HomeMy WebLinkAboutKaktovik Wind Diesel Feasibility Study Project CDR Appendices - 2010 - 2013 - REF Grant 7040025
Appendix A
Wind Project Concept Design Drawings
KAKTOVIK, ALASKA
KAKTOVIKLAGOONLANDFILLSITE 3SITE 2SITE 1DRUM ISLANDBEAUFORT SEAAREY LAGOONMET TOWERLEGEND
WIND TOWER ACCESS TRAILAW 29-225WIND TOWER 2AW 29-225WIND TOWER 1AW 29-225WIND TOWER 3150' R TOWER CLEARAREA (TYPICAL)TO KAKTOVIK310.0'(TYPICAL)60.0'R 25' (TYPICAL)16.0'
WIND TOWER ACCESS TRAILTO KAKTOVIK310.0'(TYPICAL)60.0'R 25' (TYPICAL)16.0'NPS 100-21WIND TOWER 2NPS 100-21WIND TOWER 1NPS 100-21WIND TOWER 3140' R TOWER CLEARAREA (TYPICAL)NPS 100-21WIND TOWER 5NPS 100-21WIND TOWER 4NPS 100-21WIND TOWER 6NPS 100-21WIND TOWER 7
WIND TOWER ACCESS TRAILTO KAKTOVIK310.0'(TYPICAL)60.0'R 25' (TYPICAL)16.0'V27WIND TOWER 2155' R TOWER CLEARAREA (TYPICAL)V27WIND TOWER 1V27WIND TOWER 3
08/30/2013L2259.00Wasilla, AK 99654Anchorage, AK 99503Phone (907) 276-0521Fax (907) 276-1751 Fax (907) 357-1751Phone (907) 357-15212522 Arctic BoulevardSR191 E. Swanson AvenueAKAKTOVIK WIND TURBINES1ELECTRICAL ONE-LINE DIAGRAMNO SCALE
Appendix B
V3 Energy’s August 2013 Kaktovik Wind Diesel
Analysis
Kaktovik Wind-Diesel Analysis
August 29, 2013
Douglas Vaught, P.E.
dvaught@v3energy.com
V3 Energy, LLC
Eagle River, Alaska
Kaktovik Wind-Diesel Analysis P a g e | i
This report was prepared by V3 Energy, LLC under contract to Hattenburg, Dilley and Linnell (HDL) for
development of wind power for the village of Kaktovik, Alaska. This analysis is part of a conceptual
design project funded by the North Slope Borough.
Contents
Introduction.................................................................................................................................................. 1
Project Management ................................................................................................................................ 1
Kaktovik ......................................................................................................................................................... 1
Wind Resource.............................................................................................................................................. 2
Wind Roses................................................................................................................................................ 4
Wind Frequency Rose (measured)........................................................................................................ 5
Total Value (power density) Rose......................................................................................................... 5
Wind Frequency Rose (declination adjusted)....................................................................................... 6
Total Value (power density) Rose......................................................................................................... 6
AWS Truepower and AWOS data.............................................................................................................. 6
Cold Climate Considerations of Wind Power............................................................................................ 9
Wind-Diesel Hybrid System Overview ........................................................................................................10
Wind-diesel Design Options....................................................................................................................11
Low Penetration Configuration...........................................................................................................11
Medium Penetration Configuration....................................................................................................12
High Penetration Configuration..........................................................................................................12
Wind-Diesel System Components...........................................................................................................13
Wind Turbine(s) ..................................................................................................................................13
Supervisory Control System................................................................................................................14
Synchronous Condenser .....................................................................................................................14
Secondary Load...................................................................................................................................14
Deferrable Load ..................................................................................................................................15
Interruptible Load...............................................................................................................................15
Storage Options ..................................................................................................................................15
Wind Turbine Options................................................................................................................................. 16
Aeronautica 29-225 ................................................................................................................................17
Northern Power Systems 100 (NPS 100) ................................................................................................17
..................................................................................................................................................................................................................
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Cold Climate Considerations of Wind Power ........................................................................................................................................................................................
................................................................................................................................................................................................................
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Low Penetration Configuration ......................................................................................................................................................................................................................
Medium Penetration ConfigurationMedium Penetration Configuration ........................................................................................................................................................................................................
High Penetration ConfigurationHigh Penetration Configuration ....................................................................................................................................................................................................................
Diesel System ComponentsDiesel System Components ......................................................................................................................................................................................................................
................................................................................................................................................................................................
................................................................................................................................................................................................................
..................................................................................................................................................................................................................
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Kaktovik Wind-Diesel Analysis P a g e | ii
Vestas V27...............................................................................................................................................18
Wind-Diesel Model .....................................................................................................................................19
Kaktovik Powerplant...............................................................................................................................19
Diesel Generators ...............................................................................................................................19
Caterpillar 3512 Diesel Generator ......................................................................................................20
Caterpillar 3508 Diesel Generator ......................................................................................................20
Wind Turbines.........................................................................................................................................21
Electric Load............................................................................................................................................21
Thermal Load ..........................................................................................................................................23
Wind Turbine Configuration Options......................................................................................................24
Economic Analysis.......................................................................................................................................25
Fuel Cost..................................................................................................................................................26
Modeling Assumptions ...........................................................................................................................26
Wind Turbine Project Costs ....................................................................................................................28
Modeling Results.....................................................................................................................................28
Discussion ...................................................................................................................................................30
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Kaktovik Wind-Diesel Analysis P a g e | 1
Introduction
North Slope Borough (NSB) is the electric utility for the City of Kaktovik. In October, 2012 North Slope
Borough awarded a contract to Hattenberg, Dilley, and Linnell (HDL) to complete a conceptual design
report for a possible wind-diesel project in Kaktovik. HDL subsequently subcontracted V3 Energy, LLC to
evaluate the wind resource in the community, model the Kaktovik power system with a selection of
wind turbines, and perform basic economic analyses of the proposed projects.
Project Management
The North Slope Borough has executive oversight of this project. North Slope Borough and the City of
Kaktovik are interested in the installation of wind turbines in Kaktovik primarily to reduce diesel fuel
consumption, but also to:
Reduce long-term dependence on outside sources of energy
Reduce exposure to fuel price volatility
Reduce air pollution resulting from reducing fossil fuel combustion
Reduce possibility of spills from fuel transport & storage
Reduce overall carbon footprint and its contribution to climate change.
Kaktovik
Kaktovik lies on the north shore of Barter Island, between the Okpilak and Jago Rivers on the Beaufort
Sea coast. It lies in the 19.6-million-acre Arctic National Wildlife Refuge, an occasional calving ground for
the porcupine caribou herd. The climate of Kaktovik is
arctic. Temperatures range from -56 to 78 °F. Precipitation is
light, averaging 5 inches, with snowfall averaging 20 inches.
Until the late nineteenth century, the island was a major
trade center for the Inupiat and was especially important as
a bartering place for Inupiat from Alaska and Inuit from
Canada. The city was incorporated in 1971. Due to Kaktovik's
isolation, the village has maintained its Inupiat Eskimo
traditions. Subsistence is highly dependent upon caribou.
A federally-recognized tribe is located in the community -- the Kaktovik Village. According to Census
2010, there were 87 housing units in the community and 72 were occupied. Its population was 88.7
percent American Indian or Alaska Native; 10 percent white; 1.3 percent of the local residents had multi-
racial backgrounds.
The North Slope Borough provides all utilities in Kaktovik. Water is derived from a surface source and is
treated and stored in a 680,000-gallon water tank. Water is delivered by truck to holding tanks; all
homes have running water in the kitchen. For the most part, the village is still on water and sewage
haul. Electricity is provided by North Slope Borough Power and Lights Systems. There is one school
Reduce possibility of spills from fuel transport & storage
Reduce overall carbon footprint and its contribution to climate change.Reduce overall carbon footprint and its contribution to climate change.
Kaktovik lies on the north shore of Barter Island, between the Okpilak
acre Arctic National Wildlife Refuge, an occasional calving ground for
the porcupine caribou herd. The climate of Kaktovik is
arctic. Temperatures range from
light, averaging 5 inches, with snowfall averaging 20 inches.
term dependence on outside sources of energyterm dependence on outside sources of energy
ulting from reducing fossil fuel combustion ulting from reducing fossil fuel combustion
Reduce overall carbon footprint and its contribution to climate change.Reduce overall carbon footprint and its contribution to climate change.
Kaktovik Wind-Diesel Analysis P a g e | 2
located in the community, attended by 57 students. Local hospitals or health clinics include Kaktovik
Clinic. Emergency Services have coastal and air access.
Economic opportunities in Kaktovik are limited due to the community's isolation, and unemployment is
high. Most employment is in education, the North Slope Borough, or city services. Part-time seasonal
jobs, such as construction projects, provide income.
Air travel provides the only year-round access to Kaktovik. The Barter Island Airport is owned by the Air
Force and operated by the North Slope Borough. Marine transportation provides limited seasonal
access. There are no roads leading to Kaktovik and land transportation is limited to the surrounding
area.
Topographic map of Kaktovik
Wind Resource
A met tower in Kaktovik was installed at the south side of the village near the sewage treatment plant in
June, 2009. The site was not considered at the time to be a candidate for wind turbines, but was chosen
due to ease of access and land ownership considerations. However, the open tundra environment and
relatively flat topography of Kaktovik ensure that the collected wind data is representative and usable
for siting wind turbines elsewhere on Barter Island.
Kaktovik Wind-Diesel Analysis P a g e | 3
Google Earth image of Kaktovik
With reference to two nearby Automated Weather Observing System (AWOS) sources (Barter Island
Airport and Barter Island DEW), the wind resource in Kaktovik is outstanding (Class 5 to 6), but
verification with the met tower was fraught with difficulty, namely a lost data card, significant data loss
due to icing, and loss of both 30 meter level anemometers in early January, 2008 due to ice and wind
damage. The anemometers were not replaced until early March, resulting in more data loss. Given the
anemometer problems, collected (and filtered) anemometer data could not be used by itself to calculate
mean annual wind speed, but inserting synthesized data to the data set via a gap-fill subroutine in the
wind analysis software yielded a wind resource prediction in-line with the AWOS data sources.
Besides mean wind speed, other parameters of importance to wind turbine operations, including
turbulence, wind shear, and directionality of winds indicate a desirable wind resource for wind power
development.
Kaktovik met tower data synopsis
Data start date June 26, 2009
Data end date July 19, 2010 (13 months data)
Wind power class Class 5 (excellent)
Wind speed average (30 meters) 6.32 m/s
Maximum 10-min average wind speed 29.3 m/s
Maximum wind gust 35.2 m/s (February 2010)
IEC 61400-1 3rd ed. extreme winds Class II
Wind power density (30 meters) 450 W/m
2
Weibull distribution parameters k = 1.63, c = 7.12 m/s
Roughness Class 0.67 (lawn grass)
With reference to two nearby Automated Weather Observing System (AWOS) sources (Barter Island With reference to two nearby Automated Weather Observing System (AWOS) sources (Barter Island
Airport and Barter Island DEW), the wind resource in Kaktovik is outstanding (Class 5 to 6), but source in Kaktovik is outstanding (Class 5 to 6), but
verification with the met tower was fraught with difficulty, namely a lost data card, significant data loss verification with the met tower was fraught with difficulty, namely a lost data card, significant data loss
due to icing, and loss of both 30 meter level anemometers in early January, 2008 due to ice and wind due to icing, and loss of both 30 meter level anemometers in early January, 2008 due to ice and wind
were not replaced until early March, resulting in more data losswere not replaced until early March, resulting in more data loss
collected (and filtered) anemometercollected (and filtered) anemometer
wind speed, but inserting synthewind speed, but inserting synthesized data to the data set via a gapsized data to the data set via a gap
yielded yielded a wind resource prediction ina wind resource prediction in
ther parametersther parameters
ence, wind shear, and directionality of winds indicate a desirable wind resource for wind power ence, wind shear, and directionality of winds indicate a desirable wind resource for wind power
Kaktovik Wind-Diesel Analysis P a g e | 4
Power law exponent 0.14 (moderate wind shear)
Frequency of calms (3.5 m/s threshold) 31%
Mean Turbulence Intensity 0.071 (IEC 61400-1 3
rd ed. turbulence category C)
Wind Speed Sensor Summary, Kaktovik
Original data set Synthesized data set
Variable Speed
30 A
Speed
30 B
Speed
20
Speed
30 A
Speed
30 B
Speed
20
Measurement height (m) 30 30 20 30 30 20
MMM wind speed (m/s)6.26 6.03 6.07 6.36 6.24 6.01
Max 10-min avg wind speed (m/s) 26.4 26.2 29.3
Max gust wind speed (m/s) 32.7 30.2 35.2
Weibull k 1.75 1.75 1.62 1.63 1.62 1.62
Weibull c (m/s) 7.04 6.79 6.78 7.12 6.98 6.71
MMM power density (W/m²) 360 324 393 450 431 384
MMM energy content (kWh/m²/yr) 3,158 2,834 3,440 3,943 3,774 3,361
Energy pattern factor 2.22 2.23 2.57 2.56 2.59 2.60
Frequency of calms (%) 31.8 33.5 35.0 32.4 33.2 35.6
Kaktovik Wind speed graph (with synthesized data)
Wind Roses
Winds at the Kaktovik met tower test site were measured as strongly direction east-northeast and west-
southwest. The total value (or wind power density) rose indicates that the ENE and WSW Kaktovik
winds were of nearly equal power over the course of the measurement period.
33.533.5
(with synthesized data)(with synthesized data)
393393
3,4403,440 3,9433,943
2.572.57 2.562.56
32.432.4
Kaktovik Wind-Diesel Analysis P a g e | 5
Wind Frequency Rose (measured) Total Value (power density) Rose
Comparison though with wind roses in the Barter Island AWOS data and with AWS Truepower modeling
(see following section) reveals a possible error in the vane offset (or zero direction) of the met tower.
The Barter Island AWOS and AWS Truewind wind roses both indicate strongly directional easterly and
westerly winds. It appears likely then that the met tower vane offset in the datalogger was set to
magnetic direction instead of true. This is significant in Kaktovik as magnetic declination is 22.7 degrees.
Kaktovik magnetic declination
Using an adjustment of 23 degrees of magnetic declination to correct the presumed datalogger vane
offset error, the adjusted wind frequency and power density roses shown indicate predominately
Comparison though with wind roses in the Barter Island AWOS data and Comparison though with wind roses in the Barter Island AWOS data and
(see following section) reveals a possible error in the vane offset (or zero direction) of the met tower. (see following section) reveals a possible error in the vane offset (or zero direction) of the met tower.
Barter Island AWOS and AWS Truewind wind rosesBarter Island AWOS and AWS Truewind wind roses both indicate strongly directional easterly and both indicate strongly directional easterly and
westerly winds. It appears likely then that the met tower vane offset in the datalogger was set to westerly winds. It appears likely then that the met tower vane offset in the datalogger was set to
magnetic direction instead of true. This is significant in Kaktovik as magnetic declination is 22.magnetic direction instead of true. This is significant in Kaktovik as magnetic declination is 22.
Kaktovik magnetic declination
with
Kaktovik Wind-Diesel Analysis P a g e | 6
easterly and westerly winds. This agrees within approximately 10 degrees of the wind roses obtained
from the Barter Island AWOS and AWS Truewind data and modeling.
Wind Frequency Rose (declination adjusted) Total Value (power density) Rose
AWS Truepower and AWOS data
It is acknowledged that the wind resource measured by the met tower and nearby AWOS weather
stations has some limitations in that the met tower was operational for a relatively short period of time
and experienced significant data problems. The nearby AWOS weather stations (the airport and the
USAF Barter Island DEW) are a very long term source of data but measurement height is only 8 meters
and the averaging method is somewhat different than that for the met tower, although with a long-term
perspective the averaging methodology converges.
To validate the met tower and AWOS wind speed data, AWS Truepower’s wind site assessment
dashboard software was used to survey the wind resource in Kaktovik. The wind site assessment
dashboard is a web-based too that uses AWS Truepower’s proprietary MesoMap system of mesoscale
and microscale atmospheric models. The mesoscale model simulates weather conditions for a
representative meteorological year on a horizontal grid of 2 km. Starting from an initial condition
established by regional weather data and physical equations governing the atmosphere, the model
simulates the evolution of weather conditions from the start to end of each day in the representative
year. The microscale model then refines the wind fields from the mesoscale model to capture the local
influences of the topography and surface roughness changes at a higher resolution of 200 m. For each
region, the wind maps are fine-tuned using best available surface observations.
Filtered met tower 30 meter A anemometer data indicated a mean annual wind speed of 6.26 m/s.
With inclusion of synthesized data via the Windographer gap-fill subroutine, the mean wind speed
increases to 6.36 m/s at the 30 meter level. Note below that AWS Truepower software predicts a 6.67
m/s mean annual wind speed at the met tower site; higher than that measured by the met tower itself.
and AWOS data
wind resource measured by the met towewind resource measured by the met towe
stations has some limitations in that the met tower was operational for a relatively short period of time stations has some limitations in that the met tower was operational for a relatively short period of time
and experienced significant data problems. The nearby AWand experienced significant data problems. The nearby AW
are a very long term source of data but measurement height is only are a very long term source of data but measurement height is only
and the averaging method is somewhat different than that for the met tower, although with a longand the averaging method is somewhat different than that for the met tower, although with a long
he averaging methodology convergeshe averaging methodology converges
To validate the met tower and AWOS wind speed data, To validate the met tower and AWOS wind speed data,
was used to survey the wind resource in Kaktovik. The wind site assessment was used to survey the wind resource in Kaktovik. The wind site assessment
Kaktovik Wind-Diesel Analysis P a g e | 7
The AWS Truepower data likely is a more accurate representation of met tower site wind resource in
that it references a longer term data set than the met tower.
AWS wind assessment dashboard of met tower site, 30 m level
The Barter Island DEW station is located on the Beaufort Sea coast immediately northwest of Kaktovik.
Weather data has been collected at this location since 1973, although only data since 2004 was
reviewed for a comparative wind analysis. Using a wind shear power law exponent of 0.097, the 8
meter elevation Barter Island DEW mean wind speed of 5.9 m/s was extrapolated to 30 meters (below)
as further comparison. The extrapolated mean annual wind speed of 6.7 m/s is validates the AWS
Truewind prediction of 6.73 m/s at the DEW station. Overall, agreement of the three wind assessment
methods considered in this report – met tower, AWS Truepower, and Barter Island AWOS – is very good.
Barter Island DEW Station AWOS data
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
8 m 6.8 5.9 5.7 5.2 6.0 5.2 5.3 5.2 5.8 7.0 6.9 6.2 5.9
30 m 7.7 6.7 6.5 5.9 6.8 5.9 6.0 5.9 6.6 8.0 7.8 7.0 6.7
Kaktovik Wind-Diesel Analysis P a g e | 8
AWS wind assessment dashboard of Barter Island DEW Station, 30 m level
The prospective wind turbine site is located northwest of the fresh water lagoon water supply for
Kaktovik, which is immediately west of the village proper. AWS Truepower assessment dashboard
predicts a mean annual wind speed of 6.52 m/s at the 30 meter level and 6.89 m/s at the 40 meter level
at this site. AWS Truepower predicts a slightly lower mean annual wind speed at the prospective wind
turbine site compared to the Barter Island DEW station and the met tower sites. This can be explained
by the greater roughness of the landscape surrounding the turbine site which will slow the wind a bit
compared to the DEW station and met tower sites that have greater exposure to smooth sea ice.
Considering that the three sources of wind data – met tower, AWS Truepower, and DEW station AWOS –
corroborate, selection of wind data for modeling purposes was based on the data thought most
representative of annual wind fluctuations. In this regard, AWS Truewind and the AWOS data are
preferable than the met tower as their longer timeframe mitigates somewhat the significant month-to-
month variability measured by the met tower. Using the AWS Truepower dashboard information for the
preferred wind site northwest of the water supply lagoon, Windographer software was used to
The prospective wind turbine site is locatedThe prospective wind turbine site is located
, which is immediately west of the village, which is immediately west of the village
Kaktovik Wind-Diesel Analysis P a g e | 9
synthesize hourly wind speed averages for a one year time period. This data was imported into Homer
software for modeling purposes as described later in this report.
AWS wind assessment dashboard of prospective wind turbine site, 30 m level
Cold Climate Considerations of Wind Power
Kaktovik’s harsh climate conditions is an important consideration should wind power be developed in
the community. The principal challenges with respect to turbine selection and subsequent operation is
severe cold and icing. Many wind turbines in standard configuration are designed for a lower operating
temperature limit of -4° C (-20° F), which clearly would not be suitable for Kaktovik, nor anywhere else in
Alaska. A number of wind turbine manufacturers offer their turbine in an “arctic” configuration which
includes verification that structural and other system critical metal components are fatigue tested for
severe cold capability. In addition, arctic-rated turbines are fitted with insulation and heaters in the
nacelle and power electronics space to ensure proper operating temperatures. With an arctic rating,
the lower temperature operating limit generally extends to -40° C (-40° F). On occasion during winter
Kaktovik may experience temperatures colder than -40° C which would signal the wind turbines to stop.
Kaktovik Wind-Diesel Analysis P a g e | 10
Temperatures below -40° C are relatively infrequent however and when they do occur, are generally
accompanied by lighter winds.
A second aspect of concern regarding Kaktovik’s arctic climate is icing conditions. Atmospheric icing is a
complex phenomenon characterized by astonishing variability and diversity of forms, density, and
tenacity of frozen precipitation, some of which is harmless to wind turbine operations and others highly
problematic. Although highly complex, with respect to wind turbines and aircraft five types of icing are
recognized: clear ice, rime ice, mixed ice, frost ice, and SLD ice (Wikipedia.org/wiki/icing_conditions).
Clear ice is often clear and smooth. Super-cooled water droplets, or freezing rain, strike a
surface but do not freeze instantly. Forming mostly along the stagnation point on an airfoil, it
generally conforms to the shape of the airfoil.
Rime ice is rough and opaque, formed by super-cooled drops rapidly freezing on impact. Often
"horns" or protrusions are formed and project into the airflow.
Mixed ice is a combination of clear and rime ice.
Frost ice is the result of water freezing on unprotected surfaces. It often forms behind deicing
boots or heated leading edges of an airfoil and has been a factor airplane crashes.
SLD ice refers to ice formed in super-cooled large droplet (SLD) conditions. It is similar to clear
ice, but because droplet size is large, it often extends to unprotected parts of a wind turbine (or
aircraft) and forms large ice shapes faster than normal icing conditions.
SLD ice on an airplane
Wind-Diesel Hybrid System Overview
There are now over twenty-four wind-diesel projects in the state, making Alaska a world leader in wind-
diesel hybrid technology. There are a variety of system configurations and turbine types in operation
and accordingly there is a spectrum of success in all of these systems. As experience and statewide
industry support has increased so has overall system performance. The following figure illustrates the
locations of installed wind projects in Alaska.
boots or heated leading edges of an airfoil and has been a factor airplane crashes.
cooled large droplet (SLD) conditions. It is similar to clear cooled large droplet (SLD) conditions. It is similar to clear
e droplet size is large, it often extends to unprotected parts of a wind turbine (ore droplet size is large, it often extends to unprotected parts of a wind turbine (or
faster than normal icing conditions.faster than normal icing conditions.
