HomeMy WebLinkAboutAkiachak Wind Feasibility & Conceptual Design Community Energy & Wind Resource Analysis - Dec 2016 - REF Grant 7040057Community Energy and
Wind Resource Analysis
Akiachak, Alaska
WHPacific Inc.December 2016
Akiachak Community Energy and Wind Resource Analysis Page |i
TABLE OF CONTENTS
TABLE OF CONTENTS......................................................................................................................................i
ACRONYMS ..................................................................................................................................................iii
Executive Summary...........................................................................................................................1
Introduction......................................................................................................................................2
Village of Akiachak............................................................................................................................3
Met Tower Installation......................................................................................................................4
4.1 Federal Aviation Administration (FAA) Determination.................................................................4
4.2 Met Tower Dismantle ...................................................................................................................6
4.3 FAA Requirement for Dismantling Met Tower .............................................................................6
Wind Analysis....................................................................................................................................7
5.1 Scope of Work...............................................................................................................................7
A. Windographer...............................................................................................................................7
5.2 Approaches and Objectives ..........................................................................................................7
A. Preliminary Area Identification.....................................................................................................7
B. Area Wind Resource Evaluation....................................................................................................7
C. Micrositing....................................................................................................................................8
5.3 Test Site Location..........................................................................................................................8
A. Site information............................................................................................................................8
B. Met Tower Data Synopsis.............................................................................................................8
5.4 Tower Sensor Information............................................................................................................9
A. Data Recovery...............................................................................................................................9
B. Wind Speed.................................................................................................................................10
5.5 Monthly Time Series Graph ........................................................................................................12
5.6 Mean Daily Wind Profile.............................................................................................................12
5.7 Probability Distribution Function................................................................................................12
5.8 Wind Direction............................................................................................................................14
5.9 Wind Shear and Roughness ........................................................................................................15
5.10 Wind Analysis Conclusion ...........................................................................................................16
Solar Power.....................................................................................................................................17
6.1 How Photovoltaics Work ............................................................................................................18
6.2 The Sun’s Energy.........................................................................................................................20
6.3 Akiachak Pyranometer Data .......................................................................................................21
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6.4 Collection and Conversion of Solar Energy.................................................................................22
6.5 Akiachak Average Electrical Energy Use .....................................................................................24
6.6 An Akiachak Residential Solar Array...........................................................................................24
A. Residential Solar Array Size.........................................................................................................25
6.7 A Word Regarding 30 Year Solar Data ........................................................................................26
Native Village of Akiachak Electrical Power Analysis......................................................................28
7.1 Akiachak Power Plant..................................................................................................................28
A. Key Monitoring Locations...........................................................................................................29
7.2 Electric Power Monitoring Equipment........................................................................................30
A. Kilowatt (kW) and Kilowatt Hour (kWh) Power and Energy Meter............................................30
B. Current Transformers .................................................................................................................30
C. Data Logger.................................................................................................................................31
D. HOBOware Pro Computer Program............................................................................................31
7.3 Power Analysis............................................................................................................................32
A. School Power Load......................................................................................................................33
B. School Backup Electrical Supply..................................................................................................34
C. School Power Analysis Conclusion..............................................................................................34
7.4 Power Plant Fuel Cost Savings with an Akiachak Solar Array.....................................................35
A. School Monthly Average Energy Consumption ..........................................................................35
B. Establish Akiachak Average Daily Solar Radiance.......................................................................36
C. Calculate Array Size.....................................................................................................................37
D. Calculate Power Plant Fuel Savings.............................................................................................37
E. Power Plant Fuel Cost Savings with an Akiachak Solar Array Conclusion...................................38
APPENDIX........................................................................................................................................39
B. Akiachak MET Tower Installation Memo 6 14 2012
C. FAA Supplemental Notice (7460 2) – Dismantle for 2012 – WTW 3158 OE
D. FAA Letter 7 13 2016 TERMINATION
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ACRONYMS
AEA Alaska Energy Authority
FAA Federal Aviation Administration
KPa Kilopascal (pressure)
KVA or kVA Kilovolt Ampere
KW or Kw Kilowatt
KWH or kWh Kilowatt hours
M or m Meter
MET or met Meteorological Tower
MI or mi Miles
MWH Megawatt hours
mW Milliwatt (1/1000 watt)
NREL United States National Renewable Energy Laboratory
NSRDB National Solar Radiation Data Base
PCE Power Cost Equalization
PV Photovoltaic
SQ or Sq Square
Wh Watt hour
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Executive Summary
This report investigates energy use and analyzes and discusses wind and solar renewable energy
resources in Akiachak, Alaska. Wind data collected from a meteorological tower for a period of twenty
eight months and solar data collected for a period of 13 months was used as a basis of analysis.
Additionally, the electrical energy consumption at the school was monitored and collected. Based on
the data collected and analyzed this report concludes the following:
The wind regime in Akiachak is not sufficient to allow for a cost effective use of this renewable resource
given initial results. The wind power class is considered as class 1 and is poor based on mean wind
speed, wind occurrence and duration, and other contributing factors. A wind power class 3 is considered
fair and wind regimes of this class are worthy of further engineering investigation in order to further
consider the feasibility of wind as a renewable energy source. The wind resource is not worthy of
further study.
Further, solar energy collection and its application in Akiachak is deserving of further engineering study.
This first investigation has determined that although the average household electrical consumption
exceeds the requirements of small roof top solar collectors, the possibility exists that larger commercial
units with a larger collection area may applicable. Further study is warranted.
The Akiachak power plant distributes electrical power to the Village of Akiachak solely by means of two
electrical distribution feeders. Electrical power data was collected over a 12 week period and
particularly from the Akiachak community school. It was determined that the community school is the
largest single consumer of electrical energy or approximately 25% of the total power plant load.
Lastly, this report concludes that solar energy may be a viable source of renewable energy to reduce
energy use, by approximately one quarter with a suitably sized and properly located solar array and is
worthy of further investigation. We used the school average energy consumption to illustrate this
savings. The continuing leaps in progress of the efficiency of solar cells to convert the sun’s energy to
electricity is ongoing and near future improvements in solar cell efficiency and manufacture may
significantly reduce the array areas and thus initial construction costs.
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Introduction
The Akiachak Native Community’s electrical power is generated solely by the burning of increasingly
expensive diesel fuel. Akiachak desires to reduce electrical energy cost as a result of Akiachak’s
dependency on diesel fuel by developing its own renewable energy source(s) to augment the production
of electrical power produced by fuel dependent diesel generators. The sources of renewable energy
examined in this report included the viability of solar power and resulting solar array and the viability of
wind power.
Akiachak’s village corporation, Akiachak Limited, was awarded funding in the form of a grant through
the Alaska Energy Authority’s (AEA) Round IV of the Renewable Energy Fund to complete an analysis
that would consider wind energy as a lower cost, local renewable energy source for Akiachak. The grant
encompassed a wind feasibility analysis, resource assessment and conceptual design. Also included as
part of the overall analysis was a geotechnical reconnaissance study of the proposed area for placement
of a possible wind turbine generator(s). Consequently Akiachak Limited authorized this work to be
undertaken and was subsequently awarded to WHPacific, Inc.
A meteorological (met) tower was erected in Akiachak in June 2012. The tower had to be re erected in
November 2013 after it pulled out a portion of its anchoring system and fell down due to a fierce
windstorm October 27, 2013. Wind data continued to be collected until April 2016. The tower was
ultimately taken down and dismantled in June 2016.
After the re erection of the met tower in October 2013, wind data from the met tower was informally
analyzed. The Alaska Energy Authority, Akiachak Limited and WHPacific, Inc. determined and agreed
that the wind resource in Akiachak may be less than desirable as it relates to any significant harvest of
wind energy versus the expense of erecting a new wind turbine.
Based upon this determination the project plan was re scoped and implemented in December 2013.
The re scoped plan included the gathering of equipment for instrumenting community energy loads,
acquire a pyranometer (photovoltaic sensor) to mount on the met tower for measuring the intensity of
the sun’s radiance (a possible energy resource), perform an analysis and finally provide a written report.
A wind analysis of reduced scope was also included.
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Village of Akiachak
Akiachak is an Alaskan Yup’ik village located approximately 14 air miles north northeast of the City of
Bethel, along the northern bank of the Kuskokwim River. It has a subarctic climate with long, cold
winters and short, mild summers. Summer average highs (measured at Bethel) are around 63°
Fahrenheit and the winter record low is 39° Fahrenheit. Annual precipitation is 19.6 inches, with 62.0
inches of snowfall. (Western Regional Climate Center, 2009).
The United States census of 2010 shows a population of 627 persons in 183 households. (U.S. Census
Bureau, 2010).
During the winter, traversing the nearby frozen Kuskokwim River for a distance of about 25 miles
northeast is a common travel option to Akiachak. There are no constructed roads connecting Akiachak
to Bethel. The Kuskokwim River is frozen sufficiently during the winter months and provides a primary
and most easily accessible route of travel. Conversely, during the summer months, the Kuskokwim River
is extensively used for travel between Akiachak and Bethel but at times prove difficult with low water
levels, sand bars, and sometimes ice flows. In general, traveling to Akiachak is typically achieved by a
short aircraft flight from Bethel, AK. This more direct overland flight route is about 14 miles in length.
Figure 3 1: Location of Akiachak, Alaska
Alaska
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Met Tower Installation
The met tower was installed on June 5, 2012. The met tower supported three anemometers to measure
wind speed, a temperature sensor as well as a wind vane to measure wind direction. Later a
pyranometer, manufactured by Li cor Biosciences, was installed to measure the sun’s radiance. The
pyranometer data was analyzed and used in this report to determine the feasibility of installing solar
arrays for the production of electricity as a renewable energy resource.
4.1 Federal Aviation Administration (FAA) Determination
A permit from the FAA was needed to construct a met tower. Among the FAA main priorities is to keep
all users of our national airspace safe. To maintain the safest aerospace system in the world, the FAA
must make sure the national airspace is navigable and free of obstructions. When anyone proposes new
construction or proposes to alter existing structures near airports or navigational aids, the FAA
determines how the proposal would affect the airspace.
To meet FAA requirements, an application for a study to erect the 30m met tower was submitted to FAA
in the fall of 2011. On December 12, 2011 FAA issued Aeronautical Study No. 2012 WTW 11431 OE
Determination of No Hazard to Air Navigation for Temporary Structure for the installation of a
temporary 30m above ground level met tower. Before erecting the tower, a decision was made to move
the location of the tower. A subsequent FAA approval was issued on March 23, 2012 FAA for
Aeronautical Study No. 2012 WTW 2181 OE Determination of No Hazard to Air Navigation for
Temporary Structure for the installation of a temporary 30m above ground level met tower. Again, a
second decision was made to move the location of the tower, hence the third and final FAA approval
was issued on April 26, 2012 for Aeronautical Study No. 2012 WTW 3158 OE Determination of No
Hazard to Air Navigation for Temporary Structure with an expiration date of October 26, 2013 (see
Appendix A – FAA Letter 4 26 2012 – Determination of No Hazard).
The figure below identifies the location of the installed met tower. Installation (see Appendix B
Akiachak MET Tower Installation 6 14 2012) on the specified location was in accordance with the third
and final FAA aeronautical permit.
.
Figure 4 1 Installed Location of Akiachak Met Tower
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The photographs below show the installation of the met tower.
