJECT
FINAL REPORT
By:
Michael Austin
Cody Bateman
Torrey Roberts
Mirai Takayama
Prepared For
ME 480 Senior Design
Boise State University Mechanical Engineering Department
May 5, 2005
Executive Summary
The goal of this senior design project was to determine the optimal location for an urban
wind turbine system on top of one of the Boise State University (BSU) College of
Engineering Buildings (COEN). We selected a turbine system from potential vendors
that would perform efficiently at the location. We have determined that the center of the
Micron Engineering Center (MEC) building at a height of 20-30 ft above the rooftop is
the optimal location for a wind turbine. The Bergey XL1 is a 1kW turbine that could be
purchased and installed at this location. This turbine has an 8.2 foot diameter and would
produce approximately 370 kW-hr/year at this location. Our decisions were based upon
months of wind flow analysis, wind data analysis, and turbine performance analysis
which is explained in the pursuing sections. From an economic stand point, a turbine
installation on the MEC building would be a very poor choice. A break-even point would
never be reached for the 20 to 30 year life span because of the low average wind speeds.
However, the wind turbine could be used for research and observation by BSU faculty
and students.
ii
Table of Contents
Title Page ............................................................................................................................. i
Executive Summary ............................................................................................................ ii
Table of Contents............................................................................................................... iii
Introduction......................................................................................................................... 1
Objectives ........................................................................................................................... 1
Background ......................................................................................................................... 2
Design Solution................................................................................................................... 4
Location ...................................................................................................................... 4
Turbine System Selection ......................................................................................... 11
Analysis............................................................................................................................. 12
Location .................................................................................................................... 12
Fluent Background.................................................................................................... 12
FloWorks Background .............................................................................................. 13
CFD Analysis............................................................................................................ 13
March Case Study ..................................................................................................... 19
Turbine System ......................................................................................................... 23
Safety Analysis ......................................................................................................... 26
Discussion ......................................................................................................................... 27
Conclusions....................................................................................................................... 27
Recommendations............................................................................................................. 28
References......................................................................................................................... 29
Appendix........................................................................................................................... 30
Turbine Power Curves .............................................................................................. 30
Turbine Cost Tables .................................................................................................. 32
FloWorks Wind Maps............................................................................................... 36
Fluent Wind Maps..................................................................................................... 38
Monthly Boise Airport Wind Rose ........................................................................... 40
iii
Introduction
Demand for power in urban areas is constantly increasing. Innovative ideas for
generating power are needed. Wind turbines placed on top of existing or new structures
present a possible solution. Past experience gained in installation of small wind turbines
is now being used to create systems with better performance, lower costs, and higher
reliability. Due to increased energy demand, urban wind turbines systems are under
examination.
The purpose of this senior design project was to determine the optimal location for a
wind turbine on top of one of the College of Engineering (COEN) buildings and to select
an appropriate turbine system that will operate efficiently and safely in an urban
environment. The turbine would be used primarily for educational and observational
purposes if installed. According to wind data from the Boise Airport, the average wind
speeds from 1997 to 2003 were 7.6mph. Since, most wind turbines require minimum
wind speeds of 8-10 mph to begin operating, turbines at this location will not generate
significant amounts of power. However, average wind speeds for Boise in March are 8.8
mph.
Installing a wind turbine on one of the COEN buildings is not a good economical choice;
however it will enable the university to perform research regarding urban wind turbines.
Information gathered from this research can be applied to other more economical turbine
locations.
The turbine needs to be installed in the optimal location to harvest the maximum amount
of wind power available. In addition the turbine needs to fulfill the following user needs:
•
Operate in low wind speeds.
•
Monitored easily by faculty and students.
•
Accessed easily by faculty and students.
•
Include power storage and delivery system.
•
Safe to operate in an urban environment.
Objectives
Initially our objective was to install an operational wind turbine to power the Segway and
COEN Electric Vehicle by the end of May 2005. Shortly after investigating the project
scope, we concluded the task was far too vast for a single semester project and we needed
to narrow our focus.
The new scope consisted of determining the best wind turbine location at the COEN
based on wind speed and selection a suitable wind turbine system by May 2005. A
budget for this project was not provided by BSU. Therefore our only cost objective was
to keep capital costs low.
1
Background
Several factors have influenced a renewed and increased interest in wind energy. People
want alternative forms of energy to reduce their dependency on fossil fuels.
Additionally, wind turbines have continued to become more efficient, while at the same
time becoming more cost effective. In Idaho, power is provided at one of the lowest rates
in the country. However, with increasing pressure to sustain migratory fish restrictions
and recent low water flows, power rates are sure to rise. This is driving consumers and
the power industry to look for alternative form of energy.
Ranked 13th out of 50 states for wind energy potential, Idaho has 7,370 km2 of class 3 or
greater wind area (Figure 1). Over 8,000 mega watts of wind energy potential is
available; unfortunately most of the high wind regions are not located near current
transmission lines. The state provides a personal tax deduction of 40% of the cost of
installing a solar, wind, or geothermal electric or heating system for the year of
installation, and 20% for each year thereafter. Net metering is available for wind turbine
systems less than 100kW. The Energy Division of the Idaho Department of Water
Resources (IDWR) provides five year loans at 4% interest for wind and other renewable
energy projects1.
Figure 1 – Idaho Wind Classification Map
http://rredc.nrel.gov/wind/pubs/atlas/maps/chap3/3-03m/html
According to the Department of Energy (DOE), small privately owned wind turbines
require wind speeds greater than 10 mph and the utility supplied electricity cost greater
than 10 cents per kilowatt hour for economic viability2. According to Idaho Power’s
website, the current small commercial rates are about 7.6 cents per kW-hr.
2
Other universities are also investigating the possibility of wind energy. The University of
Massachusetts has installed an alternative energy system on the top of their engineering
building; consisting of 3 different types of wind turbines and a set of solar panels. They
connected the system to a 24V battery bank and to the grid with a 4kW trace inverter.
The types of wind turbines installed included: a Bergey 1500W at 80’ (above ground), a
World Power Technologies Mariner H500 at 45’, and a Southwest Windpower Air
Marine 300 at 45’. Overall, the turbines produced 20% less power than expected, due to
the underestimated turbulence of the environment. They installed the entire system for
$52,000 in 1998; adjusted for inflation this would approximate $64,000 today. The most
expensive part of the project was the engineering required to safely install the equipment
on the roof of a public building3.
The power that can be generated from wind is linearly dependant on the swept area of the
turbine blades, but a function of the velocity cubed4.
P = 0.5(Cp )( ρ )( A)(V )3
This means wind speeds of 12.6 mph have twice the energy of wind speeds at 10 mph
(only 2.6 mph less). Therefore, small differences in wind speed can have a significant
impact on the power generated by a wind turbine. Based on conservation of energy, the
Betz limit states that the turbine blades cannot extract more than 59% of the total energy
available in the wind. In other words, assuming the rest of the system operates at 100%
efficiency, the maximum efficiency achievable is 59%. Most wind turbine systems
operate within the range of 10% to 30% combined efficiency. Also, most wind turbines
do not start to generate power until the wind reaches at least 7 to 8 mph.