"horns" or protrusions are formed and project into the airflow."horns" or protrusions are formed and project into the airflow.
g on unprotected surfaces. It often forms behind deicing g on unprotected surfaces. It often forms behind deicing
boots or heated leading edges of an airfoil and has been a factor airplane crashes.boots or heated leading edges of an airfoil and has been a factor airplane crashes.
cooled large droplet (SLD) conditions. It is similar to clear cooled large droplet (SLD) conditions. It is similar to clear
Kaktovik Wind-Diesel Analysis P a g e | 11
Alaska wind-diesel projects
Wind-diesel Design Options
Wind-diesel power systems are categorized based on their average penetration levels, or the overall
proportion of wind-generated electricity compared to the total amount of electrical energy generated.
Commonly used categories of wind-diesel penetration levels are low penetration, medium penetration,
and high penetration. The wind penetration level is roughly equivalent to the amount of diesel fuel
displaced by wind power. Note however that the higher the level of wind penetration, the more
complex and expensive a control system and demand-management strategy is required. This is a good
compromise between of displaced fuel usage and relatively minimal system complexity and is AVEC’s
preferred system configuration.
Low Penetration Configuration
Low-penetration wind-diesel systems require the fewest modifications to the existing system. However,
they tend to be less economical for village installations due to the limited annual fuel savings compared
to the total wind system installation costs.
diesel power systems are categorized based on their average penetration levels, or the overall
to the total amount of electricto the total amount of electric
diesel penetration levels are low penetration, medium penetration, diesel penetration levels are low penetration, medium penetration,
and high penetration. The wind penetration level is roughly equivalent to the amount of diesel fuel and high penetration. The wind penetration level is roughly equivalent to the amount of diesel fuel
Note however that the higher the level of windthe higher the level of wind
complex and expensive a control system and demcomplex and expensive a control system and demandand-management strategy ismanagement strategy is
compromise between of displaced fuel usage and relatively minimal system complexity and is AVEC’s compromise between of displaced fuel usage and relatively minimal system complexity and is AVEC’s
preferred system configuration.
Low Penetration ConfigurationLow Penetration Configuration
diesel systems requidiesel systems require the fewest modifications to the existingre the fewest modifications to the existing
tend to be less economictend to be less economical for village installations for village installations
to the total wind system installation costs.to the total wind system installation costs.
diesel power systems are categorized based on their average penetration levels, or the overall diesel power systems are categorized based on their average penetration levels, or the overall
to the total amount of electricto the total amount of electric
Kaktovik Wind-Diesel Analysis P a g e | 12
Medium Penetration Configuration
Many of the AVEC communities, Toksook Bay for example, have 24% of their energy from wind. Figure 8
indicates the configuration and key points on using a medium penetration, wind-diesel system.
High Penetration Configuration
Other communities, such as Kokhanok, are more aggressively seeking to offset diesel used for thermal
and electrical energy. They are using configurations which will allow for the generator sets to be turned
off and use a significant portion of the wind energy for various heating loads. The potential benefit of
these systems is the highest, however currently the commissioning for these system types due to the
increased complexity, can take longer. Figure 9 indicates the configuration and key points on using a
high-penetration, wind-diesel system.
are more aggressively seeking to offset diesel used for thermal are more aggressively seeking to offset diesel used for thermal
and electrical energy. They are using configurations which will allow for the generator sets to be turned and electrical energy. They are using configurations which will allow for the generator sets to be turned
off and use a significant portion of the wind energy for various heating loads. Thoff and use a significant portion of the wind energy for various heating loads. Th
these systems is the highest, however currently the commissioning for these system types due to the these systems is the highest, however currently the commissioning for these system types due to the
increased complexity, can take longer. Figure 9 indicates the configuration and key points on using a increased complexity, can take longer. Figure 9 indicates the configuration and key points on using a
system.
Kaktovik Wind-Diesel Analysis P a g e | 13
The above system descriptions can be summarized in Table 2 below. The level of instantaneous
penetration is important for power quality design considerations. The annual amount of wind energy on
the system is considered the average penetration level and helps to provide a picture of the overall
economic benefit.
Summary of wind-diesel penetration levels
Penetration Penetration Level Operating characteristics and system requirements
Instantaneous Average
Low 0% to 50% Less than
20%
Diesel generator(s)run full time at greater than minimum
loading level. Requires minimal changes to existing diesel
control system. All wind energy generated supplies the
village electricload; wind turbines function as “negative
load” with respect to diesel generator governor response.
Medium 0% to 100+% 20% to
50%
Diesel generator(s)run full time at greater than minimum
loading level. Requires control system capable of
automatic generator start, stop and paralleling. To control
system frequency during periods of high wind power input,
system requires fast acting secondary load controller
matched to a secondary load such as an electric boiler
augmenting a generator heat recovery loop. At high wind
power levels, secondary (thermal) loads are dispatched to
absorb energy not used by the primary (electric) load.
Without secondary loads, wind turbines must be curtailed
to control frequency.
High
(Diesels-off
Capable)
0% to 150+% Greater
than 50%
Diesel generator(s)can be turned off during periods of
high wind power levels. Requires sophisticated new
control system, significant wind turbine capacity, secondary
(thermal)load,energy storage such as batteries or a flywheel,
and possibly additional components such as demand-
managed devices.
Wind-Diesel System Components
Listed below are the main components of a medium to high-penetration wind-diesel system:
Wind turbine(s), plus tower and foundation
Supervisory control system
Synchronous condenser
Secondary load
Deferrable load
Interruptible load
Storage
Wind Turbine(s)
Village-scale wind turbines are generally considered to be 50 kW to 250 kW rated output capacity. This
turbine size once dominated with worldwide wind power industry but has been left behind in favor of
much larger 1,000 kW plus capacity turbines. Conversely, many turbines are manufactured for home or
system requires fast acting secondary load controller
matched to amatched to a seco seco
augmenting a generator heat recovery loop. Ataugmenting a generator heat recovery loop. At
power levels, secopower levels, secondndary
absorb energy absorb energy not used by the prit used by the pri
Without secondary loads, wind turbines must be Without secondary loads, wind turbines must be
to control frequencyto control frequency
ter
an 50%
DDiieesel gg eeneerraattoor(s
highigh wind power levelswind power levels
control systtrol syst
(thermal)(thermal)
and and possibly
ma
System ComponentsSystem Components
the main components of a medium to highthe main components of a medium to high
es control system capable of control system capable of
automatic generator start, stop and paralleling. To control automatic generator start, stop and paralleling. To control
system frequency during periods of high wind power input, system frequency during periods of high wind power input,
system requires fast acting secondary load controller system requires fast acting secondary load controller
ad such asas
augmenting a generator heat recovery loop. At
Kaktovik Wind-Diesel Analysis P a g e | 14
farm application, but generally these are 10 kW capacity or less. Consequently, few new village size-
class turbines are on the market, although a large supply of used and/or remanufactured turbines are
available. The latter typically result from repowering older wind farms with new, larger wind turbines.
Supervisory Control System
Medium- and high-penetration wind-diesel systems require fast-acting real and reactive power
management to compensate for rapid variation in village load and wind turbine power output. A wind-
diesel system master controller, also called a supervisory controller, would be installed inside the
Kaktovik power plant or in a new module adjacent to it. The supervisory controller would select the
optimum system configuration based on village load demand and available wind power.
Synchronous Condenser
A synchronous condenser, sometimes called a synchronous compensator, is a specialized synchronous
electric motor with an output shaft that spins freely. Its excitation field is controlled by a voltage
regulator to either generate or absorb reactive power as needed to support the grid voltage or to
maintain the grid power factor at a specified level. Grid power factor and voltage support is essential
for a wind-diesel system’s reliability.
For the Kaktovik power system, a synchronous condenser may be an economical option for voltage and
reactive power support.
Synchronous condenser at the Kokhonak, AK powerplant
Secondary Load
A secondary or “dump” load during periods of high wind is required for a wind-diesel hybrid power
system to operate reliably and economically. The secondary load converts excess wind power into
thermal power for use in space and water heating through the extremely rapid (sub-cycle) switching of
heating elements, such as an electric boiler imbedded in the diesel generator jacket water heat recovery
loop. As seen in Figure 16, a secondary load controller serves to stabilize system frequency by providing
a fast responding load when gusting wind creates system instability.
power system, a synchronous condenser power system, a synchronous condenser may bemay be
Kokhonak, AK powerplantKokhonak, AK powerplant
Its excitation field is controlled by a voltage Its excitation field is controlled by a voltage
regulator to either generate or absorb reactive power as needed to support the grid voltage or to regulator to either generate or absorb reactive power as needed to support the grid voltage or to
power factor and vopower factor and vo
economic
Kaktovik Wind-Diesel Analysis P a g e | 15
An electric boiler is a common secondary load device used in wind-diesel power systems. An electric
boiler (or boilers), coupled with a boiler grid interface control system, could be installed in Kaktovik to
absorb excess instantaneous energy (generated wind energy plus minimum diesel output exceeds
electric load demand). The grid interface monitors and maintains the temperature of the electric hot
water tank and establishes a power setpoint. The wind-diesel system master controller assigns the
setpoint based on the amount of unused wind power available in the system. Frequency stabilization is
another advantage that can be controlled with an electric boiler load. The boiler grid interface will
automatically adjust the amount of power it is drawing to maintain system frequency within acceptable
limits.
Deferrable Load
A deferrable load is electric load that must be met within some time period, but exact timing is not
important. Loads are normally classified as deferrable because they have some storage associated with
them. Water pumping is a common example - there is some flexibility as to when the pump actually
operates, provided the water tank does not run dry. Other examples include ice making and battery
charging. A deferrable load operates second in priority to the primary load and has priority over
charging batteries, should the system employ batteries as a storage option.
Interruptible Load
Electric heating either in the form of electric space heaters or electric water boilers could be explored as
a means of displacing stove oil with wind-generated electricity. It must be emphasized that electric
heating is only economically viable with excess electricity generated by a renewable energy source such
as wind and not from diesel-generated power. It is typically assumed that 40 kWh of electric heat is
equivalent to one gallon of heating fuel oil.
Storage Options
Electrical energy storage provides a means of storing wind generated power during periods of high
winds and then releasing the power as winds subside. Energy storage has a similar function to a
secondary load but the stored, excess wind energy can be converted back to electric power at a later
time. There is an efficiency loss with the conversion of power to storage and out of storage. The
descriptions below are informative but are not currently part of the overall system design.
Flywheels
A flywheel energy system has the capability of short-term energy storage to further smooth out short-
term variability of wind power, and has the additional advantage of frequency regulation. The smallest
capacity flywheel available from Powercorp (now ABB), however, is 500 kW capacity, so it is only
suitable for large village power generation systems.
Batteries
Battery storage is a generally well-proven technology and has been used in Alaskan power systems
including Fairbanks (Golden Valley Electric Association), Wales and Kokhanok, but with mixed results in
the smaller communities. Batteries are most appropriate for providing medium-term energy storage to
allow a transition, or bridge, between the variable output of wind turbines and diesel generation. This
“bridging” period is typically 5 to 15 minutes long. Storage for several hours or days is also possible with
charging batteries, should the system employ batteries as a storage option.
of electric space heaters or electric water boilers of electric space heaters or electric water boilers
generated electricity. It must be emphasized that electric generated electricity. It must be emphasized that electric
heating is only economically viable with excess electricity generated by a renewable energy source such heating is only economically viable with excess electricity generated by a renewable energy source such
generated power. It is typically assumed that 4generated power. It is typically assumed that 4
gallon of heating fuel oilgallon of heating fuel oil. .
Electrical energy storage provides a means of storing wind generatedElectrical energy storage provides a means of storing wind generated
winds and then releasing the power as winds subside. Energy storage has a similar function to a winds and then releasing the power as winds subside. Energy storage has a similar function to a
secondary load but the stored, excess wind energy can be converted back to electric power at a later secondary load but the stored, excess wind energy can be converted back to electric power at a later
y loss with the conversion of power to storage and out of storage. The y loss with the conversion of power to storage and out of storage. The
descriptions below are informative but are not currently part of the overall system design.descriptions below are informative but are not currently part of the overall system design.
there is some flexibility as to when the pump actually there is some flexibility as to when the pump actually
operates, provided the water tank does not run dry. Other examples include ice making and battery operates, provided the water tank does not run dry. Other examples include ice making and battery
A deferrable load operates second in priority to the primary load and has priority over A deferrable load operates second in priority to the primary load and has priority over
charging batteries, should the system employ batteries as a storage option.
Kaktovik Wind-Diesel Analysis P a g e | 16
batteries, but this requires higher capacity and cost. In general, the disadvantages of batteries for utility-
scale energy storage, even for small utility systems, are high capital and maintenance costs and limited
lifetime. Of particular concern to rural Alaska communities is that batteries are heavy and expensive ship
and most contain hazardous substances that require special removal from the village at end of service
life and disposal in specially-equipped recycling centers.
There are a wide variety of battery types with different operating characteristics. Advanced lead acid
and zinc-bromide flow batteries were identified as “technologically simple” energy storage options
appropriate for rural Alaska in an Alaska Center for Energy and Power (ACEP) July, 2009 report on
energy storage. Nickel-cadmium (NiCad) batteries have been used in rural Alaska applications such as
the Wales wind-diesel system. Advantages of NiCad batteries compared to lead-acid batteries include a
deeper discharge capability, lighter weight, higher energy density, a constant output voltage, and much
better performance during cold temperatures. However, NiCads are considerably more expensive than
lead-acid batteries and one must note that the Wales wind-diesel system had a poor operational history
and has not been functional for over ten years.
Because batteries operate on direct current (DC), a converter is required to charge or discharge when
connected to an alternating current (AC) system. A typical battery storage system would include a bank
of batteries and a power conversion device. The batteries would be wired for a nominal voltage of
roughly 300 volts. Individual battery voltages on a large scale system are typically 1.2 volts DC. Recent
advances in power electronics have made solid state inverter/converter systems cost effective and
preferable a power conversion device. The Kokhanok wind-diesel system is designed with a 300 volts DC
battery bank coupled to a grid-forming power converter for production of utility-grade real and reactive
power. Following some design and commissioning delays, the solid state converter system in Kokhanok
should be operational by late 2013 and will be monitored closely for reliability and effectiveness.
Wind Turbine Options
The most significant factor with respect to choice of wind turbines for Kaktovik is the height limitation
dictated by the proximity of the prospective wind turbine site to the new airport. This height limitation
eliminates consideration of larger wind turbines that would potentially be suitable, such as the 900 kW
Emergya Wind Technologies DW 52-900 wind turbine presently operational in Kotzebue or the 500 kW
Vestas V39 wind turbine operational in Sandpoint.
Turbine choice therefore was oriented turbines that are large enough to match well with the Kaktovik
load but not so large to exceed FAA height restrictions with respect to the new airport. Turbines that
meet these criteria are generally in the 100 to 250 kW size range. The wind power industry, however,
does not provide many options as village wind power is a small market worldwide compared to utility
grid-connected projects where wind turbines are 1,000 kW and larger capacity, or home and farm
applications where wind turbines are generally 10 kW or less capacity. For this project, three wind
turbines are considered:
1. Aeronautica AW 29-225: 225 kW rated output; new
Because batteries operate on direct current (DC), a converter is required to charge or discharge when
connected to an alternating current (AC) system. A typical battery storage system would include a bank connected to an alternating current (AC) system. A typical battery storage system would include a bank
of batteries and a power conversion device. The batteries would be wired for a nominal voltage of of batteries and a power conversion device. The batteries would be wired for a nominal voltage of
roughly 300 volts. Individual battery voltages on a large scale system are typically 1.2 volts DC.roughly 300 volts. Individual battery voltages on a large scale system are typically 1.2 volts DC.
n power electronics have made solid state inverter/converter systems cost effective and n power electronics have made solid state inverter/converter systems cost effective and
preferable a power conversion device. The Kokhanok windpreferable a power conversion device. The Kokhanok wind--diesel system is designed with a 300 volts DC diesel system is designed with a 300 volts DC
forming power converter for producforming power converter for produc
power. Following some design and commissioning delays, the solid state converter system in Kokhanok power. Following some design and commissioning delays, the solid state converter system in Kokhanok
should be operational by late 2013 and will be should be operational by late 2013 and will be monitoredmonitored
OOptions ptions
The most significant factor with respect to choice of wind turbines for Kaktovik is the height limitation The most significant factor with respect to choice of wind turbines for Kaktovik is the height limitation
dictated by the proximity of the prospective wind turbine site to the new airport. This height limitation dictated by the proximity of the prospective wind turbine site to the new airport. This height limitation
eliminates consideration of largereliminates consideration of larger wind turbines that would potentially be suitable, such as the 900 kW wind turbines that would potentially be suitable, such as the 900 kW
iesel system had a poor operational history iesel system had a poor operational history
Because batteries operate on direct current (DC), a converter is required to charge or discharge when Because batteries operate on direct current (DC), a converter is required to charge or discharge when
connected to an alternating current (AC) system. A typical battery storage system would include a bank connected to an alternating current (AC) system. A typical battery storage system would include a bank
of batteries and a power conversion device. The batteries would be wired for a nominal voltage of
Kaktovik Wind-Diesel Analysis P a g e | 17
2. Northern Power Systems 100-21, 100 kW rated output; new
3. Vestas V27: 225 kW rated output; remanufactured
The choice of selecting new or remanufactured wind turbines is an important consideration and one
which North Slope Borough will want to consider carefully. There are advantages and potential
disadvantages of each, including cost, support and parts availability. Note however that the three wind
turbines presented in this report have solid track records and very good support capacity within Alaska.
Aeronautica 29-225
The Aeronautica AW29-225 wind turbine is manufactured new by Aeronautica in Durham, New
Hampshire. This turbine was originally designed by the Danish-manufacturer Norwin in the 1980’s and
had a long and successful history in the wind industry before being replaced by larger capacity turbines
for utility-scale grid-connect installations. The AW29-225 turbine is stall-regulated, has a synchronous
(induction) generator, active yaw control, a 29 meter diameter rotor, is rated at 225 kW power output,
and is available with 30, 40, or 50 meter tubular steel towers. The AW29-225 is fully arctic-climate
certified to -40° C and is new to the Alaska market with no in-state installations at present. More
information can be found at http://aeronauticawind.com/aw/index.html.
Aeronautica AW 29-225 wind turbine
Northern Power Systems 100 (NPS 100)
The Northern Power System NPS 100 wind turbine is manufactured by Northern Power Systems in
Barre, Vermont. The NPS 100 turbine is rated at 100 kW, is stall-regulated and operates upwind with
active yaw control, has a direct-drive permanent magnet synchronous generator, comes equipped with
a 21 meter or 24 meter diameter rotor, and is available on 30 and 37 meter tubular steel monopole
towers, or on a 48 meter four-leg lattice tower.
The NPS 100-21 is available as fully arctic-climate certified to -40° C and is the most represented village-
scale wind turbine in Alaska with a significant number of installations in the Yukon-Kuskokwim Delta
region of the state, but also five turbine in Gambell and Savoonga on St. Lawrence Island. More
information can be found at: http://www.northernpower.com/.
http://aeronauticawind.com/aw/index.html
(induction) generator, active yaw control, a 29 meter diameter rotor, is rated at 225 kW power output, (induction) generator, active yaw control, a 29 meter diameter rotor, is rated at 225 kW power output,
and is available with 30, 40, or 50 meter tubular steel towers. The AW29and is available with 30, 40, or 50 meter tubular steel towers. The AW29
state installations at present. More state installations at present. More
http://aeronauticawind.com/aw/index.html.
Kaktovik Wind-Diesel Analysis P a g e | 18
Design class of the NPS 100-21 (21 meter rotor) is IEC (International Electrotechnical Commission) Class
II-A (air density 1.225 kg/m3, average wind speed below 8.5 m/s, and 50-year peak gust below 59.5 m/s).
Northern Power Systems 100-21 wind turbines, Toksook Bay, Alaska
Vestas V27
The Vestas V27 was originally manufactured by Vestas Wind Systems A/S in Denmark and is no longer in
production in Europe, although the turbine reported is presently manufactured under license in India.
For many years the V27 was Vestas’ workhorse wind turbine and many are still in operation worldwide.
Present availability of the V27 in Alaska is as a remanufactured unit from Halus Power Systems in San
Leandro, California. Marsh Creek, LLC of Anchorage is the distributor in Alaska for Halus Power Systems.
The V27 is pitch-regulated, has a synchronous (induction) double-wound generator, active yaw control,
a 27 meter diameter rotor, is rated at 225 kW power output, and is available with 30, 40, or 50 meter
tubular steel towers.
Vestas V27 wind turbines, Saint Paul Island, Alaska
The Vestas V27 was originally manufactured by Vestas Wind Systems A/S in Denmark and is no The Vestas V27 was originally manufactured by Vestas Wind Systems A/S in Denmark and is no
Europe, although the turbine reported is presently manufactured under license in India. Europe, although the turbine reported is presently manufactured under license in India.
For many years the V27 was Vestas’ workhorse wind turbine and many are stillFor many years the V27 was Vestas’ workhorse wind turbine and many are still
Present availability of the V27 in Alaska is as a remanufactured unit from Halus Power Systems in San a remanufactured unit from Halus Power Systems in San
Marsh Creek, LLC of Anchorage is the distributor in Alaska for Halus Power Systems. Marsh Creek, LLC of Anchorage is the distributor in Alaska for Halus Power Systems.
regulated, has a synchronous (induction) regulated, has a synchronous (induction)
diameter rotor, is rated at 225 kW power output, and is available diameter rotor, is rated at 225 kW power output, and is available
Vestas V27 wind turbines, Saint PaulVestas V27 wind turbines, Saint Paul Island, AlaskaIsland, Alaska
Kaktovik Wind-Diesel Analysis P a g e | 19
Wind-Diesel Model
HOMER renewable energy modeling software was used to analyze the potential for wind turbines to
augment the existing Kaktovik diesel generator power plant. HOMER is designed to analyze hybrid
power systems that contain a mix of conventional and renewable energy sources such as diesel
generators, wind turbines, solar panels, batteries, etc. and is widely used to aid development of Alaska
village wind power projects. It is a static energy balance model, however, and is not designed to model
the dynamic stability of a wind-diesel power system. It will, however, warn of system design with
sufficient renewable energy input to potentially result in instability. For proposed high penetration
configurations, it is advisable to model dynamic system stability with appropriate software during the
design phase of the project. The intent of this modeling exercise is to highlight the potential benefit of
wind turbines in Kaktovik.
Kaktovik Powerplant
Electric power (comprised of the diesel power plant and the electric power distribution system) in
Kaktovik is provided by North Slope Borough. The power plant being is comprised of four diesel
generators: two 910 kW Caterpillar 3512 diesel generators and two 450 kW Caterpillar 3508 diesel
generators. Kaktovik’s diesel generators will automatically parallel to meet load demand during periods
of high power usage. Via a review of the powerplant operational records, a typical operational
configuration is one Cat 3512 and one Cat 3508 on-line.
Diesel Generators
For purposes of modeling, the Kaktovik diesel generators are assigned bays (or positions) 1 through 4 in
the power house, although note that position of generators in the actual power house may be different.
Bays 1 and 2 are for the two 910 kW Caterpillar 3512 marine diesels and bays 3 and 4 are the smaller
450 kW Caterpillar 3508C marine diesels.