Figure 4 2 Meteorological Tower Installation June 2012
Figure 4 3 Meteorological Tower Installation Complete June 5, 2012
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4.2 Met Tower Dismantle
A return trip was made to Akiachak in the summer of 2016. The met tower needed to be taken down
and thus was dismantled on June 15, 2016. The tower had been erected for a total of approximately 48
months.
Figure 4 4 Met Tower Removal June 15, 2016
4.3 FAA Requirement for Dismantling Met Tower
With the dismantling of the met tower, it was necessary to e file FAA Form 7460 2, Notice of Actual
Construction or Alteration, advising FAA that the tower was no longer erect nor a possible flight safety
issue. The e filing action took place on June 30, 2016 (see Appendix C – FAA Supplemental Notice (7460
2) – Dismantle for 2012 WTW 3158 OE). The FAA responded on July 13, 2016 and issued a letter of
termination thus rendering the permit no longer valid (see Appendix D – FAA Letter 7 13 2016
TERMINATION). This closed the met tower permit process with FAA.
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Wind Analysis
5.1 Scope of Work
As explained in the Introduction at the beginning of this report, the wind analysis work was funded from
the State of Alaska, Alaska Energy Authority Round IV of the Renewable Energy Fund.
A meteorological tower was erected in Akiachak in June 2012. The tower had to be re erected in
November 2013 after it fell down during a windstorm in October 2013. Wind data used was collected
until February 2016. The tower was ultimately taken down and dismantled on June 25, 2016.
The re scoped plan included the gathering of equipment for instrumenting community energy loads,
acquire a pyranometer (photovoltaic sensor) to mount on met tower for measuring the intensity of the
sun’s energy (a possible energy resource), perform an analysis and finally provide a written report. A
wind resource analysis report was also included.
A. Windographer
The computer program utilized to perform this wind analysis is called Windographer and is a widely
recognized and a well respected analysis tool. It reads a wide variety of data files and allows for
visualization, quality control and analysis of data sets. The program is version 3.3.9 (June 2015) and is a
product of AWS Truepower, LLC. Data collected from the met tower was analyzed using this tool. The
tool also allows for statistically filling in small portions missing data based on the given data set.
5.2 Approaches and Objectives
Several approaches are utilized when investigating the wind resource within a given land area. The
preferred approach depends on wind energy program objectives and on previous experience with wind
resource assessment. These approaches can be categorized as three basic stages of wind resource
assessment: preliminary area identification, area wind resource evaluation, and micrositing. Two of the
three approaches have been employed in this effort to some degree.
A. Preliminary Area Identification
This process screens a relatively large region (e.g., state or utility service territory) for suitable wind
resource areas based on information such as airport wind data, topography, flagged trees, or other
indicators. At this stage new wind measurement sites can be selected. For Akiachak, two locations
were initially identified, one on the apron at the old airport’s west end, and one near the community
landfill. The site near the landfill was preferred and an FAA OE application was filed and approved. It
was subsequently determined that this site was too boggy to support a met tower and a second site
north of the sewage lagoon was selected. Another site on the bluff about three miles west of town was
also considered. It was initially deemed unfeasible due to distance and being across the Gweek River.
This was revisited during the rescoping of the project and again dismissed.
B. Area Wind Resource Evaluation
This stage applies to wind measurement programs that characterize the wind resource in a defined area
or set of areas where wind power development is being considered. The most common objectives of
this scale of wind measurement are to:
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• Determine or verify whether sufficient wind resources exist within the area to justify further site
specific investigations
• Compare areas to distinguish relative development potential
• Obtain representative data for estimating the performance and/or the economic viability of
selected wind turbines.
• Screen for potential wind turbine installation sites
In this case, one 30 meter (m) met tower was installed northwest of Akiachak to determine and verify
whether sufficient wind resources exist within the area to justify further site specific investigations.
C. Micrositing
Micrositing references wind turbine placement optimization within an already selected area resulting in
extracting as much energy as possible from the wind at this location. By carefully analyzing the wind
patterns over a plot of land and positioning the turbine carefully, designers can optimize wind turbine
power production. This report did not need to address micrositing.
5.3 Test Site Location
The 30m met tower was located approximately 1.0 mile northwest of Akiachak. Its location was chosen
to de conflict with the Akiachak airport and local aircraft traffic patterns.
A. Site information
Site number 01050
Latitude/longitude 60° 55' 3.10"N , 161° 27' 20.60"W (NAD 83)
Site elevation (above sea level) 6 meters
Data logger type NRG Symphonie, 10 minute time step
Tower type NRG 30 meter tall tower, 152 mm diameter
Anchor type Screw in anchor, hammered into permafrost
B. Met Tower Data Synopsis
Start date 10/8/2013 15:00
End date 2/2/2016 11:00
Duration 28 months
Length of time step 10 minutes
Calm threshold 0.4 m/s
Mean pressure 101.1 kPa
Mean air density 1.163 kg/m³
Power density at 50m 152 W/m²
Wind power class 1 (Poor)
Power law exponent 0.13
Surface roughness 0.0109 m
Roughness class 0.80
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5.4 Tower Sensor Information
Channel Sensor type Height Offset Orientation
1 NRG #40 anemometer 28 m* 0.37 NE
2 NRG #40 anemometer 27 m* 0.39 SW
3 NRG #40 anemometer 21 m** 0.42 E
8 NRG #200P wind vane 28 m -SSW
9 NRG #110S Temp C 2 m -NNE
10 Li cor Pyranometer 2 m -S
For reporting purposes * = rounds up to 30 meter height ** = rounds down to 20 meter height
Hence forth in this report, the three anemometers noted above will be referenced as follows:
The three anemometers were calibrated on February 8, 2012. The calibration results are provided the
original met tower installation report in Appendix B (see Appendix B Akiachak MET Tower Installation
Memo 6 14 2012, pages 14 16).
A. Data Recovery
Data recovery was accomplished using a data logging unit manufactured by NRG Systems. The NRG
model is called Symphonie with a recorded serial number #30905042. Overall data recovery in Akiachak
was very good with a 94.86% recovery for the 28 month recording period. The small percent loss can be
due to a small number of icing events or events of similar nature.
Data Recovery Summary Table
Channel Height Reference Name
1 28m 30A
2 27m 30B
3 21m 20
Possible Valid Recovery
DataPoints DataPoints Rate (%)
1 2013 12,150 9,760 80.33
2 2014 52,560 52,560 100
3 2015 52,560 48,822 92.89
4 2016 4,674 4,530 96.92
All Data 121,944 115,672 94.86
Year
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Percent data recovery combined by month for all years
Note:Henceforth in this report, a more complete data set is utilized. As mentioned previously, the
program was employed to statistically fill in small data gaps existing in the original data set thus
providing more complete data tables and diagrams shown below.
B. Wind Speed
Wind speed data collected from the met tower anemometers during the 28 month period was analyzed
Anemometer Data Summary Table
and is presented in the Anemometer Data Summary Table above.
Month Possible Valid Recovery
DataPoints DataPoints Rate (%)
1 Jan 13,392 13,248 98.92
2 Feb 8,274 8,274 100
3 Mar 8,928 8,862 99.26
4 Apr 8,640 8,640 100
5 May 8,928 8,928 100
6 Jun 8,640 8,640 100
7 Jul 8,928 8,928 100
8 Aug 8,928 8,928 100
9 Sep 8,640 8,640 100
10 Oct 12,294 11,652 94.78
11 Nov 12,960 8,272 63.83
12 Dec 13,392 12,660 94.53
All Data 121,944 115,672 94.86
Variable Speed 30m A Speed 30m B Speed 20m
Measurementheight (m) 30 30 20
Mean wind speed (m/s) 4.947 4.777 4.613
MoMMwind speed(m/s) 4.871 4.722 4.547
Median wind speed (m/s) 4.6 4.6 4.3
Min wind speed (m/s) 0.4 0.4 0.373
Max wind speed (m/s) 17.5 17.8 17
Weibull k 2.011 1.754 1.961
Weibull c(m/s) 5.551 5.295 5.188
Mean powerdensity (W/m²) 132 127 110
MoMMpowerdensity (W/m²) 124 121 104
Mean energycontent(kWh/m²/yr) 1,153 1,114 966
MoMMenergy content(kWh/m²/yr) 1,090 1,058 914
Energy patternfactor 1.844 1.979 1.912
Frequency of calms (%) 2.58 6.02 3.34
Possible datapoints 121,944 121,944 121,944
Valid datapoints 121,944 121,944 121,944
Missingdatapoints 0 0 0
Datarecovery rate (%) 100 100 100
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When observing the mean wind speed in combination with a mean wind power density from the table
above, the data suggests a poor wind source.Further, the wind power class 1 is poor,as indicated in
paragraph 5.3(B) Met Tower Data Synopsis.
It is important to note that the mean of monthly means (MoMM) is an average of twelve monthly
averages. Because it avoids seasonal bias, the MoMM often provides a better estimate of the long term
mean than would a simple mean.
Of particular interest in the above Anemometer Data Summary Table is the MoMM wind speed and its
importance to wind turbine operation in general. At very low wind speeds, there is insufficient torque
exerted by the wind on the wind turbine blades to make them rotate. However, as the speed increases,
the wind turbine will begin to rotate and generate electrical power. The typical wind speed at which a
wind turbine first starts to rotate and generate power is called the cut in wind speed. For smaller rated
wind turbines the cut in speed is typically between 4 5 meters per second. In Akiachak, when the wind
blows, the MoMM wind speed is barely 5m/s (highlighted in yellow in Anemometer Data Summary
Table) and it is reasonable to expect that when a wind event occurs the average wind speed may not be
suitable to turn blades of a wind turbine to generate sufficient electricity.
In Akiachak, 55.2% of the time the wind occurred at winds speeds at or below 5 m/s. See paragraph 5.7,
Probability Distribution Function,further in this report for more detailed explanation.
Additionally, due to the non linear variation of power with a steady wind speed, the mean power
obtained over time in a variable wind with a given mean velocity is not the same as the power obtained
in a steady wind of the same speed. More simply, an average variable wind will not produce as much
power as an average steady wind.
The table below depicts different attributes of the wind speed during 28 months of data collection.
Annual Wind Speed Data (30m)
Year Mean Median Min Max
(m/s) (m/s) (m/s) (m/s)
2013 4.95 4.80 0.40 14.60
2014 4.92 4.70 0.40 17.50
2015 4.80 4.40 0.40 17.50
2016 6.87 6.80 0.40 15.00
All Data 4.95 4.60 0.40 17.50
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5.5 Monthly Time Series Graph
The following graph illustrates the mean monthly wind speed during 28 months of data collection.
Ignoring the anomaly dip flanked by November 2014 and February 2015, the wind blows more rapidly
during the winter months and slows during the summer months.
5.6 Mean Daily Wind Profile
The mean daily wind profile below for Akiachak shows the lowest wind speeds occurring during the mid
morning hours and highest during the late afternoon and early evening.
5.7 Probability Distribution Function
If one were to total all the times the wind blew in Akiachak, the probability distribution function (PDF)
below displays the frequency of a particular wind speed at a height of 30m. The graph shows wind
oriented toward the lower speeds compared to a normal wind power shape curve.