Urban wind turbine installations present certain concerns not found in rural wind farms.
Traditionally noise produced by turbine blades has been bothersome to those living near
wind turbines. Wind turbines typically produce some broadband noise as their revolving
rotor blades encounter turbulence in passing air. This type of noise is described as a
“whooshing” sound. However, most modern wind turbines are typically not any louder
than passing traffic. Figure 2 shows wind turbine noise compared with noise from other
activities. The noise level of smaller wind turbines can sometimes be higher because of
the higher rotational speed. In addition, less money and research has been invested in
reducing noise on smaller turbines than larger turbines5.
Figure 2 – Typical Noise Levels
www.gov.on.ca/.../ engineer/facts/03-047.htm
3
Safety is another concern when considering the installation of a wind turbine in an urban
area. This is especially true when people are present near the base of the building.
Turbulent locations also increase the chance of failure due to the increased load variation
imposed on the system. Any failures resulting in falling objects would have catastrophic
results and a negative impact on public confidence of urban wind energy systems. When
placing an urban wind turbine, it is important to install and design for failure prevention
and provide failsafe features to prevent injury.
The turbine owner must follow a strict maintenance program. Tips of wind turbine rotor
blades can reach speeds up to 300 mph4. Hail, dirt, and insects contacting the blades at
theses speeds can cause premature wear to the blade edges causing extreme physical
forces. Thrust and vibration loads also subject the bearings and tower to loads. The
lifespan of these bearings depends on the wind conditions and level of maintenance.
Turbine manufactures will usually specify activates and intervals required for
maintenance. The entire wind system, including the tower, storage devices, and wiring
should be inspected on a regular basis. If maintained properly a wind turbine system can
last up to 20 to 30 years.
Several different types of wind turbines have been proposed that can be categorized as
being either vertical axis or horizontal axis. Vertical axis turbine designs eliminate the
need to align the turbine with wind direction and reduce issues related to turbulence.
Unfortunately the companies previously producing these turbines have all gone out of
business. Vertical axis turbines were eliminated early on in our analysis, and several
different brands of horizontal turbine manufactures were evaluated.
Design Solution
Location
We determined the center of the MEC building as the optimal location for a wind turbine
at the COEN. This location had the highest wind speeds according to our models and had
adequate mounting characteristics. The location is also safer than placing a turbine near
the edge of the building. It allows some protection for pedestrians below if a blade fails
and allows safe access for a person observing or maintaining the turbine, not near any
building edges.
We created detailed and simplified solid model for analysis using SolidWorks, a
computer aided drafting program (Figure 3). This model was used to determine wind
flow patterns over the COEN Buildings in two separate Computational Fluid Dynamics
(CFD) programs. Precise dimensions for the COEN buildings were obtained from the
building architectural drawings and field measurements. The dimensions for overall
locations and sizes of surrounding buildings were approximated from the Ada County
Assessor’s aerial maps.
4
Figure 3 - COEN & Surrounding Area
We applied Fluent and FloWorks, two CFD Modeling packages, to map the bipolar wind
patterns over the BSU COEN buildings (major wind flow patterns vary from the
Northwest and Southeast directions). Both programs indicated that the best location for
the wind turbine was in the center of the Micron Engineering Center’s penthouse roof;
where the maximum wind speed occurs at approximately 20 to 30 feet above the roof.
Wind speed data generated from Fluent and FloWorks for both major wind patterns are
indicated in Figure 4 through Figure 7.
8.0 MPH SE WIND ANALYSIS WITH FLUENT
170
Maximum Wind Speed =170 in/s
at 10ft and 15 ft above MEC Rooftop
3500 inches from origin.
165
160
Velocity Magnitude, (in/s)
155
150
145
140
135
82 ft (0ft above MEC Roof)
87 ft (5ft above MEC Roof)
92 ft (10ft above MEC Roof)
97 ft (15ft above MEC Roof)
102 ft (20ft above MEC Roof)
107 ft (25ft above MEC Roof)
112 ft (30ft above MEC Roof)
117 ft (35ft above MEC Roof)
130
125
120
115
110
122 ft (40ft above MEC Roof)
127 ft (45ft above MEC Roof)
132 ft (50ft above MEC Roof)
105
100
-200 -150 -100 -500
0
0
0
0
500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Location, (in)
Figure 4 - SE Fluent Wind Analysis
5
8.0 MPH SE WIND ANALYSIS WITH FLOWORKS
170
Maximum Wind Speed =167 in/s
at 15ft and 20 ft above MEC Rooftop
3500 inches from origin.
165
160
155
150
Velocity (in/s)
145
140
135
130
125
82 ft (0ft above MEC Roof)4@Line1_1
87 ft (5 ft above MEC Roof)4@Line1_1
92 ft (10 ft above MEC Roof)4@Line1_1
97 ft (15 ft above MEC Roof)4@Line1_1
102 ft (20 ft above MEC Roof)4@Line1_1
107 ft (25 ft above MEC Roof)4@Line1_1
112 ft (30 ft above MEC Roof)4@Line1_1
117 ft (35 ft above MEC Roof)4@Line1_1
122 ft (40 ft above MEC Roof)4@Line1_1
127 ft (45 ft above MEC Roof)4@Line1_1
132 ft (50 ft above MEC Roof)4@Line1_1
120
115
110
105
100
-2000 -1500 -1000 -500
0
500
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Location (in)
Figure 5 - SE FloWorks Analysis
8.0 MPH NW WIND ANALYSIS WITH FLUENT
170
Maximum Wind Speed =167 in/s
at 15ft above MEC rooftop
3000 inches from origin.
160
Velocity Magnitude, (in/s)
150
140
130
120
110
82ft (0ft above MEC Roof)
87ft (5ft above MEC Roof)
92ft (10ft above MEC Roof)
97ft (15ft above MEC Roof)
102ft (20ft above MEC Roof)
107ft (25ft above MEC Roof)
112ft (30ft above MEC Roof)
117ft (35ft above MEC Roof)
122ft (40ft above MEC Roof)
127ft (50ft above MEC Roof)
132ft (0ft above MEC Roof)
100
-2000 -1500 -1000 -500
0
500
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Location, (in)
Figure 6 – NW Fluent Wind Analysis
6
8.0 MPH NW WIND ANALYSIS FROM FLOWORKS
170
Maximum Wind Speed =162 in/s
at 25ft above MEC rooftop approximately
3000 inches from origin.
