HomeMy WebLinkAboutNome Joint Utility System Conceptual Design Report - Aug 2011 - REF Grant 2195438Nome Wind Farm
Conceptual Design Report
AEA Grant #: 2195438
August 19, 2011
Table of Contents
Project Progress Summary……………………………………………………………………………………….……………. 1
Revised Project Scope……………………………………………………………………………………………………………. 3
Revised Project Schedule…………………………………………………………………………………………………….… 5
Revised Project Budget…………………………………………………………………………………………………….……. 7
Performance Modeling………………………………………………………………………………………………………….. 9
Preliminary Engineering Considerations…………..……………………………………………………………………. 12
List of Included Attachments………………………………………………………………………………….……………… 14
Project Progress Summary
Nome Joint Utility System (NJUS) submitted its original grant application in October, 2008 for a 3 MW
wind installation; the originally proposed project was estimated at $15.5 million and a $4 million partial
award was offered by the State of Alaska. NJUS has been engaged in analysis to solidify project plans for
the use of awarded funding focusing analytical efforts on determining what project designs could be
implemented with the reduced funding and, of those considered, which would present the largest
benefit to the community.
NJUS has worked to identify a revised scope of work that would meet the following objectives:
1. Reduce overall diesel fuel consumption in the community of Nome
2. Stabilize and/or reduce the cost of electricity for NJUS rate payers
3. Ensure a high level of system stability that incorporates wind production already on the system
from the existing Banner Wind system
4. Identify a project design that would be expandable should additional funding become available
5. Minimize any long-term damage and increased maintenance costs to the Utility’s 5.2 MW
Wartsila diesel generators that results from operating lower on the output curves when wind
resources are available and being injected into the power grid
Essentially, NJUS has been working to answer the question: Under the current capital limitations due to
reduced funding being available, what project design would produce the greatest value to the
community of Nome?
After submitting the 2008 grant application, two separate MET towers were installed at the originally
proposed project site on Newton Peak. Both of these installed towers collapsed during icing events
before much data could be collected. While NJUS and project partners believe a strong wind resource
could be utilized at the originally proposed project site on Newton, alternate sites have been considered
as a result of the icing experiences with Newton MET towers. Additionally, the potential to utilize
existing infrastructure (power line, access) to reduce overall project costs was evaluated.
The most attractive alternate site option was determined to be on Banner Ridge in proximity to the
existing 18 turbine wind installation completed in 2008. NJUS completed the installation of new
distribution line to Banner Ridge during the wind farm’s construction which has a total transmission
capacity of approximately 3 MW. Project partners believe that the existing wind farm can be expanded
to include wind turbine generators installed through NJUS’ AEA grant award. Moreover, the wind
resource at this project site is documented, roads to and within the farm are sufficient to support
project transportation requirements, and transmission capacity exists on the installed distribution line to
support an additional 1.9 MW of wind generation equipment. Three of the turbines installed with the
Banner Ridge Project have been installed with enhanced wind measurement equipment. This data has
been reviewed in detail and is also in the process of being correlated with data from two new MET
towers installed by NJUS on Banner Ridge.
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Since construction of the Banner Wind Farm in 2008, NJUS has also worked closely with Banner Wind
Farm managers to support the project’s integration with the Utility’s existing infrastructure. Integration
of the project’s 18 induction wind turbine generators (approximate 1.1 MW total generation capacity),
has primarily involved generation and load management system adjustments. While the Banner Wind
Farm has helped to reduce some diesel fuel usage by the Utility, NJUS believes the addition of Banner’s
WTGs has resulted in some reduced diesel generation efficiencies during periods of high wind
production and low community demand. NJUS utilizes two relatively new 5.2 MW diesel generators for
primary generation in the community. While efficiencies are reduced as loading on these generators
decline, NJUS believes that low loading scenarios are also resulting in premature wear that is currently
being experienced through unscheduled maintenance activities on these particular generator sets. This
situation has encouraged NJUS to incorporate power house modifications into the scope of work to
modify existing switchgear and capitalize on the use of other diesel generation assets. This work to be
completed can result in electrical demands and wind generated electricity supplies being more
efficiently managed and long term damage to these generator sets can be limited.
Finally, the performance of the Banner Wind installation has been closely monitored by all that have
some level of involvement with the NJUS grant award. These individuals have also followed both NJUS’
progress integrating the technology as well as the owner’s projections about expected benefits.