New powerplant diesel generators in Homer model
Generator Diesel Engine Model Generator Electrical Rating Heat Recovery
1 Caterpillar 3512 Leroy-Sommer SR4 910 kW Jacket water
2 Caterpillar 3512 Leroy-Sommer SR4 910 kW Jacket water
3 Caterpillar 3508 Leroy-Sommer SR4 450 kW Jacket water
4 Caterpillar 3508 Leroy-Sommer SR4 450 kW Jacket water
Diesel generator HOMER modeling information
Diesel generator Cat 3512 Cat 3508
Power output (kW) 910 450
Intercept coeff. (L/hr/kW rated) 0.02029 0.02184
Slope (L/hr/kW output) 0.2328 0.2378
Minimum electric
load (%)
15.0%
(135 kW)
15.0%
(67 kW)
Heat recovery ratio (% of generator
waste heat energy available to serve
the thermal load; when modeled)
40 40
Notes: Intercept coefficient – the no-load fuel consumption of the generator divided by its capacity
Slope – the marginal fuel consumption of the generator
generators will automatically parallel to meet load demand during pegenerators will automatically parallel to meet load demand during pe
Via a review of the powerplant operational records, a typical operational Via a review of the powerplant operational records, a typical operational
configuration is one Cat 3512 and one Cat 3508 on-line. -line.
Kaktovik diesel generators are assigned bays (ordiesel generators are assigned bays (or
the power house, although note that position of generators in the actual power house may be different.the power house, although note that position of generators in the actual power house may be different.
two 910 kW Caterpillar 3512two 910 kW Caterpillar 3512 marine diesels and bays 3 and 4 are the marine diesels and bays 3 and 4 are the
450 kW Caterpillar 3508C marine dieselsarine diesels. .
diesel generato diesel generators in Homer modelrs in Homer model
ngine
Caterpillar 3512Caterpillar 3512 Leroy
Caterpillar 3512Caterpillar 3512
erpillar 3508erpillar 3508
r (comprised of the diesel power plant and the electric power distribution system) in r (comprised of the diesel power plant and the electric power distribution system) in
plant being plant being is is comprised of four diesel comprised of four diesel
910 kW Caterpillar 3512 diesel generators and two 450 kW Caterpillar 910 kW Caterpillar 3512 diesel generators and two 450 kW Caterpillar
generators will automatically parallel to meet load demand during pegenerators will automatically parallel to meet load demand during pe
Via a review of the powerplant operational records, a typical operational
Kaktovik Wind-Diesel Analysis P a g e | 20
Caterpillar 3512 Diesel Generator
The graphs below illustrate fuel usage and consequent electrical and thermal efficiency of the Cat 3512
diesel generator used in Homer modeling. Note that NSB did not report a seasonal or other specific
scheduling plan, hence Homer software was programmed to select the most efficient diesel for any time
period. Also note that Homer was programmed to allow parallel diesel generator operation, although
this was not specifically verified.
Cat 3512 fuel curve Cat 3512 electrical energy efficiency curve
Cat 3512 electrical and thermal energy efficiency curve
Caterpillar 3508 Diesel Generator
The graphs below illustrate fuel usage and consequent electrical and thermal efficiency of the Cat 3508
diesel generator used in Homer modeling. Note again that NSB did not report a seasonal or other
specific scheduling plan, hence Homer software was programmed to select the most efficient diesel for
any time period.
Cat 3508 fuel curve Cat 3508 electrical energy efficiency curve
Cat 3512 electrical and thermal energy efficiency curve
Caterpillar 3508 Diesel GeneratorCaterpillar 3508 Diesel Generator
hs below illustrate fuel usage and consequent electrical and thermal efficiency hs below illustrate fuel usage and consequent electrical and thermal efficiency
used in Homerused in Homer modeling. Note again that NSB did not report a seasonal or other modeling. Note again that NSB did not report a seasonal or other
specific scheduling plan, hence Homer software was programmed tspecific scheduling plan, hence Homer software was programmed t
Kaktovik Wind-Diesel Analysis P a g e | 21
Cat 3508 electrical and thermal energy efficiency curve
Wind Turbines
Wind turbine options for Kaktovik are discussed previously in this report. For Homer modeling, standard
temperature and pressure (STP) power curves were used. This is quite conservative in that actual
turbine power production in Kaktovik will typically be higher than predicted by the STP power curves
due to the cold temperature climate and consequent high air density of the area.
Aeronautica AW 29-225 power curve NPS 100-21 power curve
Vestas V27 power curve
Electric Load
For modeling purposes with Homer software, the Kaktovik electric load was derived from calendar year
2012 powerplant data forwarded to HDL and V3 Energy, LLC by North Slope Borough in an Excel
spreadsheet entitled 2012_Kaktovik_PPOR. The spreadsheet tabulates average power per hour for each
diesel engine on-line. If two diesel engines are operating in parallel, individual generator power output
is summed to equal total hour (average) load. Hours are organized into days and days into months. For
o the cold temperature climate and consequent high air density of the
NPS 100NPS 100 21 power curve
Vestas V27 power curveVestas V27 power curve
ously in this report. For Homer modeling, standard ously in this report. For Homer modeling, standard
(STP) power curves were used. This is quite quite conservative in that actual conservative in that actual
will typically be higher than predicted by the STP power curves will typically be higher than predicted by the STP power curves
o the cold temperature climate and consequent high air density of the o the cold temperature climate and consequent high air density of the areaarea
21 power curve
Kaktovik Wind-Diesel Analysis P a g e | 22
each day, generator output is summed to yield kWh produced per turbine and aggregate. Below is an
example of daily generator output/load data.
Kaktovik powerplant data, 1/3/2012
For Homer input, load data is organized into 8,760 lines, representing 24 hours per day for 365 days per
year. In a number of instances diesel generator power (load) data was missing from the data set. In
these cases, missing data was filled by interpolating from before and after the blank sections. The
graphs below show a summary of the Kaktovik load from the powerplant data.
Kaktovik electric load
Engine 1
Caterpillar 3512
Serial # 67Z01838
Engine 2
Caterpillar 3512
Serial # 67Z01839
Engine 3
Caterpillar 3508
Serial # 70Z01055
Engine 4
Caterpillar 3508
Serial # 70Z01054
Total Load Total Load Total Load Total Load
0:00 345 242 587 689
1:00 387 245 632
2:00 385 246 631
3:00 388 250 638
4:00 389 245 634
5:00 408 245 653
6:00 400 245 645
7:00 410 247 657
8:00 440 242 682
9:00 446 243 689
10:00 385 245 630
11:00 383 246 629
12:00 416 250 666
13:00 393 245 638
14:00 385 244 629
15:00 371 242 613
16:00 383 245 628
17:00 372 235 607
18:00 343 244 587
19:00 327 241 568
20:00 326 242 568
21:00 326 240 566
22:00 330 241 571
23:00 351 244 595
Total 9,089 0 0 5,854 14,943
Kaktovik Power Plant
January 3, 2012
Total Hourly
Load
Peak Load
of the DayHour
For Homer input, load data is organized into 8,760 lines, representing 24 hours per day for 365 days per For Homer input, load data is organized into 8,760 lines, representing 24 hours per day for 365 days per
year. In a number of instances diesel generator power (load) data was missing from the data set. In year. In a number of instances diesel generator power (load) data was missing from the data set. In
these cases, missing data was filled by interpolating from before and after the blank sections. The these cases, missing data was filled by interpolating from before and after the blank sections. The
0
245
247
242
Kaktovik Wind-Diesel Analysis P a g e | 23
Thermal Load
The Kaktovik powerplant is equipped with a heat recovery system to extract jacket water waste heat
from the diesel generators and supply it to the following village thermal (heat) loads: powerplant,
washeteria, school, USDW, water plant, fire station, VMS, clinic. Referencing a February, 2010 draft RSA
Engineering, Inc. report to North Slope Borough entitled North Slope Borough Village Heat Recovery
Project Analysis Report, CIP No. 13-222, the combined design day heat load of the above-referenced
structures is 3.29 MMBTU/hr. Also noted in the RSA Engineering, Inc. report is the possibility of adding
PSO and the vacuum station to the heat recovery loop, which would increase the design data heat load
by 0.13 MMBTU/hr. Data from the RSA Engineering report details on a monthly basis existing waste heat
(from the powerplant heat recovery system) consumption and the estimated contribution of waste heat
to the actual heat load. This data can be used to derive estimated actual thermal or heat demand, which
is different than the design day heat load.
RSA Engineering thermal load data, PSO and vacuum station not included
Data from the above table was converted from BTU/hr to kW (heat) load for use in Homer software to
create the following thermal load profile for modeling purposes:
Month (BTU/hr) (kW)
1 1,372,830 137,283,000 40,197.9 1,372,830 100%-
2 1,434,300 143,430,000 41,997.8 1,434,300 100%-
3 1,272,429 127,242,900 37,258.0 1,272,429 100%-
4 1,139,244 113,924,400 33,358.2 1,139,244 100%-
5 1,026,549 102,654,900 30,058.4 1,026,549 100%-
6 963,030 96,303,000 28,198.5 963,030 100%-
7 942,540 94,254,000 27,598.6 929,063 99%13,477
8 1,040,892 104,089,200 30,478.4 829,640 80%211,252
9 1,047,039 104,703,900 30,658.4 1,034,744 99%12,295
10 1,104,411 110,441,100 32,338.3 1,104,411 100%-
11 1,133,097 113,309,700 33,178.3 1,133,097 100%-
12 1,202,763 120,276,300 35,218.2 1,202,763 100%-
Heat
Available
(BTU/hr)
Heat
Consumed
(BTU/hr)
% heat
load
Unused
Heat
(BTU/hr)
Heat Demand
137,283,000137,283,000 40,197.940,197.9
1,434,3001,434,300 143,430,000143,430,000 41,997.841,997.8
1,272,4291,272,429 127,242,900127,242,900
113,924,400113,924,400
102,654,900102,654,900
96,303,00096,303,000
e RSA Engineering report details on a monthly basis existing waste heat e RSA Engineering report details on a monthly basis existing waste heat
(from the powerplant heat recovery system) consumption and the estimated (from the powerplant heat recovery system) consumption and the estimated
This data can be used to derive estimated actual thermal orThis data can be used to derive estimated actual thermal or
RSA Engineering thermal load data, PSO and vacuum station not includedRSA Engineering thermal load data, PSO and vacuum station not included
(BTU/hr)(BTU/hr)(kW)(kW)
Heat
Consumed Consumed
Heat DemandHeat Demand
the combined design day heat load of ththe combined design day heat load of th
structures is 3.29 MMBTU/hr. Also noted in the RSA Engineering, Inc. report is the possibility of adding structures is 3.29 MMBTU/hr. Also noted in the RSA Engineering, Inc. report is the possibility of adding
PSO and the vacuum station to the heat recovery loop, which would increase the design data heat load PSO and the vacuum station to the heat recovery loop, which would increase the design data heat load
e RSA Engineering report details on a monthly basis existing waste heat e RSA Engineering report details on a monthly basis existing waste heat
(from the powerplant heat recovery system) consumption and the estimated
Kaktovik Wind-Diesel Analysis P a g e | 24
Kaktovik thermal load
Wind Turbine Configuration Options
Discussions between HDL and North Slope Borough have indicated that the borough’s goals with a wind-
diesel system in Kaktovik is to offset a significant percentage of fuel used in the powerplant, but not
create a highly complex system with significant thermal offset and/or electrical storage capability. This
philosophy dictates a medium penetration design approach (see previous section of this report) where
wind power supplies 20 to 50 percent of the electric load, but at least one diesel generator is always on-
line to provide spinning reserve and control grid frequency. Medium penetration design does, though,
mean that instantaneous wind power will at times be well over 100 percent of the load. This can result
in unstable grid frequency, which can occur when electrical power generated exceeds the load demand.
In a wind-diesel power system without electrical storage, there are two options to prevent this
possibility:
1. Curtail one or more wind turbines to prevent instantaneous wind penetration from exceeding
100 percent (one must also account for minimum loading of the diesel generator).
2. Install a secondary load controller with a resistive heater. The secondary load controller is the
fast-acting switching mechanism commanding heating elements to turn on and off to order to
maintain stable frequency. The resistive heater can be as simple as a heater ejecting energy to
the atmosphere or an interior air space or, more desirably, a boiler serving one or more thermal
loads. The boiler can be installed in the powerplant heat recovery loop and operated in parallel
with fuel oil boilers.
In either case, system frequency control features are necessary in medium penetration design as,
generally speaking, the diesel generator paralleled with the wind turbines during periods of high wind
energy input may not have sufficient inertia to control frequency by itself. This design philosophy is
typical of most wind-diesel systems presently operational in Alaska and provides a solid compromise
Discussions between HDL and North Slope Borough have indicated that the borough’s Discussions between HDL and North Slope Borough have indicated that the borough’s
ficant percentage of fuel used in the powerplant, but not ficant percentage of fuel used in the powerplant, but not
create a highly complex system with significant thermal offset and/or electrical storage capability. create a highly complex system with significant thermal offset and/or electrical storage capability.
philosophy dictates a medium penetration designphilosophy dictates a medium penetration design approach (see previous section of this repoapproach (see previous section of this repo
wind power supplies 20 to 50 percent of the electric load, but at least one diesel generator is always onwind power supplies 20 to 50 percent of the electric load, but at least one diesel generator is always on
line to provide spinning reserve and control grid frequency.line to provide spinning reserve and control grid frequency.
mean that instantaneous wind power wilmean that instantaneous wind power will at times be well over 100 percent of the load. This can result l at times be well over 100 percent of the load. This can result
in unstable grid frequency, which can occur when electrical power generated exceeds the load demand. in unstable grid frequency, which can occur when electrical power generated exceeds the load demand.
diesel power system without electrical storage, there are two options to prevediesel power system without electrical storage, there are two options to preve
Curtail one or more wind turbines to prevent instantaneous wind penetration from exceeding Curtail one or more wind turbines to prevent instantaneous wind penetration from exceeding
100 percent (one must also account for minimum loading of the diesel generator).100 percent (one must also account for minimum loading of the diesel generator).
Discussions between HDL and North Slope Borough have indicated that the borough’s
Kaktovik Wind-Diesel Analysis P a g e | 25
between the minimal benefit of low penetration wind systems and the cost and complexity of high
penetration wind systems.
Many utilities prefer to install more than one wind turbine in a village wind power project to provide
redundancy and continued renewable energy generation should one turbine be out-of-service for
maintenance or other reasons. With this guideline in mind, and referencing the medium wind power
penetration design philosophy discussed above, modeled wind turbine configuration options considered
in this report are as follows:
Aeronautica AW 29-225, three turbines (675 kW capacity)
Northern Power NPS 100-21, seven turbines (400 kW to 700 kW capacity)
Vestas 27, three turbines (675 kW capacity)
Turbine types are not mixed, however, as it is assumed that North Slope Borough will select only one
type of wind turbine. A typical configuration for this project is show below. Note that turbine type can
be switched from the AW 29-225 (shown) to the NPS 100-21 or V27.
Wind-diesel configuration for Kaktovik
Economic Analysis
Installation of wind turbines in medium penetration mode is evaluated in this report to demonstrate the
economic impact of these turbines with the following configuration philosophy: turbines are connected
to the electrical distribution system to serve the electrical load. Although system configuration will
require a secondary load controller and an electric heater or boiler to divert excess electrical power, the
offset of thermal load(s) via a secondary load controller is not modeled in this report. This is due to the
relatively small amount of excess energy produced by the wind turbine configurations described in the
North Slope Borough will select North Slope Borough will select
. A typical configuration for this project is show below. Note that turbine type can . A typical configuration for this project is show below. Note that turbine type can
or V27or V27. .
Kaktovik Wind-Diesel Analysis P a g e | 26
previous section and the complications of cost modeling thermal loads together with electrical loads in
Homer software. Additionally, it is not certain that an electric boiler is the best choice to dissipate
excess energy as it is possible that space heating may prove simpler and less expensive to construct and
operate.
Fuel Cost
A fuel price of $5.27/gallon ($1.39/Liter) was chosen for the initial HOMER analysis by reference to
Alaska Fuel Price Projections 2013-2035, prepared for Alaska Energy Authority by the Institute for Social
and Economic Research (ISER), dated June 30, 2103 and the 2013_06_R7Prototype_final_07012013
Excel spreadsheet, also written by ISER. The $5.27/gallon price reflects the average value of all fuel
prices between the 2015 (the assumed project start year) fuel price of $4.50/gallon and the 2034 (20
year project end year) fuel price of $6.19/gallon using the medium price projection analysis with an
average social cost of carbon (SCC) of $0.58/gallon included.
By comparison, the fuel price for Kaktovik (without social cost of carbon) reported to Regulatory
Commission of Alaska for the 2012 PCE report is $4.28/gallon ($1.13/Liter), without inclusion of the SCC.
Assuming an SCC of $0.40/gallon (ISER Prototype spreadsheet, 2013 value), the 2012 Kaktovik fuel price
was $4.68/gallon ($1.24/Liter).
Heating fuel displacement by excess energy diverted to thermal loads is valued at $6.32/gallon
($1.67/Liter) as an average price for the 20 year project period. This price was determined by reference
to the 2013_06_R7Prototype_final_07012013 Excel spreadsheet where heating oil is valued at the cost
of diesel fuel (with SCC) plus $1.05/gallon, assuming heating oil displacement between 1,000 and 25,000
gallons per year.
Fuel cost table, SCC included
ISER med.
projection 2015 (/gal) 2034 (/gal)
Average
(/gallon)
Average
(/Liter)
Diesel Fuel $4.50 $6.19
$5.27 $1.39
Heating Oil $5.55 $7.24
$6.32 $1.67
Modeling Assumptions
HOMER energy modeling software was used to analyze the Kaktovik power System. HOMER was
designed to analyze hybrid power systems that contain a mix of conventional and renewable energy
sources, such as diesel generators, wind turbines, solar panels, batteries, etc. and is widely used to aid
development of Alaska village wind power projects.
Modeling assumptions are detailed in the table below. Many assumptions, such as project life, discount
rate, operations and maintenance (O&M) costs, etc. are AEA default values. Other assumptions, such as
diesel overhaul cost and time between overhaul are based on general rural Alaska power generation
experience. The base or comparison scenario is the Kaktovik powerplant with its present configuration
of diesel generators and the existing thermal loads connected to the heat recovery loop.
spreadsheet, 2013 value), the 2012 Kaktovik fuel price
Heating fuel displacement by excess energy diverted to thermal loads is valued at $6.32/gallon Heating fuel displacement by excess energy diverted to thermal loads is valued at $6.32/gallon
($1.67/Liter) as an average price for the 20 year project period. ($1.67/Liter) as an average price for the 20 year project period. ThisThis price was determined by reference price was determined by reference
2013_06_R7Prototype_final_07012013 Excel spreadsheet where heating oil is valued at the cost Excel spreadsheet where heating oil is valued at the cost
of diesel fuel (with SCC) plus $1.05/gallon, assuming heating oil displacement between 1,000 and 25,000 of diesel fuel (with SCC) plus $1.05/gallon, assuming heating oil displacement between 1,000 and 25,000
, SCC included, SCC included
5 5 (/gal(/gal) 2034 (/gal)(/gal)
Average Average
(/gallon)(/gallon)
4.504.50 $6.196.19
$7.24$7.24
al cost of carbon) reported to Regulatory al cost of carbon) reported to Regulatory
Commission of Alaska for the 2012 PCE report is $4.28/gallon ($1.13/Liter), without inclusion of the SCC. Commission of Alaska for the 2012 PCE report is $4.28/gallon ($1.13/Liter), without inclusion of the SCC.
spreadsheet, 2013 value), the 2012 Kaktovik fuel price spreadsheet, 2013 value), the 2012 Kaktovik fuel price
Kaktovik Wind-Diesel Analysis P a g e | 27
Modeling assumes that wind turbines constructed in Kaktovik would operate in parallel with the diesel
generators. Although excess energy could serve thermal loads via a secondary load controller and
electric boiler that would augment the existing jacket water heat recovery system, it is not modeled as
such. Installation cost of this turbine project assumes three-phase upgrade of the distribution system to
the wind turbine site.
Basic modeling assumptions
Economic Assumptions
Project life 20 years (2014 to 2033)
Discount rate for net present value
calculations
3%
System fixed O&M cost $700,00/year (reference: 2012 PCE report)
System fixed capital cost (plant
upgrades required to accommodate
wind turbines)
Included in turbine project cost
Operating Reserves
Load in current time step 10%
Wind power output 100% (forces diesels to always operate)
Fuel Properties (no. 2 diesel for
powerplant)
Heating value 46.8 MJ/kg (140,000 BTU/gal)
Density 830 kg/m
3 (6.93 lb./gal)
Price (20 year average; ISER 2013,
medium projection plus social cost of
carbon)
$5.27/gal ($1.39/Liter)
Fuel Properties (no. 1 diesel to serve
thermal loads)
Heating value 44.8 MJ/kg (134,000 BTU/gal)
Density 830 kg/m
3 (6.93 lb./gal)
Price (20 year average; ISER 2013,
medium projection plus social cost of
carbon)
$6.32/gal ($1.67/Liter)
Diesel Generators
Generator capital cost $0 (already installed)
O&M cost $2.75/hour (approx. $0.02/kWh)
Time between overhauls 15,000 hours (run time)
Overhaul cost $50,000 for Cat 3512; $30,000 for Cat 3508
Minimum load 15%
Schedule Optimized
Wind Turbines
Availability 80% (adjusted by wind speed)
Turbine hub height 30 meters (all turbines)
O&M cost $8,000 per year per turbine
Wind speed 6.52 m/s at 30 m level at prospective wind turbine site; wind
speed scaled to 5.85 m/s for 80% turbine availability and
6.18 m/s for 90% availability
Density adjustment Measured Kaktovik density of 1.286 kg/m
3 is 5.0% higher
(forces diesels to always operate)
46.8 MJ/kg (140,000 BTU/gal)46.8 MJ/kg (140,000 BTU/gal)
830 kg/m3 (6.93 lb./gal)(6.93 lb./gal)
$5.27/gal ($1.3/gal ($1.399/Liter)/Liter)
44.8 MJ/kg (134,000 BTU/gal)44.8 MJ/kg (134,000 BTU/gal)
830 kg/m830 kg/m3
Price (20 year average; ISER 201Price (20 year average; ISER 2013,
medium projection plus social cost of medium projection plus social cost of
$$6.326.32/gal ($1./gal ($1.
(forces diesels to always operate)(forces diesels to always operate)
Kaktovik Wind-Diesel Analysis P a g e | 28
than standard air density of 1.225 kg/m3. Density
compensation by setting elevation at -530 m in Homer.
Energy Loads
Electric 13,124 kWh/day mean annual electrical load
Thermal 12,110 kWh/day mean annual available via recovered heat
loop
Fuel oil boiler efficiency 85%
Electric boiler efficiency 100%
Wind Turbine Project Costs
Construction cost for wind turbine installation and integration with the diesel power plant would be
determined with high degree of accuracy during the design phase of the project. Note that costs listed
below are estimates.
Wind Turbine Costs
Turbine
No.