160
Velocity (in/s)
150
140
130
120
110
82 ft (0ft above MEC Roof)4@Line1_1
87 ft (5 ft above MEC Roof)4@Line1_1
92 ft (10 ft above MEC Roof)4@Line1_1
97 ft (15 ft above MEC Roof)4@Line1_1
102 ft (20 ft above MEC Roof)4@Line1_1
107 ft (25 ft above MEC Roof)4@Line1_1
112 ft (30 ft above MEC Roof)4@Line1_1
117 ft (35 ft above MEC Roof)4@Line1_1
122 ft (40 ft above MEC Roof)4@Line1_1
127 ft (45 ft above MEC Roof)4@Line1_1
132 ft (50 ft above MEC Roof)4@Line1_1
100
-2000 -1500 -1000 -500
0
500
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Curve Length (in)
Figure 7 - NW FloWorks Wind Analysis
For each of these graphs, 0 inches represents the origin of the solid model generated with
SolidWorks. The origin is located at the NW corner of the Engineering Technology (ET)
building (reference Figure 8). The lines in the graph represent flow trajectories in a
vertical plane 2100 inches (175 ft) southwest from the origin parallel to the NorthwestSoutheast directions. This is indicated in the top view of the model used in Figure 8
below. The solid red line represents the plane used in creating graphs above. The grid is
in squares of 500 x 500 inches with coordinates at the corners of the map.
Figure 8 – NW Wind Flow Plane Top View
7
There are some slight differences between both CFD Models. The Southeast wind graph
generated using Fluent indicates a maximum wind speed of approximately 170 in/s (9.7
mph) 10 to 15 feet above the MEC penthouse rooftop 3400 inches from the origin.
FloWorks indicates a maximum wind speed of 167 in/s (9.49 mph) 15 feet above the
MEC penthouse rooftop at 3300 inches from the origin. Comparisons between the two
models are shown in Table 1 through Table 4. The values in these tables represent the
best wind power elevations.
Table 1 – FloWorks vs. Fluent Velocity Profile Comparison 3300” From Origin SE Wind
Elevation
Above
Rooftop
10ft
15ft
20ft
25ft
30ft
35ft
FloWorks Fluent
Velocity Velocity
(in/s)
(in/s)
163
167
166
165
161
158
160
166
166
167
166
164
%
Difference
-1.88%
-0.60%
0.00%
1.20%
3.01%
3.66%
Table 2 – FloWorks vs. Fluent Velocity Profile Comparison 3400” from Origin SE Wind
Elevation
Above
Rooftop
10ft
15ft
20ft
25ft
30ft
35ft
FloWorks Fluent
Velocity Velocity
(in/s)
(in/s)
165
167
165
163
160
157
170
169
168
166
165
163
%
Difference
2.94%
1.18%
1.79%
1.81%
3.03%
3.68%
Table 3 – FloWorks vs. Fluent Velocity Profile Comparison 2700” from Origin NW Wind
Elevation FloWorks Fluent
%
Above
Velocity Velocity
Difference
Rooftop
(in/s)
(in/s)
10ft
147
161
8.46%
15ft
153
166
7.58%
20ft
160
165
3.27%
25ft
161
164
1.78%
30ft
159
163
2.08%
35ft
158
162
2.38%
8
Table 4 – FloWorks vs. Fluent Velocity Profile Comparison 3000”from Origin NW Wind
Elevation FloWorks Fluent
%
Above
Velocity Velocity
Difference
Rooftop
(in/s)
(in/s)
10ft
138
141
2.57%
15ft
149
152
2.38%
20ft
158
159
0.79%
25ft
162
161
-0.13%
30ft
161
162
0.87%
35ft
160
163
1.42%
Wind isoline maps were generated using FloWorks and are shown in Figure 9 and Figure
10. The closely spaced orange isolines indicate that the location with the best wind speed
is the center of the MEC building at this elevation.
Figure 9 – FloWorks Wind Isolines 20 feet Above Top of MEC Building SE Wind
9
Figure 10 – FloWorks Wind Isolines 20 feet Above Top of MEC Building NW Wind
Isolines were also generated using Fluent, and are as shown below. For Fluent, the
velocity isolines are in m/s. Fluent and FloWorks gave similar solutions; the middle of
the MEC is the best place to locate the turbine.
Figure 11 – Fluent Wind Isolines 20 feet Above Top of MEC Building SE Wind
10
Figure 12 – Fluent Wind Isolines 20 feet Above MEC Building NW Wind
Turbine System Selection
According to our analysis, the Bergey XL1 1kW turbine system ranked 3rd in power
output and was the least expensive. We recommend this system for the MEC building
because of its low initial capital cost. The turbine has a rotor diameter of 8.2 feet. Bergey
also provides a matching tower, generator, and power conversion system. Table 5
summarizes the parts and prices for the expandable system.
Table 5 – Bergey Turbine System Price List
`
Power Output : 1 kW
Type : Battery Charging
Company : Bergey
Model : BWC XL 1-24
Product
Turbine
Turbine and PowerCenter multi-function controller
Tower
Tower (30 ft tilt-up)
Tower wiring kit, 7 Circuit
Batteries
5.3kWh Battery Bank
Inverter
1,500 W Inverter System
Installation
Annual Profit & Loss
Energy Generation
O&M
Payback Period
Price
$
2,450
$
$
950
600
$
450
$
1,044
$
10,000
Total : $
15,494
$
$
29
(75)
NA
11
Several types of turbines were analyzed to determine how they would perform in this
area. We utilized the decision matrix in Table 6 to help select the best turbine.
Table 6 – Turbine Decision Matrix
Concept Alternatives
SW Windpower Air X
400 W
Criteria
Number of School Days Operating
Cost
Safety
kW-hrs per Year
Reliability & Maintenance
Aesthetics & Noise
Availability
Total
Importance
Weight (%)
32
20
15
12
10
7
4
100
Rating
Weighted
Rating
3
4
2
0
2
3
3
NA
0.96
0.8
0.3
0
0.2
0.21
0.12
2.59
Rating
Unsatisfactory
Just Tolerable
Adequate
Good
Very Good
Bergey 1 kW
Rating
Weighted
Rating
4
4
4
2
4
3
4
NA
1.28
0.8
0.6
0.24
0.4
0.21
0.16
3.69
Bergey 7.5 kW
Rating
Weighted
Rating
2
1
4
4
4
3
4
NA
0.64
0.2
0.6
0.48
0.4
0.21
0.16
2.69
Bergey 10 kW
Rating
Weighted
Rating
2
2
4
0
4
3
4
NA
0.64
0.4
0.6
0
0.4
0.21
0.16
2.41
Proven Energy 600 W
Proven Energy 2.5 kW Proven Energy 2.5 kW
Battery
Grid
Rating
Weighted
Rating
Rating
Weighted
Rating
Rating
Weighted
Rating
4
4
3
0
2
3
2
NA
1.28
0.8
0.45
0
0.2
0.21
0.08
3.02
4
3
3
3
2
3
2
NA
1.28
0.6
0.45
0.36
0.2
0.21
0.08
3.18
4
3
3
3
2
3
2
NA
1.28
0.6
0.45
0.36
0.2
0.21
0.08
3.18
Value
0
1
2
3
4
Analysis
Location
Fluent and FloWorks were the two CFD modeling packages used to model the wind
patterns over the BSU COEN Buildings. Using both modeling packages allowed us to
verify our results. To ensure accuracy of the results, we used architectural drawings and
Ada County Assessor maps to define elevations and locations of the COEN and
surroundings to accurately define the solid model. After the solid model was defined, we
imported it into both CFD packages for analysis.