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PDF of 30m anemometer
Interpreting the above graph, it depicts that if a wind speed of 5m/s is chosen, this speed occurred (at a
30 meter height) approximately 8.5% of the time of all wind events. As noted previously, wind turbines
require cut in speeds of approximately 5m/s to begin to generate electricity. Further, wind turbines
operate at an optimum output when the wind speeds are steady above 9m/s 10m/s. The collection of
data that produced the probability distribution function graph is presented below. This shows a
frequency of 55.23% of the time that wind occurred winds speeds are at or below 5 m/s (highlighted in
yellow). This implies the wind turbine is essentially idle or not producing much electricity for about half
of the time wind occurred. It also suggests that 41% of the time (96.29%55.23%) the frequency of
wind speeds are between 5m/s 10m/s and only 3.5% of wind occurrences are above 10m/s.
Probability Distribution Function Data Table
Bin Endpoints (m/s) Occurrences Frequency Cumulative
Bin Lower Upper (%) %
1 0 0.5 3,392 2.78 2.78
2 0.5 1 2,015 1.65 4.43
3 1 1.5 2,569 2.11 6.54
4 1.5 2 4,042 3.32 9.86
5 2 2.5 5,868 4.81 14.67
6 2.5 3 7,693 6.31 20.98
7 3 3.5 9,553 7.83 28.81
8 3.5 4 10,757 8.82 37.63
9 4 4.5 11,076 9.08 46.72
10 4.5 5 10,382 8.51 55.23
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11 5 5.5 9,595 7.87 63.10
12 5.5 6 8,040 6.59 69.69
13 6 6.5 6,835 5.61 75.30
14 6.5 7 5,703 4.68 79.97
15 7 7.5 4,821 3.95 83.93
16 7.5 8 4,083 3.35 87.27
17 8 8.5 3,524 2.89 90.16
18 8.5 9 3,050 2.50 92.66
19 9 9.5 2,528 2.07 94.74
20 9.5 10 1,888 1.55 96.29
21 10 10.5 1,456 1.19 97.48
22 10.5 11 985 0.81 98.29
23 11 11.5 653 0.54 98.82
24 11.5 12 490 0.40 99.22
25 12 12.5 353 0.29 99.51
26 12.5 13 212 0.17 99.69
27 13 13.5 139 0.11 99.80
28 13.5 14 90 0.07 99.88
29 14 14.5 47 0.04 99.91
30 14.5 15 28 0.02 99.94
31 15 15.5 24 0.02 99.96
32 15.5 16 22 0.02 99.98
33 16 16.5 13 0.01 99.99
34 16.5 17 10 0.01 99.99
35 17 17.5 8 0.01 100.00
All bins 121,944 100 100
5.8 Wind Direction
The following graphs are often referred to as “roses” and easily represent wind direction. The Wind
Frequency Rose for Akiachak indicates the winds are predominately northerly. The Mean Value Rose
depicts that, on the average, the most forceful winds emanate from the north. The Total Energy Rose
below, a combination of frequency and mean value roses, indicates the power producing winds are also
northerly.
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Wind Frequency vs Direction rose Mean Value Rose
Total Energy Rose
5.9 Wind Shear and Roughness
Reference is made to “Met Tower Data Synopsis”, paragraph 5.3(B). From the data a wind shear “Power
law exponent” of 0.13 (highlighted in yellow) indicates low wind shear at the site. In its most general
sense, wind shear refers to the change in wind velocity (speed and direction) with height above ground.
The power law exponent (sometimes called the power law coefficient or simply 'alpha') is a number that
characterizes the rate at which wind speed changes with height above ground. The variation in the wind
speed with height above ground is called the wind shear profile. The wind speed tends to increase with
the height above ground, as in the following wind shear profile graph showing mean wind speeds at
three measurement heights in Akiachak, at 20m to 30m above ground. Thus during wind events the rate
at which the wind speed changes with height above ground is generally low as characterized by the
shape of the curve. By comparison, if the power law exponent were a higher number, say 0.40, the
curve would move to the left on the graph and the curve (“bend” shape of the curve below the 20m
height) would be flatter thus indicating a greater rate of change in wind speed and a greater wind shear.
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Additionally the calculated surface roughness 0.0109 m indicates smooth terrain surrounding the tower
or a roughness class of 0.5. Comparably a high roughness class of 3 to 4 refers to landscapes with many
trees and buildings, while a sea surface is in roughness class 0. Airport concrete runways are in a
roughness class of 0.5, the same roughness class as the surface surrounding the met tower in Akiachak.
5.10 Wind Analysis Conclusion
The wind regime in Akiachak is not sufficient to allow for a cost effective use of this renewable resource
given the initial results of this study as well as current wind turbine technology. The class of wind power
in Akiachak is rated at 1 (of 7) and is considered poor based on mean wind speed, wind occurrence and
other contributing factors. Wind power class 3 is considered fair and wind regimes of this class are
worthy of further engineering investigation in order to consider the feasibility of wind turbine
construction.
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Solar Power
Extracting power from the sun’s energy is a sensible topic to explore as a source of renewable energy for
Akiachak. The following information is meant to provide a basic understanding regarding solar energy
and its possible application in Akiachak. It is not a substitute for an exhaustive engineering analysis but
rather provides a solid foundation for making informed decisions about further efforts to apply
renewable energy methods.
As mentioned in the Introduction of this report, the existing met tower had a pyranometer (photovoltaic
sensor) mounted on it to collect data about the sun’s available radiance in Akiachak. The pyranometer
started collecting data in December of 2014. The data collection terminated in January of 2016 thus
providing approximately 13 months of usable data.
In photovoltaic (PV) system design it is essential to know the amount of sunlight available at a particular
location at a given time. The two common methods which characterize solar radiation are the solar
radiance (or radiation) and solar insolation.
The solar radiance is an instantaneous power density in units of kW/m
2 (kilowatts per square meter).
The solar radiance varies throughout the day from 0 kW/ m
2 at night to a maximum of about 1 kW/ m
2
during the day. The solar radiance is strongly dependent on location and local weather. Solar radiance
measurements consist of global and/or direct radiation measurements taken periodically throughout
the day. The measurements are taken using either a pyranometer (measuring global radiation) and/or a
pyrheliometer (measuring direct radiation). As mentioned, a pyranometer was used in Akiachak. In
well established locations, this data has been collected for more than twenty years. In fact, the solar
radiance was measured for a period of more than 30 years in Bethel, Alaska. More about this later in this
report (see paragraph A Word Regarding 30 Year Solar Data).
An alternative method of measuring solar radiation, which is less accurate but also less expensive, is
using a sunshine recorder. These sunshine recorders (also known as Campbell Stokes recorders)
measure the number of hours in the day during which the sunshine is above a certain level (typically
200mW/cm2). Data collected in this way can be used to determine the solar insolation by comparing the
measured number of sunshine hours to those based on calculations.
The diagram below depicts the available sun energy as a resource for the contiguous United States,
Alaska and Hawaii. It is not surprising that Alaska shows in the low to mid range at about 4kWh/m
2/day
(or 166.7W/m
2) (Source: NREL).
Akiachak Community Energy and Wind Resource Analysis Page |18
In order to understand the usefulness of the sun’s energy for Akiachak, we need to understand how to
measure the sun’s solar radiance and then we can utilize this information to understand how effective
solar power may be as an energy resource.
6.1 How Photovoltaics Work
Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials exhibit
a property known as the photoelectric effect that causes them to absorb photons of light and release
electrons. When these free electrons are captured, an electric current results that can be used as
electricity.
The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found
that certain materials would produce small amounts of electric current when exposed to light. In 1905,
Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic
technology is based, for which he later won a Nobel Prize in physics. The first photovoltaic module was
built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was
too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious
use of the technology to provide power aboard spacecraft. Through the space programs, the technology
advanced, its reliability was established, and the cost began to decline. During the energy crisis in the
1970s, photovoltaic technology gained recognition as a source of power for non space applications.
Akiachak Community Energy and Wind Resource Analysis Page |19
Figure 6 1 A Typical Photovoltaic Circuit
The diagram above illustrates the operation of a basic photovoltaic cell, also called a solar cell. Solar cells
are made of the same kinds of semiconductor materials, such as silicon, used in the microelectronics
industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive
on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked
loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive
and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric
current that is, electricity. This electricity can then be used to power a load, such as a light or a tool.
A number of solar cells electrically connected to each other and mounted in a support structure or
frame is called a photovoltaic module. Modules are designed to supply electricity at a certain voltage,
such as a common 12 volts system. The quantity of electrical current produced is directly dependent on
how much light (solar radiance) strikes the module.
Figure 6 2 Photovoltaic Cells Form an Array
Akiachak Community Energy and Wind Resource Analysis Page |20
Multiple modules can be wired together to form an array. In general, the larger the area of a module or
array, the more electricity that will be produced. Photovoltaic modules and arrays produce direct
current (dc) electricity. They can be connected in both series and parallel electrical arrangements to
produce any required voltage and current combination.
The point to be made is that the efficiency of converting the sun’s energy is very low, approximately
5%20%, thus to energize large loads (many kilowatts) requires large areas to be covered by the
modules, as we shall see when we examine the energy use at the school.
6.2 The Suns Energy
The sun is always there; lots of energy. How many photons (energy) reach the surface of the earth on
average? The energy balance in the atmosphere is shown below:
The main components in this diagram (courtesy of the University of Oregon) are the following:
Short wavelength (optical wavelengths) radiation from the Sun reaches the top of the
atmosphere
Clouds reflect 17% back into space. If the earth gets more cloudy, as some climate
models predict, more radiation will be reflected back and less will reach the surface
8% is scattered backwards by air molecules
6% is actually directly reflected off the surface back into space
So the total reflectivity of the earth is 31%. This is technically known as an albedo
What happens to the 69% of the incoming radiation that doesn't get reflected back?
Akiachak Community Energy and Wind Resource Analysis Page |21
19% gets absorbed directly by dust, ozone and water vapor in the upper atmosphere
This region is called the stratosphere and its heated by this absorbed radiation
4% gets absorbed by clouds located in the troposphere. This is the lower part of the
earth's atmosphere where weather happens
The remaining 47% of the sunlight (often referenced as the sun’s radiance) that is
incident on top of the earth's atmosphere reaches the surface. This is not a real
significant energy loss
6.3 Akiachak Pyranometer Data
How much radiance from the sun reaches the surface of the earth on average and especially how much
reaches Akiachak on the average?
Incident solar radiance on the ground:
Average over the entire earth = 164 watts per square meter over a 24 hour day
An 8 hour summer day, 40 degree latitude is 600 watts per square meter.
More specifically, in Akiachak, at 60 degrees North latitude, during the month of June,
the average incident solar radiance is about 242.1 watts per square meter per day (see
graph below) and the sun shines about 18.8 hours a day.
The following table was generated from data obtained from the Akiachak met tower mounted
pyranometer (solar measuring device) during December 2014 to January 2016. For any given day during
each month the table below shows average daily solar radiance documented at the Akiachak met tower.
Also tabulated are the average number of daylight hours in Akiachak for any given day during each
month.
Table 6 3 Met Tower Average Daily Solar Radiance Data in Watts/Sq Meter for Each Month
The graph below shows the same data but in graphic form. The graph indicates the average daily
incident amount of the sun’s radiance (watts/square meter) that impinged on the Akiachak area per
month during the collection period. Additionally, it depicts the average hours of daily sunlight during
the month.
