PRELIMINARY FINDINGS
TURBINE FEASIBILITY/SITING EVALUATION
Dartmouth Wastewater Treatment Plant/DPW
687 Chase Road
South Dartmouth, MA
INTRODUCTION
Atlantic Design Engineers, LLC (Atlantic) has completed an initial feasibility assessment
for potential wind turbine installations at the Dartmouth Wastewater Treatment Plant
(WWTP) and DPW sites in South Dartmouth, Massachusetts. The Dartmouth WWTP
and DPW are located on neighboring parcels of town owned property, consisting of a
total of 136.9 acres. The southern most portion of the town property receives the most
favorable wind on this parcel.
The intent of this report is to evaluate commercial wind generation potential at the
locations described herein. Specific objectives of our work to date included the
following:
Prepare compiled plans of the potential wind turbine project property and surrounding
areas depicting existing conditions, approximate property lines and wind turbine
siting constraints.
Complete wind resource evaluations, turbine siting evaluation and a preliminary
commercial wind energy production review for the site.
Perform a conceptual review and develop recommendations for on-site turbine sizing,
power generation and turbine preliminary siting options.
Complete a preliminary review to confirm there are no potential or significant
FAA/MAC hazards posed by the potential WWTP turbine site.
Perform a preliminary economic analysis and cost/benefit review for the WWTP site,
including projected permitting and engineering expenses, project capital expenditures
for both turbine procurement, installation and on-site/utility interconnections, and
projected financial revenues
Prepare an Initial Wind Turbine Site Evaluation Report based on preliminary findings
presenting results of all work performed including the conceptual wind turbine site
models, wind maps and data, and other supporting documentation from the completed
work
Town of Dartmouth - Water Pollution Control Facility
Turbine Feasibility/Siting Evaluation
January 7, 2009 – Page 2
WIND SOURCE REVIEW/TURBINE EVALUATION
The table below provides relevant dimensional data for three potential wind turbine
models that Atlantic reviewed as prospective wind turbines for the Town of Dartmouth
WWTP/DPW site.
Table 1
Turbine Characteristics
MODEL
Overall Height
(TIP OF
BLADE)
Hub
Height
Rotor
Diameter
Blade Sweep
Clearance
(From Grade)
AAER A-1650
Vestas V82 1.65MW
AAER A-2000
389‟
398‟
„
466‟
263‟
263‟
328‟
253‟
269‟
276‟
136‟
128‟
190‟
Atlantic used the AAER A-1650, the Vestas V82, and the AAER A-2000 wind turbines
for the purposes of completing the energy production modeling and financial analyses
herein. These turbines are intended to be representative of the moderate wind regime
class (International Electrotechnical Commission class II or III) of 80 to 100 meter hub
height wind turbines rated between 1.5-2.0 megawatts of rated capacity available from
turbine vendors such as Fuhrlander, Vestas and General Electric. Turbine availability,
costs, and delivery timeline are subject to change, thus, these aspects should be
continually evaluated throughout the project lifespan.
Atlantic completed a wind resource review using Mass GIS, the New England Wind Map
and AWS Truwind wind data. Wind speeds selected for the energy production estimates
were based upon a correlation of the former Dartmouth Landfill Sodar data (See
Appendix H for details) and our predictive wind mapping for the property. Met tower
data was not incorporated due to concerns with the low wind speed measurements at 50
meter height and extremely high wind shear levels identified. These measurements may
have been, in our opinion, influenced by the proximity of high trees in the area
surrounding the met tower. Accordingly, the predictive wind speed of 6.7 meters per
second, in our opinion, is a conservative approach and, accordingly generates a high
confidence level in the predictive energy output.
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Town of Dartmouth - Water Pollution Control Facility
Turbine Feasibility/Siting Evaluation
January 7, 2009 – Page 3
The key factors from our assessment are summarized as follows:
Table 2
Energy Production Estimate for Sample Turbines
Number
of
Turbines
Turbine Model
Hub
Height (M)
Wind Speed
(m/sec)
Operating
Turbine
Capacity
Factor (%)*
Energy
Delivered
(kWh/Year)
1
1
1
2
2
AAER A-1650
Vestas V82
AAER A-2000
AAER A-1650
Vestas V82
80
80
100
80
80
6.3
6.3
6.7
6.3
6.3
27%
30%
30%
27%
30%
3,994,000
4,289,000
5,399,000
7,828,000
8,579,000
2
AAER A-2000
100
6.7
30%
10,581,000
These projected capacity factors are higher than the currently operating turbines at the
Massachusetts Maritime Academy, Hull Landfill (Hull Wind II) and Portsmouth Abbey
but are consistent with the Hull High School (Hull Wind I) operating data. Key factors
for capacity factor, in our opinion, are proper turbine siting, turbine height selection,
appropriate turbine selection for the site-specific wind regime, and blade swept area.