Fluent Background
Fluent is the industry CFD software leader. It is a very robust and accurate software
package. Fluent uses GAMBIT as its modeling and meshing program that enables the
user to model complex geometry where the fluid flow analysis takes place. In our case
we imported the model defined in SolidWorks as an IGES file into GAMBIT. The model
was then broken up into an unstructured grid, called a mesh that consists of user defined
shape elements. Smaller element shapes and sizes provide more accurate result.
However, decreasing an elements size greatly increases the computation time. So, the
solid model was simplified to allow a timely analysis of the wind flow patterns. The
simplification of the solid model is shown in Figure 13 and Figure 14.
12
Figure 14 – Initial Model COEN &
Surrounding Buildings
Figure 13 – Simplified Model COEN &
Surrounding Buildings
This simplified model was analyzed in both FloWorks and Fluent to check precision
between the two modeling packages. The result precision is tabulated in the “%
Difference” column in Table 1 thru Table 4. The more complex initial model was used in
SolidWorks for a March wind study when the average wind speeds increase to around 8.8
mph.
FloWorks Background
Fluent’s user interface requires extensive knowledge and experience to produce accurate
results. For this reason, user friendly CFD packages like FloWorks are available to the
average user. FloWorks is the CFD modeling package fully embedded within the
SolidWorks Computer Aided Drafting Program. Its user interface is designed for the
average design engineer who may not have the expertise required to operate Fluent. One
of the drawbacks to its user friendliness involves lack of functionality. For example
FloWorks does not have the ability to model two phase flows nor will it allow you to
change the mesh elements shape like Fluent. However, you can control mesh element
gap size represents, so more accurate results may be obtained.
CFD Analysis
The initial analysis of the wind flow patterns over the COEN Buildings involved both
Fluent and FloWorks. Analyzing the same model with the same inputs allowed us to
verify the accuracy of the results with respect to each CFD system. In this case, we
imported the simplified model shown in Figure 13 into both Fluent and FloWorks. The
input velocity for this analysis was 8.0 mph which is close to the spring time wind speed
average. We did multiple studies in which we altered the wind direction between
Northwest and Southeast. The parameters associated with the modeling can be found
below in Table 7.
Table 7 – CFD Modeling Parameters
Modeling Parameters
Fluent
Floworks (Using Floworks Wizard)
Time step size
Time Frame Analyzed
Unsteady Formulation
Every 0.2 seconds
0 - 40 seconds
2nd order implicit
Absolute
OFF
K-epsilon
No slip shear
condition
Air
Turbulent
NA
Steady State
Steady State
NA
Velocity Formulation
Energy Equation
Viscous Model
Boundary condition of the
building surface
Fluid Type
Physical Features
Analysis Type
Velocity Parameters
Pressure
Temperature
Result Resolution
Gap Size
NA
Adiabatic (OFF)
Default
.06 in Surface Roughness
Air
Turbulent
External (excluded internal spaces and excluded
cavities without flow conditions)
8.0 mph (SE and NW directions)
8.0 mph (SE and
NW directions)
101.3kPa (Default) 101.3 kPa (Default)
291K (Default)
NA
3”-600” (at each
edge of
Tetrahedral)
291K (Default)
3
Default at 1088” (edges of parallelogram) Mesh
Elements are approximately twice the size of
Fluent
13
The difference in mesh sizes can be seen in the Figure 15 and Figure 16. Where Figure
15 represents the tetrahedral meshes made by Fluent and Figure 16 represents the
rectangular prism meshes generated by FloWorks. Figure 17 and Figure 18 represent the
NW velocity contour maps of the plane passing directly through the center of the MEC
building. The location of the plane is 2100 inches from the origin and the plane is
parallel to the SE direction.
Figure 15 – Fluent Mesh
Figure 16 – FloWorks Mesh
14
Figure 17 – NW Wind FloWorks Contour Map at 2100” from Origin
Figure 18 – NW Wind Fluent Contour Map at 2100” from Origin
The FloWorks output velocity is in inches/second whereas the Fluent output velocity is in
m/s. Both of the color scale maximums are equal (i.e. 177 in/s = 4.5 m/s) so there is a
direct correlation between the two color schemes. If both contour maps show the same
color in the same area the wind speeds experienced in that area are similar. This is
evident in the region directly above the center of the roof of the MEC building. Both
contour maps show a trend of increased velocity over the top edge at about the same
elevation. This is evident in Table 1 through Table 4.
Alternatively, if the contour maps do not show the same color in the same area the
conclusion could be made that the wind speeds are different for that area between the
models. This phenomenon is evident in the tail section of the flow indicated in dark blue
by the FloWorks model. There is a slight difference in the wind tail colors where the
recirculation occurs. This is more than likely due to the different mesh sizes. The
FloWorks mesh is approximately twice the size of the Fluent mesh. The mesh size
difference was an oversight in the initial stages of the modeling project. However, the
maximum wind speed results due not seem to differ by more than 3.2% in the attractive
wind turbine placement elevations between 10-35 ft above the roof. This is apparent in
the highlighted regions of the following tables.
15
Further analysis shows that there is a slight vertical component to the wind vectors in
these areas. The following figures show that this vertical component is nearly the same
between both modeling packages.
Figure 19 – SE Wind Vector Gradient Map
Figure 20 – SW Wind Vector Gradient Map
16
When looking at the graphs of the y-velocity vector vs. location, the magnitude of the yvelocity is negligible at the center of the MEC building (2800 to 3300 in).