Turbines
HDL’s
Estimated
Project Cost
Installed
kW
Cost per kW
Capacity Tower Type
Tower
Height
(meters)
Aeronautica
AW29-225 3 $7,815,795 675 $11,579 Monopole 30
Northern Power
NPS100-21 7 $11,312,500 700 $16,161 Monopole 30
Vestas V27 3 $7,122,795 675 $10,552 Monopole 30
Modeling Results
The following modeling information assumes the existing thermal loads without addition of the PSO and
vacuum station. Economic benefit-to-cost is shown by the ISER method which does not account for heat
loss from the diesel engines with respect to heating oil offset. ISER cost modeling assumptions are
noted above or are discussed in the 2013_06_R7Prototype_final_07012013 Excel spreadsheet.
675675
11,312,500 700700 $$16,16116,161
7,122,795 675675 $$10,55210,552
The following modeling information assumes the existing thermal loads without addition of the PSO and The following modeling information assumes the existing thermal loads without addition of the PSO and
. Economic benefit-to--costcost is shown by the ISER method which does notis shown by the ISER method which does not
loss from the diesel engines with respect to heating oil offsetloss from the diesel engines with respect to heating oil offset
noted above or are discussed in the noted above or are discussed in the 2013_06_R7Prototype_final_070120132013_06_R7Prototype_final_07012013
Cost per kW Cost per kW
CapacityCapacity Tower TypeTower Type
11,579
Kaktovik Wind-Diesel Analysis P a g e | 30
Discussion
Installing wind turbines and creating a wind-diesel power system in a small village is a demanding
challenge. At first glance, the benefits of wind power are manifest: the fuel is free and it is simply a
manner of capturing it. The reality of course is more complicated. Wind turbines are complex machines
and integrating them into the diesel power system of a small community is complicated. With wind-
diesel, a trade-off exists between fuel savings and complexity. A system that is simple and inexpensive
to install and operate will displace relatively little diesel fuel, while a wind-diesel system of considerable
complexity and sophistication can achieve very significant fuel savings.
The ideal balance of fuel savings and complexity is not the same for every community and requires
careful consideration. Not only do the wind resource, electric and thermal load profiles, and
powerhouse suitability vary between villages, so does technical capacity and community willingness to
accept the opportunities and challenges of wind power. A very good wind-diesel solution for one village
may not work as well in another village, for reasons that go beyond design and configuration questions.
Ultimately, the electric utility and village residents must consider their capacity, desire for change and
growth, and long-term goals when deciding the best solution to meets their needs.
The purpose of this Conceptual Design Report is to introduce and discuss the viability of wind power in
Kaktovik. As discussed, many options are possible, ranging from a very simple low penetration system
to a highly complex, diesels-off configuration theoretically capable of displacing 75 percent or more of
fuel usage in the community. It’s possible that North Slope Borough and Kaktovik residents will
ultimately prefer a very simple or very complex option, but from past discussions and work it has been
determined and possibly also assumed that a moderate approach to wind power in Kaktovik is
preferred, at least initially.
With a moderately complex project design framework in mind, a configuration of relatively high wind
turbine capacity but without electrical storage and without diesels-off capability was chosen. This
provides sufficient wind capacity to make a substantive impact on fuel usage but does not require an
abrupt transition from low to high complexity. Although conceptually elegant, there is a trade-off to
consider with this approach. Installing a large amount of wind power capacity (approximately 700 kW
are recommended) is expensive, but without electrical or thermal storage some of the benefits of this
wind power capacity cannot be captured and will be lost.
The thermodynamics of energy creation and use dictates that wind power is more valuable when used
to offset fuel used by diesel generators to generate electricity than fuel used in fuel oil boilers to serve
thermal loads. Referring to the energy production summaries for the three turbine configurations under
Modeling Results, one can see that the wind turbines are expected to produce minimal excess
electricity, even at 90 percent turbine availability. This excess electricity, although minimal, must be
shunted via a secondary load controller to the diesel generator heat recovery loop or simple radiation
heaters to avoid curtailing wind turbines during periods of high wind and relatively light electrical load.
term goals when deciding the best solution to meets their needs.term goals when deciding the best solution to meets their needs.
The purpose of this Conceptual Design Report is to introduce and discuss the viability of wind power in The purpose of this Conceptual Design Report is to introduce and discuss the viability of wind power in
. As discussed, many options are possible, ranging from a very. As discussed, many options are possible, ranging from a very
off configuration theoretically capable of displacing 75 percent or more of off configuration theoretically capable of displacing 75 percent or more of
fuel usage in the community. It’s possible that fuel usage in the community. It’s possible that North Slope BoroughNorth Slope Borough
y simple or very complex option, but from past discussions and work it has been y simple or very complex option, but from past discussions and work it has been
determined and possibly also assumed that a moderate approach to wind power in determined and possibly also assumed that a moderate approach to wind power in
With a moderately complex project design framework in mind, a configuration of relatively high wind With a moderately complex project design framework in mind, a configuration of relatively high wind
turbine capacity but without electrical storage and without dieselsturbine capacity but without electrical storage and without diesels
provides sufficient wind capacity to make a substantive impact on fuel usage but does not require an provides sufficient wind capacity to make a substantive impact on fuel usage but does not require an
transition from low to high complexity. Although conceptually elegant, there is a tradetransition from low to high complexity. Although conceptually elegant, there is a trade
consider with this approach. Installing a large amount of wind power capacity (approximately consider with this approach. Installing a large amount of wind power capacity (approximately
good windgood wind
may not work as well in another village, for reasons that go beyond design and configuration questions. may not work as well in another village, for reasons that go beyond design and configuration questions.
Ultimately, the electric utility and village residents must consider their capacity, desire for change and Ultimately, the electric utility and village residents must consider their capacity, desire for change and
term goals when deciding the best solution to meets their needs.term goals when deciding the best solution to meets their needs.
Kaktovik Wind-Diesel Analysis P a g e | 31
Although perhaps not readily apparent in the report, this compromise of wind capacity versus
complexity is contained within the economic benefit-to-cost tables. Because excess wind energy is not
modeled as serving the thermal load nor stored in batteries, it is not valued in the net present value
calculations. So, a compromise, which is common with wind-diesel designs, is that capital costs are high,
but usage of energy generated is imperfect, from an efficiency point of view. The most efficient usage
of energy from a technical point of view, however, may be too expensive from a cost-benefit
perspective.
It is important to not focus strictly on benefit-to-cost ratio of a particular configuration design or
particular turbine option, but also consider a wider view of the proposed wind project for Kaktovik.
Installing approximately 700 kW capacity of wind power has considerable short-term benefit with
reduction of diesel fuel usage, but more importantly it would provide a platform of sustainable
renewable energy growth in Kaktovik for many years to come. This could include enhancements such as
thermal load offset, battery storage to enable diesels-off capability, creation of deferred heat loads such
as water heating, and installation of distributed electrical home heat units (Steffis heaters or similar)
controlled by smart metering. The latter, presently operational to a limited extent in the villages of
Kongiganak, Kwigillingok, Tuntutuliak, has enormous potential in rural Alaska to not only reduce the very
high fuel oil expenses borne by village residents, but also to improve the efficiency and cost benefit of
installed and future wind power projects. These opportunities and benefits are tangible and achievable,
but their cost benefit was not modeled in this report.
Lastly, it must be acknowledged that a wind power project in Kaktovik will provide benefits that are not
easily captured by the economic modeling contained in this report. These are the externalities of
economics that are widely recognized as valuable, but often discounted because they are soft values
compared to the hard numbers of capital cost, fuel quantity displaced, etc. These include ideals such as
long-term sustainability of Kaktovik, independence of Kaktovik from foreign-sourced fuel, reduction of
Kaktovik’s carbon footprint, and opportunities for education and training of Kaktovik residents, among
others.
has enormous potential in rural Alaska to not only reduce the very
high fuel oil expenses borne by village residents, but also to improve the efficiency and cost benefit of high fuel oil expenses borne by village residents, but also to improve the efficiency and cost benefit of
installed and future wind power projects. These opportunities and benefits are tangible ainstalled and future wind power projects. These opportunities and benefits are tangible a
but their cost benefit was not modeled in this report.but their cost benefit was not modeled in this report.
Lastly, it must be acknowledged that a wind power project in Lastly, it must be acknowledged that a wind power project in Kaktovik Kaktovik
easily captured by the economic modeling contained in this report. These are theeasily captured by the economic modeling contained in this report. These are the
economics that are widely recognized as valuable, but often discounted because they are economics that are widely recognized as valuable, but often discounted because they are
compared to the hard numbers of capital cost, fuel quantity displaced, etc. These include ideals such as compared to the hard numbers of capital cost, fuel quantity displaced, etc. These include ideals such as
term sustainability of term sustainability of KaktKaktovikovik, independence of , independence of
carbon footprint, and opportunities for education and training of carbon footprint, and opportunities for education and training of
off capability, creation of deferred heat loads such off capability, creation of deferred heat loads such
as water heating, and installation of distributed electrical home heat units (Steffis heatersas water heating, and installation of distributed electrical home heat units (Steffis heaters
controlled by smart metering. The latter, presently operational to a limited extent in the villages of controlled by smart metering. The latter, presently operational to a limited extent in the villages of
has enormous potential in rural Alaska to not only reduce the very has enormous potential in rural Alaska to not only reduce the very
high fuel oil expenses borne by village residents, but also to improve the efficiency and cost benefit of
Appendix C
NSB Village Heat Recovery Project Analysis Report
North Slope Borough
Village Heat Recovery
Project
Analysis
Report
CIP No. 13-222
Submitted to:
North Slope Borough
CIPM Division
February, 2010
2522 Arctic Boulevard, Suite 200
Phone (907) 276-0521 Fax (907) 276-1751
Anchorage, AK 99503-2516
ASR
Executive Summary
Report Scope
The North Slope Borough CIPM (NSB) requested that the 2006 Waste Heat Recovery Project
Analysis Report (PAR) be updated to reflect work completed during the 2008 waste heat
expansion project and to address the current potential for waste heat in the NSB. This report
addresses the waste heat recovery systems in the villages of Anaktuvuk Pass, Atqasuk,
Kaktovik, Nuiqsut, Point Hope, and Wainwright.
Project Background
CIP 13-222, the 2008 Areawide Waste Heat Recovery project connected numerous new
facilities to the waste heat system infrastructure and previously connected facilities were
brought back into operation in the villages of Anaktuvuk Pass, Atqasuk, and Kaktovik. This
project was considered to be substantially complete February of 2009. The newly connected
facilities were provided with direct digital controllers, which control and record the waste heat
usage into each facility. Significant fuel savings have been realized in the time these systems
have been in operation.
Research
RSA Engineering visited the villages of Point Hope and Wainwright to evaluate the existing
waste heat systems and their potential for heating additional Borough facilities. A waste heat
usage calculation was performed analyzing the theoretical amount of available waste heat for all
of the NSB villages with the exception of Point Lay. In both Point Hope and Wainwright the
existing power plant and waste heat connected buildings were noted to not be recovering waste
heat efficiently and will likely require troubleshooting, maintenance and upgrades to the controls
to re-establish effective use. Calculations indicate that the villages of Anaktuvuk Pass,
Kaktovik, & Atqasuk are at capacity for waste heat recovery, and additional expansions of these
systems are not recommended. Nuiqsut currently has natural gas available from the Alpine gas
field and additional waste heat expansion is not cost effective.
Recommendations
At this time expansions to the waste heat systems in the above referenced villages are not
recommended until such time as additional electrical power generation occurs, thus increasing
the availability of waste heat. Work at this time should be limited to troubleshooting problems
with the existing Point Hope and Wainwright systems. It is also recommended that new remote
monitored direct digital controllers with BTU meters be installed to replace existing outdated
controllers on the large waste heat utilizing facilities to assure efficient usage, provide remote
monitoring and determine the actual annual usage. Additionally Point Hope and Wainwright
facilities may be added to the waste heat recovery project if a history of surplus heat is
established. These facilities are listed in this report with rough order of magnitude construction
costs estimates. If repairs are completed at the Wainwright and Point Hope power plants, and a
history of waste heat availability is established with the use of BTU meters, the proposed new
connections may be re-evaluated for payback and viability.
Table of Contents
Section Page
Abstract………………………………………………………………………………………………….. 1
Project Background…………………………………………………………………………… 1
Engineering Considerations……………………………………………………………………………. 2
General………………………………………………………………………………………… 2
Methodology and Assumptions…………………………………………………………….. 2
Technical Considerations for Waste Heat Design………………………………………... 4
2009 Site Visits …………………………………………………………………………………………. 6
Point Hope…………………………………………………………………………. 6
Wainwright…………………………………………………………………………. 10
Site Visits Udated for CIP 13-222 Work………………………………………………………………13
Anaktuvuk Pass…………………………………………………………………… 13
Atqasuk……………………………………………………………………………. 15
Kaktovik……………………………………………………………………………. 17
Nuiqsut…………………………………………………………………………… 20
Conclusions and Recommendations……………………………………………………………….. 22
General ……………………………………………………………………………………… 22
Recommendations…………………………………………………………………………… 22
Construction Costs …………………………………………………………………………. 23
Appendixes
A – Waste Heat Availability and Fuel Savings Workbooks
B – Community Maps – Waste Heat Main Locations
C – Wainwright and Pt. Hope ROM Construction Cost Estimates
D – 13-222 DDC Record of Waste Heat Recovery & Screenshots
Tables
1 - Facilities Waste Heat Usage (Jan-09 to Nov-09)
2 - Village Fuel Costs History
3 - Point Hope Facilities
4 - Point Hope Glycol Usage
5 - Wainwright Facilities
6 - Anaktuvuk Pass Facilities
7 - Atqasuk Facilities
8 - Kaktovik Facilities
9 - Nuiqsut Facilities
10 - Facilities reccommended for controller upgrades
Page 1
Abstract
This report addresses the waste heat recovery systems in the villages of Anaktuvuk Pass,
Atqasuk, Kaktovik, Nuiqsut, Point Hope, and Wainwright. Point Lay was not considered in this
report. This report will address each facility connected to the waste heat systems, identify
equipment currently installed, and recommend additional measures to expand or optimize the
operation of each waste heat system.
Project Background
CIP 13-222, the 2008 Areawide Waste Heat Recovery project connected numerous new
facilities to the waste heat system infrastructure and previously connected facilities were
brought back into operation in the villages of Anaktuvuk Pass, Atqasuk, and Kaktovik. This
project was considered to be substantially complete February of 2009. The newly connected
facilities were provided with direct digital controllers, which control and record the waste heat
usage into each facility. Significant fuel savings have been realized in the time these systems
have been in operation. The following table lists the recorded waste heat recovery and fuel
savings up until November of 2009. Please refer to Appendix D for screenshots of these
controllers.
Table 1 - Facilities Waste Heat Usage (Jan-09 to Nov-09) 1
Waste Heat Fuel Fuel Cost (2009) 2 Cost Savings
Kaktovik Usage (BTUx106) (Gallons) (Dollars/Gal) (Dollars)
Clinic 177 1,539 $4.43 $6,818
Water Plant 361 3,139 $4.43 $13,906
Washateria 3 N/A N/A N/A $0
School 3 N/A N/A N/A $0
TOTAL 538 4,678 $20,725
Anaktuvuk Pass
Fire Station 149 1,296 $4.89 $6,336
HEMF 30 261 $4.89 $1,276
School 1,825 15,870 $4.89 $77,602
TOTAL 2,004 17,426 $85,214
Atqasuk
Fire Station 316 2,748 $2.75 $7,557
Public Safety Office 22 191 $2.75 $526
Clnic 243 2,113 $2.75 $5,811
TOTAL 581 5,052 $13,893
Areawide Total 3,123 27,157 $119,832
1 Not all waste heat connected facilities are listed below. Facilities with new digital controllers capable of remote monitoring
and btu usage recording are listed. 2 Cost savings calculated at 2009 fuel costs.
3 Kaktovik School and Washateria Controllers are not accessible - Anecdotal information from school maintenance personnel
report $600 per day savings in November.
Page 2
Engineering Considerations
General
The North Slope Borough is in a unique position for system wide energy conservation. The
Borough owns and operates all of the utilities, fuel systems, and public services supporting all of
the North Slope Borough villages. The operation of all the Borough facilities and services
requires a large quantity of fuel oil to generate electricity, heat buildings, and operate
equipment. The Borough purchases, stores and supplies all of the fuel used in the villages.
The Borough can save money on several levels by reducing the usage of fuel oil in the villages.
The primary and most easily accounted for direct cost savings is the reduction of fuel
purchased. Indirect savings include reducing or eliminating the need for additional fuel storage
tanks, reducing the handling of fuel oil, which reduces the risk of costly fuel spills, and the direct
savings associated with reduction in maintenance costs of heating systems. The potential
savings have increased dramatically in recent years due to the rising price of fuel oil, and will
likely continue to do so in the future.
A secondary advantage to the connected facilities is the redundant heating protection provided
by the waste heat system. The waste heat source is independent of the functionality of the
connected facility boilers. Although the Borough facilities are typically designed with redundant
boiler capacity, if the facilities were to run out of fuel or if there were to be problem causing all of
the boilers to stop operating, the waste heat system will protect the building from a catastrophic
freeze until the boilers can be brought back online.
Methodology and Assumptions
RSA Engineering visited the villages of Point Hope and Wainwright for the purpose of updating
this report as requested by the Borough.
Experience in construction administration and review of construction records of the 2008 waste
heat project provided the information needed to update this report for the villages of Atqasuk,
Anaktuvuk Pass, Kaktovik & Nuiqsut. We were not instructed to visit Point Lay, as a new power
plant is under design and the Point Lay waste heat system will be addressed under that project.
The design team performed a review of each of the buildings that were targeted by the NSB in
the villages of Point Hope and Wainwright as potential candidates for connection to the waste
heat systems. The review included analysis of existing building and waste heat drawings to
verify which of the buildings were sufficiently close and of sufficient size to warrant the capital
outlay of extending waste heat lines to the targeted buildings. Actual historical fuel costs and
power plant heat output was considered when determining the availability of waste heat and
feasibility of connection.
Heat usage of the facilities, which contain no industrial processes, were estimated on a
preliminary gross estimate by multiplying the area of the building by an estimate of heat loss in
terms of heat loss per square foot. Typically single story buildings, were assumed to consume
40 British thermal units per hour per square foot (Btu/Hr*ft2) on a design day, these estimates
were verified on a case by case basis with boiler sizing and record drawings available in the
RSA database. Boiler runtime was not considered for an estimate of heat usage for these
buildings as the investigative site visit was performed during the summer season. The larger
Page 3
industrial facilities heat usage estimates were taken from boiler sizing, and record drawings
when available. Water treatment plants, sewer treatment facilities, and some heavy equipment
maintenance facilities use a large amount of energy to support their operations. The sewer
treatment facilities in particular are designed for as much as 600 Btu/Hr*ft2 on a design day.
When boiler sizing was used to estimate heat usage it was assumed the boilers were designed
for 100% redundancy, or the building design day heat usage is one-half of the total boiler rated
outputs.
Estimates for buildings in villages other than Wainwright and Point Hope were carried over from
the previous waste heat reports, which utilized observation of boiler runtimes during the winter
season as well as building footprints to estimate heat usage.
Available waste heat from each village power plant was calculated based on actual historical
power production for the past year (2008). A typical diesel generator converts approximately
one third (1/3) of the energy stored in the diesel fuel to electricity, another third is converted to
heat which is rejected to the water jacket and pumped to the radiator or recovered by the waste
heat system, and the remainder is lost as heat with the exhaust gas, radiated heat, noise, and
minor inefficiencies within the motor. Using this model it follows that there is approximately the
same amount of heat available for recovery as there is power generated, and we conservatively
estimated that approximately 80% of this heat can be effectively captured and delivered to the
buildings when taking into account line loses and heat exchanger efficiencies.
Due to transportation costs and the limited time frame for purchase of fuel, the cost of fuel in
each village can vary significantly. The variance from year to year can also change due to the
price of crude oil, etc. The following costs were received from NSB-DMS for use in this report.
It should be noted that the costs listed are delivered costs of the fuel only. The listed price does
not include costs associated with transfer of the fuel to the Borough storage facilities or the cost
of the fuel storage facilities themselves. The listed cost does not include additional expenses
for transferring the fuel, spill clean up, or the cost of the distribution system. The value for these
additional items is not readily identifiable but could increase the true cost to twice the indicated
cost.
Table 2
Village Fuel Cost History
Village FY 2009 FY 2008 FY 2007 FY 2006
Anaktuvuk Pass $4.89/gal $5.52/gal $3.85/gal $4.31/gal
Atqasuk $2.75/gal $2.79/gal $3.62/gal $2.09/gal
Kaktovik $4.43/gal $2.85/gal $3.00/gal $2.51/gal
Nuiqsut $2.88/gal $4.30/gal $3.62/gal $2.56/gal
Point Hope $4.52/gal $2.85/gal $3.03/gal $2.58/gal
Point Lay $4.43/gal $2.85/gal $3.03/gal $2.51/gal
Wainwright $4.43/gal $2.85/gal $3.03/gal $2.51/gal
The fuel savings model for each village uses this calculated available waste heat; and on a
monthly basis subtracts the waste heat usage from buildings currently connected to the system.
The model then takes the remaining available waste heat and distributes it to the potential new
facility connections. The potential additional recovered heat is totaled and converted to gallons
of fuel savings. Note that the heat demand for the existing waste heat connected facilities and
new potential connections are scaled based on the average historical temperature versus the
ASHRAE design temperature for the area. Please refer to Appendix A for community fuel
savings summary workbooks.
Page 4
It is assumed that too much waste heat cannot be recovered since each of the power
generators has an internal thermostat which will prevent overcooling of the engine. A three way
mixing valve at the engine coolant outlet further controls waste heat temperatures going to the
waste heat loads. The engine pre-alarms are typically set at 205 degrees F, with engine shut
downs typically set at 214 degrees as suggested by the engine manufacturer. With this in mind,
a waste heat temperature of 190-200 degrees is optimal. These temperatures can be set by the
DDC system at the generator building. On a very cold or design day, the overall supply and
return temperatures of the waste heat loop will lower as end users maximize the available waste
heat, and the entire system will drop in temperature. When this occurs the end user waste heat
exchanger control valves begin to close off supply of the waste heat and the boilers will begin to
fire to maintain their buildings at the minimum boiler set point. During these design days when
the available waste heat is at capacity supplemental heat may be periodically required in the
generator building.
To achieve maximum heat recovery, the end user boilers must be set at each of the sites to
operate at temperatures that are as low as possible. Most boiler manufacturers require that the
boiler not operate below 140 degrees F return temperature to avoid condensation in their heat
exchangers, which typically results in corrosion. It is recommend that all boiler systems utilizing
waste heat be set to turn on at 145 degrees F and cycle back off at 165 degrees F.
On a case by case basis, if some rooms in a waste heat connected facility cannot keep up and
maintain temperatures during a design day, than it may be necessary to reset boiler setpoints
higher for that particular location. This is due to the output of baseboard and other heat transfer
devices degrading exponentially as the heating fluid temperature drops. When operating the
boilers at a lower temperature we are relying on the extra capacity that is typically installed in
radiation systems to provide adequate heat to the space.
Thermal energy backfeed is a real concern with this type of system. If the boiler setpoint is
higher than the available waste heat temperature and the waste heat control system has
malfunctioned or has been disconnected allowing the waste heat system to continue to
exchange energy with the hotter building boiler system, the boilers will heat the waste heat loop
returning energy to the generator building or other connected facilities. It is important to have
robust and reliable controllers monitoring the waste heat exchange at the end user facilities.
