HomeMy WebLinkAboutPreliminary Evaluation of Hydropower Alternatives for Chitina Alaska 1981TJ
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PRELIMINARY EVALUATION OF HYDROPOWER
ALTERNATIVES FOR
CHITINA, ALASKA
u.s. DEPARTMENT OF ENERGY
ALASKA POWER ADMINISTRATION
FEBRUARY 1981
ARL IS
Jaska Re urccs Lib rnr\ . Informati on Servi ces
Li brary l3 ui ldl ng. Su it e 111
32 11 ProviLlcnce Drive
\ n r h f)r"P'f' A I( Q{)"n~-1fi t 1\
Department Of Energy
Alaska Power Administration
P.O. Box 50
Juneau, Alaska 99802
FOREWORD:
February 23, 1981
This is Alaska Power Administration's (APA) preliminary evaluation of
Hydropower Alternatives for Chitina, Alaska. The report includes a
brief assessment of four potential hydro sites near Chitina, and a
potential inter tie with the Copper Valley Electric Association (CVEA).
Under the assumption made for this report, APA concludes that development
of a hydro project of the size required to suit Chitina's needs would be
infeasible when compared to a diesel generation system. However, if a
hydro project could be tied into a larger market available through the
CVEA system, there appears to be a reasonable chance of developing a
feasible plan.
We recommend that any further studies be oriented around the possibility
of integrating a Chitina hydro development with the CVEA system.
Copies of this report are being sent to CVEA, the Alaska Power Authority,
Corps of Engineers, State Division of Energy and Power Development, and
interested people in Chitina.
Sincerely,
Robert J. Cross
Administrator
T J"
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TITLE
PART I
PART II
PART III
PART IV
PART V
PART VI
CONTENTS
INTRODUCTION AND BACKGROUND ••••••••••••••••••••••••••••
S"UMMARY ••••••••••••••••••••••••••••••••••••••••••••••••
EXISTING SITUATION •••••••••••••••••••••••••••••••••••••
POWER DEMAND •••••••••••••••••••••••••••••••••••••••••••
ALTERNATIVE GENERATION RESOURCES •••••••••••••••••••••••
Hydropower •••••••••••••••
Hydrology •••••••••••
o 'Brien/ Fox Creek •••
Fivemile Creek ••••••
Liberty Creek •••••••
. . . . . . . . . . . . . . . . . . . . . . ~ ..
Haley Creek •••.•.••••.••••••
Hydropower Cost Comparison ••
Diesel Generation System •••••••••
Copper Valley Electric Association
Transmission Line Extension.
Other Alternatives •••••••••••••••••••
COST ANALYSIS OF ALTERNATIVE PLANS •••••••••••••••••••••
Ca se 1 •••••••••••••••••••••••••••••••••••••••
Case 2 ••••••••••••••••••••
Case 3 ••••••••••••••••••••
Distribution System Costs •••••
System Costs •••••••••••••••••
Sensitivity Analysis •••••••••
PAGE NO.
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5
7
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8
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9
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17
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29
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31
FIGURES
NUMBER PAGE NO.
1. GENERAL MAP ••••••••••••••..•••••••••••••.•••••••••••.•••••. 2
2. O'BRIEN CREEK AND HALEY CREEK LOCATION MAP •••••••••••••••.• 12
3. FIVEMILE CREEK AND LIBERTY CREEK LOCATION MAP •••••••••••••• 18
TABLES
1. SUMMARY OF INCREMENTAL COSTS FOR HyDROPOWER •••••••••••••••• 25
2. COST OF TRANSMISSION LINE TO COPPER VALLEY
ELECTRIC ASSOCIATION'S LINE................................ 28
3. SYSTEM COSTS ••••••••••••••••••••••••••••••••••••••••••••••• 32
APPENDIX
O'BRIEN CREEK HYDROLOGY
O'BRIEN CREEK ESTIMATED COSTS
ACKNOWLEDGEMENTS
INTRODUCTION AND BACKGROUND
The purpose of this study is to make a preliminary assessment of small
hydroelectric potentials near Chitina to determine if the resource is
sufficiently attractive to merit further study.
This study is a result of a petition by citizens of the Village of
Chitina to Senator Stevens, urging a study of the Fox Creek and O'Brien
Creek power potentials. Alaska Power Aministration (APA) was requested
to look into the matter. After coordination with the Corps of Engineers
(COE), Alaska Power Authority (AKPA), and State Division of Energy and
Power Development (E&P), a field reconnaisance of the power potentials
of the Chitina area was made July 14, 1980. Three sites were inspected
from the air and the ground~ They were the O'Brien/ Fox Creek area,
Fivemile Creek area, and the Liberty Creek area. An additional site,
Haley Creek, was inspected only from the air and maps.
Chitina is located 70 miles northeast of Valdez on the bank of the
Copper River at the end of the Edgerton Highway. In 1908, when the
Copper River Northwest Railroad was built up the Copper River, Chitina
was a major center for mining activity and a stop along the route to
Interior Alaska. By 1939 the principle mines and the railroad were
closed. Chitina is an unincorporated village within an unorganized area
of the state. The most active entity in the community is the Chitina
Native Corporation. Chitina does not now have a central electric power
utility system, and construction of a local distribution system, would
be required before any hydropower development. There may be a problem
as to whether or not a town the size of Chitina could sustain its own
utility.
Figure 1 shows the study area near Chitina. The following APA photographs
show the general area including the abandoned diesel powerplant.
1
Figure 1
\ ~ ..
LOCATION MAP
UN IT ED STATES DE PARTMENT OF ENERGY
ALASKA POWER ADMINISTRATION
HYDROPOWER POTENTITALS
NEAR CHITINA, ALASKA
GENERAL MAP
Scale in miles
The town of Chitina. Native community building is at extreme left side
of photo. Copper River bridge is at extreme right side.