8.0 mph NW Analysis with Floworks
60
82 ft (0ft above MEC Roof)4@Line1_1
87 ft (5 ft above MEC Roof)4@Line1_1
92 ft (10 ft above MEC Roof)4@Line1_1
97 ft (15 ft above MEC Roof)4@Line1_1
102 ft (20 ft above MEC Roof)4@Line1_1
107 ft (25 ft above MEC Roof)4@Line1_1
112 ft (30 ft above MEC Roof)4@Line1_1
117 ft (35 ft above MEC Roof)4@Line1_1
122 ft (40 ft above MEC Roof)4@Line1_1
127 ft (45 ft above MEC Roof)4@Line1_1
132 ft (50 ft above MEC Roof)4@Line1_1
55
50
45
40
35
Y-velocity (in/s)
30
25
20
15
10
5
0
-5
-10
-15
-20
-2000 -1500 -1000 -500
0
500
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Curve Length (in)
Figure 21 – NW Vertical Velocity Analysis
8.0 mph NW Analysis with Fluent
70
82 ft (0ft above MEC Roof )
87 ft (5ft above MEC Roof )
92 ft (10ft above MEC Roof )
97 ft (15ft above MEC Roof )
102 ft (20ft above MEC Roof )
107 ft (25ft above MEC Roof )
112 ft (30ft above MEC Roof )
117 ft (35ft above MEC Roof )
122 ft (40ft above MEC Roof )
127 ft (45ft above MEC Roof )
132 ft (50ft above MEC Roof )
60
50
Y-velocity (in)
40
30
20
10
0
-10
-20
-30
-2000 -1500 -1000 -500
0
500
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Location (in)
Figure 22 – NW Vertical Velocity Analysis
17
8.0 mph SE Analysis with Floworks
50
40
30
Y-velocity (in/s)
20
10
0
82 ft (0ft above MEC Roof)4@Line1_1
87 ft (5 ft above MEC Roof)4@Line1_1
92 ft (10 ft above MEC Roof)4@Line1_1
97 ft (15 ft above MEC Roof)4@Line1_1
102 ft (20 ft above MEC Roof)4@Line1_1
107 ft (25 ft above MEC Roof)4@Line1_1
112 ft (30 ft above MEC Roof)4@Line1_1
117 ft (35 ft above MEC Roof)4@Line1_1
122 ft (40 ft above MEC Roof)4@Line1_1
127 ft (45 ft above MEC Roof)4@Line1_1
132 ft (50 ft above MEC Roof)4@Line1_1
-10
-20
-30
-2000 -1500 -1000 -500
0
500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Curve Length (in)
Figure 23 – SE Vertical Velocity Analysis
8.0 mph SE Analysis with Fluent
60
82 ft (0ft above MEC Roof )
87 ft (5ft above MEC Roof )
92 ft (10ft above MEC Roof )
97 ft (15ft above MEC Roof )
102 ft (20ft above MEC Roof )
107 ft (25ft above MEC Roof )
112 ft (30ft above MEC Roof )
117 ft (35ft above MEC Roof )
122 ft (40ft above MEC Roof )
127 ft (45ft above MEC Roof )
132 ft (50ft above MEC Roof )
50
40
Y-velocity (in)
30
20
10
0
-10
-20
-30
-40
-2000 -1500 -1000 -500
0
500
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Location (in)
Figure 24 – SE Vertical Velocity Analysis
The following table analyzes the vertical vector magnitude at the center of the MEC
building 3000 inches from the origin. The location can be seen in Figure 8.
18
Table 8 – Vertical Vector Magnitudes NW at 3000” from Origin
Elevation
Above FloWorks
MEC
(in/s)
Rooftop
5.73
5ft
8.39
10ft
10.78
15ft
13.32
20ft
10.31
25ft
11.97
30ft
9.44
35ft
13.51
40ft
13.94
45ft
13.66
50ft
Fluent
(in/s)
0.15
1.94
5.89
8.00
9.07
8.17
7.86
10.87
8.47
11.12
Difference
(in/s)
5.59
6.45
4.89
5.32
1.24
3.80
1.58
2.63
5.48
2.54
Table 9 – Vertical Vector Magnitudes SE at 3000” from Origin
Elevation
Above FloWorks
MEC
(in/s)
Rooftop
-4.64
5ft
-3.20
10ft
-2.11
15ft
1.40
20ft
2.94
25ft
2.59
30ft
4.21
35ft
5.51
40ft
6.48
45ft
7.46
50ft
Fluent
(in/s)
-5.12
-3.75
-2.33
-0.74
0.80
0.01
0.53
3.77
2.52
5.55
Difference
(in/s)
0.48
0.55
0.22
2.14
2.14
2.57
3.68
1.73
3.96
1.91
The data in the above tables shows that the maximum difference in vertical velocity
magnitude in the NW direction is 5.59 in/s (.32 mph) and 3.96 in/s (.23 mph) in the SE
direction. This is a small variation in the velocity in the y-direction so we can be assured
that wind velocities experienced by turbine blades between the elevations of 20-35 ft will
be mostly normal to the blades ensuring the optimum performance of the turbine.
March Case Study
We used the initial model shown in Figure 14 to run a March case study of wind speeds
from the Northwest and Southeast at an average of 8.8 mph. Due to the complexity of
the solid model, we chose to analyze the wind flow using FloWorks only. Time was not
available to run the analysis with Fluent.
19
The FloWorks results indicated that the best location for the wind turbine is the center of
the MEC building between 20ft and 30 ft above the penthouse rooftop. Figure 25 and
Figure 26 shows vector gradient maps of these results. The vertical components of the
velocity vectors are still approximately 10% of the vector magnitudes. So the results
were very similar to that of the studies done with the simplified model discussed in the
previous section. However, due to the increase in the initial wind speed the vertical
components are slightly larger.
Figure 25 – SE Wind Vector Gradient Map March Case Study
Figure 26 – NW Wind Vector Gradient Map March Case Study
20
Evident from the above figures, the maximum wind speeds for the model are 180 in/sec.
The figures above show the turbine blade axis 25 ft above the rooftop. The surrounding
red color indicates this is a very suitable location for the turbine.
Boise airport wind data from 1997 to 2003 was utilized to get a general idea of the wind
characteristics in this area. This data indicated that, for an entire year, we could expect
an average wind speed of 7.6 mph. Average wind speed for each month ranges from 6.7
mph low in January to an 8.8 mph high in March as shown in Figure 27.
10
Monthly Average Wind Speed (mph)
9
8
7
6
5
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Month
Figure 27-Monthly Avg. Wind Data Boise Airport 1997-2003
The Boise airport wind data also indicated that the wind direction in our area is generally
bi-polar; the wind typically blows from either the NW or the SE. A wind rose for the
month of March is illustrated in Figure 28.
Figure 28-Wind Rose Data March Boise Airport
21
Data from the wind anemometer and the Boise airport was compared in an attempt to
determine the wind correlation factor. Figure 29 shows a correlation equation between
wind speeds at the airport to wind speeds at the MEC roof top. According to our
correlation, the MEC roof tops will have higher wind speeds than the Boise Airport for
wind speeds greater than 6mph. Wind speeds below 6mph are in the non-operational
range for our turbine.
35
MEC Roof-Top Wind Speed (mph)
30
25
y = 1.8601x - 6.0624
R2 = 0.8029
20
15
10
5
0
4
6
8
10
12
14
16
18
20
Airport Wind Speed (mph)
Figure 29 – MEC and Boise Airport Wind Speed Correlation
However, the wind direction between the MEC and Boise airport is similar about 23% of
the time within a 22.5 degree range. The variation is greater from 12:00pm to 7:00pm
than other times of the day. Wind speeds measured at the same time for the Boise airport
and the MEC are shown in Figure 30.