Decisions on how to proceed with the partial grant funding received through the State of Alaska have
been delayed as city officials evaluate progress with and operation of the Banner project to determine a
defined scope of work that can be completed with available capital resources as well as an overall
design that the community believes will be in their best interest.
With these considerations in mind, NJUS hired a research and analysis firm, DNV Renewables, to
evaluate community generation and wind resource data to develop project recommendations. This
work was completed through assistance from NJUS and its’ larger project team including Electric Power
Systems (electrical engineering and integration) and STG Incorporated (construction services). DNV’s
produced report (Analysis of Wind-Diesel Power System in Nome, Alaska) incorporates the latest
progress completed with the NJUS project, has been included as an attachment, and serves as a
supporting element to the revised scope of work detailed in this document.
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Revised Project Scope
NJUS proposes to utilize awarded grant funds through the State of Alaska’s Renewable Energy Fund
program to complete a project with a reduced scope in comparison to that contained in the Utility’s
original grant application. NJUS originally proposed to complete a 3 MW project consisting of five 600
KW Vestas RRB wind turbines in the application submitted to the Alaska Energy Authority (AEA) on
October 8, 2008. As a result of capital constraints resulting from a partial award, NJUS proposes to
utilize the funds allocated through the AEA program along with additional match contributions, to
implement a smaller 900 KW project consisting of a single EWT 900 KW wind turbine and, if residual
funds are available, begin modifications to NJUS’ power plant. The reduced project scope offers these
specific benefits:
1. All project activities can be completed though the total funding amount allocated to NJUS
2. Diesel fuel usage at NJUS will be reduced by 560,000 gallons annually (a 15% reduction in total
consumption)
3. Reduced scope of work will limit integration complexity and costs
4. Project costs can be reduced through the utilization of existing energy system assets recently
installed in Nome (Banner Wind Farm, Banner Wind Farm Line Extension, NJUS Power Plant
Upgrade)
5. Project construction expenses can be reduced if work is completed by summer 2012
6. Wind farm could be expanded at a later date if additional funding is obtained and NJUS chooses
to implement a larger wind system
NJUS intends to install the wind turbine on Banner Ridge within proximity to the existing Banner Wind
Farm. NJUS also proposes to complete power plant renovations under the scope of this project to more
efficiently balance system generation assets with community demand. Integration activities associated
with the project’s scope of work include:
1. Integration of existing 1875 KW and 3660 KW diesel generators with new power plant. These
generators are currently operated periodically, but usually only on an emergency basis being
they are not fully integrated with Nome’s primary generation system. The 1875 kW generator is
to be moved from its current location inside of the old NJUS power plant, an air permit
requirement. It is now planned to be reinstalled in a new connected structure adjacent to the
3600 kW generator or inside of the new power plant. NJUS’ old power plant cannot be fully
decommissioned until the 1875 KW generator is removed from this existing facility.
2. Integration of existing 400 KW diesel generator. This generator is located within the new
powerhouse, but is not utilized for primary generation – serving primarily as an emergency
“black start” unit. Under the scope of this project, the set can be integrated with existing
switchgear and SCADA controls.
3. Modification of existing switchgear and SCADA systems in new power plant. Switchgear will be
reconfigured to integrate existing diesel generation sets from the old facility and more
efficiently manage electrical supply/demand requirements from all generation assets connected
to the NJUS system. Without integration, operation is limited as it requires additional personnel
to be present to operate and monitor the equipment in the off-site location.
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NJUS plans to utilize the same project team described in the initial grant application and follow a similar
implementation plan as proposed, with one exception. Due to the reduced project size, project partners
believe that the originally proposed system stability equipment (fly-wheel) is no longer a necessary
project component. The project remains as a Phase III / Phase IV Project (Final Design and Construction)
and, depending on NJUS’ ability to obtain turbines, could be completed during 2012. The reduced scope
of the wind project is also expected to simplify the integration process for the engineering team.
Total project costs for the revised scope of work are estimated to be $6,442,000. This project has
advanced through conceptual design activities; however, some pre-construction activities remain. Initial
conceptual design and planning efforts were borne by NJUS and project partners, but NJUS intends to
utilize awarded grant funding to proceed with the implementation of this revised scope moving forward.