Month Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Jul 15 Aug 15 Sep 15 Oct 15 Nov 15 Dec 15 Jan 16
Jan Dec
2015
YearlyAvg
Avg
Watts/Sq
Meter
6.1 17.9 37.3 98.2 154.5 163.1 242.1 157.8 124 76.3 44.9 17.9 6.1 11.8 95.0
Avg
Daylight
Hours
6 6.2 8.4 11.1 14 16.8 18.8 18.6 16.4 13.5 10.7 7.9 6 6.2 12.4
Akiachak Community Energy and Wind Resource Analysis Page |22
In science, energy is measured in units of watt hours. A watt is not a unit of energy, it is a measure of
power. Thus, ENERGY = POWER x TIME. One kilowatt Hour = 1kWh = 1,000 watts used in one hour. For
example, ten 100 watt light bulbs left on for an hour consumes 1kWh of energy.
So over this day with an average of 18.8 hours of daylight Akiachak receives:
18.8 hours x 242.1 watts per square meter = 4,551 watt hours per square meter which
also equals 4.6 kilowatt hours (1,000 watts = 1 kilowatt) per square meter. This is an
average daily solar energy for any day in the month of June 2015.
But to go from energy received by the sun to usable energy generated requires conversion of solar
radiance into some other form (heat, electricity) at some reduced level of efficiency. As mentioned
earlier, the salient point to make here is that the conversion efficiency is quite low! Solar modules
(arrays) are about 15% to 20% efficient.
6.4 Collection and Conversion of Solar Energy
To effectively capture of the sun’s power for conversion to electricity, a solar array needs to be pointed
toward the direction of the sun. This is generally south at latitudes above the earth’s equator.
Additionally, the amount of captured solar energy depends on orientation of solar module(s) with
respect specifically to the angle of the sun as it moves across the horizon.
Under optimum conditions at some locations on earth, one can achieve instantaneous
solar radiance (fluxes) as high as 2000 watts per square meter. In Akiachak, the
maximum instantaneous quantity recorded on any given was in June 2015 and was
approximately 850 watts per square meter (not to be confused with the average daily
amount calculated over a month’s time as mentioned above of 242 watts per square
meter).
6.1
242.1
11.8
0
2
4
6
8
10
12
14
16
18
20
0
50
100
150
200
250
300
Dec14Jan15Feb15Mar15Apr15May15Jun15Jul15Aug15Sep15Oct15Nov15Dec15Jan16Avg DaylightHoursAvg Watts/Sq Meter
Month
Akiachak Average Daily Solar Radiance
Solar Radiance
Daylight Hours
Akiachak Community Energy and Wind Resource Analysis Page |23
In the winter, for a location at 40 degrees latitude, the sun is lower in the sky and the
average flux received is about 300 watts per square meter. In Akiachak, at 60 degrees
latitude, the sun is even lower in the sky thus the maximum instantaneous December
2014 quantity was approximately 120 watts per square meter. Compare this amount
with the measured daily December average at only 6.1 watts per square meter.
The Akiachak pyranometer was mounted on the met tower to face a southerly direction and its
directionality, once set, was static (it did not follow the sun’s movement as it traversed the horizon).
The ability for the Akiachak pyranometer to track the sun’s movement was not part of the scope of this
report but the overall consequence, had the sun’s movement been tracked, would be to more
accurately record the total available sun’s radiance.
More importantly, research for this report uncovered a 30 yearlong study referenced by NREL that
employed pyranometers that tracked the sun’s movement. The pyranometers were located at 239
different locations across the United States, one of those locations being Bethel, Alaska. This data is
presented in paragraph A Word Regarding 30 Year Solar Data further below in this report.)
The graph below is typical of data collected during the recording period in Akiachak and depicts the solar
radiance in watts per square meter for each day of the month of June 2015. This report employed
computer software to analyze the data. The data logger software which produced the graph also
calculated the average value of solar radiance, shown at the bottom of the graph, 242.1 watts/square
meter. (The name of the data logger software is called Symphonie Data Retriever, Version 7.03.15.)
Akiachak Community Energy and Wind Resource Analysis Page |24
6.5 Akiachak Average Electrical Energy Use
A typical United States household average energy use is approximately 911 kWh per month (Source: US
Energy Information Administration, October 2015). In Akiachak, the average residential monthly
electrical energy use is approximately 306 kWh per month (Source: extracted from State of Alaska,
Alaska Energy Authority 2015 Power Cost Equalization Statistical Report). The electrical energy use was
based on an annual amount and thus was averaged over a year’s time. Data for actual monthly energy
used for each household was not available.
6.6 An Akiachak Residential Solar Array
So how much daily energy is available that can be used to help displace some of the monthly Akiachak
household consumption of 306 kWh? Recall we said earlier “to go from energy received by the sun to
usable energy generated requires conversion of solar radiance into some other form (heat, electricity) at
some reduced level of efficiency.” We must install a solar array to convert the sun’s radiance into usable
electricity.
Assume we install a solar array that is about 6 square meters (an area about 64 square feet, about the
same size as two sheets of standard plywood laid side by side) in Akiachak. We face the array south and
tilt it at about 60 degrees, the same latitude as Akiachak. We can now measure the energy produced.
We need to calculate the energy (kWh) the sun provides per month. During an average sunny June day
in Akiachak, the average energy available is therefore 242.1 watts/square meter x 18.8 hours/day x 6
square meters is about 27.3 kWh per day. To achieve a monthly total multiply by 30 days per month
thus the monthly quantity is 30 days per month x 27.3 kWh per day equals 819 kWh per month. More
than is needed for 306 kWh per month.
But remember the efficiency problem. Solar arrays need to convert the sun’s radiance to electricity.
Solar arrays are currently only 5%20% efficient. Applying this efficiency factor to our summer 819 kWh
per month:
5% efficiency results in an average of 40.9 kWh per month
10% efficiency results in an average of 81.9 kWh per month
20% efficiency results in an average of 163.9 kWh per month
At the best efficiency factor of 20%, this represents about 53% of the typical household monthly
summer energy usage and it assumes the sun shines on the array for about 19 hours each day during the
entire month. Cloudy days would naturally reduce each of the quantities calculated above.
For winter conditions, the average solar radiance is about 6.1 watts/square meter and the sun shines
about 6 hours a day (at a very low angle on the horizon as well). So, 6.1 watts/square meter x 6
hours/day x 6 square meters is about 220 Wh per day. 30 days per month x 220 Wh per day is 6.6 kWh
per month.
Again, applying the array efficiency to our average winter 6.6 kWh per month:
5% efficiency results in an average of 0.33 kWh per month
10% efficiency results in an average of 0.66 kWh per month
Akiachak Community Energy and Wind Resource Analysis Page |25
20% efficiency results in an average of 1.3 kWh per month
At 20% efficiency, 1.3kWh per month equates to an average of less than 0.5% needed for a monthly
household consumption of 306 kWh per the month of December.
A. Residential Solar Array Size
So what is the approximate solar energy generated with different sized arrays. The table below
identifies some standard array size areas (in meters) and their approximate equivalent sized areas in
square feet. Also presented are an approximate physical sized areas in identifiable length and width (in
feet.
Table 6 4 Solar Array Size
Further, the table below shows the estimated average kWh produced per month over a 12 month
period using a 20% efficient 6 square meter array. To further compare, arrays sized to 12 square meters
and 25 square meters are also presented.
Table 6 5 Kilowatt Hours Produced From Different Array Sizes
A graphical representation using the values in the table is provided below. The graph also depicts the
average Akiachak monthly electrical home usage (kWh).
Figure 6 6 Comparison of Different Sized Solar Arrays and Average Energy Generated per Array
SolarArrayArea
(Square Meters)
Approximate
EquivalentArea
(Square Feet)
Approximate
Length x
Width(Feet)
6 64.6 8x 8
12 129.2 12x 11
25 269.1 15x 18
ArraySize Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
6Sq m(kWh)4.0 11.3 39.2 77.9 98.6 163.9 105.7 73.2 37.1 17.3 5.1 1.3
12 Sqm(kWh)8.0 22.6 78.5 155.7 197.3 327.7 211.3 146.4 74.2 34.6 10.2 2.6
25Sqm(kWh)16.6 47.0 163.5 324.5 411.0 682.7 440.3 305.0 154.5 72.1 21.2 5.5
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
AVERAGE KILOWATT HOURS
GENERATED WITH DIFFERENT SIZED
SOLAR ARRAYS
6 Sq m (kWh)12 Sq m (kWh)
25 Sq m (kWh)Avg Monthly Home Usage (kWh)
Akiachak Community Energy and Wind Resource Analysis Page |26
In the case discussed above, the graph shows that the larger sized array may be worth further
engineering investigation.
6.7 A Word Regarding 30 Year Solar Data
During the research The Solar Radiation Data Manual for Flat Plate and Concentrating Collectors was
referenced in this report. This manual provides the solar resource available for the United States and its
territories using various types of solar collectors. The data in the manual were modeled using hourly
values of direct beam and diffuse horizontal solar radiation from the National Solar Radiation Data Base
(NSRDB). The website for NSRB can be found online here:
http://rredc.nrel.gov/solar/old_data/nsrdb
This website contains updates to databases up through 2014. The NSRDB contains modeled (93%) and
measured (7%) global horizontal, diffuse horizontal, and direct beam solar radiation for 1961 1990. One
of the locations that was monitored during this 30 year period was Bethel, Alaska. Akiachak is 14 miles
from Bethel. The terrain is very flat and similar, thus the data is directly applicable.
This manual was produced by the National Renewable Energy Laboratory's (NREL's) Analytic Studies
Division under the Solar Radiation Resource Assessment Project. These tasks were funded and
monitored by the Photovoltaics Branch of the Department of Energy's Office of Energy Efficiency and
Renewable Energy. The manual can be found online at the following website:
http://rredc.nrel.gov/solar/pubs/redbook/html/redbook_HTML_index.html
The collected solar radiance data for Akiachak is not exhaustive in nature, for instance did not track the
sun, and was captured over a very modest time period of approximately one year. However, comparing
the NREL (Bethel) solar radiance data with Akiachak data is useful. Both sets of data may be compared
as they both utilized the same units of measure, i.e., watts/square meter.
Figure 6 7 30 Year Bethel Radiance Data vs Akiachak 2015 Data
0.00
50.00
100.00
150.00
200.00
250.00
300.00
350.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecWatts/Sq Meter
Bethel 30 Yr Radiance vs Akiachak 1 Yr Radiance
Bethel 1961 1990
Akiachak 2015
Akiachak Community Energy and Wind Resource Analysis Page |27
The radiance values shown tend to depict that the 30 year history points to more robust springtime
radiance values than recorded during the recent short one year collection. This surprising aspect may be
due to the fact that 2015 was a cloudier spring for Akiachak, there was less winter fog in Bethel, the
Akiachak pyranometer was pointed in a somewhat different direction than the Bethel collector or
perhaps the Bethel collector tracked the sun more effectively. A conclusion might be drawn that the
sun’s energy may be more slightly more robust than the Akiachak data suggests.
This report suggests that there may be enough existing evidence that solar energy in Akiachak may be a
possible renewable energy resource. There would be value in a follow on detailed analysis regarding
historical solar data as well as performing an engineering concept design for specific solar arrays located
in Akiachak.
Akiachak Community Energy and Wind Resource Analysis Page |28
Native Village of Akiachak Electrical Power Analysis
The major electrical power loads and directed electrical power consumption of the Native Village of
Akiachak, Alaska is examined and analyzed in this report.