The recently installed waste heat systems use current internet compatible direct digital controls
(DDC) to operate diverting valves at each building to automatically return the waste heat if it is
cooler than the building glycol return, protecting the system from thermal energy backfeed.
Technical Considerations for Waste Heat Design
All replacement power plants in the NSB operate high efficiency generators that produce lower
quality (lower temperature) waste heat than their predecessors. However, other gains in waste
heat efficiency have been included in the power plant designs to boost energy recovery as
much as possible. These advances increase the efficiency of waste heat production, as well as
waste heat distribution.
All replacement generators throughout the NSB include marine engine cooling headers to
maximize heat transfer to the waste heat loop. As more generators are replaced, the amount of
available waste heat at each village will increase. Radiator fans are now powered by variable
Page 5
frequency drivers (VFDs), which allow them to operate at the best efficiency instead of over-
cooling the jacket water or cycling on and off. Main circulation pumps are also on VFDs. For
safety and maintenance reasons, we did not consider addition of exhaust gas waste heat
capture.
Depending on the proximity of buildings connected to the waste heat system, we may be able to
improve distribution efficiency by installing new circulation pumps in the power plant, or new
dedicated service to distant buildings, especially if the most remote building is a large fuel user
such as the school. This would guarantee that the flow intended to serve the school does not
get short circuited at other buildings.
There is a limit to the operating pressure allowed with the HDPE arctic piping previously used
for transferring waste heat glycol from the power plant to connected facilities. HDPE arctic pipe
was previously chosen to be the piping system for direct bury applications due to is non-
corrosive and flexible characteristics, high insulation value and local availability. Due to the high
temperature of the waste heat fluid, the HDPE piping is not rated to operate above 40 pounds
per square inch (psi). This pressure rating limits the distance the fluid can be pumped with a
single pump station. Generally the fluid cannot be pumped more than 4000' depending on flow
rates and piping size, which is the combined piping distance of the loop (ie. 2000' one way). For
piping loops greater than 4000' in length a pump booster station is required, or high pressure
piping will need to be utilized. If a high pressure system is utilized, pressure relief valves and
expansion tanks part of the existing system may need to be replaced with equipment rated for
the new higher pressure.
The preferred method of connecting the waste heat into an existing boiler loop without affecting
the constant flow of the waste heat loop, or the pressure of the existing boiler loop is to pipe the
heat exchanger in a primary/secondary arrangement. A small pump is required to inject heat
from the heat exchanger into the boiler return header, and the waste heat flows continuously
through the heat exchanger allowing for point of use temperature monitoring. A 3-way valve is
included to divert the flow in case the boiler return temperature is higher than the waste heat
that would be injected.
The system must include a local DDC controller that is programmed to determine whether or not
waste heat is available, and open or close the diverting valve to prevent the boiler from heating
the waste heat loop. A stand-alone controller provides for efficient waste heat use at each
building without coordination of waste heat use throughout the village, and would be interlocked
with the existing boiler control systems. Additional piping and controls could be included to
provide a coordinated village wide effort. However, the added complexity and cost would
provide energy savings at the pump only and would not provide more efficient use of the waste
heat. In order to keep construction costs down and reduce maintenance costs, we recommend
keeping the system as simple as possible.
Page 6
2009 Site Visit Reports
Point Hope
Table 3
Point Hope Facilities
On Waste Heat Unconnected
Power Plant PSO
School Fire Station
Utilidor USDW
Grey Water Building Sewage Treatment Plant
Health Clinic
Old Water Plant/Washeteria
The first priority at Point Hope should be performing overdue maintenance to the current system
to improve waste heat recovery. Maintenance items include repair of known waste heat glycol
leaks within the power plant, location of other leaks if detected, and repair/upgrades to the
power plant DDC monitoring. It is recommended that where users are currently connected to
the waste heat, upgrades of controls for monitoring and thermal energy back feed protection be
installed. Once monitoring has been installed and waste heat is proven to be available,
expansion of the waste heat system may be considered. Future modifications include the
installation of a heat exchanger in the end user facilities, the installation of piping to tie the heat
exchanger into the existing heat system and controls required for operation of the system.
Power Plant
The point hope power plant contains eight (8) generators, #1, #2 & #3 are rated to 310 KW
output, #4 is 410 KW, #5 is 210 KW, #6 & #7 are 665 KW and #8 is a 910 KW generator. As of
our last visit, our understanding was generators #3, #4 & #5 were to be demolished or relocated
from the facility.
Calculations based on historical power plant electrical output and current connected load
indicate that there is not adequate waste heat available from this power plant to allow for
expansion of the system with acceptable payback. (see Appendix A) Point Hope has an
extensive waste heat system routed in an above ground utilidor which in addition to the waste
heat piping mains, contains the domestic cold water piping, waste piping, groundwater/grey
water piping, fire protection piping for the utilitor and abandoned fuel oil piping all of which serve
the connected buildings listed above. Some maintenance work has been completed on the
waste heat system since the last waste heat report, and the waste heat system is partially
operational. New waste heat circulation pumps were installed in March ’08 and known leaks in
the generator #1 heat exchanger and piping was repaired. At the time of this inspection
additional leaks were still present in the power plant, specifically at the Generator #2 waste heat
exchanger, which has proven to be uncorrectable and had been isolated from the system.
During this inspection, the waste heat system pressure across the new circulation pumps was
observed to be 0 PSIG at the suction, and 15 PSIG at the outlet. The waste heat inline pump
must have positive (typically 5 PISG) suction inlet pressure to operate properly. Upon my
direction, the operators added approximately 40 gallons of glycol mixture which brought the
suction pressure up to 7 PISG and the discharge pressure to 17 PSIG, which is a satisfactory
Page 7
operating condition. Over the next two days the waste heat system glycol pressures were noted
to drop to 3 PSIG at the inlet and 16 PSIG at the discharge. This pressure drop indicates that
there remains a leak in the waste heat system. Records were obtained from the power plant
operator and the following values of glycol usage were reported from Dec-07 to May-09:
Table - 4 Point Hope PP Glycol Usage
Month Start Month End Glycol (Gal.)
Dec 12 07 Jan 21 08 110
Jan 21 80 Feb 18 08 270
Feb 19 08 Mar 17 08 110
Mar 17 08 Apr 21 08 120
Apr 21 08 May 19 08 165
May 19 08 June 16 08 165
Jun 16 08 Jul 21 08 110
Jul 21 08 Aug 18 08 110
Aug 19 08 Sep 15 08 110
Sep 15 08 Oct 20 08 25
Oct 20 08 Nov 17 08 25
Nov 17 08 Dec 15 08 200
Dec 15 08 Jan 19 09 250
Jan 19 09 Feb 16 09 25
Feb 16 09 Mar 16 09 110
Mar 16 09 Apr 20 09 140
Apr 20 09 May 18 09 75
Although glycol usage has marginally declined starting in October 2008, there is still an
unacceptably high loss of glycol from the system at the time of the visit. Fortunately the entire
waste heat system is accessible above ground within the utilidor. During this inspection, the
engineer inspected the portion of the waste heat system up to the connection to the end user
heat exchangers in its entirety and found no evidence of a leak. It is possible that the glycol may
be leaking through the end user heat exchangers and into the connected facilities boiler
systems. A brief conversation with the maintenance staff available reported no unaccounted for
glycol gains in the School. The other facilities maintenance staffs were not available to
comment.
In order to locate the source of the glycol loss, it is recommended that first, the remaining minor
leaks within the power plant waste heat system be repaired, including replacement of the
generator #2 and #1 heat exchangers, piping and controls. Second the end user buildings
should be individually isolated, and the waste heat system brought up to operating pressure. If
the system holds pressure with all the end user building isolated, each individual end user heat
exchanger may be reconnected and tested for leaks.
A recommendation for maintenance is the replacement of the waste heat system expansion
tank, which is suspected to be waterlogged. Adequate expansion compensation is fundamental
for the waste heat system, which undergoes significant temperature changes under normal
operation. Without good expansion compensation, pressure spikes will occur damaging
equipment and creating additional leaks.
Point Hope PP Glycol Usage
0
50
100
150
200
250
300
Jan
21
08
Feb
18
08
Mar
17
08
Apr
21
08
May
19
08
June
16
08
Jul
21
08
Aug
18
08
Sep
15
08
Oct
20
08
Nov
17
08
Dec
15
08
Jan
19
09
Feb
16
09
Mar
16
09
Apr
20
09
May
18
09
Dec
12
07
Jan
21
80
Feb
19
08
Mar
17
08
Apr
21
08
May
19
08
Jun
16
08
Jul
21
08
Aug
19
08
Sep
15
08
Oct
20
08
Nov
17
08
Dec
15
08
Jan
19
09
Feb
16
09
Mar
16
09
Apr
20
09
DateGallons
Page 8
A definitive amount of waste heat recovered is not available at this time as there are currently
no BTU meters installed on the connected facilities, or historical records of the waste heat
system operating temperatures. It was reported from the power plant operator, George
Koonaloak, that the power plant had become cold during the previous January and February,
which indicates that all the extracted waste heat was being utilized during that time.
A review of the waste heat system DDC control system is advisable, as the power plant
operators have all but stopped using it as a reliable indication of the status of the system.
Temperature and pressure sensors should be verified with hand held instruments and replaced
as necessary. The radiator VFD’s and waste heat three way mixing valves should be verified as
operating per the sequence of operation. The system must have accurate indication of the
coolant temperatures, to allow for automatic operation. The previous PAR reported the power
plant operators had been controlling the engine radiator fans manually because the automatic
control was not reliable. Manual operation of the radiators discharges available waste heat to
the atmosphere which may be otherwise used.
Health Clinic
The Clinic was remodeled and reconnected to the waste heat system in 2007 (CIP 19-068).
During this project, the existing heat exchanger was re-built and new circulation pumps
provided. A new DDC system was installed in the clinic, monitoring both the building HVAC
systems and the waste heat input. During an unrelated site visit in the winter of 2008, the Clinic
fuel oil tank was noted by RSA to have been run dry, and the boiler was not operating. The
building had been maintaining comfortable temperature from the waste heat system alone, and
maintenance was not aware of the problem with the boiler. No further work is recommended in
this facility.
Water Distribution Building/Washateria
This building is presently served with waste heat which flows both into the water distribution
waste heat exchanger, and runs directly into the old Washateria air handler. The Water
Distribution building heat exchanger is a Polaris model S30-81 designed for 1273 MBH of heat
transfer. Relatively low temperatures (~100 °F) were apparent on the waste heat piping leading
into the heat exchanger and it is suspected that the motorized valve controlling flow of waste
heat into the water distribution waste heat exchanger was closed. This building is potentially a
large user of waste heat, and the system needs to be tested for correct operation during the
winter season. In order to establish a record of waste heat usage it is recommended that a BTU
meter be installed.
Additionally, we recommend the waste heat piping which currently feeds the abandoned
Washeteria air handler should be demolished to avoid potential leaks. As part of the effort to
track down power plant glycol usage, the heat exchanger in the building should be isolated and
tested for leaks.
School
The school waste heat recovery equipment is located within the old Grey Water building. The
waste heat glycol is pumped via 4" piping from the power plant up through a heat exchanger
and returned to the power plant. The heat exchanger is a Tranter Superchanger model US-
295-HP-93 designed for 2365 MBH of heat transfer. The school 4" heating glycol is circulated
through the waste heat exchanger as controlled by a manual inline butterfly valve, and a series
of four (4) WeilMclain gold WTGO-9 cast iron boilers are piped in parallel to the supply piping
manifold after the waste heat exchanger. A 2" heating pipe is tee'd into the schools 4" supply
piping just before it leaves the building. This 2" supply piping is served by its own set of duplex
Page 9
pumps and is believed to supply heat to the elementary school. The return line from this 2"
supply to the elementary school was not apparent, and it is assumed it is connected to the
larger 4" school return piping main within the school facility.
The current method of controlling the transfer of heat between the school loop the waste heat
loop are manual butterfly valves. It is recommended that a digital control system be installed to
monitor the temperature differential of the waste heat loop versus the school loop, and
automatically control the flow valve open when heat is available for recovery. This will both
protect against thermal backfeed from the school and have the capability to monitor waste heat
usage.
As mentioned in the power plant system description, as part of the effort to track down and
account for the power plant glycol usage, this heat exchanger should be tested for internal
leakage.
During the design phase to troubleshoot and upgrade the existing waste heat system, additional
inspection of the internal school boiler system layouts and operations will be required to ensure
waste heat usage is effective.
PSO Building
The PSO building has two Weil McLain Gold boilers, each firing with 1.2 GPH, resulting in a 146
MBH heat capacity for each boiler. This facility is the nearest to the existing waste heat loop
and the least expensive to connect. We would recommend installing a heat exchanger on the
wall opposite the boilers. We estimate a heat load at the PSO building of about 175 MBH,
which could be served with a 1-1/2” waste heat line. Connection to this facility would depend on
proven available heat from the power plant once digital monitoring is established.
Fire Station
The fire station does not currently have any waste heat service. The building is served with two
cast iron sectional Weil McLain Gold boilers model WGO-9, each with a gross output of 295
MBH. The boilers have a common return line, which is sized at 2”. This facility is the same floor
plan and equipment layout as is typical of the standard NSB fire station design. A future waste
heat exchanger, controls and valves may be located in the water tank room adjacent to the
boiler room if additional waste heat is available in the future.
USDW Building
The USDW building is quite far away from the power plant, so waste heat service to this building
would be expensive, with a marginal payback. The HDPE piping used on previous projects has
limited pressure ratings, and the length of run to the building may require the use of an
intermediate booster station or higher pressure steel piping, both increase the cost of the
installation dramatically. The building has two cast iron sectional boilers, each with 1,553 MBH
gross output. The boiler room was noted to be excessively hot, with little available room for a
waste heat exchanger. The building can be carried with only one boiler, and it never runs
continuously. If a waste heat system were added, power would be routed from the control panel
in the maintenance office below the boiler room.
Sewage Treatment Plant
The sewage treatment is the most remote NSB facility in Point Hope, it is also potentially one of
the largest heat consuming facilities. This building contains has two boiler rooms with a total of
Page 10
three boilers. The fist boiler room contains a single WeilMclain 578 boiler with a total rated
output of 453 MBH. The second boiler room contains two WeilMclain 688 boilers each with a
rated output of 1358 MBH. It is assumed that only one of the two 688 boilers is required to meet
the building design day demand, and the potential for waste heat usage is on the order of 1800
MBH. There is available space within the vacuum pump room, which may be used for the
location of waste heat equipment. The length of run demanded for this building (and the USDW
building) may require the use of a booster station or high-pressure steel piping. Similar to the
other buildings in this village, connection to the waste heat system will depend on proven
availability of waste heat, which may mean waiting for an increase in electrical use producing
more waste heat.
Heavy Equipment Maintenance Facility
This facility utilized oil fired furnaces, which cannot be retrofitted to use waste heat. Waste heat
usage in the facility would require the installation of a hydronic system, and is considered to be
cost prohibitive.
Wainwright
Table 5
Wainwright Facilities
On Waste Heat Unconnected
Power Plant School
Public Works PSO
HEMF Clinic
Sewer Plant Water Plant
Fire Station
Power Plant
The Wainwright Power Plant contains five operating generators, three (3) 430 KW units and two
910 KW models. Generators #4 & #5 were installed from '99-'01 and carry the majority of the
village electrical load.
Calculations based on historical power plant electrical output and current connected load
indicate that there is not adequate waste heat available from this power plant to allow for
expansion of the system with acceptable payback. (see Appendix A) In addition to providing the
local heating for the power plant building, currently the HEMF/Public Works building and
Sewage Treatment plant are connected to the waste heat system. These connected building
are extremely high demand facilities, and together are a good balance for the current output of
the power plant.
Although calculations indicate waste heat should be available to supplement a minimum of 50%
of the total heat for the existing connected facilities, it is reported from the power plant operator,
and local maintenance personnel that the power plant gets cold during the winter months and
the HEMF/Public works building requires ample use of their boilers to maintain the building
heat.
Page 11
It is recommended that an engineer perform site visit during the winter months to evaluate and
trouble shoot the existing waste heat systems and subsequent connected building heating
systems for inefficiencies in operation.
Items which may be contributing to the lack of available waste heat include but are not limited
to:
Improper control of generator dampers: It was noted by the operators that the generator
#5 & #6 radiator return dampers are sticking open, and must be manually reset. All
outside air dampers are operated manually. The generators #1, #2 & #3 return dampers
are disconnected.
Improper control of 3-way valves and fans: It is reported that the radiator fans operate
year around. This indicates that heat is being rejected to the atmosphere rather than
being directed to the waste heat system. The waste heat exchangers are sized to fully
cool the generators if waste heat demand is present.
Improper control of end user waste heat exchanger controls.
Plugged or damaged heat exchangers
Cavitating/damaged pumps.
End user boiler system set to high.
Improper piping layout/sizing in power plant and end user buildings.
Once the current waste heat system is established to operate effectively, the system may be re-
evaluated for expansion of the loop to serve the school and adjacent North Slope facilities. If
the village demand for power is increased, the subsequent increase in waste heat may warrant
an expansion of the system.
The proposed future below grade insulated arctic HDPE glycol supply and return line would be
routed around the current west edge of the village to the grouped location of facilities in the
center of the village. The approximate length of the supply and return loop is 8000 feet. Due to
the low pressure capacities of HDPE pipe at the waste heat operating temperatures, a minimum
of one booster pump station will be required located at the midpoint of the loop to provide the
necessary boost pressure required for the length of run. An alternative construction method,
using welded steel arctic pipe may be utilized enabling the use of high pressure pumping
(greater than 40 psi) to avoid the use of booster stations. This would require replacement of
components of the exiting waste heat system to with ASME certified and high pressure
equipment. This equipment replacement would include expansion tanks and pressure relief
valves as well as heat exchangers and associated valves based upon analysis of their existing
rated capacities.
HEMF / Public Works
The HEMF/Public Works building is currently connected to the waste heat system and is a large
user of heat. The maintenance facility portion of the building has an apparatus bay which likely
requires constant heating during the winter. The building's primary heat source is three
Burnham model 4FW.277.45.LB 2062 MBH boilers manifolded to 6"ø HGS/HGR piping. Waste
Page 12
heat is provided by a Mueller Accu-Therm model AT40 B-20 plate and frame heat exchanger
with 4"ø flanged connections designed for 2914 MBH heat transfer. The heat exchanger is
currently 21 years old and may need to be cleaned or replaced if efficiency has declined due to
deposits on the plates.
As mentioned above the maintenance personnel have been relying on the boilers for heat
during the winter, and operating them at a setpoint of 180 deg. F, effectively receiving no
benefits from the waste heat system. The boilers must be set below the temperature of the
waste heat in order to receive waste heat. It is common design practice and likely that this
building was designed to have 180 degree hydronic circulation to meet the design day
(maximum expected) heating load. The maintenance staff are likely operating the boilers at this
high temperature setpoint to guarantee the building remains comfortable during extreme cold
snaps. It is recommended that a new control system with outside air reset to automatically reset
the boiler loop temperature during more mild periods be considered for installation in this
building which would increase the waste heat use in this building.
Sewer Plant
This facility is currently connected to the waste heat system via above grade 4" arctic pipe on
pipe piers across the tundra. The waste heat exchanger is a Graham model GPE-42 designed
for 1987 MBH heat transfer. This unit was manufactured and installed in 2002 concurrent with
the replacement of the generators #4 & #5. The sewer plant primary heat source is two (2)
Smith series 28A-10 boilers with individual outputs of 1939 MBH each. This system would also
benefit from the addition of an outside air reset schedule based on outdoor air temperature.
Automatically lowering the temperature of the buildings hydronic loop will allow for more use of
the available waste heat.
School
Both the elementary and high school wings are supplied by a single boiler room, located on the
west end of the complex. There are three boilers in this facility, two (2) WeilMclain model 788-
WS boilers with a rated output 1632 MBH each, and one (1) WeilMclain model 588W with a
rated output of 1357 MBH. These three boilers are manifolded to a 4" glycol hydronic line, and
the system appeared to be in good operating condition. There is no available space in the
school boiler room for a waste heat exchanger; however the adjoining storage room which
contains a chest freezer may be utilized for future waste heat equipment. This building is a
good candidate for waste heat utilization if additional heat is available in the future.
Fire Station
The fire station does not currently have any waste heat service. The building is served with two
cast iron sectional Weil McLain Gold boilers model WGO-9, each with a gross output of 295
MBH. The boilers have a common return line, which is sized at 2”. This facility is the same floor
plan and equipment layout as is typical of the standard NSB fire station design. A future waste
heat exchanger, controls and valves may be located in the water tank room adjacent to the
boiler room if additional waste heat is available in the future.
Water Treatment Plant
The water treatment plant is another potential large user of waste heat. Currently the facility is
heated with two (2) Smith cast iron series 28A-14 boilers with a gross output of 3098 MBH each.
Page 13
The boilers are manifolded to supply a 6" HGS/HGR service to the building. Although there is
no available space in the existing boiler room, the adjacent garage area/workshop may be
rearranged to accommodate the equipment. A significant increase in electrical usage will be
required to provide enough heat to supplement this building.
Public Safety Building
The PSO office is along the route of the proposed future line to the School, and could be
connected to the waste heat system. The boilers in the PSO are Weil Mclain cast iron model
WTGO-9 1.5 GPH cast iron sectionals, with 181 MBH capacity. Power for the new system can
be taken from panel E in the garage, using empty circuit spaces 22 & 44. The panel is a
Square D NQOD panelboard. We propose using a 1-1/2” branch line to the PSO building, with
a 175 MBH heat exchanger.
Site Reports Updated for CIP 13-222 Work
Anaktuvuk Pass
Table 6
Anaktuvuk Pass Facilities
On Waste Heat Unconnected
Power Plant Museum
USDW Public Safety Office
Fire Station Terminal Building
Sewer Plant Clinic
DMS Warm Storage Water Treatment Plant
School
HEMF
CIP 13-222 included routing of a new below grade branch loop to connect the School and
HEMF building to the waste heat system. Our waste heat availability calculation indicates that
there is not currently enough waste heat to provide payback for the piping extension and pumps
necessary to add additional new facilities. Refer to Appendix A.
Data from the 2008 Area Wide Waste Heat Recovery project digital controllers is available at
this time. From February, 2009 through November 2009, the new DDC BTU meters recorded
2,000 MBTU (million British thermal units) recovered to the newly connected Fire Station HEMF
and School. At 2009 fuel costs this equates to 17,426 gallons of fuel or approximately $85,000.
Refer to Appendix D.
It is recommended that buildings previously connected to the waste heat system prior to the
2008 construction be updated with new web enabled digital controllers for ease of maintenance
and remote monitoring.
Power Plant
The Anaktuvuk Pass power plant had new VFD controlled waste heat circulation pumps
installed to serve the School and HEMF building in 2008 during CIP 13-222. The new
Page 14
circulation pumps supply below grade 4” HDPE arctic pipe to the school, with a 1-1/2” branch to
the HEMF building.
The waste heat at the Anaktuvuk Pass Power Plant is distributed off a 6” header, located at the
southeast corner of the building. The main circulation pumps are manufactured by Grundfos,
sized at 345 GPM, 60’ Head. The school circulation pump is manufactured by Bell and Gossett
sized at 267 GPM, 190’ Head.