Key aspects of this location that are favorable for wind turbines are as follows:
The site is located in South Dartmouth with an adequate wind regime at the
installation heights of 80 to 100 meters, in our opinion, and is suitable for commercial
turbine operation. The average projected wind speed at a height of 100 meters ranges
from 6.75 meters per second along the western boundary of the locus parcel to 6.85
meters per second along the eastern border of the property.
The WWTP property borders the undeveloped land to the north and northeast, giving
the site significant property line setback distances for a turbine.
Based upon our experience on other projects, in our opinion, noise impacts from
turbine operation are expected to conform to noise requirements of the State of
Massachusetts and will be significantly below the 10 db increase at the property line
standard. The noise impacts are expected to be minimal due to siting distance from
residences, predominant wind direction and existing tree cover on the property
between the proposed turbine site and the residential properties. This is further
supported by our experience on noise studies completed in similar turbine projects in
other communities.
The project is expected to have a moderate visual impact on the surrounding
residential properties. The elevations of homes in the area are in the same or similar
range as the proposed turbines locations and are located 1,000 feet or more away
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Town of Dartmouth - Water Pollution Control Facility
Turbine Feasibility/Siting Evaluation
January 7, 2009 – Page 4
from the turbine. The turbines have been sited to minimize or eliminate off-site
shadow flicker impacts.
The distance from the closest Municipal Airport (New Bedford Municipal Airport) is
greater than five (5) statute miles to the North Northeast. It is anticipated the FAA
and MAC are likely to give the wind turbine a “No Presumed Hazard to Air
Navigation”.
The Town of Dartmouth has a Wind Turbine Bylaw in place, with an established
procedure for utility–scale turbine approval/permitting.
The concerns and constraints identified with this location with respect to wind
turbine installations are as follows:
There may be negative response/concerns from the residential neighbors in direct line
of sight from the turbine. Some of the residential properties surrounding the site will
be subject to various degrees of shadow flicker. As the project moves forward
shadow flicker issues and potential impacts should be fully evaluated and reviewed
with the residential neighbors that may be impacted to determine the best mitigation
approach.
Due to the extent of wetlands on the property, project permitting, survey, and
construction budgets have been developed accordingly.
The wind resource assessments (Met tower and SODAR) completed to date have
shown relatively high wind shear levels. These shear factors should be incorporated
into the final turbine model selection.
CAPITAL CONSTRUCTION COSTS
For purposes of this initial assessment, the following projected construction costs have
been estimated:
Table 3
Estimated Construction Costs
Number
of
Turbines
Vendor
Hub
Height
in meters
Preliminary Cost
Estimate
1
1
1
2
2
2
AAER A-1650
Vestas V82
AAER A-2000
AAER A-1650
Vestas V82
AAER A-2000
80
80
100
80
80
100
$ 4,444,000.00
$ 4,444,000.00
$ 5,508,000.00
$ 8,407,000.00
$ 8,406,000.00
$10,529,000.00
4
Rated
Machine
Capacity
(kilowatts
1,650
)
1,650
2,000
3,300
3,300
4,000
Cost/kWh
of Rated
Capacity
$2,690.00
$2,690.00
$2,750.00
$2,550.00
$2,450.00
$2,630.00
Town of Dartmouth - Water Pollution Control Facility
Turbine Feasibility/Siting Evaluation
January 7, 2009 – Page 5
For this assessment, Atlantic used the following financial assumptions for the turbine
project financial analyses; 15 year debt term, 7% interest rate, 0% down. Renewable
Energy Credits and ISO New England Forward Capacity Market payments were also
included (Please see contents of Appendix A for more details).
A detailed line item cost estimate for each model included in Appendix B, Cost Analysis,
of this Report.
Please note these are preliminary estimates based upon our best estimates for anticipated
site-specific development costs. We have included a rough estimate of on-site utility
interconnect costs which will require further assessment if the Town of Dartmouth elects
to proceed with a wind turbine for this site. These budget costs should be re-evaluated
and refined as the project moves forward.
PROJECT COST/BENEFIT ANALYSIS
Based upon the preliminary wind assessment checklist and supplemental information
provided by Ron DiPippo, Chairman, Alternative Energy Committee and David Hickox.
Department of Public Works Superintendent, the current cost of energy to the Town of
Dartmouth DPW/WWTP is 15.78 cents per kilowatt hour for energy. This includes a
waste water treatment plant/sewer system electrical demand of 3,437,560 kWh/per year
at a cost of $531,026.62 and a water distribution system electrical demand of 1,991,152
kWh/year at a cost of $325,855.38.