The abandoned powerhouse contains two diesel units about 60 kWh each
which have been run without oil and are inoperable. Remnants of
the distribution system are in the background.
3
New Native village community building and old Bure au of Indian Affai rs
school house. Students now attend school at Ki n ne y Lake, 25 miles
north of town.
Houses in Chitina from the early century mining days. People have
private generating plants ranging from 5 to 10 kWh per household.
4
SUMMARY
Alaska Power Administration engineers examined the hydropower potentials
in the Chitina area from the air and on the ground July 14, 1980. From
this data and office studies, it was determined there are four potential
hydropower sites within 10 miles of the village. They are O'Brien
Creek, Fivemi1e Creek, Liberty Creek, and Haley Creek. The visit to
Chitina also revealed the existing distribution system and generation
system are both inoperative. Before any outside power source could be
used, a distribution system and backup generation would need to be
provided.
The hydroelectric resources in the area appear to be adequate from an
engineering viewpoint for development of run-of-river plants up to 500
kW or more at each of the four identified sites. Of these, the O'Brien
and Fivemi1e Creek sites seem to have the best potential. There is a
high likelihood that the plants would not provide significant amounts of
winter power supplies. No sites were found that could provide storage
for winter operation.
Near future power demands for Chitina are estimated at 108,000 to 240,000
kWh per year with an annual peak of 100 kW, if utility service were
provided. This is premised on 30 to 50 customers using an average of
300 to 400 kWh per month. Considering the seasonal nature of the identified
hydro sites, a 100 kW plant operating during the summer six months of
the year could satisfy roughly half of the Chitina power needs, say
54,000 to 120,000 kWh per year.
For comparison purposes the baseline cost for establishing a diesel
generation central utility service in Chitina is probably on the order
of 57C/kWh. This includes a basic diesel generator, a backup unit,
fuel, new fuel tanks, a new distribution system to deliver energy to all
the customers in town, and funds to operate and maintain the diesels and
manage the finances.
Three plans of development or cases were examined, rough cost estimates
made, and compared to the diesel alternatives.
Case 1--This plan considers construction of a 100 kW hydro powerp1ant on
O'Brien Creek or Fivemi1e Creek for a summer energy source. Estimated
construction costs for the 100 kW plant are on the order of $750,000,
(1980 costs) including transmission to Chitina. Assuming 7 percent cost
of money and a 20-year amortization, annual costs would be approximately
$82,000. Assumming the usable energy is 120,000 kWh per year, this
evaluation shows incremental cost of delivery of seasonal hydro from
O'Brien or Fivemi1e Creek would likely be in excess of 68C/kWh.
In addition, a local distribution system would be required to utilize
the hydropower--its costs would likely be from $100,000 to $250,000,
bringing the total investment to $850,000 to $1,000,000 for a "minimum"
hydro development plan. This assumes that each customer would still
supply a similar amount of energy from home diesel generators during the
5
winter. The value of the hydro project to Chitina would be a savings
in fuel and some operations savings. However, total cost would be
higher when compared to the total diesel system. Therefore, we consider
there is very little likelihood of a feasible plan for use of the local
hydros in Chitina, primarily due to the expected seasonal operation of the
hydro plant.
Case 2--Chitina is approximately 16 miles from the present Copper Valley
Electric Association (CVEA) power distribution system. A CVEA line
extension to Chitina would likely cost about $640,000 ($40,000/mile).
Adding a local distribution system, a total investment of about $740,000
to $890,000 would be needed. Assuming a level of use at 240,000 kWh per
year, the cost of extending the CVEA system to provide utility service
in Chitina would likely be about 55¢/kWh, including distribution system
and backup generation. We recognize this could not be accomplished
under normal utility financing. However, it is APA's opinion that this
is a better option than establishing a local utility in Chitina. It is
very difficult to support an efficient utility operation for such a small
community.
Case 3--A combination of plans were analyzed that included an intertie
between Chitina and the CVEA system using a 500 kW hydroelectric plant
at Fivemile Creek. This case examined the 500 kW plant running continuously
during the summer with the excess energy assumed to be used in the CVEA
system. The capital cost for this plant including the distribution
system would be $1.57 million. The revenues from the summer hydro
operation would help offset the cost of the transmission and distribution
system for Chitina. The net cost to the Chitina power users would be
about 35¢/kWh including the distribution system. This is based on an
assumed energy use of 240,000 kWh per year used by Chitina and a revenue
of $182,500 annually from the hydropower plant. The value of energy to
the CVEA system was assumed to be the fuel replacement value of 8.33¢/kWh
based on fuel at $1 per gallon and 12 kWh per gallon.
This case shows somewhat more favorable economics for a larger hydro
development at either Fivemile Creek or Liberty Creek, on the assumption
that excess energy could be used in the CVEA system.
Basically, APA concludes that the outlook for small hydro at the Chitina
sites is not very favorable. However, there may be some chance of
feasibility if a larger market for available energy is developed.
APA recommends that any further studies be oriented toward confirming
the hydro potential and integrating the hydro with the CVEA system.
This would include field surveys, stream gaging, and preliminary designs
and cost estimates. If a feasible hydro plan is established, discussions
should be initiated with CVEA.
6
EXISTING SITUATION
Up until several years ago, the town was served by two old diesel
generators, approximately 60 kW each. The generators were allowed to be
operated without oil, which resulted in burn-outs, and are considered
not repairable. There is a remnant of a distribution system which needs
replacing. Currently, electric generation is provided to most of the
households of Chitina by small, individual generators. The sizes of the
generators range from 5 to 9 kW. Residents talk about shutting off
appliances in one part of the house to be able to operate other appli-
ances to keep from overloading their small generators. The current
expenditure for fuel, generator repairs and maintenance appears to be
running between $2,000 and $4,000 per household annually.