School
The school is heated by eight (8) small cast iron sectional boilers: three (3) Slantfin and five (5)
Weil McLain Gold (263 MBH each). The main supply and return headers are 4”. A new heat
exchanger manufactured by Tranter model GXD-026-L-5-NP and a Grundfos model 3.0LM6.3
injection pump were installed in the large open space where water and sewer tanks had been
removed. It is anticipated that the payback time will decrease further as energy production is
increased at the power plant.
The new waste heat arctic pipe is routed through the boiler room floor, east to Illionis Rd. and
back to the power plant along the north side of Summer St.
We have received favorable reports regarding the reduction in fuel usage for this facility.
Unfortunately due to equipment failure in the NSB network we do not have access to the digital
controller. A total amount of waste heat recovered in this facility will be provided as a
supplemental index when available.
Heavy Equipment Maintenance Facility
Waste heat service to the HEMF was established in 2008 with CIP 13-222. Two (2) Weil
McLain BL-776-WS boilers heat the building, each with an output of 480,000 Btu. The main
supply and return headers are 2-1/2”.
Fire Station
2” waste heat piping enters through the south wall of the fire station and serves the two unit
heaters in the apparatus bay directly. The waste heat piping was rerouted from apparatus bay
unit heaters to supply the boilers with CIP 13-222. The building received a new waste heat
exchanger, pump and controller similar to the rest of the newly connected buildings.
Sewage Treatment Building
An issue with the ventilation system resulting in bad septic odors was previously reported in
2006. It is unknown if this problem still remains. The building is presently connected to waste
heat, and no further work is anticipated. Digital waste heat usage monitoring is recommended in
this facility.
USDW Building
Page 15
The USDW is presently connected to waste heat with a 3” Alfa Laval heat exchanger, piped
directly into the boiler return header with a 3-way valve. The main building circulators flow glycol
through the heat exchanger. The waste heat supply was at 180 degrees F, returning at 160
degrees F, and the boilers were not firing. The system appears to be functioning properly.
Digital waste heat usage monitoring is recommended in this facility.
PSO, Terminal Building, Clinic, Water Treatment Plant & Museum
These facilities are not located in close enough proximity to the power plant for waste heat
addition without the use of pump booster stations. These building represent a significant
amount of potential waste heat usage, and may be re-considered for waste heat service if
power plant output significantly increases.
Atqasuk
Table 7
Atqasuk Facilities
On Waste Heat Unconnected
Power Plant Warm Storage
Washeteria HEMF
School Waste Treatment Plant
Vacuum Building
Water Plant
Fire Station
Public Safety Office
USDW
Clinic
Community Center
The work completed in Atqasuk with CIP 13-222 included providing new waste heat connections
to the public safety office, fire station and clinic. Other work completed included restoring
operation in the USDW building, repairing a major glycol leak, replacing the waste heat
circulation pumps with new VFD controlled pumps, and rebalancing the system.
Data from the 2008 Area Wide Waste Heat Recovery project digital controllers recorded 851
MBTU recovered to the newly connected Fire Station HEMF and School. At 2009 fuel costs this
equates to 5,052 gallons of fuel or approximately $13,900. Refer to Appendix D. This recorded
fuel savings does not include fuel savings from the existing connected facilities which have no
BTU monitoring capibility.
At this time all facilities within a reasonable distance are connected to the waste heat system.
New connections to NSB owned facilities are not feasible due to their remote location in relation
to the power plant. It is recommended that the existing obsolete controllers in buildings
previously connected be updated with new web enabled controllers, for monitoring and ease of
maintenance.
Power Plant
Page 16
The waste heat at the power plant is distributed off a 6” header that runs out to a second
building, which is adjacent to the old washeteria. The existing waste heat pumps were identified
as damaged from excessive cavitation were replaced as a change order to CIP 13-222 with new
pumps, and reconnected to the VFD drives. Additionally the bladder of the large waste heat
tank was replaced to help provide positive inlet pump pressure on the VFD pumps. At the time
of substantial inspection the pumps were operating satisfactory and controlled by the existing
controllers to maintain waste heat hydronic pressure.
It is recommend that the power plant DDC control system be inspected and considered for a
system wide upgrade. The control system, typical for all power plants is supported by obsolete
computer controllers. There is a heat exchanger located in the adjacent Washateria that we
understand is no longer in use and should be demolished.
Fire Station
This building was connected to the waste heat system in 2008, complete with a web based DDC
controller. The building is served with two cast iron sectional Weil McLain Gold boilers, each
with a gross output of 295 MBH. The boilers have a common return line, which is sized at 2”.
No additional work is needed in this building.
Clinic
A wall mounted, brazed plate heat exchanger was installed in 2008 to serve the clinic. The clinic
building has a current web based controller for maintenance and monitoring. The clinic also
houses the community center heat exchanger.
Public Safety Building
The PSO office is along the route of the existing 4” line to the School and USDW, and is now
currently connected to the waste heat system with work done under CIP 13-222. The boilers in
the PSO are 1.5 GPH cast iron sectionals, with 181 MBH capacities. This building has a current
DDC controller.
Community Center
The community center is connected to the waste heat system with 2” pipes, through the clinic,
as mentioned above. The community center was reported to be relying almost entirely on waste
heat in the 2006 PAR. A new DDC controller is recommended in this facility.
Water Treatment Plant
The new water plant was served with waste heat from the power plant prior to 2006. A new
DDC controller is recommended in this facility.
Vacuum Plant
The vacuum plant was served with waste heat prior to 2006. A new DDC controller is
recommended in this facility.
School
The school is presently served with a 4” line that originates at the room just outside the power
plant and now branches to the fire station, PSO, and HEMF building. New zone control valves
were installed within the school, and the existing controller was repaired. At the time of
completion of the 2008 waste heat project the school was receiving waste heat. It is
recommended that a new digital controller with remote monitoring capabilities be installed in this
facility to aid in maintenance and monitoring.
Page 17
USDW
The USDW building’s existing 3” waste heat service and heat exchanger were reconnected and
returned to service. Additionally a side stream filter was installed to remove particulates from
the boiler loop to reduce the risk of future valve malfunction. The waste heat system is currently
using the original building controller which is outdated. A new waste heat controller similar to
those installed in the fire station and PSO should be installed for ease of monitoring and
maintenance.
Kaktovik
Table 8
Kaktovik Facility Status
On Waste Heat Unconnected Facilities
New Power Plant Vacuum Station
School Public Safety Office
Old Power Plant / Washateria Vehicle Maintenance & Storage
USDW
Fire Station
Health Clinic
Water Treatment Plant
Work performed under CIP 13-222 connected the majority of the NSB buildings with the
exception of the new USDW, VMS, public safety office and vacuum building. It is understood
that the new USDW building was connected to the waste heat system during its construction.
There are 4” buried waste heat mains presently installed and operating from the new power
plant to the old power plant with a 4” tee off to the USDW building. A 3” above ground arctic
pipe loop was installed during CIP 13-222 to supply the Firestation, Clinic, and Water Treatment
Plant.
Data from the 2008 Area Wide Waste Heat Recovery project digital controllers recorded 531
MBTU recovered to the newly connected Clinic and Water Plant. At 2009 fuel costs this
equates to 4,678 gallons of fuel or approximately $20,700. Refer to Appendix D. This recorded
fuel savings does not include fuel savings from the School, Washeteria, or from the existing
connected facilities. The School and Washeteria were provided with DDC controllers and
remodeled waste heat recovery systems with CIP 13-222 however they are currently not
operating. The reason for this failure is currently not known. Prior to the failure the School
maintenance personnel reported approximately $600 per day in fuel savings. It is our
understanding that the NSB maintenance personnel were working on troubleshooting the failure
and repairing the problem.
Currently all waste heat connected facilities in Kaktovik are updated with current web enabled
DDC controllers. It is recommended that in addition to restoring the operation of the School and
Washateria waste heat system the power plant control system including the waste heat
monitoring system receive a full checkout to verify correct output to the user interface and
replacement of damaged sensors.
Page 18
Power Plant
The new power plant has 910 kW generators. The power plant has 2-4” waste heat supply and
two 4” waste heat return blind flanges at the main waste heat header. A new 4” line was added
from the header to serve the water treatment plant, clinic, and fire station with CIP 13-222.
USDW Building
This building was recently demolished and rebuilt. RSA Engineering has not had an opportunity
to inspect this facility, however we are informed that it is currently connected to the waste heat
system. No other information is available at this time.
VMS Building
This Vehicle Maintenance and Storage building is heated with four oil fired unit heaters elevated
on the structure. There is also an oil fired ventilation make up air unit in the mezzanine of the
VMS building that is was not operational at the time of the 2006 PAR inspection. Oil fired unit
heaters that are elevated are very difficult to service, so they typically suffer from a lack of
scheduled maintenance. Both the oil fired unit heaters and the oil fired make up air ventilation
units present a fire hazard that could be eliminated if the units were replaced with hydronic unit
heaters and a hydronic make up air unit. We could remove the oil burner section of the
ventilation unit and retrofit it with a coil and coil control valve if desired. This would require the
installation of a complete hydronic system sized to handle the load in the absence of a waste
heat system.
The new proposed unit heaters would be sized at 100 MBH each, with four vertical oriented
heaters spaced along the center of the shop. These heaters would be hydronic units, with the
hot glycol coming from the USDW boiler room. This will require extending a 2-1/2” heating
supply and return line from the USDW boiler room over to the VMS building. The suggested coil
retrofit for the make up air unit would be sized based on the airflow the unit is required to carry.
Currently, the waste oil burner heats the shop with free oil. Therefore we only recommend
adding waste heat as part of a larger project that includes the USDW.
Clinic Building
The clinic was connected to the waste heat system with the completion of CIP 13-222. This
facility has a current digital controller with remote monitoring capability. This is a relatively new
building, with two Weil McLain cast iron boilers, each sized at 1.25 GPH. There is no additional
waste heat work required in this facility.
New Fire Station
The new fire station was connected to the waste heat system with the completion of CIP 13-
222. The heat exchanger and controller installed with the building construction was utilized, and
is of a different manufacturer than the other controllers installed with the project. No remote
monitoring is available in this facility. Upon completion of CIP 13-222 this system was reported
to be recovering waste heat.
Old Power Plant and Washeteria
Prior to the CIP 13-222 project the building was noted to be a hazardous location and a target of
vandalism. The Washeteria portion of the building was still in need of cleanup efforts as of the
end of summer 2008.
Page 19
The facility was re-commissioned to serve as housing of the waste exchangers and equipment
to provide heat to both the Old power plant/Washateria building and the School. The boilers in
this building are without burners, and the piping to them has been cut. Minimum heat was
restored to this building by repairing the existing heating piping to serve two existing hydronic
mounted unit heaters. Currently this building has been moderately cleaned up and is serving as
a storage facility. The building has been locked.
This building receives a 4” waste heat line from the new power plant. A large plate and frame
heat exchanger was relocated to the Mezzanine and the existing 5 hp Grundfos duplex pumps
were reused to provide waste heat to the school. A new brazed plate heat exchanger and 1/6
hp pump were installed to provide heat to the Old Powerplant/Washateria. Both waste heat
systems received current digital controllers and are remotely accessible.
As mentioned above, these controllers are currently not operating and in need of maintenance.
Current work should include returning these systems to operating status as soon as possible.
School
A 4” waste heat main in Kaktovik serves the school via the old power plant/washateria building.
An existing Alfa-Laval plate and frame heat exchanger & Grundfos 5hp pumps were reused
within the old power plant/washateria to supply heat to the school. There is no heat exchanger
or pump in the school. Additional modification within the school facility included providing
rounaround pump on the boiler for shock protection, re-routing of the school side waste heat
piping from the preheat coils to tie directly into the boiler return header, and modification of the
schools Metasys control system to delete the waste heat from their control sequence.
The control of the waste heat injection into the School system has been relayed to the new NSB
controller located in the old power plant/Washateria. This system is remotely accessible and
was working to provide waste heat to the school upon completion of the project. Preliminary
reports from the School maintenance person, Dave Tetreau were favorable, noting significant
fuel savings during the winter of 2008, and up to $600 per day savings in November of 2009.
Additional information will be available on the total amount of heat transfer once access to the
controller is re-established.
As mentioned above, these controllers are currently not operating and in need of maintenance.
Current work should include returning these systems to operating status as soon as possible.
Water Treatment Plant
The water treatment plant has two cast iron sectional boilers that make heat for the building as
well as heat for the domestic water that is circulated through town. A new heat exchanger and
controller were installed in this facility with CIP 13-222. This system has current controls,
remote monitoring, and was operating to collect waste heat at the conclusion of the 2008 waste
heat project. No additional work is anticipated for this facility.
Nuiqsut
Page 20
Table 9
Nuiqsut Facilities
On Waste Heat Unconnected
New Power Plant Water Treatment Plant
School
Washeteria/Old PP
The new Nuiqsut Power Plant was connected to the school when it was started. The only other
Borough facility in the area is the water plant. This presents the best option for expansion of the
waste heat system. No other sizable facilities are within economical distance of the power
plant. Additionally, two natural gas fired generators are currently installed at the power plant.
With the installation of natural gas in the village, the situation is changed in regards to waste
heat usage and cost effectiveness in the village.
The availability of natural gas in Nuiqsut changes the payback for waste heat projects in this
village. It is less attractive to extend waste heat piping to remote buildings such as the fire
station or USDW buildings than to just convert the heating systems to natural gas. While
economical to continue heating existing facilities, it is not economical to invest in new waste
heat infrastructure with the supply of natural gas in the village.
Power Plant
Similar to the other power plants, we recommended inspecting the power plant direct digital
control system and repairing as necessary. The existing digital display should be referenced
against measurements taken from hand held devices, and the sensors and actuators calibrated
to work per the sequence of operations.
School
The school is presently served with waste heat that is piped from the new power plant, through
the old power plant/washeteria/water plant, and then on to the school. The waste heat line
between the Washeteria and school had experienced several failures, but they have been fixed
and the school is back on waste heat. The repaired waste heat line still needs some insulation
installed at fittings, and that work is planned. We did notice that the school boiler fired
occasionally. The existing controls need to be inspected and considered for replacement with a
new DDC controller in this facility.
Water Treatment Plant
The boilers in this building are dual fuel gas/oil units. It is assumed that natural gas piping is or
will be or have been supplied to these units to save on fuel oil costs. No waste heat expansion
is recommended in this facility.
USDW
We looked at the USDW, and feel that it is too far from the power plant to make waste heat
economically feasible, especially if natural gas can be piped to this building much cheaper. We
therefore do not recommend piping of waste heat to the USDW.
Old Power Plant/Washeteria
Page 21
The old power plant is presently not heated, but the old water treatment plant and washeteria
are both heated, even though they are not occupied. The waste heat piping from the new
power plant to the school is still routed through this building, so if this building is to be
demolished than the waste heat needs to be rerouted around the building. There is a fair
amount of heat being radiated off the two hot heat exchangers that represents an energy loss,
especially if in the future these buildings are planned to be cold soaked. We need direction
from the NSB as to the disposition of this building in order to make further recommendations
regarding relocation of the school heat exchanger.
The buried waste heat pipe serving the building was abandoned in place and replaced with a
new, highly insulated, buried pipe. This was completed as part of CIP 13-222.
Fire Station
We looked at the Fire Station, but decided that it was too far to economically install waste heat
at this building, especially in view of potential natural gas service.
Page 22
Conclusions and Recommendations
General
Based on our observations and calculations, there is not a sufficient amount of unused waste
heat available in each NSB village to warrant new expansion of the distribution system. We
visited Wainwright and Point Hope, and conversations with the local maintenance personnel
advised that during extreme cold winter months the waste heat has not been able to keep up
with the heating requirements for all connected buildings. These reports corroborate the
conclusions we derived from our fuel savings models for these locations. The expansions we
propose in this report will only be viable and cost effective if the village power consumption
increases or upgrades to the power plant controls are completed, thus increasing the available
amount of waste heat.
Recommendations
It is recommended that the Wainwright and Point Hope power plant, and end user facility boiler
systems be evaluated for possible adjustments or improvements to increase the efficiency of
waste heat system as described in the Site Report section. This effort should also include the
installation heat recovery monitoring at the end user facilities (mentioned below) to establish a
history of usage to assist in identifying waste heat inefficiencies. Once these systems are
operating efficiently and a history of available waste heat has been established, the construction
cost of expansion in these villages may be re-evaluated for payback.
It is also recommended that the waste heat controllers in the following facilities be replaced with
current digital controllers, which will provide remote BTU metering capabilities and a more
robust system. The following table lists the facilities which are currently connected to the waste
heat system which are operating with outdated controllers. The facilities have been listed in
order of estimated annual fuel usage in order to prioritize installation of new controllers.
Table 10
Facilities recommended for waste heat controller upgrades
Village Facility Estimated Annual Fuel
Consumption (Gallons)
Wainwright Public Works 96,078
Point Hope School 76,548
Nuiqsut School 72,445
Wainwright Sewage Treatment 68,473
Atqasuk School 45,975
Point Hope Washateria/WTP 41,200
Nuiqsut Washateria/Old PP 41,000
Anaktuvuk Pass Waste Water Treatment 40,576
Anaktuvuk Pass Warm Storage 20,676
Atqasuk USDW 15,112
Anaktuvuk Pass USDW 6,892
Anaktuvuk Pass Fire Station 6,272
Atqasuk Vacuum Station 1,992
Page 23
Construction Costs
Rough order of magnitude construction costs were developed for the future waste heat
expansion work proposed for Wainwright and Point Hope. This work is not recommended until
available waste heat has been proven in these locations through the use of new BTU meters,
and upgrades to the power plant control systems.
The opinions of cost shown and any resulting conclusions on the project financial or economic
feasibility or funding requirements have been reviewed, updated, and prepared for guidance in
project evaluation and implementation from the information available at the time the opinion was
prepared. The final cost of the project and the resulting feasibility will depend on actual labor
and material costs, competitive market conditions, actual site conditions, final project scope,
implementation schedule, continuity of personnel and engineering, and other variable factors.
As a result, the final project cost will vary from the opinions of cost presented herein, and the
project feasibility, benefit-cost ratio, risk, and funding needs must be carefully reviewed before
making specific financial decisions or establishing project budgets to help ensure proper project
evaluation and adequate funding.
Construction cost have been developed and updated for this section by tabulating items of
construction based on actual construction costs of CIP 13-222. The estimated construction cost
should be escalated by 3.15 percent for every year beyond 2008. It is recommended that a 10
percent contingency be added to construction cost.
Please refer to Appendix C for ROM construction costs for future expansion of the waste heat
systems in Point Hope and Wainwright.
Construction costs for replacement of a DDC controller installation of BTU metering equipment
may be approximated at $15,000 per facility, based on a $1,000 per control point guideline plus
minor mechanical installation. Upgrades to power plant and facility boiler controls will require
additional troubleshooting and engineering to determine the extent of required work. It is
recommended that engineering be performed to develop a plan set and a cost estimate
performed on that data in order to arrive at a more accurate budget.