Cumulative Electrical Production Costs
The cumulative cost review is a projection of the total cost per kWh generated by each
individual machine over the anticipated 25 year project life span.* The estimated kWh
production costs for the project life cycle (25 years) are shown on the following table:
Table 4
Estimated Cost per Kilowatt Hour
Number
of
Turbines
Wind Turbine
Model
Hub Height
(in Meters)
Height of
Turbine
(Tip of
Blade)
1
1
1
2
2
2
AAER A-1650
Vestas V82
AAER A-2000
AAER A-1650
Vestas V82
AAER A-2000
80
80
100
80
80
100
389‟
398‟
466‟
389‟
398‟
466‟
5
Estimated
Realized
Cost per
kWh (with
REC's and
FCP)
$0.0196
$0.0147
$0.0136
$0.0156
$0.0096
$0.0105
Estimated Raw
Cost per kWh
Produced (without
REC‟s and FCP)
$.0834
$.0777
$.0756
$.0794
$.0727
$.0725
Town of Dartmouth - Water Pollution Control Facility
Turbine Feasibility/Siting Evaluation
January 7, 2009 – Page 6
The amortized cost above is the total of all payments, interest, cost of planning and
development, operations and maintenance for the life of the machine divided by the total
amount of power (kWh) produced over the lifetime of the machine. The actual electrical
production costs were developed using a Renewable Energy Credit Value of $0.044 per
kWh and Forward Capacity market monthly payments from IS0-New England. The ISO
forward capacity payments were calculated at $3.75 per kW of rated capacity.
*The life span of a wind turbine, per wind turbine manufacturer‟s specifications, range
between 20 to 25 years. There are numerous turbines still in service with life spans
exceeding 25 years. At the end of the initial life cycle turbines are typically refurbished
(new blades, gearbox, electronics, etc) and can either be kept in service or installed at a
new site.
Funding, Incentives and Financing:
LORI Grant: A Massachusetts State Grant Program that distributes funding for the
feasibility studies, design and construction of on-site wind turbines. The program
currently requires that the applicant must consume greater than 25% of the capacity
of the generation facility. Presently grant amounts for turbine feasibility studies are
limited to $40,000 with an applicant cost share of 15%. Design grants are limited to
$125,000 or 75% of actual costs. Construction grants are limited to $275,000, or 75%
of actual construction costs. The Town of Dartmouth would be eligible for LORI
funding as more than 25% of the electricity generated would be utilized on-site.
Other projects we are working on are currently receiving MTC funding under the
LORI program.
Clean Renewable Energy Bonds (CREB’s): These are zero coupon bonds that are
approved by the IRS. This bond would allow the Town of Dartmouth to issue debt
for renewable energy projects at 0% interest.
Conventional Municipal Bonds for Capital Construction Projects:
General
obligation bonds issued by municipalities for project construction financing purposes.
Typical interest rates for these bonds are currently ranging from 4.0 to 4.5 percent.
These bonds are for the purposes of assisting a municipality in the procurement of
large and costly infrastructure projects.
FINDINGS
1. In our opinion favorable siting and adequate wind resources exist for wind turbine
development at the Town of Dartmouth Wastewater Treatment Plant and DPW site.
2. The Dartmouth DPW and Wastewater Treatment Plant site has an adequate wind
regime and could, in our opinion, accommodate either one or two commercial grade
(scale) wind turbines on 80 meter towers. A turbine over 200 feet in height will
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Town of Dartmouth - Water Pollution Control Facility
Turbine Feasibility/Siting Evaluation
January 7, 2009 – Page 7
involve review and approval process (Determination of Significant Hazard) by the
FAA and MAC for siting approval.
3. Turbines could be installed as net meter applications allowing the Town of Dartmouth
to directly benefit from on-site avoided electrical costs. The most cost-effective
turbine evaluated for the Dartmouth DPW/WWTP site (Vestas V-82 80 meter) is
projected to provide 4,289,000 kWh per year of electricity. The Town of Dartmouth
WWTP and DPW uses approximately 5,428,712 kWh per year on site. A single
turbine, accordingly, will reduce the DPW/WWTP energy requirements by
approximately 80%.
4. A second turbine installed under net metering provisions could provide electricity to
any other designated electrical meters in the Town (Town Hall, School Department,
etc.).
5. In order to erect the turbines the Town of Dartmouth will need a Special Permit
granted by the Select Board to erect a wind turbine per the current wind energy
bylaw.
RECOMMENDATIONS
The following recommendations are made based upon the work performed:
1. Town officials review this initial assessment report and siting recommendations for
concurrence.
2. The Town of Dartmouth pursues public funding and incentives using this report as
supporting documentation for feasibility financing.
3. Evaluate funding options including the MTC grant program, CREB funding sources
and issuance of General Obligation Bonds, for proceeding with a single turbine
project to supply net metered energy for Town of Dartmouth Wastewater Treatment
Plant/DPW operations.
4. Meet with town officials to establish a public outreach program to provide public
education on the project and the anticipated benefits/impacts, develop and
evaluate/address the concerns of any neighborhood opposition to the project.
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