This section of the analysis determines the total electrical power generated by Akiachak power plant
and how much is consumed by the largest load on the electrical distribution system. The intention of
understanding how the total quantity of energy is used by Akiachak will assist in determining a possible
alternate energy plan for the village thus bringing into a sharper focus the goal of lowering the cost of
energy used by Akiachak.
7.1 Akiachak Power Plant
The power plant at Akiachak houses four diesel powered engine generator sets manufactured by
Caterpillar, a well known manufacturer of power plant generators.
Figure 7 1 Akiachak Power Plant Showing West (500KVA) and East (225KVA) Distribution Transformers
The installed generator capacity of the plant is 1,500 kW. There are two 500 kW and two 250 kW diesel
generators housed in the power plant.
Akiachak Community Energy and Wind Resource Analysis Page |29
Figure 7 2Akiachak Power Plant Diesel Generators #1 and #2
Figure7.4.250kW Generator Nameplate
The electrical energy is generated at 480 volts three phase and then once immediately outside the
power plant it is stepped up to 12,470 volts three phase where upon it is distributed to the village.
A. Key Monitoring Locations
There are only two electrical feeders that emanate from the power plant. These two feeders provide
electrical power to the entire village of Akiachak. These are referenced as the East Feeder and the West
Feeder. The largest single electrical load in Akiachak is the School and it is connected to the West
Feeder. Thus the three key locations selected to monitor electrical power consumption are:
East Feeder (power plant)
West Feeder (power plant)
School (connected to West Feeder)
To determine the profile of the energy produced by the village power plant as well as that of the school,
electrical power consumption meters (kWh meters) needed to be installed at key locations and the
Figure 7.3 500kW Generator
Nameplate
Akiachak Community Energy and Wind Resource Analysis Page |30
power consumption captured by the kWh meters need to be recorded (logged) with data recording
loggers.
The three key locations were chosen such that the entire quantity of electrical energy leaving the power
plant would be captured and of that energy, how much was being consumed by the largest single load
connected to the power plant.
7.2 Electric Power Monitoring Equipment
The equipment required to quantify the power consumed (kilowatt hours) by the circuit of interest as
well as keeping a data record of that power is identified below.
The equipment was manufactured by Onset Computer Company and Continental Control Systems, LLC
and consisted of three primary components. They are:
Power and Energy Meter (kW and kWh meter)
Current Transformer (one for each phase of the three phase system)
Data Logger (recorder)
A. Kilowatt (kW) and Kilowatt Hour (kWh) Power and Energy Meter
The meter’s primary purpose is to interpret the electrical inputs from the circuit of interest. The meter
requires two types of input. These two inputs are current and voltage and are derived from connected
current transformers and the connected voltage sources. The meter then automatically calculates the
instantaneous power as well as the energy consumed by the circuit. This data can be logged (recorded)
on a data logger.
The meter is programmable thus allowing for various characteristics of the circuit to be calculated as
well as being scalable thus possibly allowing for the multitude different voltages and currents that may
be encountered. These characteristics can be shown on the device’s output display. The shown outputs
are voltage, current, real power and energy and reactive power and energy.
A total of three individual power meters were required, one for each key location being monitored. The
model number of the power and energy meter is Onset Computer Company T VER E50B2.
B. Current Transformers
As the above paragraph states, the power meter requires an electrical current input. Since the electrical
currents in the various key locations were greater than the maximum capacity for which the power
meter was designed, the currents had to be scaled downward. This was accomplished by installing
appropriately sized current meters. The current meters installed were manufactured by Continental
Control Systems, LLC.
The Akiachak electrical system is a three phase electrical system. This requires a current transformer for
each phase of the circuit of interest thus a total of three for each key location. A total of three sets of
three each current transformers were installed, one set at each key location.
Two different current transformer models were selected. They are:
Akiachak Community Energy and Wind Resource Analysis Page |31
East Feeder (power plant); CTS 2000 600 (set of three)
West Feeder (power plant); CTS 2000 600 (set of three)
School (connected to West Feeder); ACT 1250 400 (set of three)
C. Data Logger
A data logger records electronic pulses from an external sensing device over a specified time period.
The information recorded into the electronic memory of the device can be downloaded to a computer
and interpreted by a computer program. The pulse data logger is a versatile, 4 channel energy data
logger that combines the functionality of four separate data loggers into one compact unit and easily
tracks building energy consumption, equipment runtimes, and water and gas flow rates. The HOBO
UX120 Pulse Data Logger utilized had an expanded memory and is capable of over 4,000,000
measurements.
The model number of the data logger used is HOBO UX120 017M. A total of three data loggers were
used, one data logger for each of the selected locations.
The data loggers captured volts (v), amperes (A), kilowatt (kW) power, kilowatt hour (kWh) energy,
reactive power (kVAR) and other electrical attributes. Kilowatt (power) and kilowatt hour kWh) are the
primary attributes explored in this report.
D. HOBOware Pro Computer Program
Data analysis of the power and energy data was performed using Onset Computer Company’s data
analysis computer program. The HOBOware Pro number is BHW Pro CD version 3.7.1. All required
updates to the program were also installed.
The monitoring equipment is summarized below:
Current transformers – provided data input to the kW/kWh Power and Energy Meter
Kilowatt and Kilowatt Hour Power and Energy Meter – captured input data provided by current
transformers and voltage sources
Data Loggers – recorded output data from Kilowatt and Kilowatt Hour Power and Energy Meter
HOBOware Pro Computer Program – analysis tool. Interpreted information recorded by Data
Logger
Akiachak Community Energy and Wind Resource Analysis Page |32
7.3 Power Analysis
Adjustment multipliers were required to adjust raw logger data due to physical limitations of the current
transformers. The current transformers were physically too small to encompass all phase conductors.
More particularly, to measure current for data collection, for any given phase of a three phase electrical
system, the ideal situation calls for passing all current carrying conductors of each phase through the
hole of the donut shaped current transformer.
For example, if each phase of a three phase power system required four cables per phase, all four cables
would need to pass through the hole of the current transformer for that particular phase. In our case,
the hole of the current transformers used to measure power data were physically too small to pass all
required current carrying phase cables through the hole.
The solution is straight forward and simple. In the example above, if the four cables for a single phase
cannot physically pass through the hole of the current transformer, then pass only one of the cables
through the hole. The collected data for the one phase can then be multiplied by four thus simply
accounting for the total current of that phase.
This was also the situation for the power plant West feeder as well as the School feeder. The collected
data for the West feeder needed to be adjusted to compensate for allowing only two of the three
feeders being able to physically fit in the current transformer. The table below identifies each data
collection location and the correction “Adjustment Factor” required to normalize all data.
Kilowatt (kW) Power Meter Readout Correction Factor Table
Circuit
Number of
conductors
per phase
Number of phases
encompassed by
current
transformer
Meter
Reading
(kW) Actual
Adjustment
Factor
Meter
Reading
(kW)
Corrected
West Feeder 3 2 139 1.5 208
East Feeder 2 2 102 102
School 6 1 7.5 6 45
For the purpose of this table, the “Meter Reading (kW) Actual” are illustrative only.
The installation of the energy monitoring equipment at the school’s main electrical service entrance
switchgear is shown below:
Figure 7.5 kWh Meter installation at school
Current Transformers
Power and Energy Meter
Voltage connection (typ)
Akiachak Community Energy and Wind Resource Analysis Page |33
Figure 7.6 Data Logger installation at school
The analysis of the data from the data logger determined the following:
Power Plant East Feeder
Total kW
(225 KVA Transformer)
Power Plant West Feeder
Total kW
(500 KVA Transformer)
School Total kW
(connected to West
Feeder)
West
Feeder
kW w/o
School
Maximum 164.8 249.5 141.8 107.7
Minimum 37.0 49.5 11.7 37.8
Average 102.3 136.6 61.4 75.2
Based on the table above, the total average school load is approximately 45%of the West Feeder load
(61.4 kW/136.6 kW) and 25.7%of the total average load of the power plant [61.4 kW/(102.3 kW + 136.6
kW)].
Additionally, further analysis of the data also portrays that the weekend loads at the school (Saturday
and Sundays) never exceeded a maximum of 90.3 kW nor a minimum load below 28.2 kW.
There were six occasions that the school feeder experienced a loss in power. Of those six occasions it is
interesting to note that three occasions were on weekends and of those three occasions two were on a
Saturday during the morning hours.
A. School Power Load
The following graph shows the school’s actual electrical load during the monitoring period. As stated,
the graph’s y axis values need to be multiplied by a factor of 6 to compensate for the monitoring
equipment’s input signal limitations. The monitoring period was September 10, 2015 to January 14,
2016.
Data Logger mounted in school
switchgear cabinet
Akiachak Community Energy and Wind Resource Analysis Page |34
Figure 7.7 Akiachak School Power Consumption (multiply kW x 6)
One can surmise from viewing the graph that the average load is approximately 60 kW [or (10 kW x 6)]
which matches closely with the table above 61.4 kW (highlighted in yellow).
B. School Backup Electrical Supply
In the event that electrical service is interrupted or discontinued, the school does have a backup
generator capability that is sufficient for running the entire school load for an extended length of time.
C. School Power Analysis Conclusion
The total school load is approximately 25% of the average total power plant load of 239kW and is 45% of
the average West Feeder load of 137kW.
Akiachak Community Energy and Wind Resource Analysis Page |35
7.4 Power Plant Fuel Cost Savings with an Akiachak Solar Array
Relative array inefficiency can be compensated for with a suitably sized collecting area. This section
describes the relative sizing of a solar array with sufficient area to offset some of the electrical energy
used by the school and provides a preliminary power plant fuel cost savings estimate. This section
quantifies an array area in square feet and may be used as a preliminary future planning number.
The following uses the same methods as described above in calculating the size of a solar array. The
quantities required to calculate a solar array size that provides a predetermined amount of energy are
the same as noted previously; solar radiance, number of daylight hours and array efficiency. The largest
load in Akiachak is the school load and this load can serve as the example load and basis for this
calculation. Additionally, the load was measured and metered so it is a logical place to suggest for an
example for displacing energy with a renewable energy source thus reducing energy costs for the village.
Although the following suggests a need for a more detailed analysis regarding the use of existing
historical solar data as well as performing an engineering concept design for specific solar arrays in
Akiachak it is worth performing preliminary calculations as a basis for future investigation of solar
technology.
A. School Monthly Average Energy Consumption
In our example, using a school average energy consumption quantity and an average solar radiance
quantity one may calculate an array size.
As mentioned, the data logger captured multiple electrical attributes of the energy supplied by the
power plant feeders and in particular the electrical energy delivered to the school. Besides capturing
the power (kW) load the school represents to the power plant, energy (kWh) usage was concurrently
recorded by the logger. Below is a graph depicting the energy usage during the same period of time as
the power usage graph shown in Figure 7.7, for the duration September 9, 2015 to January 14, 2016.
Figure 7.8 Akiachak School Energy Consumption (multiply kWh x 6)
Akiachak Community Energy and Wind Resource Analysis Page |36
Both the power (kW) and energy (kWh) graph timelines coincide exactly and thus the graph data can be
superimposed one on another producing the graph below incorporating a two y axis graph.
Figure 7.9 Graph of school kW and kWh superimposed on top of one another.
The load at the school is logically the highest when school is in session, especially during winter months.