NJUS is requesting that AEA make available awarded funding to proceed with the project based on the
following:
AEA REF Grant Funds: $ 4,000,000
NJUS REF Committed Match: $ 444,444
Additional Capital Contributions required for Integration Activities: $ 2,020,000
Total Project Cost $ 6,464,444
The completed project is estimated to provide the community of Nome with 3,675 MWH of wind
generated electricity annually and is expected to provide a net displacement of approximately 560,000
gallons of diesel per year. Considering a current average avoided fuel cost of $3.75 per gallon, the
project is estimated to reduce fuel costs for the utility by $2,100,000 annually.
Other benefits of the project include the reduction of atmospheric pollution, potential tourism
development within the Nome area, a contribution towards decreased reliance on imported fossil fuels
(national security) and anticipated operating cost reductions, which will also reduce the State of Alaska’s
PCE payments to the community due to the reduced electricity costs.
NJUS also believes the original project design (in terms of total wind generation capacity) remains a
viable option for the community. NJUS will use awarded grant funds for the installation of a single 900
KW turbine.
NJUS is currently engaged in efforts to obtain additional funding to install additional project
components. As this additional funding is obtained, it will be utilized to procure and install additional
wind turbine generators and integration equipment (generator, switchgear modifications, operational
adjustments) that will maximize overall system efficiency and allow NJUS to receive greater benefits
from the project’s (and existing wind generation assets in the community) wind generated electricity.
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Revised Project Schedule
An updated project schedule for the proposed revised scope of work can be found on the following
page.
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Revised Project Budget
Project activities for the NJUS wind project are currently underway. As of August, 2011, conceptual
design portions of the project have been completed and NJUS is prepared to move forward with
implementation activities. The revised budget is reflective of a 2012 turbine delivery and construction
schedule. NJUS and project partners believe that significant cost savings can be realized through
reduced mobilization costs if construction can be completed during 2012. A 250 Ton crawler crane,
necessary for the erection work associated with the project, will be leaving from Kotzebue, Alaska at the
beginning of the 2012 season. This equipment is generally staged in Anchorage (or made available from
lower 48 crane service providers). By avoiding a lengthy mobilization from Anchorage or some other
location further south to Nome, significant savings can be obtained.
Total project costs are estimated to be $6,464,444 and can be separated as follows:
900 kW EWT Turbine w/75 M Tower F.O.B. Seattle $ 1,965,000
Estimated Project Logistics Costs $ 750,000
Estimated Project Construction $ 1,729,444
Total Wind Project Costs $ 4,444,444
Total Integration/Control Costs $ 2,020,000
Total Project Costs $ 6,464,444
Consistent with NJUS’/AEA’s grant agreement, the project budget is included below. A detailed
construction budget will be completed under the next set of project deliverables.
A
TOTAL GRANT
BUDGET
BY TASK OR MILESTONE
$ 200,000
$ 259,346
$ 3,885,098
$ 100,000
$ 4,444,444
BY BUDGET CATEGORIES
$ 25,000
$ 5,000
$ 429,346
Construction Services $ 3,985,098
$ 4,444,444
BY FUND SOURCES
$ 4,000,000
$ 444,444
Other Contributions
$ 4,444,444 TOTAL
Grant Funds (90%)
Grantee Match – Cash (10%)
Contractural Services
Travel
Materials & Supplies
TOTAL
Equipment
TOTAL
Direct Labor and Benefits
BUDGET SUMMARY
Milestone 1 (Reconnaissance/Study)
Milestone 2 (Final Design)
Milestone 3 (Construction)
Milestone 4 (Project Close-Out)
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NJUS intends to utilize funding awarded through this award for the installation of a single EWT turbine.
NJUS will also concurrently pursue funding for completion of the remaining project activities (generator,
switchgear, system adjustments) while completing this single turbine installation.
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Performance Modeling
During the 2011 spring season, NJUS contracted with DNV Renewables to complete an analysis of the
Utility’s existing wind-diesel system to identify areas where changes could be made to improve overall
system efficiency and reduce diesel fuel consumption in the community. The conclusions and
recommendations offered from this study have served as the basis for the proposed scope of work to be
completed with awarded grant funds.