The population of Chitina was 75 according to preliminary reports from
the 1980 census. The number of potential e1ectric .customers was esti-
mated at 30 including homes, a garage, store, bar, post office, etc. One
satellite telephone serves the entire village.
POWER DEMAND
The power demand of the community is estimated at 100 kW to meet the
current population needs. This is based on a population of 75 with 30
customers. Peak demand estimate was based on a level of use 'between the
communities served by Alaska Village Electric Cooperative (AVEC) and
CVEA. AVEC has a rather low level of use at one-third kW peak demand
per person whil~ CVEA has an average peak of about 1.2 kW per person.
Since a central electrical system in Chitina is likely to have a more
adequate energy supply than the current small diesel generators, the
level of use may be higher in Chitina with a central system than it is
now or that exists in the AVEC villages. The CVEA peak of 1.2 kWh per
person is equivalent to 90 kW peak for Chitina. The 100 kW figure was
chosen to allow for a higher level of use by Chitina residences and
provide for some growth.
The energy need is estimated at 300 to 400 kWh per month per customer.
For the current 30 customers, and possibly 50 customers considering some
future growth, the annual customer energy use would be 3600 to 4800 kWh
per year for a total community use of 108,000 to 240,000 kWh per year.
This is generally consistent with a 100 kW peak demand.
Most of the residents APA visited in Chitina indicated that they knew
people who would like to move back to Chitina if electricity and water
were available. Chitina is a summer fishing and recreation area for
many Anchorage residents. Several of the persons who signed the peti-
tion for this hydro power study live in Anchorage, own property in
Chitina, and would be potential summer electric users. Because of the
expected winter peak and the potential increased summer use, it is not
certain whether peak demand will be in the summer or winter. There is a
good possibility that summer and winter peak use will be similar.
7
ALTERNATIVE GENERATION RESOURCES
This section of the study presents alternative generation resources
available to Chitina and estimates of their costs. The resources
include hydro potentials on four streams, central diesel system, connec-
tion to the CVEA system, and the possibility of wind power. Costs are
not developed for the diesel and wind power alternatives.
Costs for the most promising combinations of alternative plans are
included in the following Chapter.
In addition to development of any plan, Chitina would need to construct
a distribution system to serve the individual homes and businesses.
This cost could well be an additional $100,000 to $250,000, assuming~
roughly $3,000 to $8,000 per customer hookup. There would also need to
be an organization formed that would be responsible for contracting,
providing new hookups, collecting revenues, paying bills, and generally
managing the system. A backup diesel generator system would be required
to assure firm power in case of a transmission line outage or low winter
water flow conditions.
A description of each energy alternative follows.
Hydropower
APA reconnaissance showed four sites having hydropower potential near
Chitina-O'Brien Creek, Liberty Creek, Fivemile Creek, and Haley Creek.
After APA examined the sites July 14, 1980, plans of development were
made locating and determining the size of the powerplant and pipeline
road location, transmission line lengths, and diversion dam location.
No storage sites were found on any of the streams. Consequently, the
plans of development assume run-of-river operations. Each of the streams
are in steep incised canyons. Based on measured flows in O'Brien
Creek, high summer flood flows can be expected. These floods tend to
carry large rocks, debris, and heavy sediment. This will ultimately
need to be a consideration in project design of diversion dams, intake
structures, and pipeline supports near the stream bed area.
Because of the relative flat stream gradient, 2,000 to 2,700 feet of
pipeline is needed to develop 300 feet of head.
Costs were estimated and the results are presented for each site based
on 1980 prices. Rough estimated unit prices installed are:
Powerplant, prepackaged unit
Pipeline, based on steel pipe
Diversion structure, lump sum
Transmission line, single pole, 14.4kV
Access roads, unimproved
8
$1,000/kW
$2/lb
$50,000
$40,000/mile
$25,000/mile
Contingencies of 25 percent were added to anticipate unforeseen items
and events. Project construction supervision is estimated at 20 percent.
The annual cost to repay the capital investment was calculated assuming
a 20-year loan with seven percent interest. Operation and maintenance
costs were estimated based on a part-time employee and minimum supplies
and services being needed.
Hydrology--More hydrology data is needed to confirm the capability of
the power projects in the critical winter periods. Local residents
state O'Brien Creek and Liberty Creek flow year-round. However, there
has been a low winter flow of four cubic-feet per second measured at the
mouth of O'Brien Creek April 23, 1976. Flow at a potential diversion
point upstream from the mouth of Fox Creek would be roughly 25 percent
less. The other streams investigated have smaller drainage areas than
O'Brien Creek and would likely have corresponding lower flows with less
likelihood of more than 40 to 60 percent power production during winter.
Roughly 5 c.f.s. are needed with 300 feet head to produce 100 kW.
The only similar stream for correlation in the area with flow records is
Squirrel Creek near Tonsina, 25 miles northwest of Chitina. It has a
drainage area 70.5 square miles, more than twice the area of the alternative
sites studied near Chitina. Continuous stream flow records are available
from 1965 through 1975. Examination of the stream flow records indicated
O'Brien Creek has higher summer peak periods of run-off per square mile
of drainage area than Squirrel Creek. For the 10 years of record, the
stream gage on Squirrel Creek was generally inoperable from roughly
November through April, the critical low flow period. The flow character-
istic of Squirrel Creek is that summer flows vary from 30 to 150 c.f.s.
from roughly May through September and then stabilize at 10 to 12 c.f.s.
from mid-November through mid-April. October and April are transition
months.
Severe cold weather conditions could force shutdowns of the plant in the
winter limiting the opportunity for a firm power supply from hydro.
Significant problems associated with icing should be anticipated, and
will need to be considered seriously in design of the diversion dam,
intake structure, pipeline, and the powerplant discharge area.