The period of time during which the data was collected was precisely during this peak consumption
period. Further, the consumption of the power at the school shows usage is highest during week days,
depicted as the peaks, and is lowest during weekends, depicted in the spaces between peaks. The dip in
energy consumption is most notable during the November Thanksgiving and December Christmas
holidays timeframe.
From Figure 6.7 30 Year Bethel Radiance Data vs Akiachak 2015 Data (page 26), the winter months do
not have sufficient solar radiance to help displace any sizable energy consumption during this time,
however, there may be enough solar radiance during the spring and summer months to help offset
energy use at the Akiachak school with a suitably sized array.
Analysis of the kWh logged data determined that the daily school average energy consumption is
approximately 1,022kWh/day during the data collection period. We will use this quantity for the
following calculations.
Additionally, since no other data exists for summer months, for purposes of this analysis, we will assume
that summer consumption (likely less than during winter) is the same as the winter consumption.
B. Establish Akiachak Average Daily Solar Radiance
The daily values of average solar radiance from both the NREL source and the Akiachak met tower are
consolidated and shown in the table below. It is the same data already documented above and is shown
again in the table below for convenience of the reader.
Akiachak Community Energy and Wind Resource Analysis Page |37
Figure 7.10 Average Daily Solar Radiance (watts/square meter) and Average Daily Daylight Hours. Compare NREL 30 year Bethel
data (blue numerals) to the Akiachak 1 year met tower collected data (black numerals). NREL data shows higher average
radiance values.
Comparing NREL 30 year data (blue numerals) to the shorter termed 1 year met tower collected data
(black numerals) it is noticeable the NREL data has higher monthly average radiance values thus we will
use the NREL radiance for Akiachak.
C. Calculate Array Size
To size the array that provides a sufficient amount of useful electrical power, we will use the yearly daily
average solar radiance, 172.9 watts/square meter/day and the average annual number of daylight hours
per day, 12.4 hours/day (both highlighted in yellow in Figure 7 10 above). We will choose to displace
approximately 25% of the daily average energy usage of 1,022 kWh or 255 kwh/day.
Calculate average kWh/sq m per day and convert to kWh/sq m per day
172.9 w/sq m x 12.4 hours/day x 1kW/1,000 W = 2.14 kWh/sq m/day
The array efficiencies range from 10% to 20 %. If 10% is chosen (a conservative choice)
the electrical output of the array yields 2.14 kWh/day x 0.10 = 0.214 kWh/sq m/day
The school uses 1,022kWh during the day. To offset approximately 25% or about 255
kWh per day, calculate a solar panel array size.
255 kWh divided by 0.214 kWh/sq m = 1,189.4 sq m
Convert to square feet
1 sq meter = 10.76 sq ft
1,189.4 sq m x 10.76 sq ft/sq m = 12,797.8 sq ft
So an array size of approximately 113 feet x 113 feet (or equivalent) will offset approximately 25% of the
school energy consumption and save the burning of fuel at the power plant.
D. Calculate Power Plant Fuel Savings
Assuming an array size (or equivalently sized) of 113 feet x 113 and produces 225 kWh per day, what is
the yearly savings in fuel cost for the power plant?
Calculate monthly energy produced by array
From above, 255 kWh per day x 30 days per month = 7,650 kWh
Calculate quantity of fuel saved
Assume generator efficiency is 14.14kWh/gal and price per gallon of diesel fuel is
$3.89/gallon (Source: extracted from State of Alaska, Alaska Energy Authority 2015
Power Cost Equalization Statistical Report)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec YearlyAvg
66.7 150.0 233.3 287.5 279.2 270.8 237.5 179.2 154.2 104.2 66.7 45.8 172.9
17.9 37.3 98.2 154.5 163.1 242.1 157.8 124.0 76.3 44.9 17.9 6.1 95.0
Average Akiachak
DaylightHours 6 6.2 8.4 11.1 14 16.8 18.8 18.6 16.4 13.5 10.7 7.9 12.4
Average Solar
Radiance (w/sqm)
Akiachak Community Energy and Wind Resource Analysis Page |38
7,650 kWh x 1/14.14kWh/gal = 541 gal x $3.89/gal = $2,104/mon x 12 mon/year =
$25,255/year
E. Power Plant Fuel Cost Savings with an Akiachak Solar Array Conclusion
Based on this preliminary analysis, a solar array size (or equivalent size) of approximately 113 ft x 113 ft
can save approximately 541 gals of diesel fuel and $25,255 at 2015 fuel prices of $3.89. The location of
the array does not necessarily need to be placed at the school but should be chosen to best
accommodate the sun’s radiance as well as the most effective integration with the existing village
electrical system.
Akiachak Community Energy and Wind Resource Analysis Page |39
APPENDIX
Akiachak Community Energy and Wind Resource Analysis Page |40
Mail Processing Center
Federal Aviation Administration
Southwest Regional Office
Obstruction Evaluation Group
2601 Meacham Boulevard
Fort Worth, TX 76137
Aeronautical Study No.
2012-WTW-3158-OE
Page 1 of 4
Issued Date: 04/26/2012
Edward George
Akiachak Limited
PO Box 51010
Akiachak, AK 99551
The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C.,
Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning:
Structure: Met Tower Akiachak Met Tower
Location: Akiachak, AK
Latitude: 60-55-03.30N NAD 83
Longitude: 161-27-26.34W
Heights: 20 feet site elevation (SE)
98 feet above ground level (AGL)
118 feet above mean sea level (AMSL)
This aeronautical study revealed that the temporary structure does not exceed obstruction standards and would
not be a hazard to air navigation provided the following condition(s), if any, is (are) met:
Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/
lighting are accomplished on a voluntary basis, we recommend it be installed and maintained in accordance
with FAA Advisory circular 70/7460-1 K Change 2.
Construction of a permanent structure at this location requires separate notice to the FAA.
This determination expires on 10/26/2013 unless extended, revised or terminated by the issuing office.
NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST
BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION
OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO
SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE
ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD.
This determination is based, in part, on the foregoing description which includes specific coordinates and
heights. Any changes in coordinates and/or heights will void this determination. Any future construction or
alteration, including increase to heights, requires separate notice to the FAA.
This determination does include temporary construction equipment such as cranes, derricks, etc., which may be
used during actual construction of a structure. However, this equipment shall not exceed the overall heights as
Page 2 of 4
indicated above. Equipment which has a height greater than the studied structure requires separate notice to the
FAA.
This determination concerns the effect of this temporary structure on the safe and efficient use of navigable
airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law,
ordinance, or regulation of any Federal, State, or local government body.
Any failure or malfunction that lasts more than thirty (30) minutes and affects a top light or flashing obstruction
light, regardless of its position, should be reported immediately to (800) 478-3576 so a Notice to Airmen
(NOTAM) can be issued. As soon as the normal operation is restored, notify the same number.
A copy of this determination will be forwarded to the Federal Aviation Administration Flight Procedures Office
if the structure is subject to the issuance of a Notice To Airman (NOTAM).
If you have any questions, please contact our office at (907) 271-5863. On any future correspondence
concerning this matter, please refer to Aeronautical Study Number 2012-WTW-3158-OE
( TMP )
Robert van Haastert
Specialist
Attachment(s)
Map(s)
Page 3 of 4
Page 4 of 4
300 W 31
st Ave
Anchorage, AK 99503
Phone: 907 339 6500 Fax: 907 339 5331
Memorandum
To:Akiachak Native Community
From:Katherine Keith, WHPacific
Date: 6/14/2012
Re: Akiachak MET Tower Installation
The information below summarizes the events that occurred while installing the MET tower for the Akiachak
Native Community. Please note that there are four appendices included with this memo: photo log, installation
log, calibration reports, and FAA Determination letter.
Day One (Monday, 6/4/2012)
Departed Anchorage at 6:40 A.M. and arrived in Bethel at approximately 8:00 A.M. Northern Air Cargo (NAC)
did not open until 9:00 A.M.; so Kristine and I went for breakfast where we met up with WHPacific employee
and boat driver, Mike Williams Jr. We drove back to NAC to find that the equipment; which was manifested for
the previous Saturday, did not arrive and was scheduled to be on the 1:30 P.M. plane. Efforts to locate another
jackhammer began so that we could immediately start working on the anchor holes and have a second
jackhammer to speed up the process after the NAC shipment arrived. After many calls we found that
Orutsararmiut Native Council (ONC) had one for loan and did not charge a rental fee. After picking up the
jackhammer we preceded to Mike’s boat in the harbor and headed out to Akiachak; which took approximately
40 minutes. The power plant operators (Ryan and Joel) were there upon arrival with a truck. After meeting Ryan
and Joel we located all the tower sections and components that had been previously sent out. We then moved
the equipment out to the wind site. The site was tremendously difficult to access with a combination of deep
muddy marsh, steeply sloped hillside, and deep tussaks. The power plant workers had a 4 wheeler that was
used to move the equipment. There was a funeral in town so Ryan and Joel were unable to work from that
point until 5:00 P.M. The three of us went back to Bethel to get the other equipment from NAC. We then
boated back to Akiachak to continue work. Ryan and Joel were needed to work on a water project and therefore
could not help. We were also lacking a working generator to start the anchor holes. The operator’s (Ryan’s)
brother had one out at fish camp; which he would have ready for the following morning. There were a few
missing components including bolts, gin pole rocker, and carabineers. The missing components were planned to
be retrieved from Kwethluk the following day. After sorting out the tower as best we could we boated back to
Akiak for the night and got in at 9:30 P.M.
Total Labor Hours: 48.5
Joel (Powerplant): 3
K. Keith (WHP): 15
K. Zajac (WHP): 15
M. Williams Jr. (WHP): 12.5
R. Nose (Powerplant): 3
Day Two (Tuesday, 6/5/2012)
The tower was able to be installed on day two with a crew of seven people throughout most of the day. We
used two jackhammers with one 2.8 kW generator. Operating two jack hammers at the same time shorted out
the generator; so the two teams of two workers needed to alternate. Although that took slightly more time it
did allow for breaks. The generator was rented for $65 a day and the payment went to Ryan Nose’s brother.
The anchor placement went well by screwing the end of the anchor into the permafrost. This took a
June 19, 2012
Page | 2
combination of hitting the anchor with a sledge hammer, screwing the top with a copper grounding rod, and
standing on the anchor to apply pressure. We tried to lift the gin pole as a test run for the rigging and the winch
anchor began to pull. This likely happened because the welding on the screw anchor itself was bad. We had to
re bury a newanchor (we had brought a spare) and add to it two more copper ground rods placed in the
opposite direction (we had extra ground rods). The three anchor points worked very well and created a secure
and stable base for the cable hoist. I will use this again moving forward. Since we did not have a rocker plate
we had to rig up an alternative solution using shackles and carabineers. This all worked well. Using the cable
hoist mechanism went smoothly and proved to be a safe and secure method of raising the tower that only took
one man to operate it. The top level lifter cable was too long so we had to lower the gin pole and create a
loop/splice in the lifter cable so that it would be the correct tension.
Total Labor Hours: 102.5
Eddie (IRA): 12:30 P.M.12:30 A.M. (12)
Jack (IRA): 12:30 P.M.12:30 A.M. (12)
Joel (Powerplant): 10:30 A.M.10:30 P.M. (12)
K. Keith (WHP): 9:00 A.M.1 A.M. (17)
K. Zajac (WHP): 9:00 A.M.1 A.M. (17)
M. Williams Jr. (WHP): 9:00 A.M.1 A.M. (17)
R. Nose (Powerplant): 9:00 A.M.12:30 A.M. (15.5)
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 1
Travel by boat to Akiachak from Bethel on the Kuskokwim River.