35
30
Wind Speed, (mph)
25
20
15
10
5
0
12:50 2:50 3:50 4:40 5:50 6:50 8:50 9:50 10:50 11:50 12:50 2:50 3:50 4:50 5:50 6:50 7:50 8:50 9:50 10:50 11:50
AM AM AM AM AM AM AM AM AM AM PM PM PM PM PM PM PM PM PM PM PM
Time
Airport Wind speed
MEC roof top Wind speed (mph)
Figure 30 - Boise Airport/COEN Wind Speed Correlation Avg. 4/18/05 to 4/25/05
22
The entire COEN complex was measured in order to generate models of the buildings.
This was done with a combination of field measurements and Architectural drawings.
Wind measurements were taken with a hand held anemometer during the month of March
to get a general feel for the wind characteristics on top of the building. Other wind
measurements were collected from the airport and the tower mounted anemometer on the
MEC east side. Table 10 shows some of the wind measurements recorded in March with
a hand held anemometer at about 14.5 feet.
Table 10 - MEC Wind Measurements 3/8/05 (left) & 3/10/05 (right)
NW corner (10 feet from west side edge and 10 feet from north side edge)
SW corner (10 feet from west side edge and 10 feet from south side edge)
Max, (mph) Min, (mph) Average, (mph)
13.7
5.5
9.3
12.4
6.0
7.1
7.2
1.4
1.9
13.5
0.0
6.4
10.3
4.5
5.7
9.1
4.6
5.1
10.3
5.2
7.0
14.6
5.1
11.2
15.0
7.2
11.7
15.9
8.4
10.9
Time Direction, (degree)
4:18
315
4:24
315
4:26
315
4:29
295
4:33
280
4:35
310
4:37
300
4:39
300
4:41
310
4:43
310
7.6
305
Average of this period 4:18pm - 4:43pm
North End (21feet from west side edge and 10 feet from north side edge)
Time Direction, (degree)
4:46
310
4:48
285
4:50
280
4:52
295
4:54
295
4:55
290
4:57
310
5:00
300
5:02
310
5:03
320
9.9
300
NE corner (35 feet from west side edge and 10 feet from north side edge)
13.2
291
Average of this period 3:48pm - 4:03pm
Max, (mph) Min, (mph) Average, (mph)
15.4
4.0
9.2
17.9
7.4
11.4
21.2
8.5
11.6
20.1
7.6
11.4
21.3
11.3
14.4
16.6
8.2
14.0
20.6
7.1
15.2
13.3
1.1
12.1
17.0
4.0
6.4
15.0
2.4
9.3
Time Direction, (degree)
4:10
280
4:12
280
4:13
290
4:15
285
4:17
280
4:18
285
4:20
280
4:22
270
4:24
270
4:26
270
11.5
279
Average of this period 4:10pm - 4:26pm
SE corner (38 feet from west side edge and 10 feet from south side edge)
Max, (mph) Min, (mph) Average, (mph)
13.0
6.8
9.6
12.3
4.3
4.9
6.5
0.0
4.7
10.3
5.0
6.3
12.2
2.6
7.7
14.1
8.0
9.3
14.1
4.5
10.8
12.6
6.5
9.9
14.3
6.9
10.4
13.9
5.0
8.5
Time Direction, (degree)
5:09
290
5:11
290
5:13
290
5:16
300
5:18
290
5:19
300
5:22
310
5:24
300
5:25
300
5:26
300
8.2
297
Average of this period 5:09pm - 5:26pm
Time Direction, (degree)
3:48
320
3:50
300
3:52
290
3:54
290
3:56
285
3:58
300
3:59
290
4:01
270
4:03
270
South End (23feet from west side edge and 10 feet from south side edge)
Max, (mph) Min, (mph) Average, (mph)
15.9
4.9
11.1
11.8
5.4
9.3
17.1
4.1
5.6
14.2
0.0
8.0
11.4
6.7
7.4
13.6
8.2
12.9
14.2
6.4
8.4
16.9
9.3
11.2
16.2
5.3
15.1
12.8
7.4
9.5
Average of this period 4:46pm - 5:03pm
Max, (mph) Min, (mph) Average, (mph)
15.9
0.0
11.7
23.1
0.0
14.2
18.7
4.5
11.7
18.8
4.5
12.3
16.7
2.2
7.0
18.2
0.0
15.1
18.0
9.7
11.3
24.9
4.7
20.4
24.9
4.7
14.8
Max, (mph) Min, (mph) Average, (mph)
15.0
6.9
8.4
16.7
3.7
13.5
8.5
7.0
8.0
19.2
4.9
14.1
17.5
8.0
10.9
17.8
5.2
11.9
19.0
1.4
16.1
17.1
8.4
14.7
21.6
5.7
11.3
18.2
1.5
14.5
Time Direction, (degree)
4:29
290
4:31
290
4:33
280
4:35
275
4:36
270
4:39
270
4:40
280
4:43
280
4:45
285
4:47
280
12.3
280
Average of this period 4:29pm - 4:47pm
Turbine System
When analyzed at the MEC location, none of the turbines will produce enough energy to
overcome annual overhead and maintenance costs. The greatest producing turbine will
generate a mere $68 of energy per year, at an installation cost of approximately $50,000.
A wind turbine installation on the BSU campus, and at nearly any location in the Boise
metro area, does not meet economic justification. However, setting aside return on
investment or other like investment comparators, we can use the initial cost estimates to
aid in selecting a turbine. Educational purposes are the primary reason for this turbine
installation, therefore we continued with our selection greatly based on the number of
operating days per year, and the least costly method to achieve a working unit.
23
Manufactures data was used to create a performance curve for each horizontal axis
turbine analyzed. With Microsoft Excel’s© curve fit function we were able to generate a
polynomial function of power vs. wind speed for each turbine. The R-squared values for
the curve fit were greater than 0.99 for all of the turbines. The average wind speed from
each day for the past 7 years was then plugged into the polynomial functions to determine
how the turbine would perform in this area. The graph in Figure 31 shows performance
for several different brands of turbines through one year based on average wind speeds
from 1997 to 2003.
6
5
Kilowatt Hours Per Day
4
3
2
1
Bergey Excel R 7.5kW
Proven Energy WT600 0.6kW
Bergey XL1 1kW
Bergey Excel 10kW
J
D
N
O
S
A
J
J
M
A
M
F
J
0
Proven Energy WT2500 2.5kW
Southwest WP Air X 0.9kW
Figure 31 – Predicted Turbine Power Output 15 Day Moving Average
The 7.5 kW turbine manufactured by Bergey would produce the most power. At around
$50,000 to install, the Bergey Excel 7.5 kW has a rotor diameter of 22 feet. Installing a
turbine this expensive may not be a feasible solution. Table 11 summarizes the turbine
types and cost. The 2nd and 3rd best power producers included a 2.5 kW turbine
manufactured by Proven Energy and a 1 kW turbine manufactured by Bergey,
respectively. Both of these turbines were much more cost effective and would operate
for many more school days per year than the larger turbine. An example power curve
that we used in the analysis is illustrated in Figure 32 for the Bergey XL1.