9
O'Brien/Fox Creek--The combined flow of O'Brien and Fox Creek enters the
Copper River 2.75 miles south of Chitina. The lower one mile reach of
O'Brien Creek rises only 140 feet, which is not adequate for a desirable
hydropower site. However, the next mile rises over 9 0 0 feet through a
series of falls, which presents several options for hydropower develop-
ment. For 12 miles in the upper part of the drainage area, O'Brien
Creek flows in a broad valley between peaks reaching to 5,500 feet
elevation.
The O'Brien/Fox Creek drainage area is 44.8 square mi le s. Local residents
state the stream runs year-round. Stream flow recor ds are spotty and
n ot adequate for a full design of the project. There i s a stream measuring
p oint on O'Brien Creek just above the bridge where t he U.S. Geological
Survey has made occasional measurements in the summmer to co l l ect peak
f low data for the Alaska Division of Highways. The re a r e n o 'winter
stream flow measurements during October through Mar ch. The da te doe s
indicate some extremes need to be dealt with, such a s a l ow wi nt er f l ow
of 4 cubic feet per second in April, 1976 and a high f l ow of 1,670 c u bic
f e e t in August, 1971. A summary of the published a n d unpubli shed s tream
fl ow record s available from the U.S. Geological Su rvey a r e appended at
the end of this study.
Fox Creek contains 9.75 s quare miles of the O'Brien Cr ee k dr ainag e area,
or less than one-f ou rth the O'Brien Creek area. The Fox Cre ek hydropower
site does not appear to be as desirable as O'Brien Cr eek due to its
smaller size and more difficult access in a steep n a rrow "V" shaped
canyon. Figure 2 shows the location of O'Brien Creek and the ph ysical
f e atures needed to develop the site. The better h ydropower s ite s on
O'Brien Creek are upstream from the mouth of Fox Creek, roughl y 1 .2
miles upstream from the Copper River. The pl an tha t app ear s to i nv o l ve
the least costly engineering features would be to l ocate the po werplant
300 feet downstream from the confluence of O'Brien a nd Fox Cr eek. An
access road about one-mile long would be needed on t h e nor th side of
O'Brien Creek. The powerplant comprised of a 100 kW t urb i ne generator
set, complete with controls. The head on the powerplant would be 300
feet. The pipeline would be 2,700 feet long, approximately 16" to 18"
in diameter, located on the west slope of O'Brien Creek Canyon. The
diversion dam would be an overflow structure capable of withstanding the
high flows of O'Brien Creek. A 14.4 kV transmission line would transmit
the power 2.75 miles to Chitina.
An effort was made to forecast the low winter flow and power production
recognizing icing conditions may hinder or shut down hydropower operations
from mid-November to mid-April. The area above the proposed O'Brien
Creek drainage area is a 34.25 square-mile or 76 percent of the total
drainage area. This results in an estimated 3.1 c.f.s. potential
winter low flow. Reducing this further to consider that the
April 23, 1976 measured flow may have been somewhat higher than the low
January flow (based on Squirrel Creek April 23, 1975 data), the low flow
would be 10/14 of 3.1 c.f.s., or 2.2 c.f.s.
10
Using another method of estimating and assuming winter flows are less
than 0.1 c.f.s. per square mile, the low flow would be up to 3.4 c.f.s.
and the power production would be 70 kW.
The appendix includes a summary of engineering characteristics and
estimated costs for a 100 kW plan assuming full operation for 6 months
in the summ er. The annual cost to repay the construction cost of $756,000
at 7 percent interest within 20 years amounts to $71,000. An additional
cost for operation, maintenance and replacements of parts that wear out
is estimated at $11,000 per year for a total of $82,000 per year.
Pictures of the O'Brien Creek potential power site follow.
11
Figure 2
ALASKA POWER ADM I NISTRATION
Hydropower Potentials
Near Chitina, Alaska
-O'BRIEN CREEK
HALEY CREEK
12/80
Mouth of O'Brien Creek where it enters the Copper River. Chitina
is two miles to the right of the photo. The tributary in the
center of the photo is Fox Creek.
O'Brien Creek near mouth just above the bridge at USGS stream
gaging site.
13
Mouth of O'Brien Creek.
The old railroad grade
along the bank of the
Copper River is usable
by 4-wheel drive vehic-
les. The bridge over
O'Brien Creek is more
suitable for foot
traffic. The right
side (looking upstream)
of the canyon floor is
a potential road access
route.
Typical rocky road bed site with little clearing required for access
road on north side of O'Brien Creek for lower 0.5 mile.
14
O'Brien Creek looking
upstream from the bend
0.5 mile from mouth.
Access road and pipeline
would be on right side.
O'Brien Creek showing more detail of pipeline location. Note the
waterfalls in upper center.
15
O'Brien Creek in foreground with Fox Creek flowing into it on the left.
Chitina is near the second lake at the junction of the Copper and Chitina
Rivers.
O'Brien Creek looking upstream in the head waters.
16
Fivemile Creek--Fivemile Creek has a drainage of about 11.5 square miles
and enters the Copper River five miles north of Chitina. The lower part
of the creek is in a steep walled "V" shaped canyon that drops 1,500
feet in two miles. The upper half of the drainage area lies above the
3,500 foot elevation and contains several small lakes and mountain peaks
rising to the 5,500 foot elevation. The entire flow of the stream goes
through a ten foot wide, sixteen foot high culvert under the main road
near the airport. No hydrologic records are available. Flow the day of
the visit was roughly 110 cubic feet per second. Data from the Alaska
Division of Highways indicate that Fivemile Creek has severe winter
glacering problems above the road culvert, in the culvert, and in the
area below the culvert. It appears that Fivemile Creek should not be
expected to provide water for power more than six months of the year due
to the glacering and icing problems.
Figure 3 shows the location and general plan of project development.