Anchors and ground rods pictured during travel to Akiachak by boat on the Kuskokwim
River.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 2
Jackhammer shipped from Anchorage pictured during travel to Akiachak by boat on
the Kuskokwim River.
Mike Williams Jr. pictured navigating Kuskokwim River by boat.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 3
Facing approximately west. Pictured center: Joel hammering ground rods through
tower base plate into the tundra.
Temporary removal of organic mat to prepare for digging with a jackhammer and
shovel. The mat is replaced after anchor placement to minimize impact on the tundra.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 4
Facing approximately west. Pictured left to right: Jack and Eddie at west anchor site
location.
Lowest anchor location filled with water after digging with a jack hammer and shovel.
Screw anchor is being place at the correct 45 degree angle.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 5
Facing approximately south. Pictured from left to right: Joel, Kat, Mike, and Ryan
assembling tower sections.
Facing approximately west. Kat connecting anemometers and wind vane to the NRG
data logger.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 6
Facing approximately south and looking up. Top of tower section with anemometers
and wind vane. Not the spliced loop in the top lifter guy wire to take up excess slack.
Northeast anchor site re-covered with organic mat.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 7
Northeast anchor site with guy wires shown looped in order to allow for a winter tower
removal that is free of tangles. Yellow strips with reflectors protect snowmachiners.
Facing approximately southeast. Assembly crew pictured from left to right: Kat, Jack,
Mike, Ryan, and Eddie.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 8
Facing approximately southwest. Gin pole pictured on pallets for easy winter
demobilization. Notice the extra ground rods that were used to strengthen the winch
Facing approximately northeast. Data collection box pictured.
Akiachak Wind Feasibility Study
Akiachak, Alaska
Photo Log
June 4 6, 2012 Installation
WHPacific, Inc. Page 9
Facing approximately north from south side of sewage lagoon. Tower pictured.
Project Name: Site Number:
Nearest Hub: Property Owner:
City Manager: Contact Person:
IRA Contact & Title: Phone Number:
Utility Company: Cell Number:
Email:
Latitude: Latitude:
Longitude: Longitude:
Datum Type: Datum Type:
Elevation:
Installation Date: FormCompleted By:
Date of Report:
Photos Taken:
Description:
Nearest Landmarks:
Tower Type: Anchors:
Tower Height: Aircraft Deterrant:
Logger Type:
Logger S/N:
Sensor 1 Sensor 2 Sensor 3 Sensor 4 Sensor 5
1 2 3 8 9
#40 aneo #40 aneo #40 aneo #200 wind vane Temperature
92' 89' 9" 70' 5" 92' 7'
45 degrees 220 degrees 270degrees 200 degrees
60.5" 60.5" 60.5" 60.5"
179500196590 179500196592 179500196591
0.766 0.766 0.765
0.37 0.39 0.42
X X X X X
Mag Dec:13 degrees
____ Carabiners Lifter Wires
____ Gin Pole Ropes
____ Gin Pole Bolts
____ Rocker Plates
____ Winch Shackle ____
__X__ Gin Pole on pallets
_N/A_ Helper pole on pallets
__X__ Guy wires taped up aboveground
____
akiachakltd@hotmail.com
____ Helper Pole Bolt ____ Extra SD Card
__X__ NRG Screw Driver
____ Pallets
NRG 30 meter tower
30 meters
Symphonie
__X__ Gin Pole
____ Helper Pole
Akiachak Wind Project
Bethel
Edward George, General Manager
1050
20'
Tower Location
Sensor 1: 92'
Equipment Information
Sensor Information
Planned Location Actual Location
Installation Details
6/4 5/2012
6/13/2012
60°55' 3.30" N
161°27' 26.34" W
NAD 83
Sensor Number & Height:
K. Keith, K. Zajac, M. Williams Jr.(WHP); R. Nose & Joel
(Powerplant); Jack & Eddie (IRA)
Installation Team:
Akiachak Ltd.
WHPacific MET Tower Installation
Cold Climate Consideration
Site Inventory (Equipment left behind)
Akiachak Ltd.
Edward George
907 825 4328
Boom Length (inches):
Serial Number:
Slope (m/s / Hz):
Offset (m/s):
Functional Checks:
Instruments
Logger Terminal # (channel):
Type (#40 ano, #200 vane, ect):
Monitoring Height (feet):
Boom Orientation (degrees true bearing):
60° 55' 3.1" N
161° 27' 20.6" W
Screw anchors with coverplate in permafrost.
Red and white painted sections at the top of tower.
Sensor 2: 89' 9" Sensor 3: 70' 5" Sensor 4: 92'
Tower View From Above
Determination Expiration Date:10/26/2013
K. Keith & K. Zajac
Tundra & boggy terrain with trees surrounding the area. Sewage
lagoon approximately northwest of tower location.
Exposure: (Tree
height & proximity,
terrain description,
ect)
K.Keith & K. Zajac
Sewage Lagoon
Diameter/Face (inches):6 inches Snowmachine Deterrant:Yellow protectors
ANEMOMETER VANE
N
APPENDIX B
Picture 1: Screw anchor shown.
Picture 2: Cable hoist anchor with rebar shown.
Notes & Photos
630 Peña Drive, Suite 800
Davis, CA 95618-7726
Office: (530) 757-2264
http://www.otechwind.com
Customer Information Instrument Under Test (IUT)
NRG Systems, Inc. Model No: NRG #40 Sine
110 Riggs Road Serial No: 179500196590
Hinesburg, VT 05461 Output: Sine Wave
USA IUT Power: 0 VDC
Heater Power: 0 VDC
Mount Diameter: 12.7 mm
Test Procedure: OTECH-CP-001
Wind Tunnel Test Facility Data Acquisition
Otech Tunnel ID: WT1C
Type : Eiffel (open circuit, suction)
Test Section Size : 0.61 m x 0.61 m x 1.22 m Software : National Instruments LabVIEW 2010
Manufacturer : Engineering Laboratory Design, Inc.Signal Reduction Method for IUT: FFT Analysis
Measuring Equipment Test Conditions
Reference Speed Position Correction = 1
Reference Speed Blockage Correction = 1.00735
Mean Ambient Pressure = 101,882 Pa
Amb. Pressure : Setra Model 270 Barometer (NIST traceable)Mean Ambient Temperature = 23.5 deg C
Amb. Temperature : OMEGA HX94 SS Probe (NIST traceable) Mean Relative Humidity = 45.4% RH
Relative Humidity : OMEGA HX94 SS Probe (NIST traceable) Mean Density = 1.1911 kg/cubic meter
Hardware : National Instruments CDAQ-9172 USB 2.0 chassis
with NI 9205 32-chan 16-bit AI module
ANEMOMETER CALIBRATION REPORT
Test Date: 8 February 2012 Revision No: 0
Reference Speed : Four United Sensor Type PA Pitot-static
tubes sensed by an MKS Barotron Type 220D
Differential Pressure Transducer (NIST traceable)
0
5
10
15
20
25
30
Reference Speed, V [m/s]-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
0.30
0.40
Speed Residual, V [m/s]Reference
Speed [m/s]
Anemometer
Output [Hz]
Residual
[m/s]
Ref. Speed
Uncertainty
4.028 4.909 -0.100 0.626%
std. err. slope =0.00212 m/s per Hz 8.063 10.024 0.019 0.607%
12.083 15.177 0.094 0.600%
16.100 20.477 0.054 0.618%
20.129 25.871 -0.046 0.597%
24.145 31.109 -0.040 0.602%
26.156 33.635 0.038 0.602%
22.125 28.529 -0.085 0.607%
18.098 23.163 -0.005 0.599%
14.085 17.834 0.062 0.607%
10.069 12.593 0.058 0.596%
6.040 7.470 -0.049 0.618%
References available upon request.179500196590_2012-02-08.pdf
This document reports that the above IUT was tested at Otech Engineering, Inc., a wind tunnel laboratory accredited in accordance with the
recognised International Standard ISO/IEC 17025:2005 (Certificate number CL-126). This accreditation demonstrates technical
competence for a defined scope and the operation of a laboratory quality management system (refer joint ISO-ILAC-IAF Communiqué
dated January 2009). Uncertainties estimated at 95 % confidence level. This report shall not be reproduced except in full, without written
approval from Otech Engineering, Inc.
V [m/s] = 0.766 f [Hz] + 0.37
Approved by: John Obermeier,
President
r = 0.99996
slope =0.766 m/s per Hz
offset =0.37 m/s
std. err. estimate =0.0665 m/s
std. err. offset =0.04501 m/s
Regression Parameters
Transfer Function Test Results:
Page 1 of 1
0
5
10
15
20
25
30
0 10 20 30 40Reference Speed, V [m/s]Anemometer Signal, f [Hz]
-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
0.30
0.40
0 10 20 30 40Speed Residual, V [m/s]Anemometer Signal, f [Hz]
Note: Generic photo of test set-up
APPENDIX
630 Peña Drive, Suite 800
Davis, CA 95618-7726
Office: (530) 757-2264
http://www.otechwind.com
Customer Information Instrument Under Test (IUT)
NRG Systems, Inc. Model No: NRG #40 Sine
110 Riggs Road Serial No: 179500196591
Hinesburg, VT 05461 Output: Sine Wave
USA IUT Power: 0 VDC
Heater Power: 0 VDC
Mount Diameter: 12.7 mm
Test Procedure: OTECH-CP-001
Wind Tunnel Test Facility Data Acquisition
Otech Tunnel ID: WT1C
Type : Eiffel (open circuit, suction)
Test Section Size : 0.61 m x 0.61 m x 1.22 m Software : National Instruments LabVIEW 2010
Manufacturer : Engineering Laboratory Design, Inc.Signal Reduction Method for IUT: FFT Analysis
Measuring Equipment Test Conditions
Reference Speed Position Correction = 1
Reference Speed Blockage Correction = 1.00735
Mean Ambient Pressure = 101,867 Pa
Amb. Pressure : Setra Model 270 Barometer (NIST traceable)Mean Ambient Temperature = 23.5 deg C
Amb. Temperature : OMEGA HX94 SS Probe (NIST traceable) Mean Relative Humidity = 45.3% RH
Relative Humidity : OMEGA HX94 SS Probe (NIST traceable) Mean Density = 1.1910 kg/cubic meter
Hardware : National Instruments CDAQ-9172 USB 2.0 chassis
with NI 9205 32-chan 16-bit AI module
ANEMOMETER CALIBRATION REPORT
Test Date: 8 February 2012 Revision No: 0
Reference Speed : Four United Sensor Type PA Pitot-static
tubes sensed by an MKS Barotron Type 220D
Differential Pressure Transducer (NIST traceable)
0
5
10
15
20
25
30
Reference Speed, V [m/s]-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
0.30
0.40
Speed Residual, V [m/s]Reference
Speed [m/s]
Anemometer
Output [Hz]
Residual
[m/s]
Ref. Speed
Uncertainty
4.018 4.866 -0.125 0.617%
std. err. slope =0.00236 m/s per Hz 8.044 9.929 0.029 0.620%
12.083 15.081 0.126 0.602%
16.076 20.442 0.018 0.600%
20.123 25.803 -0.036 0.596%
24.146 31.110 -0.072 0.598%
26.153 33.609 0.023 0.596%
22.113 28.440 -0.063 0.598%
18.065 23.018 0.037 0.613%
14.043 17.727 0.062 0.598%
10.021 12.477 0.056 0.607%
6.035 7.412 -0.056 0.610%
References available upon request.179500196591_2012-02-08.pdf
This document reports that the above IUT was tested at Otech Engineering, Inc., a wind tunnel laboratory accredited in accordance with the
recognised International Standard ISO/IEC 17025:2005 (Certificate number CL-126). This accreditation demonstrates technical
competence for a defined scope and the operation of a laboratory quality management system (refer joint ISO-ILAC-IAF Communiqué
dated January 2009). Uncertainties estimated at 95 % confidence level. This report shall not be reproduced except in full, without written
approval from Otech Engineering, Inc.