24
1400
1200
Power (W)
1000
800
600
400
200
0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
Wind Speed (mph)
Figure 32 – Bergey XL1 Theoretical Power Curve
To facilitate observation by facility and students, the turbine should operate on school
days, even if the power produced is minimal. Table 11 summarizes turbine size, yearly
estimated power produced, and number of school days the turbines operates. If the
average wind speed for the day exceeded the minimum start up speed for the turbine, the
turbine was considered to operate on that day.
Table 11 – Turbine Performance Summary
Turbine Type
Bergey Excel-R
Proven WT2500
Bergey XL1
Proven WT600
Bergey Excel
Southwest WP Air X
Rating
7.5kW
2.5kW
1kW
0.6kW
10kW
0.6kW
Blade Diameter (m)
6.7
3.5
2.5
2.55
6.7
1.14
Power Produced
Yearly (kW*hr)
882
580
373
124
106
27
Number School Days
in Operation
122
247
247
247
122
187
Total
System
Cost
$50,590
$22,141
$15,594
$17,172
$37,000
$12,191
Power produced by the turbine and generator must be conditioned into an acceptable
format. The system could delivery power to a battery bank, to the municipal grid, or
directly to the load (appliances, lighting, etc.).
Lower voltage (12 to 48 V), direct current power is a good choice for battery charging
and some low load residential requirements. Battery charging is more expensive, due to
the high cost of the special batteries required. However, if the goals are to net meter and
connect the power with the grid, a certified signal conditioner will be required. Net
metering will require working with Idaho Power to complete the install.
25
Most turbine applications significantly benefit from towers, where the turbine is
positioned into faster wind speed above the ground surface. Our turbine will be located
on the roof top of the MEC building, already 80 ft above street level; a tower is mostly
needed to overcome any turbulence effects of the roof structure. The MEC building’s
height already helps position the turbine above the transition region of ground and
surface objects.
Existing towers and wiring packages from turbine manufactures can be purchased in sizes
ranging from 20 to 100 ft. Our wind modeling analysis determined that using a tower 20
ft high on the MEC building would place the turbine above any ill effects of the
building’s own turbulence. Any tower taller than 20 ft would not significantly improve
wind harvesting capability over the cost incurred in the tower.
Monitoring systems purchased from the turbine manufacturer are designed with the
specific turbine performance and output in mind. We were able to locate the different
types and costs for monitoring systems available; however, a more detailed user
requirement study is needed to finalize a monitoring decision.
Safety Analysis
We considered the failure modes of turbines and possible design accommodations to
identify and reduce the risk of injury from the wind turbine. A competent individual
must inspect the turbine system on a regular basis to check for fatigue wear. In addition,
most turbines will require yearly maintenance and upkeep to reduce the possibility of
failure and extend the lifespan. Placing the turbine near the center of the building would
increase the probability of a failed blade landing on the building structure and not striking
a pedestrian.
A structural and vibration analysis of the building at the install location should be
performed. Local building codes will need to be meet in the installation and the turbine
will probably have to be inspected by building code officials after installation. A permit
may be required to erect the turbine.
24
22
Wind Speed, (mph)
20
18
16
14
12
10
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
51
Week 1 thru 52
Figure 33 - Maximum Avg. 2 min. Wind Gust 1997-2003
26
Figure 33 shows the maximum average 2 minute wind gust from 1997 to 2003. The
highest wind speed for a 2 minute gust is around 21 mph. However, instantaneous gust
were up to twice as high at the Boise airport (a few measurements on the MEC roof
exceeded 100 mph, however these velocity measurements occurred during steady wind
speeds of approximately 6mph so they were negated for this study). The turbine selected
must have safety features to stop operation when the force from the wind speed will
exceed design stresses. Most turbines stop operation via a brake or unfurling mechanism
at about 40 mph.
Discussion
This project only encompassed a portion of the work that would need to be performed to
complete a turbine installation on top of the MEC building. Safety and structural
mounting conditions will have to be addressed as mentioned in the previous section. A
joint effort between the mechanical and electrical engineering departments at BSU is
imperative to the completion of a functioning wind turbine.
Foot traffic, even in small amounts, on top of the MEC building will degrade the life of
the roof and cause premature wear and failure. Precautions should be taken to minimize
damage to the membrane roof, as it is not designed to handle foot traffic. Incorporating
required structural features and safety features will encompass the majority of the
installation cost. This design work could be used for another senior design project that
builds on this one.
Due to the poor economics of the project and the safety issues, we speculate that the
turbine system will probably never reach installation. Installing urban wind turbines on
existing building presents several problems, and the benefit achieved at this location
simply is not very significant.
Conclusions
We have concluded that the best location for a wind turbine at the COEN is at the center
of the MEC building 20-30 feet above the penthouse roof. This structure is
approximately 80 feet high and appears to have the best wind characteristics of the three
COEN buildings. The highest magnitude of wind velocity was also at the center of this
building. Installing the turbine in the center enables easy access and the ability to tie off
the turbine tower at more locations. The Bergey XL1 1 kW turbine appears to be the best
turbine package that could be purchased and installed on the MEC roof. This turbine was
the 3rd best performer and was by far the most cost effective.
27
Recommendations
To complete the installation several important items will have to be performed, some of
which are included below:
•
Structural analysis of roof structure where turbine is to be installed.
•
Contact the roofing contractor who performed the installation for the MEC
roof to certify the warranty will not be in-validated and to have additional
mounts installed as needed.
•
Safety needs to be further considered before installation.
•
Building permits may have to be obtained.
•
A vibration analysis of the structure and turbine should be performed to
ensure that the turbine is not going to produce any undesirable vibrations that
could create failure of the turbine or the structure.
•
Involving the electrical engineering department in the power connection
would be beneficial.
•
Install a maintenance path to the turbine to avoid premature wear of the
membrane roof.
•
If the wind tunnel in the HML high bay become operational in the near future.
It could be used to perform scaled testing and verify the results of our models.
This was part of our original plan; however the wind tunnel was not operation
through out the semester.
28
References
1
Idaho Department of Water Resources. 15 February 2005. http://www.idwr.state.id.us/energy/Energy/
altenergy.htm
2
Small Wind Energy Systems for the Homeowner. U.S. Department of Energy. GO-10098-374. FS 135.
January 1997.
3
Case Study of a Residential-Scale Hybrid Renewable Energy Power System in an Urban Setting. Z.M.