The Creek would be diverted 1,500 feet upstream from the highway. The
pipeline would be located along the north side of the stream, and pass
under the highway to the powerplant site roughly 300 feet downstream
from the main road. An overflow diversion capable of handling high
summer flows and low winter flows would be needed. Total leng~h of the
pipeline would be 2,000 feet. Much of the pipeline could be layed on
the bench next to the stream. Some trestle work may be needed to support
the pipeline in the upper reaches of the stream. The powerplant would
have 100 kW installed initially with a head of 300 feet. A 14.4 kV
transmission line five miles long would be needed to transfer the power
to town.
The estimated cost to construct a Fivemile Creek hydroelectric plan is
almost identical to the O'Brien Creek cost--$743,000. The O'Brien Creek
plan requires a mile of access road and a longer pipeline, but the
Fivemile plan would have a longer transmission line, which offsets the
other costs. Annual costs to repay construction costs would be $70,000
based on 7 percent interest and a 20 year repayment period. Operation
and maintenance costs are estimated at $11,000 for a total annual cost
of $81,000.
For study purposes the cost of a 200 kW plan without transmission, was
calculated. Construction cost would be $683,000. Annual costs would be
~64,000 plus $10,000 for operation and maintenance for a total annual
cost of $74,000. Assuming the plant operated at full capacity for the
summer six months of the year could produce a total of 876,000 kWh.
Energy in excess of Chitina's needs would have to be sold or traded to
the larger CVEA system, providing further studies show it is economically
feasible and in the interest of CvEA. This plan is considered further
in the Finanacial Analysis Chapter of this study.
Pictures of the site follow.
17
ALASKA POWER ADM I N ISTRATION
Hydropower Potentials
Near Chitina, Alaska
FIVEMILE CREEK
-LIBERTY CREEK
12/80
c Sea lei n m-j I es ., ... (fr2lIiWd/f//.Tf//f<f!)
Fivemile Creek with the
Chitina airstrip and Cop-
per River in background.
Upper drainage basin of Fivemile Creek contains several small lakes
surrounded by 5,500 foot elevation peaks.
19
0;:'
i:,;
(
/
.r
I
~
Lower portion of Fivemile
Creek. The powerplant
would be in the lower
right corner of photo.
Diversion dam and intake
would be upstream of the
road 1,500 feet. Pipe-
line would follow the
right stream bank look-
ing upstream.
20
""-,,
Diversion point would be
upstream. The pipeline
would be on the bench in
the foreground and needs
to be supported along the
cliff face further up-
Liberty Creek--The drainage area of Liberty Creek is 28 square miles,
and flows year-round according to local residents. The lower re~ch of
the river is a steep incised canyon for one-half mile downstream from
the road and two and one-half miles upstream. The upper drainage basin
is a broad valley lying generally between the 3,000 and 4,000 foot
elevation, and surrounded with numerous mountain peaks between the 5,000
and 6,000 foot elevation. The upper b~sin contains a dozen lakes with
10 acres or less surface area which tend to regulate the stream. The
amount of winter water flow would need to be established to see if it is
adequate to support year-round operation of the powerplant.
Figure 3 shows the plan of development for Liberty Creek. The plan
involves diverting the water below the Liberty Falls Campground using a
low gab ion type overflow diversion dam. The pipeline would run under
the highway bridge along the canyon wall and follow the canyon rim on
the left side downstream approximately 2,000 feet. The powerplant would
be in the canyon at the bottom of a steep slope, 200 feet vertically and
300 feet horizontally. A road roughly 2,000 feet long would be needed
to connect the main highway just north of the bridge to the powerplant.
The powerplant would be a pre-packaged system with 100 kW installed.
Total head on the powerplant would be 250 feet. The transmission line
to town would be ten miles long.
Construction cost for a 100 kW plan is estimated at $1,080,000. This
includes the 10 miles of transmission line to Chitina, but excludes the
distribution system in town. Annual cost to repay construction costs
would be $102,000 based on 7 percent interest and a 20 year repayment
period. Operation and maintenance costs are estimated at $16,000 annually.
The total annual cost would be $118,000, excluding costs of the distribution
system and utility administration. Pictures of the site follow.
21
Looking upstream on Liberty Creek, a low diversion dam would be at the
bridge. The pipeline would emerge from the canyon on the right side of
the stream just below the road. The powerplant would be on the stream
bank at the bottom of hoto.
Liberty Creek looking
on the photo points to the
22
Looking downstream from the upper drainage are a of Liberty Creek.
The ar ea contains several sm all lakes.
The Liberty Creek falls and the campgrounds from a popular recreation
area. The falls would not be involved in the power project under
this plan.
23
Haley Creek--Haley Creek was examined briefly from the air and office
map studies. The drainage area is 37.3 square miles. The lower two and
one-half miles of the Haley Creek drainage area is a steep "V" shaped
canyon typical of the area. The upper part of the drainage area is a
long straight valley two to three miles wide with several hanging glaciers
between the peaks along the rim of the valley which rise to the 5,000 to
6,000 foot elevation.
Figure 2 shows a plan of development for each site for comparison purposes.
Roughly 10 percent larger than O'Brien Creek above the proposed diversion
point. The site is five miles south of the O'Brien Creek site and would
thereby require that much more transmission line. In addition, five
miles of road would need to be upgraded and a bridge built over O'Brien
Creek. Haley Creek could be developed by a similar type diversion dam,
a 2,700 foot similar length pipeline, and a 100 kW powerplant near the
mouth of the creek. The head on the powerplant would be 300 feet.
The estimated construction cost of the Haley Creek plan of development
is $1,074,000. The annual cost would be $101,000 to repay a 20 year
loan at 7 percent interest plus $16,000 operation and maintenance cost
for a total annual cost of $117,000.
Hydropower Cost Comparison--Table 1 presents a summary of the hydropower
increment of costs. For a 100 kW plant at Fivemi1e Creek and O'Brien
Creek, costs are roughly $81,000 to $82,000 annually including operation,
maintenance, and repayment of construction costs. Haley Creek and
Liberty Creek annual costs are--$117,000 to $118,000 per year.