Appendix A
Waste Heat Availability and Fuel Savings Workbooks
RSA ENGINEERING WORKSHEETPROJECT: NSB Village Waste Heat PARWaste Heat Availability - Anaktuvuk PassCLIENT: NSBDATE: 1/20/2010Borough FacilitiesConnected to Waste HeatProposed ConnectionsDesign DayFacility Building Size Design Day Heat Load Building Size Heat Load(sq. ft.) (BTU/Hr) (sq. ft.) (BTU/Hr)P Pl t45751830003800152000FacilityMPower Plant4575 183000 3800 152000USDW 4000 200000 1500 60000Fire Station 4550 182000 1700 68000Sewer Plant 4000 1200000 4430 177200VMS 12000 600000 1900 76000School 57500 2300000Total 152000HEMF 3800 152000Total 4817000Waste Heat UsagePotential Waste Heat Usage for Proposed AdditionsExisting WasteAvg. Power Available Waste Heat Consumption % Heat UnusedMuseum% HeatPSO% HeatTerminal Bld.% HeatClinic% HeatWater Treatment% HeatTotal SavingsExcess(kW) Heat (BTU/hr) (BTU/hr) Load (BTU/hr) (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) (BTU/hr)January 367 1,002,391 1,002,391 31% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0February 257 702,818 702,818 21% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0March3821 042 5431 042 54333%000%00%00%00%00%00MuseumWater TreatmentPSOTerminal Bld.ClinicMarch3821,042,5431,042,54333%000%00%00%00%00%00April 479 1,309,744 1,309,744 54% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0May 401 1,096,780 1,096,780 77% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0June 445 1,216,783 651,171 100% 565,612 20,548 100% 8,111 100% 9,192 100% 23,954 100% 10,274 100% 72,079 493,533July 576 1,573,830 560,524 100% 1,013,307 17,687 100% 6,982 100% 7,913 100% 20,620 100% 8,844 100% 62,045 951,262August 447 1,220,362 777,924 100% 442,438 24,547 100% 9,690 100% 10,982 100% 28,617 100% 12,274 100% 86,109 356,329September 486 1,328,167 1,328,167 73% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0October 494 1,348,333 1,348,333 56% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0November 496 1,354,936 1,354,936 45% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0December502 1,372,640 1,372,640 38% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0Total (BTU/hr) 62,782 24,782 28,087 73,191 31,391 220,233Equivalent Fuel Oil (Gal)393 155 176 458 197 1,379Price per Gallon $4.89Potential Savings (Dollars) $1,922 $759 $860 $2,241 $961 $6,743
RSA ENGINEERING WORKSHEETPROJECT: NSB Village Waste Heat PARWaste Heat Availability - AtqasukCLIENT: NSBDATE: 1/20/2010Borough FacilitiesConnected to Waste Heat Proposed ConnectionsFacility Building Size Design Day Heat Load Req'd Flow Building Size Design Day Heat Load Flow(sq ft )(BTU/Hr)(GPM)(sq ft )(BTU/Hr)(GPM)Facility(sq.ft.)(BTU/Hr)(GPM)(sq.ft.)(BTU/Hr)(GPM)Power Plant 4050 162000 18Washeteria 4550 182000 20School 30000 1200000 133Total 00Vacuum Bldg. 1300 52000 6Water Plant 3900 156000 17Comm. Center 4400 176000 20Clinic 4650 186000 21USDW 9861 394440 44Fire Station 6650 266000 30PSO 2800 112000 12Comm. Center 4400 176000 20Total 3062440340Waste Heat UsagePotential Waste Heat UsageNo Proposed Facilitiesggfor Proposed AdditionsExisting WasteNoAvg. Power Available Waste Heat Consumption % Heat UnusedFacilities Total SavingsExcess(kW) Heat (BTU/hr) (BTU/hr) Load (BTU/hr) (BTU/hr) (BTU/hr) (BTU/hr)January 431 1,176,269 1,176,269 54% 0 0 0 0February 339 925,534 925,534 40% 0 0 0 0March 433 1,182,872 1,182,872 55% 0 0 0 0April 434 1,185,601 1,185,601 62% 0 0 0 0May 300 820,415 820,415 62% 0 0 0 0June 404 1,103,341 987,219 100% 116,122 0 0 116,122July 316 863,194 838,803 100% 24,391 0 0 24,391August 277 755,420 748,771 100% 6,649 0 0 6,649September 195 533,412 533,412 54% 0 0 0 0October 479 1,307,394 1,305,354 100% 2,040 0 0 2,040November 335 915,414 915,414 46% 0 0 0 0,,December 383 1,046,136 1,046,136 51% 0 0 0 0Total (BTU/hr) 0 0Equivalent Fuel Oil (Gal) 0 0Price per Gallon $2.75Potential Savings (Dollars) $0 $0
RSA ENGINEERING WORKSHEETPROJECT: NSB Village Waste Heat PARWaste Heat Availability - KaktovikCLIENT: NSBDATE: 1/20/2010Borough FacilitiesConnected to Waste Heat Proposed ConnectionsFacility Building Size Design Day Heat Load Building Size Design Day Heat Load(sq. ft.)(BTU/Hr)(sq. ft.)(BTU/Hr)Facility(sq.ft.)(BTU/Hr)(sq.ft.)(BTU/Hr)Power Plant 4150 166000 2000 80000Washeteria 4150 166000 1300 52000School 31500 1260000USDW 10300 618000Total 132000Water Plant 5000 300000Fire Station 4500 180000VMS 4200 420000Clinic4500 180000Total 3290000Waste Heat UsagePotential Waste Heat Usagefor Proposed AdditionsExisting WasteAvg. PowerAvailable Waste Heat Consumption % Heat UnusedPSO% HeatVacuum Station% HeatTotal SavingsExcessPSOVacuum StationAvg.PowerAvailableWasteHeatConsumption%HeatUnusedPSO%HeatVacuumStation%HeatTotalSavingsExcess(kW) Heat (BTU/hr) (BTU/hr) Load (BTU/hr) (BTU/hr) Load (BTU/hr) Load (BTU/hr) (BTU/hr)January 727 1,986,895 1,986,895 83% 0 0 0% 0 0% 0 0February 711 1,942,314 1,942,314 79% 0 0 0% 0 0% 0 0March 604 1,648,971 1,648,971 62% 0 0 0% 0 0% 0 0April 675 1,844,931 1,844,931 94% 0 0 0% 0 0% 0 0May 644 1,760,557 1,334,822 100% 425,735 32,458 100% 21,097 100% 53,555 372,180June 894 2,442,890 1,103,197 100% 1,339,693 26,825 100% 17,437 100% 44,262 1,295,431July 468 1,278,774 929,063 100% 349,711 22,591 100% 14,684 100% 37,275 312,436August 546 1,491,055 829,640 100% 661,416 20,174 100% 13,113 100% 33,286 628,129September 618 1,688,281 1,034,744 100% 653,537 25,161 100% 16,355 100% 41,516 612,022October 686 1,872,804 1,479,005 100% 393,800 35,964 100% 23,376 100% 59,340 334,460November 528 1,443,524 1,443,524 61% 0 0 0% 0 0% 0 0December 608 1,660,604 1,660,604 76% 0 0 0% 0 0% 0 0Total (BTU/hr) 163,173 106,062 269,235Equivalent Fuel Oil (Gal)1,0226641,686EquivalentFuelOil(Gal)1,0226641,686Price per Gallon $4.43Potential Savings (Dollars) $4,526 $2,942 $7,467
RSA ENGINEERING WORKSHEETPROJECT: NSB Village Waste Heat PARWaste Heat Availability - Point HopeCLIENT: NSBDATE: 1/20/2010Borough FacilitiesConnected to Waste Heat Proposed ConnectionsFacility Building Size Design Day Heat Load Building Size Design Day Heat Load(sq ft )(BTU/Hr)(sq ft )(BTU/Hr)Facility(sq.ft.)(BTU/Hr)(sq.ft.)(BTU/Hr)Power Plant 5200 208000 2000 80000School 57500 2365000 (From HX sizing) 4550 182000Water Plant 2000 1272900 (From HX sizing) 13000 520000Clinic3600 180000 4700 2820000Total 4025900 Total 3602000Waste Heat UsagePotential Waste Heat Usage for Proposed AdditionsExisting WasteAvg. Power Available Waste Heat Consumption % Heat UnusedPSO% HeatFire Station% HeatUSDW% HeatSewer Plant% HeatTotal SavingsExcess(kW) Heat (BTU/hr) (BTU/hr) Load (BTU/hr) (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) (BTU/hr)January 762 2,080,440 2,080,440 91% 0 0 0% 0 0% 0 0% 0 0% 0 0February 660 1,802,429 1,802,429 63% 0 0 0% 0 0% 0 0% 0 0% 0 0March 602 1,644,099 1,644,099 71% 0 0 0% 0 0% 0 0% 0 0% 0 0USDWSewer PlantPSOFire StationApril 708 1,933,398 1,933,398 86% 0 0 0% 0 0% 0 0% 0 0% 0 0May 495 1,353,368 1,353,368 92% 0 0 0% 0 0% 0 0% 0 0% 0 0June 737 2,013,287 1,065,766 100% 947,521 21,178 100% 48,180 100% 137,658 100% 740,504 99% 947,521 0July 532 1,453,883 747,920 100% 705,963 14,862 100% 33,811 100% 96,604 100% 523,891 100% 669,169 36,794August 456 1,246,681 713,918 100% 532,762 14,187 100% 32,274 100% 92,212 100% 394,089 79% 532,762 0September 481 1,313,466 943,891 100% 369,575 18,756 100% 42,671 100% 121,916 100% 186,232 28% 369,575 0October 629 1,719,074 1,511,897 100% 207,178 30,043 100% 68,349 100% 108,785 56% 0 0% 207,178 0November 523 1,429,910 1,429,910 67% 0 0 0% 0 0% 0 0% 0 0% 0 0December 709 1,937,326 1,937,326 77% 0 0 0% 0 0% 0 0% 0 0% 0 0Total (BTU/hr) 99,027 225,286 557,176 1,844,717 2,726,206Equivalent Fuel Oil (Gal) 620 1,410 3,488 11,550 17,068Price per Gallon $4.52Potential Savings (Dollars) $2,802 $6,375 $15,768 $52,204 $77,149
RSA ENGINEERING WORKSHEETPROJECT: NSB Village Waste Heat PARWaste Heat Availability - WainwrightCLIENT: NSBDATE: 1/20/2010Borough FacilitiesConnected to Waste HeatProposed ConnectionsFacility Building Size Design Day Heat Load Building Size Design Day Heat Load(sq ft )(BTU/Hr)(sq ft )(BTU/Hr)Facility(sq.ft.)(BTU/Hr)(sq.ft.)(BTU/Hr)Power Plant 3200 128000 46000 1840000Public Works/HEMF 21900 2914100 (From HX sizing) 2500 100000Sewer Plant 3200 1987000 (From HX sizing) 5600 2240004500 1800006600 264000Total 2608000Total 5029100Waste Heat UsagePotential Waste Heat Usage for Proposed AdditionsExisting WasteAvg. Power Available Waste Heat Consumption % Heat UnusedSchool% HeatPSO% HeatClinic% HeatWater Plant% HeatFire Station% HeatTotal SavingsExcess(kW) Heat (BTU/hr) (BTU/hr) Load (BTU/hr) (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) Load (BTU/hr) (BTU/hr)January 755 2,063,549 2,063,549 60% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0February8872,423,3372,423,33770%000%00%00%00%00%00ClinicWater PlantFire StationSchoolPSOFebruary8872,423,3372,423,33770%000%00%00%00%00%00March 639 1,745,766 1,745,766 53% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0April 920 2,513,121 2,513,121 99% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0May 472 1,290,345 1,290,345 87% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0June 853 2,331,041 679,843 100% 1,651,198 248,735 100% 13,518 100% 30,281 100% 24,333 100% 35,688 100% 352,554 1,298,644July 693 1,893,136 585,204 100% 1,307,932 214,109 100% 11,636 100% 26,065 100% 20,945 100% 30,720 100% 303,476 1,004,456August 437 1,193,700 812,178 100% 381,523 297,152 100% 16,150 100% 36,175 100% 29,069 100% 2,977 7% 381,523 0September 501 1,369,897 1,369,897 72% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0October 599 1,637,015 1,637,015 65% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0November 564 1,542,180 1,542,180 49% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0December718 1,960,2761,960,27651% 0 0 0% 0 0% 0 0% 0 0% 0 0% 0 0Total (BTU/hr) 759,996 41,304 92,521 74,347 69,385 1,037,553Equivalent Fuel Oil (Gal)4,758 259 579 465 434 6,496Price per Gallon $4.43Potential Savings (Dollars) $21,079 $1,146 $2,566 $2,062 $1,924 $28,777
Appendix B
Community Maps – Waste Heat Main Locations
Appendix C
Wainwright and Point Hope ROM Construction Cost Estimates
RSA ENGINEERING WORKSHEET Project Construction Cost - Point Hope
PROJECT:NSB Village Waste Heat PAR
CLIENT:NSB
DATE:Dec-09
Construciton Item Quantity $/Unit Total
Project Submittals 1 $5,000 $5,000
Stored Materials 4860 $108 $524,880
Mobilization - Materials/Tools/Equipment 1 $250,000 $250,000
Inventory Stage Freight 1 $30,000 $30,000
Excavation for Buried Pipe 2430 $72 $174,960
Installation Buried Piping 4860 $27 $131,220
Backfill Buried Piping 2430 $88 $213,840
Interior Mechanical Powerplant 1 $200,000 $200,000
Interior Mechanical WWTP 1 $200,000 $200,000
Interior Mechanical PSO 1 $25,000 $25,000
Interior Mechanical USDW 1 $25,000 $25,000
Interior Mechanaical Fire Station 1 $25,000 $25,000
Interior Electrical 1 $25,000 $25,000
System Startup & Testing 1 $20,000 $20,000
Site Demobilization 1 $10,000 $10,000
TOTAL CONSTRUCTION COST $1,859,900
Administration Cost $185,990
Design Cost $185,990
PROJECT COST FOR POINT HOPE $2,231,880
RSA ENGINEERING WORKSHEET Project Construction Cost - Wainwright
PROJECT:NSB Village Waste Heat PAR
CLIENT:NSB
DATE:Dec-09
Construciton Item Quantity $/Unit Total
Project Submittals 1 $5,000 $5,000
Stored Materials 8000 $108 $864,000
Mobilization - Materials/Tools/Equipment 1 $250,000 $250,000
Inventory Stage Freight 1 $30,000 $30,000
Excavation for Buried Pipe 4000 $72 $288,000
Installation Buried Piping 8000 $27 $216,000
Backfill Buried Piping 4000 $88 $352,000
Interior Mechanical Powerplant 1 $175,000 $175,000
Booster Pump Station 1 $200,000 $200,000
Interior Mechanical School 1 $65,000 $65,000
Interior Mechanical PSO 1 $25,000 $25,000
Interior Mechanical Clinic 1 $18,000 $18,000
Interior Mechanical Water Plant 1 $25,000 $25,000
Interior Mechanaical Fire Station 1 $25,000 $25,000
Interior Electrical 1 $40,000 $40,000
System Startup & Testing 1 $20,000 $20,000
Site Demobilization 1 $10,000 $10,000
TOTAL CONSTRUCTION COST $2,608,000
Administration Cost $260,800
Design Cost $260,800
PROJECT COST FOR WAINWRIGHT $3,129,600
Appendix D
Appendix D - CIP 13-222 DDC Record of Waste Heat Recovery &
Screenshots
SRATTGRRDAUG-2013L2259BTI MAPNORTH SLOPE BOROUGHKAKTOVIKWASTE HEAT ROUTEKAKTOVIK COMMUNITY WASTE HEAT PIPINGNO SCALELEGEND
Appendix D
Community Meeting Notes
June 11, 2013 Page 1 of 4 Kaktovik City Council Meeting
City Council Meeting Notes
Kaktovik Wind Feasibility Study
Meeting Date: June 11, 2013
Kaktovik Community Center
Mark Swenson and Jason Johnston with HDL along with and Tom Nicolos with the
North Slope Borough traveled to Kaktovik on the above date. The purpose of the trip
was to present the ongoing wind feasibility study at the Kaktovik City Council Meeting.
In the weeks prior to the meeting, HDL contacted the Native Village of Kaktovik (NVK)
and the Kaktovik Inupiat Corporation (KIC) to make them aware of the wind project
discussion and encourage attendance at the City Council meeting. Meeting attendees
are listed on the attached sign-in sheet.
Mark Swenson introduced the project to the Council and explained that the purpose of
this presentation was to inform the community that a wind feasibility study is occurring
and to gather input on preferred locations for wind towers. Mr. Swenson presented
project maps showing three locations that HDL considered feasible for wind turbine
construction. Mr. Swenson also updated the community on the current project status as
well as the next steps for the project including preparation of the wind feasibility study
for North Slope Borough review. He said that if a wind turbine project is deemed
feasible in the report, further community outreach will be performed prior to land
acquisition, permitting, design, and construction. Following his presentation Mr.
Swenson answered questions and addressed concerns from the City Council and
community members.
Presentation: Mark Swenson presented the following information to a group of
approximately 20 members of the Kaktovik community:
HDL is under contract with the North Slope Borough to investigate the
feasibility and cost effectiveness of incorporating wind power into the
existing Kaktovik diesel power generation system.
The study is in the preliminary stages and HDL would like to gauge the
community interest in the project, determine if there is significant
opposition to wind turbines on Barter Island, and incorporate community
input in the feasibility study.
Many utility companies across the state are studying wind as a potential
source of power. It is attractive because it is renewable energy that has
the potential to reduce a rural community’s dependence on imported
diesel. The challenges with wind include high initial capital costs,
increased maintenance and operating costs, and complex integration with
the existing power generation infrastructure.
June 11, 2013 Page 2 of 4 Kaktovik City Council Meeting
Mr. Swenson said that an avian study will most likely be required by the
U.S. Fish and Wildlife Department during the permitting process.
Mark described 3 feasible sites for wind turbine construction on Barter
Island. All three sites were a minimum of half a mile from the coastline to
minimize danger to coastal birds. The sites are also below the Part 77
airspace for the new airport that is currently under construction. The sites
include the following:
Site 1: Northwest portion of Barter Island, south of the
existing trail, and immediately east of the existing
graveyard site.
Site 2: Centrally located in the north portion of Barter
Island, south of the existing trail, and west of the fresh
water lake.
Site 3: South of the new airport and immediately east of
the new landfill.
See attached figure for proposed site locations.
Mr. Swenson said that one of the important determining factors in deciding
if wind power is feasible in Kaktovik will be the benefit/cost (B/C) ratio that
is determined in the report. He said that the B/C ratio is the ratio of the
benefits of reduced diesel consumption, increased recovered heat, and
less expensive power generation compared to the cost of constructing and
operating the wind turbines. If the B/C ratio is less than 1.0, then the cost
of the project will outweigh the benefits.
Questions and Concerns from the Community: Community members raised the
following questions and concerns.
Q: Fenton Rexford stated that Site 3 should not be considered because it
is near their subsistence waterfowl hunting areas and would adversely
impact the hunting in the area.
A: Mr. Swenson thanked Mr. Rexford for his comment and said he would
incorporate it into the feasibility study.
Q: Mr. Rexford asked how long an avian study usually takes.
A: Mr. Swenson responded that the study would most likely be focused
during a spring or fall migration period and the actual study duration would
be dictated by the U.S. Fish and Wildlife Department.
Q: Mr. Rexford recommended that HDL investigate constructing the
turbines on Martin Point (Drum Island) across the Kaktovik Lagoon. He
June 11, 2013 Page 3 of 4 Kaktovik City Council Meeting
stated that this location would not adversely impact the community. He
acknowledged that it would be difficult to connect the turbines to the
existing power plant.
A: Mr. Swenson thanked Mr. Rexford for his comment and said he would
give it further consideration. He said that the remote location of Drum
Island would present operation and maintenance challenges that may
make it an unfeasible turbine location.
Q: Carolyn Kulukhon asked is the turbines work with the existing power
plant generators or if they would negatively affect the quality of the power
that is currently provided.
A: Mr. Swenson said that a properly designed system would have the
wind turbines working in harmony with the existing generators to provide
enhanced performance from the existing power plant. He said that the
existing services should not be negatively affected.
Q: Carolyn Kulukhon asked if there were other villages with wind turbines.
A: Mr. Swenson responded that turbines have been installed in many of
AVEC rural villages, as well as Nome, Kotzebue, Kodiak, and Anchorage.
He said that, to his knowledge, no turbines have been installed north of
Kotzebue.
Q: Someone asked how tall the turbines were expected to be and if there
would be batteries incorporated into the system?
A: Mr. Swenson stated that the maximum height is anticipated to be 150’
to 160’ above ground level. He also stated that at this time battery storage
was an unproven technology for rural arctic wind systems and he did not
anticipated batteries as part of proposed project.
Q: Ida Angasan asked how many turbines are anticipated and which
direction will they be facing.
A: Mr. Swenson said that there will most likely be 3 to 4 turbines,
depending on the results of the wind study. The turbines will be
perpendicular to the direction of the prevailing wind but the heads of the
turbines will rotate to take advantage of wind from different directions.
Q: Nora Jane Burns asked if the turbine materials are strong enough for
extreme arctic conditions.
A: Mr. Swenson said any turbines considered will have to be arctic rated.
June 11, 2013 Page 4 of 4 Kaktovik City Council Meeting
Q: Ida Angasan asked if there would be road access to the new turbines.
A: Mr. Swenson said turbines will have to have road or trail access for
maintenance and construction.
Q: Mr. Rexford stated the following concerns:
The avian study needs to last two seasons.
No handouts were provided with the presentation.
There is not an EA, FONSI, or public hearing on this
project.
A: Mr. Swenson responded that the study is just beginning and the Wind
Feasibility Report will identify the permits and public process required prior
to construction.
Q: Mr. Rexford asked what action HDL was requesting of the City
Council.
A: Mr. Swenson responded that the purpose of the meeting was to inform
the community of the project and no Council action was being requested.
Q: Nora Jane asked when additional community meetings would be held
on this project.
A: Mr. Swenson responded additional community meetings would be held
once it is determined that wind power is economically feasible in Kaktovik.
With no further questions or discussion, the presentation was concluded.
Respectfully submitted,
Mark Swenson, P.E.
Appendix E
Capital Cost Estimates
Concept Level EstimateKaktovik Wind ProjectAlternative Cost Summary8/28/13SUMMARYDescription Estimated Construction Installed kW Estimated Construction Tower TypeCost Cost/ Installed kWAlternative 1 - Three Aeronautica AW29-225s at Site 2 $ 7,815,795 675 $ 11,579 MonopoleAlternative 2 - Seven NP 100s at Site 2 $ 11,312,500 700 $ 16,161 Monopole Alternative 3 - Three Vestas V27s at Site 2 $ 7,122,795 675 $ 10,552 Monopole
Concept Level Estimate
Kaktovik Wind Project
Alternative 1
8/28/13
Item Estimated
Quantity Unit Price ($) Subtotal ($)
Alternative 1 Three Aeronautica AW29 225s at Site 2
1 12,800 CY Gravel 45 576,000
2 1,000 CY Surfacing Course 100 100,000
3 13,300 SY Geotextile 1.15 15,295
4 375,000 BF Rigid Insulation 1.00 375,000
5 0 CY Topsoil
6 0 SY Seed
7 24 Each 18" Steel Piles 60 ' total length (11 Kips x 24 ea = 264 kips) 30,000 720,000
8 24 Each Hole Augering / Slurry Back 10,000 240,000
9 3 Each Steel Base Plate (5 kips) 25,000 75,000
10 3 Each Aeronautica AW29 225s 600,000 1,800,000
11 1 Sum Secondary Boiler System 100,000 100,000
12 1.23 Miles OH Power line to New Power Plant Location 300,000 369,000
13 1 Sum Wireless Communication System 75,000 75,000
14 1 Sum Wind Turbine Power Integration (VFDs) 300,000 300,000
15 1 Sum Labor 300,000 300,000
16 1 Sum Equipment 150,000 150,000
17 950 Tons Freight 1,800 1,710,000
18 1 Sum Indirects 200,000 200,000
Subtotal Construction 7,105,295$
Land Acquisition $0
Project Contingency @ 10% 710,500$
0 Years Inflation @ 2% $0
Total 7,815,795$
Installed Generation Capacity 675 kW
Total Cost 7,815,795$
Cost/Installed kW $11,579
Description
Concept Level Estimate
Kaktovik Wind Project
Alternative 2
8/28/13
Item Estimated
Quantity Unit Price ($) Subtotal ($)
Alternative 2 Seven NP 100s at Site 2
1 21,000 CY Gravel 45 945,000
2 1,600 CY Surfacing Course 100 160,000
3 22,000 SY Geotextile 1.15 25,300
4 615,000 BF Rigid Insulation 1.00 615,000
5 0 CY Topsoil
6 0 SY Seed
7 56 Each 18" Steel Piles 60 ' total length (11 Kips x 24 ea = 264 kips) 30,000 1,680,000
8 56 Each Hole Augering / Slurry Back 10,000 560,000
9 7 Each Steel Base Plate (5 kips) 25,000 175,000
10 7 Each NP 100 Wind Turbines 375,000 2,625,000
11 1 Sum Secondary Boiler System 100,000 100,000
12 1.23 Miles OH Power line to New Power Plant Location 300,000 369,000
13 1 Sum Wireless Communication System 75,000 75,000
14 1 Sum Wind Turbine Power Integration (no VFDs) 100,000 100,000
15 1 Sum Labor 100,000 100,000
16 1 Sum Equipment 150,000 150,000
17 1,336 Tons Freight 1,800 2,404,800
18 1 Sum Indirects 200,000 200,000
Subtotal Construction 10,284,100$
Land Acquisition $0
Project Contingency @ 10% 1,028,400$
0 Years Inflation @ 2% $0
Total 11,312,500$
Installed Generation Capacity 700 kW
Total Cost 11,312,500$
Cost/Installed kW $16,161
Description
Concept Level Estimate
Kaktovik Wind Project
Alternative 3
8/28/13
Item Estimated
Quantity Unit Price ($) Subtotal ($)
Alternative 3 Three Vestas V27s at Site 2
1 12,800 CY Gravel 45 576,000
2 1,000 CY Surfacing Course 100 100,000
3 13,300 SY Geotextile 1.15 15,295
4 375,000 BF Rigid Insulation 1.00 375,000
5 0 CY Topsoil
6 0 SY Seed
7 24 Each 18" Steel Piles 60 ' total length (11 Kips x 24 ea = 264 kips) 30,000 720,000
8 24 Each Hole Augering / Slurry Back 10,000 240,000
9 3 Each Steel Base Plate (5 kips) 25,000 75,000
10 3 Each Vestas V27 Turbines 390,000 1,170,000
11 1 Sum Secondary Boiler System 100,000 100,000
12 1.23 Miles OH Power line to New Power Plant Location 300,000 369,000
13 1 Sum Wireless Communication System 75,000 75,000
14 1 Sum Wind Turbine Power Integration (VFDs) 300,000 300,000
15 1 Sum Labor 300,000 300,000
16 1 Sum Equipment 150,000 150,000
17 950 Tons Freight 1,800 1,710,000
18 1 Sum Indirects 200,000 200,000
Subtotal Construction 6,475,295$
Land Acquisition $0
Project Contingency @ 10% 647,500$
0 Years Inflation @ 2% $0
Total 7,122,795$
Installed Generation Capacity 675 kW
Total Cost 7,122,795$
Cost/Installed kW $10,552
Description
Appendix F
Geotechnical Review and Feasibility Study for
Kaktovik Wind Turbines
Geotechnical Review and Feasibility Study for Kaktovik Wind Turbines
North Slope Borough
GEOTECHNICAL REVIEW AND FEASIBILITY STUDY FOR KAKTOVITK WIND
TURBINES
North Slope Borough
Kaktovik, Alaska
August 29, 2013
Prepared By:
Trevor Crosby
Staff Geologist
Reviewed By:
Doug P. Simon, P.E.