DNV’s completed study is included as an attachment to this document. The study included analysis to
document performance from the existing Banner Ridge Wind Farm (correlated against wind data
obtained from the project site), historic diesel generation data provided by NJUS, three potential load
growth scenarios and currently available mid-sized wind turbines (500 kW – 1 MW) to evaluate future
contributions of wind generated electricity on the Utility’s system, and integration modifications that
could be made to increase overall system efficiency. A more detailed description of the utilized
assumptions and methodology can be found in the attachment; however, the study offered the
following conclusions:
If smaller sized diesel generators are not incorporated into the new powerhouse, the installation
of an additional wind turbine on Banner Peak will not result in significant additional diesel fuel
savings. One of the 5.2-MW Wartsila generators will still be in use at all times to supply the base
electric load. Operating time of the second 5.2-MW Wartsila will not be reduced significantly as
the second Wartsila is still needed during peak hours to provide spinning reserve in case wind
power production drops off-line.
Installation of one or both of the 1875 KW and 3660 KW diesel generators would eliminate the
need to operate the second 5.2-MW Wartsila during peak hours and would reduce the
operating hours of the primary Wartsila when the wind power output and smaller diesel
generator are able to supply the community demand.
Assuming additional sizes of diesel generators are integrated into the new powerhouse,
installation of an additional wind turbine on Banner Peak would lead to increased diesel fuel
savings of up to 5%, or approximately 100,000 gallons per year.
All cases considered result in maximum wind penetration levels of about 60% or less, which will
decrease as the community electric demand increases. In general, these penetration levels do
not require the addition of an electric dump load or energy storage device to maintain system
stability: however, we recommend that NJUS monitor the performance of the wind-diesel
system closely during initial operations and consider adding such devices if power quality
problems are experienced.
Many cases considered result in a reduction in the cost of electricity of up to 5 cents per kWh,
meaning that the fuel cost savings outweigh the capital cost and maintenance costs of
implementing each scenario. Additional benefits of reduced diesel fuel consumption, such as
reduced fuel storage requirements, reduced risks of spills, and reduced emissions, we not
included in this analysis.
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While NJUS believes that additional wind generation assets can be added to their electrical system in a
safe and efficient manner, DNV’s initial analysis considered only single turbine installations due to
budget constraints. Of the turbines considered, the 900 KW EWT turbine presented the most favorable
economic results in the modeling exercise. Analysis was completed to evaluate EWT turbine
performance with both 50M and 75M tower options. At the request of AEA, additional analysis was also
completed to evaluate the costs and benefits of installing a second turbine through the project. Cost
quotes were obtained from EWT and DNV executed additional analysis to complete the AEA request.
This work revealed the following:
Base Price for EWT Turbine w/ 50M Tower F.O.B. Seattle: $ 1,715,000
Base Price for EWT Turbine w/ 75M Tower F.O.B. Seattle: $ 1,965,000
Price Difference for Tower Options: $ 250,000
Annual fuel savings generated through 25M increase in tower height: 16,000 Gallons
Benefit/Cost Ratio for Tower Upgrade: 6.27*
Simple Payback for Tower Upgrade: 3.1 Years*
Based on budgetary limitations, the project team believes that the best project design to pursue with
currently available grant funds is the single turbine option on a 75M tower. NJUS also agrees with DNV
recommendations that additional integration activities (modification of existing diesel generation
system and switchgear) should also be completed to support more efficient/productive utilization of
wind generation equipment installed through this project. Funding for system integration activities will
be pursued concurrently with the implementation of the scope of work defined in this project
(installation of WTG).
A Benefit/Cost summary of project components can be found below:
Estimated Cost for Wind Turbine Installation: $ 4,444,000
Estimated Cost for Integration Activities: $ 2,020,000
Total Estimated Project Costs: $ 6,464,000
Annual Fuel Savings from single EWT Turbine Installation: 144,000 Gal
Additional Annual Fuel Savings from Integration Activities: 400,000 Gal
Total Estimated Annual Fuel Savings: 544,000 Gal
Benefit/Cost Ratio for Wind Turbine Installation: 3.18*
Benefit/Cost Ratio for Integration Activities: 19.41*
Benefit/Cost Ratio for Complete Project: 8.3*
Simple Payback for Wind Turbine Installation: 6.3 Years*
Simple Payback for Integration Activities: 1.0 Years*
Simple Payback for Complete Project: 2.4 Years*
Once installed and with the existing WTGs already operational on Banner Ridge, an average wind energy
penetration level of 7% is expected for the NJUS system. Considering the total possible wind generation
on Nome’s distribution grid, the minimum reported loads for the community, and projected load growth
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scenarios, the maximum wind penetration level for the Nome system has been estimated at 42%. These
average and maximum instantaneous wind power contribution levels indicate that the proposed scope
of work will result in a low penetration system.