Table 1 shows the cost for a 200 kW scheme on O'Brien Creek. The unit
cost of ener~y is only about two-thirds as much as a 100 kW plant. Even
though there is some economy of scale, this is more than twice the size
of the near future power needs in Chitina.
Another analysis was made assuming either a 200 kW or 500 kW plant on
Fivemile Creek with full capacity all summer. Excess power is assumed
to be sold outside the Chitina area over a new line to the CVEA system.
The power could be sold or traded for winter power. The average cost
for the 200 kW plant would be roughly the same as fuel replacement cost
for generation using large diesel generator. The 500 kW plarit would be
2¢/kWh cheaper than the 200 kW plant and potentially provide revenues
for Chitina to buy energy in the winter. Costs to the consumers would
have to include additional costs for the transmission system, distribution
system, administration and the winter energy supply.
24
TABLE 1 SUMMARY OF INCREMENTAL COSTS. FOR HYDROPOWER
Installed Annual
Power Potential KW KWH/year Cost $ ¢/KWH***
O'Brien Creek 100 120,000* 82,000 68
200 240,000* 114,000 48
Fivemile Creek 100 120,000* 81,000 68
200 876,000** 74,000 8
500 2,168,000 134,000 6
Liberty Creek 100 120,000 118,000 98
Haley Creek 100 120,000 117,000 98
* Six months of summer operation assumed.
** Assumes full-time six month summer operation. The cost includes only
0.5 mile of power line to connect the powerp1ant to a transmission line
between Chitina and the CVEA system. The 16 mile transmission line
between Chitina and the CVEA system, would be necessary before this
power could be sold.
*** Incremental cost of just the hydrop1ant with a transmission to
Chitina. The town distribution system is not included.
25
Diesel Generation System
The following tabulation presents generation costs for supplying energy
from a central diesel generation plant to small villages such as Chitina.
They are presented here for comparative purposes.
Date
of Costs
Tlingit Haida Rural Electric Association 1980
Alaska Village Electric Cooperative 1979
Bristol Bay Study 1979
Generation
Cost ¢/KWH
20.0
28.0
45.2
Distribution system and administrative costs add another 12 to l5¢/kWh.
The Tlingit Haida REA serves five small towns in Southeast Alaska. The
Alaska Village Electric Cooperative serves roughly 48 villages in Western
Alaska with peak demand requirements ranging from 40 kW to 350 kW. The
costs shown for the Bristol Bay area are from a study prepared for
Alaska Power Administration December 1979. The 45.2¢ includes estimated
costs for three components of the generation costs; fixed costs, variable
costs, and fuel. Fixed costs include the cost of paying for the generators,
powerplants and insurance. The variable costs include the maintenance,
operation, and lubrication. The fuel costs are figured separately based
on 8 kWh per gallon. Two 60-kW units were assumed to be installed and
the interest rate was assumed to be 5 percent. These costs may be
slightly higher than would be experienced by Chitina since the Bristol
Bay locations are more remote than Chitina. Conversely, Chitina has
fewer customers than most of the other villages, and thereby the total
cost per customer would be higher just to cover fixed costs of the
generation plant and basic administration.
For purposes of this study 45¢/kWh was assumed to be a likely estimate
of diesel generation costs for Chitina. This would include a back-up
unit, fuel, and operation and maintenance cost.
Local residents in Chitina indicated that in 1980 their individual home
generation systems were costing $2,000 to $4,000 per year. This cost
includes fuel at just under $1 per gallon, and the replacement of the
generators every few years.
Copper Valley Electric Association Transmission Line Extension
The CVEA transmission line currently extends south of Kinney Lake School
to the bluff near Lower Tonsina, which is 16 miles from Chitina. The
location is shown on Figure 1. It is a 14.4 kV wood pole, single phase
line. One of the resource options for Chitina would be to extend this
line to Chitina and purchase energy from Copper Valley Electric Associa-
tion. The 16 mile-line is estimated to cost $40,000 per mile, or
$640,000 to construct.
26
In addition to paying for the transmission line, Chitina would purchase
energy from CVEA based on the 1980 rate structure. The cost of 400 kWh
would be 19.7¢/kWh.
First 100 kWh at
Next 100 kWh at
Next 200 kWh at
24.0¢/kWh
20.0¢/kWh
l7.0¢/kWh
$78.50/400 kWh = 19.7¢/kWh
$24.00
20.50
34.00
$78.50
The cost of 240,000 kWh at 19.7¢/kWh is $47,280.
Table 2 adds the annual cost for purchasing the energy and shows the
average cost per kilowatt-hour for this method of analysis to compare
with other energy alternatives in the area. The resulting energy rate
in 1980 dollars would vary from 36 to 49¢/kWh, depending upon the interest
rate on the loan to repay the transmission line. Operation and maintenance
of the transmission line and the monthly billing and management of the
system are assumed to be included along with other typical utility
services in the cost of purchased energy. The cost of the distribution
system within the town of Chitina is not included.
27
TABLE 2 COST OF TRANSMISSION LINE TO COPPER VALLEY
ELECTRIC ASSOCIATION'S LINE
Annual Cost to Repay
$640,000 Transmission Line
Annual Cost to Purchase
Energy 1/
Total Annual Cost
Average Rate, ¢/kWh
Annual Cost 20 Year Period
Interest Rate
2% 7% 9%
$39,140 $60,420 $70,110
47,280 47,280 47,200
$86,420 $107,700 $117,390
36 45 49
1/ Annual cost of energy is based on 100 kW and sale of 240,000 kWh per
year at 19.7¢/kWh. This would be equivalent to 400 kWh/month for
50 customers at the CVEA 1980 rate to their existing customers.
Chitina distribution sytem costs are not included.