Salameh and A.J. Davis. University of Massachusetts. 2003
4
Wind Energy Manual. 1 February 2005. http://www.energy.iastate.edu/renewable/wind/wem/wem01_print.html
5
Facts About Wind Energy and Noise. American Wind Energy Association. Washington, D.C. 2001
6
Engineering Design. Eggert, R. J., Prentice Hall, Inc., 2004, Englewood Cliffs, New Jersey
7
Specifications for Small Wind Turbines for Autonomous Energy Systems. C.G. Condaxakis. et.al. Wind
Energy and Power Plant Synthesis Lab. Crete, Greece
29
Appendix
Turbine Power Curves
Bergey Excel-R 7.5kW
7000
6000
Power (W)
5000
4000
3000
2000
6
5
4
3
2
y = 0.0029x - 0.0976x + 0.2003x + 13.382x - 41.402x + 15.171x + 2.5
2
R = 0.9988
1000
0
0
2
4
6
8
10
12
14
16
18
20
30.0
35.0
40.0
45.0
50.0
Wind Speed (m/s)
Bergey XL1 1kW
1400
1200
3
2
y = -0.1275x + 7.0907x - 60.187x + 136.88
2
R = 0.9953
Power (W)
1000
800
600
400
200
0
0.0
5.0
10.0
15.0
20.0
25.0
Wind Speed (mph)
30
Proven WT2500-2.5kW
3500
3
2
y = -2.77x + 74.138x - 321.27x + 392.01
2
R = 0.9998
3000
Power (W)
2500
2000
1500
1000
500
0
0
5
10
15
20
25
Wind Speed (m/s)
Southwest WP Air X
700
600
3
2
y = -0.5848x + 17.073x - 95.006x + 149.44
2
R = 0.9986
Power (W)
500
400
300
200
100
0
0
5
10
15
20
25
30
Wind Speed (m/s)
31
Bergey BWC Excel-10kW
14000
3
2
y = -5.3868x + 196.9x - 1304.4x + 2419.8
2
R = 0.9976
12000
Power (W)
10000
8000
6000
4000
2000
0
0
5
10
15
20
25
30
35
Wind Speed (m/s)
Turbine Cost Tables
`
Power Output : 1 kW
Type : Battery Charging
Company : Bergey
Model : BWC XL 1-24
Product
Turbine
Turbine and PowerCenter multi-function controller
Tower
Tower (30 ft tilt-up)
Tower wiring kit, 7 Circuit
Batteries
5.3kWh Battery Bank
Inverter
1,500 W Inverter System
Installation
Annual Profit & Loss
Energy Generation
O&M
Payback Period
Price
$
2,450
$
$
950
600
$
450
$
1,044
$
10,000
Total : $
15,494
$
$
29
(75)
NA
32
Power Output : 7.5 kW
Type : Battery Charging
Company : Bergey
Model : BWC Excel-R/120
Product
Price
Turbine
Turbine and PowerCenter multi-function controller
Tower
Tower (64 ft tilt-up)
Tower wiring kit
Batteries
84 kWh Battery Bank (5 string at $1,944 each)
Inverter
11 kW Inverter System
Power Center
DC Power Center Option, 7 circuit
Installation
$
19,900
$
$
1,250
1,000
$
9,720
$
8,030
$
690
$
10,000
Total : $
50,590
Annual Profit & Loss
Energy Generation
O&M
$
$
Payback Period
Power Output : 10 kW
Type : Grid Connect
NA
Company : Bergey
Model : BWC Excel-S/60
Product
Price
Turbine
Turbine and PowerCenter multi-function controller w/ GridTek 10 Inverter
Tower
Tower (64 ft tilt-up)
Tower wiring kit
Batteries
NA
Inverter
NA
Power Center
NA
Installation
Annual Profit & Loss
Energy Generation
O&M
Payback Period
68
(75)
$
24,750
$
$
1,250
1,000
$
-
$
-
$
-
$
10,000
Total : $
37,000
$
$
8
(100)
NA
33
Power Output : 600 W
Type : Battery Charging
Company : Proven Energy
Model : WT600/048
Product
Price
Turbine
600 Watt 48V wind turbine/generator
Tower
100 ft. guyed-lattice tower kit
$
3,610
$
$
2,163
-
$
410
$
-
$
$
665
323
$
10,000
Total : $
17,172
Batteries
5.3kWh Battery Bank (from Bergey)
Inverter
NA
Power Center
charge controller with HV control. Included MCB Isolator (No Meters).
48V Analogue Volt and Ammeters for use with ECM600 Controllers
Installation
Annual Profit & Loss
Energy Generation
O&M
$
$
Payback Period
Power Output : 2.5 kW
Type : Battery Charging
NA
Company : Proven Energy
Model : WT2500/048
Product
Price
Turbine
2.5 kWatt wind turbine/generator
Tower
Tilt-up self supporting wind turbine mast (6.5m).
$
7,152
$
2,163
$
820
$
-
$
2,005
$
10,000
Total : $
22,141
Batteries
10kWh Battery Bank (from Bergey)
Inverter
NA
Power Center
2.5kW, 24 or 38V DC battery charging controller. Includes 2 DC and
3 AC divert load connections, V&I meters plus 8 system status indicators.
Suitable for use with a DC system or DC/AC using an inverter.
Installation
Annual Profit & Loss
Energy Generation
O&M
Payback Period
9
(75)
$
$
45
(75)
NA
34
Power Output : 2.5 kW
Type : Grid Connect
Company : Proven Energy
Model : WT2500/300
Product
Price
Turbine
600 Watt wind turbine/generator
Tower
Tilt-up self supporting wind turbine mast (6.5m).
Batteries
NA
Inverter
NA
Power Center
Isolation and rectification controller for use with grid connect inverter.
Included V&I meters for perfomance monitoring.
Installation
Annual Profit & Loss
Energy Generation
O&M
$
7,152
$
2,163
$
-
$
-
$
1,018
$
10,000
Total : $
20,333
$
$
Payback Period
Power Output : 400 W
Type : Battery Charging
Product
Turbine
900 Watt wind turbine/generator
Tower
45 ft. tower kit
Batteries
5.3kWh Battery Bank (from Bergey)
Inverter
1,500 W Inverter System (from Bergey)
Power Center
NA
Installation
Annual Profit & Loss
Energy Generation
O&M
Payback Period
45
(100)
NA
Company : Southwest Windpower
Model : Air X 24V
Price
$
538
$
199
$
410
$
1,044
$
-
$
10,000
Total : $
12,191
$
$
2
(75)
NA
35
FloWorks Wind Maps
FloWorks Wind Map 1 – NW Wind Velocity Path Lines Colored by Magnitude
FloWorks Wind Map 2 – South Face MEC Building NW Wind Velocity Path Lines
36
FloWorks Wind Map 3 – SE Wind Velocity Path Lines Colored by Magnitude
FloWorks Wind Map 4 - South Face MEC Building SE Wind Velocity Path Lines
37
Fluent Wind Maps
Fluent Wind Maps 1 – NW Wind Velocity Path Lines Colored by Magnitude
Fluent Wind Maps 2 – SE Wind Velocity Path Lines Colored by Magnitude
38
Fluent Wind Maps 3 – South Face MEC Building SE Wind Velocity Path Lines
Fluent Wind Maps 4 – South Face MEC Building NW Wind Velocity Path Lines
39
Monthly Boise Airport Wind Rose
January
February
March
April
May
June
40
July
August
September
October
November
December
41