Greater details regarding energy contributions of the proposed wind system can be found in the
attached DNV analysis.
* Calculations based on an avoided fuel price of $4.90/gallon and a 20 year project life.
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Preliminary Engineering Considerations
Civil Engineering
Project partners believe that the utilization of Banner Ridge as an installation site offers significant
benefits through an ability to expand upon existing infrastructure. Some civil works will be required to
provide minor improvements to existing roadways on the mountain itself, but the project will be able to
utilize existing electrical distribution lines previously constructed for the Banner Wind Farm. The
specific location for the proposed installation is included in the attached site plan and project partners
believe that site control can be negotiated and obtained relatively quickly.
NJUS and Banner Wind, a LLC comprised of the Sitnasuak Native Corporation and Bering Straits Native
Corporation, are currently engaged in discussions to enter in to a land agreement to allow installation of
NJUS turbines at the Banner site. Documentation of this progress is included in the attached
correspondence between NJUS and Banner Wind.
While the exact installation site is not finalized, project partners believe the EWT installation could be
completed at the existing site of WTG1 of the Banner Ridge Wind Farm. Over the past winter, WTG2 of
the Banner Farm was destroyed during a high wind event though the tower remains intact. NJUS and
Banner Wind are currently evaluating the possibility of moving the turbine currently installed at site
WTG1 to the WTG2 tower after which the existing WTG1 tower and foundation would be demolished.
Following this activity, the proposed EWT turbine would be installed at this location and tied into
existing distribution infrastructure.
Regardless of the final installation site, all efforts will be made to utilize existing infrastructure to the
greatest extent possible to reduce total project costs.
Geotechnical Engineering
Geotechnical conditions are expected to be similar to those documented during 2008 study at the
Banner Wind Farm Site. Approximately 25 test borings were drilled during the execution of this
previous study which consistently revealed relatively shallow bedrock depths between 5-15 feet across
the project site. Project partners believe that similar findings will be encountered when the proposed
project site is drilled. If this new geotechnical investigation/analysis reveals similar conditions to those
previously documented on Banner Ridge, the project team believes a foundation solution consisting of
either poured or pre-cast concrete with appropriate bedrock connections will provide adequate support
for the EWT turbine.
Geotechnical investigation/drilling has been scheduled for the fall, 2011 season pending agreement to
utilize the existing WTG1 site. If the existing WTG1 site can be utilized, it is possible that previously
completed geotechnical investigations can be used to complete structural designs.
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Structural Engineering
The foundation design will be determined after geotechnical study at the proposed site is completed.
The final design is expected to be similar to what was deployed at Sand Point, Alaska to support an
installation of Vestas V-39 turbines. It is anticipated that BBFM Engineers will complete all of the
project’s structural engineering work. BBFM completed structural engineering work for the existing
Banner Ridge Wind Farm along with the foundation design for EWT turbines being installed in Kotzebue,
Alaska during 2012. BBFM also completed the foundation design for the referenced V-39 project in
Sand Point.
The foundation design for the Sand Point installation is included as an attachment and is for reference
purposes only. A review of existing geotechnical information along with some cost comparisons for
available options will be required to make a final determination as to the most appropriate foundation
solution for the project site. The development of foundation designs will begin after geotechnical
analysis is completed.
Electrical Engineering
Minor distribution system adjustments will be required to be completed at the project site. Integration
design for the modification of existing switchgear will begin during the fall, 2011 season.
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List of Included Attachments
1. Analysis of Wind-Diesel Power System in Nome Alaska
2. Report Addendum – FSRP0084-B Letter Report Update 20110616
3. Banner Ridge Geotechnical Analysis (8/23/2008)
4. Preliminary (potential) Foundation Design (BBMF V-39 project)
5. Preliminary Project Site Plan
6. NJUS/Banner Wind Correspondence
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