28
Othe r Alternatives
Wind power is an old technology which is being revived and might be a
supplemental energy source to hydropower. Wind data is being collected
in Alaska and demonstration projects for the near future are being
planned. For a specific project in Chitina, wind data would need to be
collected year round to determine the amount of po tential energy that
could be developed. Future studies should include an evaluation of wind
power.
COST ANALYSIS OF ALTERNATIVE PLAN S
Each of the al te rnat ive energy resources discu ssed to t h i s point have
been considered to be independent. It is like l y t h a t a c om b ination of
t he se a l ternati ves will be needed to insure a f irm reliable power
sys tem ye ar-round. The hydro projects will need t o have more winter-
f l ow d ata to insure continuous operation. It is suspec t ed that in some
years severe wi nt er freeze-up could cause redu ced or fu ll loss of power
produc tion. Transmission outages between Chit ina a n d Glennallen or
Valde z could interrupt power. A new diesel gener ation p l a n, with an
extra unit for backup, looks reliable, but appears costly. Wind power
would need a backup for during periods of low wi nd. One form of backup
wo uld be to maintain the existing small 5 kW t o 9 kW individual powerp1ants
in a standby condition so that each electric c ustomer would have his own
emergency supply.
The f oll owing cases outline alternative plans of gener ation combinations
t h at c ou l d g ive higher re liable service t han an en ergy supp ly from a
single sou r ce.
Ca s e 1--0'Br ien Creek hydropower development wi th small individual
gene r ators for sup p lemental energy supply and backu p .
O'Brien Cre e k i s assumed to provide 50 percent of t h e annual energy
d ur ing the summer, and the remaining 50 percen t would be prov i ded from
the e xisting small home generators during the winter. The energy cost
f r om O'Brien Creek based on energy sales of 12 0,00 0 kWh would be
68.3~/kWh. (See cost sheet in Appendix). Diesel fuel cost for the home
generators is estimated at 12.5C per gallon based on fuel cost of $1 per
g allon and 8 kWh per gallon for the small gene r ators. In addition to
fuel, a distribution system and administration would need to be provided.
Case 2--CVEA intertie with small individual generator backup.
This case assumes full energy supply from CVEA with the home diesel
generators providing only standby and emergency power. Administration
and service are assumed included in the CVEA energy charge. A Chitina
distribution system would be needed.
Case 3--CVEA intertie with a 500 kW hydroplant.
This case assumes one of the hydro potentials along the transmission
intertie route to Chitina (Fivemile or Liberty Creek) would be developed
to provide summer power with excess power fed to the CVEA system. A
200 kW unit was studied, but it was found to just break even, so a
29
500 kW size was selected to provide additional revenue for Chitina.
Credit for the summer hydro generation was calculated at 8.33~/kWh based
on $1 per gallon on fuel cost and 12 kWh per gallon heat rate for the
large more efficient utility generators. Transmission losses were not
included. Winter power for Chitina would come from the CVEA generation
system. The possibility of this plan will need to be examined carefully
in further studies, and coordinated closely with CVEA. It is assumed
that administration would be provided by CVEA. A distribution system in
Chitina would be needed.
Distribution System Costs--Based on costs for distribution systems in
similar sized towns around the state, the distribution system would cost
$100,000 to $250,000. The annual cost to repay the $250,000 figure over
20 years with seven percent interest would be $23,600 per year. This
amounts to 9.8~/kwh assuming a 100 kW plant that sells 240,000 kWh per
year.
Administration of Chitina utility-distribution system is assumed to
amount to $6,000 per year. This would be all additional 2.5~/kWh based
on the 100 kW and the same 240,000 kWh annual sales.
System Costs--Table 3 presents rough costs for the three alternative
cases that would provide a total system including generation, transmission
lines, distribution and administration.
For comparison purposes, the cost for a diesel generation system would
be 45~/kWh (construction cost repayments, 0 & M, fuel, etc.), plus the
same 9.8~/kWh for the distribution system and 2.5~/kWh for administration
making a total of 57.3~/kWh. The following tabulation presents the
incremental cost between the three cases and a central diesel generation
plan.
Case l--O'Brien for Summer energy
and small diesels for winter
energy
Case 2--Intertie to CVEA
Case 3--Intertie to CVEA and a
summer 500 kW hydropower
plant.
~/KWH
52.8
54.7
34.5
Incremental
Cost Compared to
Diesel Plan
@ 57.3~/KWH
(-4.5)
(-2.6)
(-22.8)
Cases 1 and 2 are within less than 10 percent of the cost of a diesel
system at current $1 per gallon fuel prices. However, Case 1 does not
include replacement costs for the small generators which would make the
costs even closer. The big difference between Case 3 and the diesel
plan is due to the sale of excess summer energy to the larger CVEA
30
system. The excess energy sales would help pay for part of the intertie,
distribution system, and administrative cost.
The value of the diesel fuel displaced by the O'Brien Creek summer
operation plan would be $15,000 for 15,000 gqllons, based on 120,000 kWh
with the small generators producing 8 kWh per gallon. For Case 3, the
intertie with the 500 kW plan would displace 2,190,000 kWh at 12 kWh per
gallon (the larger diesel generators are more efficient) for a value of
$182,500 or a diesel fuel savings of 182,500 gallons.
Sensitivity Analysis--This analysis examines the potential impacts on
study results if different assumptions are made:
1. Different concepts of developing the hydroprojects: Only one
day was spent examining the hydro sites. Further examination or
surveys may locate reaches on the streams that are steeper and
would require less pipeline, thereby reducing the the cost. Other
plans could be made that would use more water and larger and shorter
pipelines which may reduce the cost some also. If one-third to
one-half of the pipeline cost could be saved, power costs would be
reduced 9 to 14C/kWh, based on O'Brien Creek costs.