V [m/s] = 0.765 f [Hz] + 0.42
Approved by: John Obermeier,
President
r = 0.99995
slope =0.765 m/s per Hz
offset =0.42 m/s
std. err. estimate =0.0741 m/s
std. err. offset =0.04997 m/s
Regression Parameters
Transfer Function Test Results:
Page 1 of 1
0
5
10
15
20
25
30
0 10 20 30 40Reference Speed, V [m/s]Anemometer Signal, f [Hz]
-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
0.30
0.40
0 10 20 30 40Speed Residual, V [m/s]Anemometer Signal, f [Hz]
Note: Generic photo of test set-up
630 Peña Drive, Suite 800
Davis, CA 95618-7726
Office: (530) 757-2264
http://www.otechwind.com
Customer Information Instrument Under Test (IUT)
NRG Systems, Inc. Model No: NRG #40 Sine
110 Riggs Road Serial No: 179500196592
Hinesburg, VT 05461 Output: Sine Wave
USA IUT Power: 0 VDC
Heater Power: 0 VDC
Mount Diameter: 12.7 mm
Test Procedure: OTECH-CP-001
Wind Tunnel Test Facility Data Acquisition
Otech Tunnel ID: WT1C
Type : Eiffel (open circuit, suction)
Test Section Size : 0.61 m x 0.61 m x 1.22 m Software : National Instruments LabVIEW 2010
Manufacturer : Engineering Laboratory Design, Inc.Signal Reduction Method for IUT: FFT Analysis
Measuring Equipment Test Conditions
Reference Speed Position Correction = 1
Reference Speed Blockage Correction = 1.00735
Mean Ambient Pressure = 101,845 Pa
Amb. Pressure : Setra Model 270 Barometer (NIST traceable)Mean Ambient Temperature = 23.4 deg C
Amb. Temperature : OMEGA HX94 SS Probe (NIST traceable) Mean Relative Humidity = 45.2% RH
Relative Humidity : OMEGA HX94 SS Probe (NIST traceable) Mean Density = 1.1908 kg/cubic meter
Hardware : National Instruments CDAQ-9172 USB 2.0 chassis
with NI 9205 32-chan 16-bit AI module
ANEMOMETER CALIBRATION REPORT
Test Date: 8 February 2012 Revision No: 0
Reference Speed : Four United Sensor Type PA Pitot-static
tubes sensed by an MKS Barotron Type 220D
Differential Pressure Transducer (NIST traceable)
0
5
10
15
20
25
30
Reference Speed, V [m/s]-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
0.30
0.40
Speed Residual, V [m/s]Reference
Speed [m/s]
Anemometer
Output [Hz]
Residual
[m/s]
Ref. Speed
Uncertainty
4.014 4.871 -0.106 0.616%
std. err. slope =0.00219 m/s per Hz 8.038 9.970 0.012 0.620%
12.064 15.090 0.116 0.606%
16.074 20.463 0.010 0.609%
20.115 25.841 -0.069 0.597%
24.145 31.055 -0.033 0.596%
26.155 33.633 0.003 0.599%
22.103 28.388 -0.031 0.602%
18.076 23.080 0.008 0.598%
14.047 17.722 0.083 0.598%
10.025 12.489 0.069 0.600%
6.035 7.450 -0.061 0.612%
References available upon request.179500196592_2012-02-08.pdf
This document reports that the above IUT was tested at Otech Engineering, Inc., a wind tunnel laboratory accredited in accordance with the
recognised International Standard ISO/IEC 17025:2005 (Certificate number CL-126). This accreditation demonstrates technical
competence for a defined scope and the operation of a laboratory quality management system (refer joint ISO-ILAC-IAF Communiqué
dated January 2009). Uncertainties estimated at 95 % confidence level. This report shall not be reproduced except in full, without written
approval from Otech Engineering, Inc.
V [m/s] = 0.766 f [Hz] + 0.39
Approved by: John Obermeier,
President
r = 0.99996
slope =0.766 m/s per Hz
offset =0.39 m/s
std. err. estimate =0.0687 m/s
std. err. offset =0.04636 m/s
Regression Parameters
Transfer Function Test Results:
Page 1 of 1
0
5
10
15
20
25
30
0 10 20 30 40Reference Speed, V [m/s]Anemometer Signal, f [Hz]
-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
0.30
0.40
0 10 20 30 40Speed Residual, V [m/s]Anemometer Signal, f [Hz]
Note: Generic photo of test set-up
Mail Processing Center
Federal Aviation Administration
Southwest Regional Office
Obstruction Evaluation Group
2601 Meacham Boulevard
Fort Worth, TX 76137
Aeronautical Study No.
2012-WTW-3158-OE
Page 1 of 4
Issued Date: 04/26/2012
Edward George
Akiachak Limited
PO Box 51010
Akiachak, AK 99551
The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C.,
Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning:
Structure: Met Tower Akiachak Met Tower
Location: Akiachak, AK
Latitude: 60-55-03.30N NAD 83
Longitude: 161-27-26.34W
Heights: 20 feet site elevation (SE)
98 feet above ground level (AGL)
118 feet above mean sea level (AMSL)
This aeronautical study revealed that the temporary structure does not exceed obstruction standards and would
not be a hazard to air navigation provided the following condition(s), if any, is (are) met:
Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/
lighting are accomplished on a voluntary basis, we recommend it be installed and maintained in accordance
with FAA Advisory circular 70/7460-1 K Change 2.
Construction of a permanent structure at this location requires separate notice to the FAA.
This determination expires on 10/26/2013 unless extended, revised or terminated by the issuing office.
NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST
BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION
OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO
SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE
ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD.
This determination is based, in part, on the foregoing description which includes specific coordinates and
heights. Any changes in coordinates and/or heights will void this determination. Any future construction or
alteration, including increase to heights, requires separate notice to the FAA.
This determination does include temporary construction equipment such as cranes, derricks, etc., which may be
used during actual construction of a structure. However, this equipment shall not exceed the overall heights as
Page 2 of 4
indicated above. Equipment which has a height greater than the studied structure requires separate notice to the
FAA.
This determination concerns the effect of this temporary structure on the safe and efficient use of navigable
airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law,
ordinance, or regulation of any Federal, State, or local government body.
Any failure or malfunction that lasts more than thirty (30) minutes and affects a top light or flashing obstruction
light, regardless of its position, should be reported immediately to (800) 478-3576 so a Notice to Airmen
(NOTAM) can be issued. As soon as the normal operation is restored, notify the same number.
A copy of this determination will be forwarded to the Federal Aviation Administration Flight Procedures Office
if the structure is subject to the issuance of a Notice To Airman (NOTAM).
If you have any questions, please contact our office at (907) 271-5863. On any future correspondence
concerning this matter, please refer to Aeronautical Study Number 2012-WTW-3158-OE
( TMP )
Robert van Haastert
Specialist
Attachment(s)
Map(s)
Page 3 of 4
Page 4 of 4
Mail Processing Center
Federal Aviation Administration
Southwest Regional Office
Obstruction Evaluation Group
2601 Meacham Boulevard
Fort Worth, TX 76137
Aeronautical Study No.
2012-WTW-3158-OE
Page 1 of 4
Issued Date: 04/26/2012
Edward George
Akiachak Limited
PO Box 51010
Akiachak, AK 99551
The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C.,
Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning:
Structure: Met Tower Akiachak Met Tower
Location: Akiachak, AK
Latitude: 60-55-03.30N NAD 83
Longitude: 161-27-26.34W
Heights: 20 feet site elevation (SE)
98 feet above ground level (AGL)
118 feet above mean sea level (AMSL)
This aeronautical study revealed that the temporary structure does not exceed obstruction standards and would
not be a hazard to air navigation provided the following condition(s), if any, is (are) met:
Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/
lighting are accomplished on a voluntary basis, we recommend it be installed and maintained in accordance
with FAA Advisory circular 70/7460-1 K Change 2.
Construction of a permanent structure at this location requires separate notice to the FAA.
This determination expires on 10/26/2013 unless extended, revised or terminated by the issuing office.
NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST
BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION
OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO
SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE
ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD.
This determination is based, in part, on the foregoing description which includes specific coordinates and
heights. Any changes in coordinates and/or heights will void this determination. Any future construction or
alteration, including increase to heights, requires separate notice to the FAA.
This determination does include temporary construction equipment such as cranes, derricks, etc., which may be
used during actual construction of a structure. However, this equipment shall not exceed the overall heights as
APPENDIX
Page 2 of 4
indicated above. Equipment which has a height greater than the studied structure requires separate notice to the
FAA.
This determination concerns the effect of this temporary structure on the safe and efficient use of navigable
airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law,
ordinance, or regulation of any Federal, State, or local government body.
Any failure or malfunction that lasts more than thirty (30) minutes and affects a top light or flashing obstruction
light, regardless of its position, should be reported immediately to (800) 478-3576 so a Notice to Airmen
(NOTAM) can be issued. As soon as the normal operation is restored, notify the same number.
A copy of this determination will be forwarded to the Federal Aviation Administration Flight Procedures Office
if the structure is subject to the issuance of a Notice To Airman (NOTAM).
If you have any questions, please contact our office at (907) 271-5863. On any future correspondence
concerning this matter, please refer to Aeronautical Study Number 2012-WTW-3158-OE
( TMP )
Robert van Haastert
Specialist
Attachment(s)
Map(s)
Page 3 of 4
Page 4 of 4
Mail Processing Center
Federal Aviation Administration
Southwest Regional Office
Obstruction Evaluation Group
10101 Hillwood Parkway
Fort Worth, TX 76177
Aeronautical Study No.
2012-WTW-3158-OE
Page 1 of 1
Issued Date: 07/13/2016
Edward George
Akiachak Limited
PO Box 51010
Akiachak, AK 99551
The aeronautical study concerning the following project has been terminated:
Structure: Met Tower Akiachak Met Tower
Location: Akiachak, AK
Latitude: 60-55-03.30N NAD 83
Longitude: 161-27-26.34W
Heights: 20 feet site elevation (SE)
98 feet above ground level (AGL)
118 feet above mean sea level (AMSL)
We are in receipt of notification that the project described above was dismantled on 06/15/2016.
If you need to reactivate the study, it will be necessary for you to re-file notice using the electronic filing system
available on our website oeaaa.faa.gov.
If we can be of further assistance, please contact Cesar Perez, at (404) 305-5041. On any future correspondence
concerning this matter, please refer to Aeronautical Study Number 2012-WTW-3158-OE.
( TER -WT )
Mike Helvey
Manager, Obstruction Evaluation Group