Senior Geotechnical Engineer
3335 Arctic Blvd., Ste. 100
Anchorage, AK 99503
Phone: 907.564.2120
Fax: 907.564.2122
Kaktovik Wind Project
North Slope Borough Geotechnical Review and Feasibility Study
Page i
TABLE OF CONTENTS
1.0 INTRODUCTION ...............................................................................................1
2.0 SITE INFORMATION ......................................................................................... 2
2.1 TOPOGRAPHY, DRAINAGE, AND VEGETATION ........................................................... 2
2.2 REGIONAL CLIMATE INFORMATION ........................................................................ 2
3.0 EXISTING GEOTECHNICAL DATA....................................................................... 3
4.0 FOUNDATIONS CONCEPTS AND CONSTRUCTABILITY CONSIDERATIONS ........... 5
5.0 USE OF REPORT ............................................................................................... 6
LIST OF FIGURES
Figure 1 Site Map
Figure 2 Barrow Mean Annual Temperature
Figure 3 Vicinity and Boring Map
LIST OF TABLES
Table 1 Engineering Climate Indices for Barrow, Alaska
LIST OF APPENDICIES
Appendix A Existing Geotechnical Data
Kaktovik Wind Project
North Slope Borough Geotechnical Review and Feasibility Study
Page 1
1.0 INTRODUCTION
Hattenburg Dilley & Linnell (HDL) is pleased to present our geotechnical review and
feasibility study of the proposed wind power project for the community of Kaktovik,
Alaska in the central portion of Barter Island. The purpose of our geotechnical review is
to identify potential geotechnical hazards and to provide conceptual foundation
recommendations for the proposed wind turbine sites.
There are three potential wind turbine sites proposed on Barter Island: Site “1” is to the
west of the community, Site “2” is located closer to the community near a freshwater
lake and Site “3” is to the south of the new airport and northeast of the new landfill. All
the sites are located on Kaktovik Inupiat Corporation (KIC) lands. The approximate
proposed wind turbine sites are presented on Figure 1 below.
Figure 1: Site Map
We understand that three wind turbine combinations are being considered for this
project. The proposed wind turbine and base combinations are presented below.
The first configuration consists of three (3) Aeronautica AW 29-225 arctic
turbines. The AW29-225 turbine has a 29 meter diameter rotor and is supported
by 30, 40, or 50 meter tubular steel towers.
Kaktovik Wind Project
North Slope Borough Geotechnical Review and Feasibility Study
Page 2
The second turbine configuration consists of seven (7) Northern Power NPS 100-
21 turbines. The NPS 100 turbine has a 21 meter or 24 meter diameter rotor,
and can be supported by a 30 meter or 37 meter tubular steel monopole towers,
or on a 48 meter four-leg lattice tower.
The third turbine configuration consists of three (3) Vestas V27 turbines. The V27
turbine has a 27 meter diameter rotor and is supported by 30, 40, or 50 meter
tubular steel towers.
2.0 SITE INFORMATION
This project is located near the village of Kaktovik, in the central portion of Barter Island
at approximately 70°06’ North Latitude and 143°39’ West Longitude, in Sec. 13, T9N,
R33E, Umiat Meridian. Barter Island lies approximately 115 miles east of Deadhorse,
along the northern coast of Alaska, in the Barrow Recording District.
2.1 Topography, Drainage, and Vegetation
Barter Island is part of the Arctic Coastal Plain, which is characterized by low rolling hills
and treeless tundra. The treeless tundra is underlain by continuous permafrost
extending to depths of 1,000 feet. The permafrost is typically cold, on the order of less
than 25°F, and generally occurs about two to five feet below the ground surface. The
project area has less than 20 feet of relief, and the topography is patterned due to the
permafrost.
2.2 Regional Climate Information
The temperatures in the arctic climate near Kaktovik range from -56°F to 78°F.
Precipitation averages 5 inches per year, with 20 inches of snowfall per year. Figure 3.1
presents the mean annual air temperature for Barrow from 1920 to 2010, as observed
by the Arctic Research Climate Institute at the University of Alaska, Fairbanks. The data
shows that there has been an increase in the mean annual air temperatures of about
0.1°F per year over the past 90 years.
Kaktovik Wind Project
North Slope Borough Geotechnical Review and Feasibility Study
Page 3
Figure 2. Mean Annual Air Temperatures for Barrow from 1920 to 2010, Arctic Research Climate
Institute, University of Alaska Fairbanks.
Design climate data including thawing and freezing degree days for the Barrow area are
presented in Table 1. The indices are computed by the National Weather Service
Alaska-Pacific River Forecast Center.
Table 1: Engineering Climate Indices for Barrow, AK
Last Season Observed Average
Freezing Degree Days 7400 8700
Thawing Degree Days 1000 480
Note: The last season for freezing degree days was the winter of 2012-2013. The last season for thawing
degree days was the summer of 2013 and included a projection of the remaining number of thawing
degree days.
3.0 EXISTING GEOTECHNICAL DATA
Historical reports were reviewed to provide a general understanding of the subsurface
conditions near the proposed turbine sites. Subsurface conditions summarized in this
section include select boreholes which are presented in Appendix A. The approximate
locations of select borings are shown in Figure 3, attached.
Kaktovik Airport Relocation, January 2012, Hattenburg Dilley & Linnell: HDL
conducted a field investigation in support of the airport relocation project that
Trend Line
5-year Moving
Average (red line)
Kaktovik Wind Project
North Slope Borough Geotechnical Review and Feasibility Study
Page 4
included drilling and sampling 19 borings with a track mounted rig. The
subsurface soils generally consisted of a layer of organic-rich, sandy silt from the
surface to about 2.5 feet below existing ground surface (bgs). Ice rich sandy silts
to silty sands with up to 39 percent gravel were encountered beneath the
organic silt. Ice lenses containing less than 25% soils were encountered and
varied in thickness from approximately 2.5 to 5 feet thick.
Thermistors were installed in select borings and the observed subsurface
temperatures ranged from about 14°F to 22°F and a steady temperature of
approximately 16°F was estimated to be present at a depth of 20 feet. Based on
thermistor data through August 1, 2013, the depth of the active layer may be
approximately 8 feet to 9 feet beneath graveled construction areas.
Engineering Evaluation/Cost Analysis for Old Landfill LF001, February 2008, U.S.
Air Force: “The soils encountered near the landfill are visible along the bluff face
adjacent to the project site. The upper foot of soil consists of peat underlain by
silty, fine-grained sand. The sand is occasionally interbedded with thin (1-to 2-
foot) layers of gravel and both are bound by ice (permafrost), except where the
ice is exposed and thawed. Thawed soils are not cohesive and slump or flow
down the face of the bluff. The toe of the slope is occasionally covered by blocks
of peat, which have sloughed off the top of the bluff. The upper beach face
consists of poorly sorted sand. The sand transitions into pebbles and cobbles
near the shoreline.”
Based on test pits, permafrost was present at approximately 4 to 5 feet bgs near
the landfill area. Active zone water observed in test pits was at an approximate
depth of 3 to 5 feet below ground surface (bgs).
EBA Engineering Borings, August 1986: HDL reviewed boring logs from 1986 for
what appeared to be a proposed building. Based on the boring location plan the
proposed building appeared to be close to or within the current village, although
the exact location could not be determined. The borings encountered organic
silt and sand to a depth of approximately 1 to 4 feet bgs. Silty sand with ice
lenses was generally encountered beneath the organic layer. The reported
salinity was 10 to 80 parts per thousand.
Material Source Evaluation, Varying Dates: Material source evaluations were
conducted approximately 2.5 miles southeast of the proposed wind turbine Site
3. Borings were drilled in 1984 and 1986 by Arctic Slope Consulting Engineers
and additional borings were drilled in 2009 by HDL to evaluate potential material
sources. The shallow subsurface conditions encountered in the borings were
generally consistent with the materials encountered at near the runway. Silt and
lean clay was generally encountered at depths of 35 to 40 feet bgs.
Kaktovik Wind Project
North Slope Borough Geotechnical Review and Feasibility Study
Page 5
4.0 FOUNDATIONS CONCEPTS AND CONSTRUCTABILITY CONSIDERATIONS
The soils on Barter Island generally consist of sands and silts with varying amounts of
gravels underlying an organic mat of several feet thick. At depths of approximately 35
to 40 feet, we expect the soils to transition to silt or lean clay. Active layer depth
(seasonal thaw depth) is expected to be in the range of four to five feet, but will likely
be deeper in areas with disturbed surface vegetation or along margins of patterned
(polygonal) ground. Large thaw strains will occur if the underlying permafrost is
disturbed. Accordingly, the design for the site should keep the underlying permafrost
frozen using such methods as insulation and/or thermosiphons (if building heat is
anticipated). Creep may occur if the permafrost is allowed to thaw.
Elevated pore water salinities were encountered in the EBA borings. It is believed those
borings were located closer to the coast and do not represent the salinity conditions
that would be expected at the proposed turbine locations. However, if elevated pore
water salinity concentrations are encountered at the sites, it may impact foundation
performance and creep rates under sustained loads. It is important the site-specific
geotechnical efforts verify pore water salinity concentrations throughout the expected
foundation embedment depths at the planned turbine sites as part of the geotechnical
engineering work.
While a site-specific geotechnical exploration and engineering assessment is required
for the tower foundations, several conceptual-level foundation design elements should
be considered at the feasibility stage.
The turbine site subsurface conditions will most likely consist of sands and silts with
varying amounts of gravels under the tundra. The tundra mat must be protected during
the turbine construction and for operations and maintenance access. A gravel pad
should be included as part of the project for construction and regular maintenance.
During construction of the new runway in 2013, HDL recorded thaw depths that
penetrated a four foot gravel layer and into the underlying tundra. To protect the
tundra at the proposed turbine sites, we recommend insulation be placed below five
feet of fill. In lieu of insulation the gravel pad would be on the order of 8 feet thick.
An adfreeze pile foundation system should be used for the proposed turbine foundation
with an above grade pile cap/tower base system. Cast-in-place concrete, pre-cast
concrete and steel frame pile cap/tower base systems have been used in permafrost
regions.
A clear space between the ground and tower base is necessary. However, the turbine
systems are not heated thus an 18 to 24-inch clear space may be suitable if a gravel pad
is used. The tower base should not rest directly on the pad or tundra in order to allow
for seasonal frost related pad movements. Also, access for welding and mechanical
Kaktovik Wind Project
North Slope Borough Geotechnical Review and Feasibility Study
Page 6
connections between the pad or tundra and the tower base typically requires 18 to 24
inches.
Assuming the soils have a low salinity content, the foundations should be steel pipe piles
installed with drill and slurry methods. The pipe pile may include a two- to four-inch
helix around the bottom portion of the pile to develop additional capacity. The pile
boreholes should be dry augured without use of drill muds or added heat, with
equipment sufficient to provide a nominal three-inch radial annulus between the pile
(or helix if used) and the borehole sidewall. The slurry should be clean sand and gravel
mixed with potable water, placed and densified in the annular space.
The pipe pile dimensions will depend on the structural loads, but pipe piles in the range
of 18 to 20 inches in diameter have been used for similar turbine units in similar
conditions. Pile groups of 6 piles supporting a continuous concrete or steel base frame
have been used for similar turbine systems in Alaska.
Pile embedment depth will depend on structural loads, ground temperatures, pore
water salinity, and adfreeze bond capacity under sustained and transient load
conditions, but pile embedment depths in the range of 40 feet are anticipated.
In general, settlements will be controlled by long-term creep in ice rich permafrost and
can be significantly impacted by pore water salinity. The foundation system should be
designed to maintain long-term creep rates in the primary and secondary phase. If
properly designed and installed, creep movement in the range of 1 to 2 inches over a 20
year design life can be established.
Lateral capacity will depend on the pile and cap material and connection (free or fixed
head), gravel pad thickness and seasonal thaw depths. In general, the point of fixity is
considered to be about one foot below the base of maximum seasonal thaw.
Exterior appurtenances such as electric conduits should be designed for total and
differential movements at the turbine system.
5.0 USE OF REPORT
This report has been prepared for use by the North Slope Borough for the wind turbine
feasibility assessment near Kaktovik, Alaska. The geotechnical engineering concepts
presented herein are based on assumptions regarding the proposed wind turbine
systems and are not developed for design or construction. The subsurface conditions
are based on existing geotechnical data, and the surface and subsurface conditions at
the proposed sites may vary from the descriptions and soil index data presented herein.
In our opinion, site-specific geotechnical investigations and engineering are required at
each turbine location. If there are significant changes in the nature, design, or location
MATERIAL SOURCE B
MATERIAL SOURCE A1
PROPOSED LANDFILL
AND SEWAGE LAGOON
PROPOSED LANDFILL
ACCESS ROAD
PROPOSED
RUNWAY/AIRPORT
MATERIAL SOURCE A2
KAKTOVIK WIND PROJECT - GEOTECHNICAL REVIEW AND FEASIBILITY STUDY
VICINITY & BORING MAP
NORTH SLOPE BOROUGH
LEGEND
2009 BORINGS
1986 BORINGS
1984 BORINGS
ENGINEERING EVALUATION/COST
ANALYSIS FOR OLD LANDFILL LF001 ,
FEBRUARY 2008, U.S. AIR FORCE
APPENDIX A
Existing Geotechnical Data
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1984
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1984
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1984
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1984
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1984
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1984
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1984
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
KAKTOVIK AIRPORT RELOCATION
ASRC KAKTOVIK GRAVEL FIELD BORING LOGS - 1986
NORTH SLOPE BOROUGH
Appendix G
Miscellaneous
T3P7
T3P5
T3P8
T3P1
T3P2
T3P6T3P4
T3P3
TAP7
TAP1
TAP9
TAP5
TAP6
TAP8
TAP4
TAP2
TFP1
TFP6
TFP7
TFP2
TFP3
TFP4
TFP5
B1P6
TFP9
TFP8
B1P4
B1P2
B1P5
B1P1
B1P3
TEP7
TXP7
TXP9
TEP1
TXP1
TEP5
TXP3
TXP2
TEP8
TXP8
TEP3 TEP4
TEP6
TXP5
TEP2
TXP4
TEP9
TXP6
TDP1
THP1
TDP6
TDP5
TDP3
THP2
TDP4
THP4
TDP7
THP3
THP6
TDP8
THP5
TDP2
TGP1
TGP4
TGP3
TXP11
TFP10
T4AP1
TXP16
TXP10
TXP14
T2AP2
T2AP5
T2AP1
TXP18
TXP12
TXP13
T2AP4
TEP10
T2AP3
TXP17
TXP15
TGP2
TB-2P1
TB-1P1
TB-1P2
B3L3P2
B5L4P2
B2L2P1
B3L2P1
B3L1P2
B9L1P5
B5L5P2
B4L4P1
B4L5P2
B4L1P1
B1L1P1
B7L6P1
B1L5P2
B2L4P1
B7L5P1
B5L6P4
B1LXP10
B1LXP11
B9L1P1
B8L6P2
B5L6P1
B2L6P2
B6L1P1
B1L1P3
B1L5P3
B1L1P2
B8L6P1
B3L2P2
B6L6P2
B9L3P1
B5L5P1
B8L6P3
B1L2P1
B9L1P4
B2L4P2
B2L1P1
B1L3P2
B6L6P1
TGP3
B9L1P3
B5L4P1
B2L6P1
B7L4P1
B1L6P2
B4L3P1
B2L3P1
B1L1P6
B4L5P1
B1L5P1B1L3P1
B3L2P1
B1L1P5
B9L2P1
B1L1P4
B6L2P2
B1L4P1
B3L5P1
B5L6P3
B3L6P3
B6L2P1
B7L6P2
B6L3P1
B9L2P2
B4L6P1
B3L4P1
B4L6P3
B3L3P1
B6L1P2
B2L3P2
B9L6P2
B8L4P1
B5L6P2
B2L1P2
B8L5P1
B4L6P2
B3L6P1
B3L1P1
B2L5P1
B3L6P2
B7L3P1
B1L4P2
B1L6P1
B7L2P1
B4L6P4
B5L1P1
B1LXP8
B1LXP1
B1LXP3
B1LXP5
B1LXP9
B1LXP6
B1LXP7
B1LXP4
B1LXP2
B10L3P2
B12L1P1
B10L5P4
B12L2P1
B12L5P2
B10L1P1
B10L5P2
B10L2P1
B10L1P3
B10L2P2
B12L4P1
B10L4P3
B10L3P1
B10L5P3
B12L3P1 B12L6P1
B12L5P1
B12L6P2
B10L5P1
B10L1P2
B10L4P1
B10L4P2
B1L7FP2
B1L7FP1
B1L8FP1
B1L8FP2
B1L8EP2
B1L8EP1
TC1L1P1
B1L9EP2
B1L7BP1
B1L7EP1
B1L8AP1
B1L9BP1
B1L4BP4
B1L9EP1
B1L4BP1 B1L4BP2
B1L7AP2
B1L7BP2
B1L7EP2
B1L4BP3
B1L7AP1
B1L4DP3
B1L4DP1
B1L8DP2
B1L7CP1
B1L4CP1
B1L8CP1
B1L7DP1
B1L7DP2
B1L9DP2
B1L9DP1
B1L8DP1
B1NL1P1
B2NL1P1
B1L4DP2
B1L4CP2
B11L11P1
TC-1L3P1
B3TC-1P4
B3TC-1P5
B3TC-1P3
B3TC-1P1
B3TC-1P2
B1P7 B1L7BP3
B12L6P1
B12L1P2
TGP4
TGP5
TGP6
TGP7
TGP8
TGP9
TGP10
TGP11
TGP12
B10L5P5
B10L5P6
B7L6P3
B8L5P2
B8L1P1
1072
4250
919
923
4091
4092
3091
40904089
1093B
840
3092838
3089833739
836
829737 914
4090
834 825735
2094
2039821
828733
817
2088729
813
4070
1093A
725 822734
818730
721 8144068
726
717629
810627722713
625 806439718
8026212074529
705617
622
527
7016132070618
704
1074
614
429
2064
601
2051
4042
425
421
1069
413
510422
5012050
5062041
502325
321327 405
323 410
2039
401
406
309
305
301
1040310
2031B
2031A 2024
2011
2009
210
206
109 202
105
2006
101
2001
9
102
5
1
10
6
919
915
905
633
2071
2066
606
306
1029
1025
2004 110
807
H arold Kav elook
S chool
NSBShop
FireStation
QargiCommunityCenter
Marsh C reek
Inn
Wa ldoA rm s
Hote lNS B
Utility D ept .Kaktovik
Pow erP lant
PoliceDept.
KaktovikStore
ASTAC
U.S.PostOffice
ArcticNationalWildlifeRefuge
Native VillageofKaktovik
TeleconferenceCenter
Kaktovi kPre sbyte rian Ch urc h
Vacuum-li ft stati on
Health
Clin ic
(3) 15 KVA
(3) 15 KVA
(3) 25 KVA
(3) 25 KVA
(3) 25 KVA
(3) 37.5 KVA
(3) 37.5 KVA
(3) 50 KVA Phase
(3) 50 KVA Phase
(3) 50 KVA Phase
(3) 50 KVA Phase
15 KVA A (X) Phase
25 KVA A (X) Phase
25 KVA A (X) Phase
25 KVA A (X) Phase
25 KVA A (X) Phase
15 KVA A (X) Phase
25 KVA A (X) Phase
25 KVA A (X) Phase
25 KVA A (X) Phase
37 KVA A (X) Phase
25 KVA C (Z) Phase 25 KVA C (Z) Phase
25 KVA C (Z) Phase
25 KVA C (Z) Phase
37 KVA C (Z) Phase
25 KVA C (Z) Phase
15 KVA C (Z) Phase
15 KVA C (Z) Phase
15 KVA C (Z) Phase
15 KVA C (Z) Phase
50 KVA C (Z) Phase
25 KVA C (Z) Phase
15 KVA C (Z) Phase
37 KVA B (Y) Phase
15 KVA B (Y) Phase
25 KVA B (Y) Phase
15 KVA B (Y) Phase
50 KVA B (Y) Phase
25 KVA B (Y) Phase
25 KVA B (Y) Phase
37 KVA B (Y) Phase
15 KVA B (Y) Phase
15 KVA B (Y) Phase
15 KVA B (Y) Phase
15 KVA B (Y) Phase
15 KVA B (Y) Phase
A C
ACPRIMARY RISERS
C
C
CA
AC
C
A
Pad Mount Gang Switch
3 Phase Refrigeration Pad Mount Gang Switch
NEW DMS BLDG
Pad Mount Gang Switch
225 KVA
4160/2400V
2400V Transformer
Pad Mount Gang Switch
Pad Mount Gang Switch
Pad Mount Gang Switch
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(X) A PHASE(X ) A P H A S E
(Y) B PHASE
(Z )C PHASE
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E(Z)CPHASE(Z) C PHASE (Y) B PHASES
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KAKTOVIK, AK
ELECTRIC UTILITIES
0 2,000 4,000 6,000 8,0001,000 Feet
DISCLAIMER. ALL MAPS AND OTHER INFORMATION PROVIDED HEREIN ARE
PROVIDED “AS IS” AND WITHOUT ANY WARRANTY, REPRESENTATION OF ACCURACY,
OR GUARANTEE OF ANY KIND. THE NORTH SLOPE BOROUGH MAKES NO
WARRANTIES, EXPRESS OR IMPLIED, AS TO THE USE OF THE MAPS OR OTHER
INFORMATION. THERE ARE NO IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR ANY PARTICULAR PURPOSE. THE RISKS AND LIABILITIES RESULTING
FROM THE USE OF THE MAPS OR OTHER INFORMATION IS ASSUMED BY THE USER.
Map created by Jeffrey Utter, Systems Programmer, Planning/GIS Department, North Slope Borough.
S/Projects-Jeffrey/2010 April/Public Works/Application/KAK63010
NORTH SLOPE BOROUGH
Department OF Community Planning/GIS
P.O. Box 69
Barrow, AK 99723
(907) 852-0333
Legend
SERVICE-DROP
Service Drop (X) A Phase
Service Drop (Y) B Phase
Service Drop (Z) C Phase
A (X) Phase
B (Y) Phase
C (Z) Phase
Unknown Phase
Underground Primary
PRIMARY-1PHASE
(X) A PHASE
(Y) B PHASE
(Z) C PHASE
3 Phase UG
3 Phase Pad Mount
Pad Mount Transformer
(3) 15 KVA
(3) 25 KVA
(3) 37.5 KVA
(3) 50 KVA
15 KVA A (X) Phase
15 KVA B (Y) Phase
15 KVA C (Z) Phase
25 KVA A (X) Phase
25 KVA B (Y) Phase
25 KVA C (Z) Phase
37 KVA A (X) Phase
37 KVA B (Y) Phase
37 KVA C (Z) Phase
50 KVA A (X) Phase
50 KVA B (Y) Phase
50 KVA C (Z) Phase
GANG-SWITCH
Service Meter
S
Structures
Poles