2. Better stream flow, which would produce more energy than
assumed: Stream flow records are meager and if winter flows could
provide half of the winter power need, the hydro costs would be
reduced significantly. For example, the O'Brien Creek energy cost
would be 45.5C/kWh instead of 68.3C/kWh if 2.7 cubic feet per
second winter flow proves to be available. In the event full
winter flow of 5.3 c.f.s. were available, the cost of O'Brien Creek
energy would be 34.2C/kWh instead of 68.3C/kWh.
3. Other factors that could reduce costs: One cost reduction
possibility is a potential subsidy for part of the construction
costs. There may be a potential for a demonstration wind project
in Chitina. The distribution system could be less costly than
estimated. Underground powerlines may be a possibility. Then
also, part of the existing distribution system may be salvageable,
even though it looked rather neglected during the brief field
visit. Another possible cost reduction would occur if residents
used more than the extimated 30 percent of the total powerplant
production over several years.
4. Detailed studies could also point out other costs which are
not now reflected and thereby substantially reduce the benefits of
a hydro project to Chitina.
31
TABLE 3 SYSTEM COSTS
Case 1: O'Brien Creek with
Individual Gener-
ator Supplement
O'Brien Creek Project
(Provide 120,000 kWh in summer)
o & M
Customer Small Diesel Generators
(assume all units are paid for)
Fuel (Provide 120,000 kWh/yr
@ $1/ga1 and 8 kWh/gal)
Distribution System
Administration
Total
Capital
Cost
$1,000
756
250
1,006
Annual
Cost
$1,000
71.0
11.0
15.0
23.6
6.0
126.6
Note: This case does not include some sunk and hidden costs to the
customer for cost of small backup diesels for winter use.
Case 2: CVEA Intertie with
Individual Generator
Backup
CVEA Intertie
Energy, Service & Administration
(Provide 240,000 kWh @ 19.7¢/kWh)
Customer Small Diesel Generators
Fuel
Distribution System
Administration (included with
energy cost)
Total
Case 3: CVEA Intertie and
500 KW at Fivemi1e
Creek
640
o
o
250
890
CVEA Intertie 640
Energy, Service & Administration
(Provide 240,000 kWh @ 19.7¢/kWh)
Fivemi1e Creek (excluding
transmission line to town) 1,228
o & M
Credit for Fivemi1e Creek Energy
(2,190,000 kWh @ 8.33¢/kWh)
Distribution System 250
Administration (included with
energy cost) 0
1,573
32
60.4
47.3
o
o
23.6
131. 3
60.4
47.3
116.0
18.0
(182.5)
23.6
o
82.8
¢/kWh
29.6
4.6
6.3
9.8
2.5
52.8
25.2
19.7
9.8
54.7
25.2
19.7
9.8
34.5
APPENDIX
O'Brien Creek Hydrology
Estimated Cost of O'Brien Creek
Acknowledgement
33
Year
1970
1971
1972
1973
1974
1975
1976
O'Brien Creek
Hydrology -USGS data
Drainage Area a = 44.8 sq. mi.
Recording
date
Gage
Ht.-ft
7/71
8/72
6/9/72
9/29/72
7/73
6/74
7/1/75
8/76
7.32
5.16
4.34
3.66
4.47
3.87
Miscellaneous data from USGS report 1976, Page 260
5/14/70
8/18/70
8/18/70
10/01/70
6/7 /71
6/9/72
8/16/72
9/29/72
6/7 /73
6/19/74
7/26/74
6/25/75
9/4/75
4/23/76
7/13/76
8/24/76
1977 7/77 4.12
1978 6/12/78 unknown
Unpublished USGS data
5/24/77
7/6/77
8/9/77
9/28/77
7/6/78
5/3/79
5/25/79
6/26/76
cfs
310
1670
830
192
36
492
317
530
440
93
231
74
36
137
192
111
36
101
80
69
291
46
4.0
153
58
770
102 or more
107
576
210
74
182
47
86
180
U.S. DEPARTMENT OF ENERGY
ALASKA POWER ADMINISTRATION
JUNEAU. ALASKA
EST IMATED HYDRO COSTS
*********************************************************************~**
PL AN T SITE -O'BRIEN CREEK
FL OW (CFS) -5.3
HE AD (FT) -300
P IP ELENGTH (FT ) -2700
TR ANSMISSION LINE LENG TH (MILES) -2.75
ROA D LENGTH (MILES) -1. 1
CALC ULATED VALUES
PIPESIZE (IN) -14
HEA DLOSS (FT) -16.2335
PIP E COST ($/FT ) -80
MAXIMUM POWER (KW) -100
ENERGY at 30'Y. P . F . (l( Wh) -262800
CONSTRUCTION COS TS
PO WER PLANT -100 KW X $ 1000/KW =
DIVE RSION S TR UCTURE -
PIP ELINE -2 7 00 FT X $ 801F T ~
TR ANSMISSION LI NE -2 . 75 MILES X $ 40000/MILE -
ROA D -1. 1 MILES X $ 25000 /MI L E :=:
MI SCELLANEOUS COSTS =
BASE COS T
CONTINGENC I ES (25%)
FIELD COS T
OVERHEAD (20'Y.)
CONSTRUCTION COST
ANNUAL COST (20 yrs. at 7'Y. interest)
ANNUAL O~~M COST
INSTALLED COST PER KILOWATT
$
$
$
$
$
$
1 00·900
50.000
216,00 0
110,000
28.000
o
************
$ 504,000
$ 126,000
************
$ 630,000
$ 126,000
************ »>$ 756,000 «<
$ 71. 000
$ 11.000
$ 7,600
COST PER kWh Summer Operation--120,.OOOKWH/yr
NOTE: A 11 fig u res are to bee 0 n sid ere d r 0 ugh est i ma t e s
APA 1/81
ACKNOWLEDGEMENTS
The people of Chitina were helpful to the Alaska Power Administration
by providing information for this study. Specific people we would
like to acknowledge for furnishing data include:
John Billium Mrs. Howard Knutson
Mary Ann Rambosex Vern Ivey