HomeMy WebLinkAboutKiseralik Chikuminuk Hydro App part 4I
a
fl
4.2.3
4.2.4
1916/485(15)
at the villages. (Taken from Retherford
Associates, Single Wire Ground Return Report,
1982)
Regional intertie cost of construction -
$16,946,384. 0&M - $201,590 annual.
Lake Chikuminuk Hydroelectric Projects
9.5 MW Project:
Construction Cost - $152,549,913 (per
Harza Engineering)
0&M - $469,980
24 MW Project:
Construction Cost - $209,764,264 (per
Harza Engineering)
0&M - $766,515
Note: Costs for construction and 0&M included
here cover only generation and transmission of
the power to Bethel and do not include the
costs of distribution to the Region. Therefore
the costs of the Regional intertie must be
included to provide a complete picture of
project costs.
Coal -Fired Steam Turbine Plant
0&M - Fixed component $62.70/Kw/Yr
- Variable component $4.32/Mwh
Price of coal utilized is $140.00 per ton
delivered to Bethel (Cape Beaufort coal per
the consultant). Nominal BTU values are 13,000
per pound.
The coal price is escalated at an average
annual rate of 1.5%.
The coal efficiency rate used was 7618 KWH/ton.
This figure is subject to further losses due to
plant efficiency rates.
4 MW Project:
Construction Cost - $17,648,868 (per
Harza)
0&M - $447,944
10 MW Project:
Construction Cost - $38,503,671 (per
Harza)
0&M - $995,432
9
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ed
0
11
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Note: Above construction costs only include
those relative to power at Bethel. Full cost
profiles for the region must include the
distribution intertie.
4.3 Present Worth Analysis
The following table is an illustration of the present
worth of the base case costs in relation to selected
proposed alternatives and the associated present worth
ratios. Benefits of waste heat are not included in the
present worth values. The diesel base case, the diesel
intertie and coal scenarios would benefit as a result of
waste heat capture. The hydroelectric cases would not as
there is no heat production with hydro power generation
without implementation of a sophisticated load management
program.
Construction Cost
Present Worth*
Present Worth Ratio
TABLE 4
COST OF ELECTRICAL ENERGY SUPPLY
$1985
(1986-2041)
Base Case
157,585,808
Regional
Intertie
18,975,878
192,336,286
.82
Sub -Regional interties
Akiachak
Athmautlauk
Oscarville
Oscarville
Napaskiak
Akiak
Kwethluk
Nunapitchuk
Kasigluk
Akiachak
Akiak
499,421
159,085,388
846,013
159,690,713
3,250,002
161,108,189
3,252,307
161,725,159
2,358,420
164,036,808
.99
.99
.98
.97
.96
Construction Cost
Present Worth*
Present Worth Ratio
Construction Cost
Present Worth*
Present Worth Ratio
* A11 Project Costs
1916/485(16)
Coal Fired Steam Plant
4MW IOMW
36,624,746 57,479,549
195,167,043 247,460,175
.81 .64
Lake Chikuminuk Hydroelectric Project
9.5MW 24MW
171,525,791 228,739,142
410,952,298 512,643,449
.38 .31
I
Note: Above construction costs only include
those relative to power at Bethel. Full cost
profiles for the region must include the
distribution intertie.
4.3 Present Worth Analysis
The following table is an illustration of the present
worth of the base case costs in relation to selected
proposed alternatives and the associated present worth
ratios. Benefits of waste heat are not included in the
present worth values. The diesel base case, the diesel
intertie and coal scenarios would benefit as a result of
waste heat capture; the hydroelectric cases would not.
11
7
7
1 1916/485(16)
I
The alternatives are ranked in order of their present
worth ratio (present worth cost of the base case divided
by present worth cost of the alternative). All the
coal-fired steam turbine cases and the Lake Chikuminuk
cases are more capital intensive and have present worths
much greater than the Base Case; therefore, their ratios
fall below 1.0 by substantial margins. The intertie
options, except for the Regional intertie, all cluster at
1.0. the project alternative break-even value.
The price of fuel has the greatest effect on the outcome
of the present worth analysis. A sensitivity analysis
was performed increasing the escalation rate of the price
of fuel to 0% for the first 3 years, then 3.5% for the
next 17 years. It would be expected that the diesel
alternative cases would be more attractive. Although the
present worth of the base case increased 17%, the present
worth ratios of the alternatives were affected minimally,
and the order of the above rankings was retained.
5.0 CONCLUSION
An economic energy source for the Bethel Region appears to lie
neither in the coal-fired steam plant nor the Lake Chikuminuk
hydroelectric options. Further, APA analysis of Harza's Lake
Chikuminuk project designs revealed that the 9.5 MW project
had insufficient capacity to meet the load requirements of the
Bethel Region due to significant line losses. The 24 MW
project, at an approximate cost of $33,000 per capita in the
Region, may also suffer from design problems in power
transmission. These conditions result from characteristics
inherent in a transmission and distribution system which is
too long for the load
amount of being served.
- Line losses on the order of thirty percent were
calculated due to excessive charging current relative to
the light loads.
Balancing the load and maintaining proper voltages would
require sophisticated and costly monitoring and control
equipment to ensure safe and reliable operation of the
transmission and distribution network.
No redundancies or loops were incorporated in the consultant's
design and no roadways for operation and maintenance would
exist.
A more direct solution to a dependable, less costly source of
electrical generation appears to be in an alternative under
the expanded base case options. In the short term, the
intertie(s) would allow for greater economies of scale, less
duplication of generation in the village --separate generation
for school and village --and more dependable electricity.
1916/485(17)
Because cost estimates and routing distances utilized for the
Power Authority analysis were extremely conservative, it is
felt that sufficient justification exists to perform more
detailed site reconnaissance to refine the cost data and to
develop a conceptual design specific to the needs and
conditions of the Bethel region.
Although the coal-fired steam plant has a high present worth
cost in relation to the base case, the use of coal in the
Region should not be dismissed summarily. The extensive coal
resources in Alaska are the subject of increasing interest and
study. At present, Arctic Slope Engineering, under contract
to the Alaska Federation of Natives, is engaged in a
development study of the Deadtall Syncline near Cape Beaufort
for use in Western Alaska, including the Bethel Region. If
the demand for coal were greatly increased, as it would be if
all space heating in the villages were converted to direct
coal combustion and a coal-fired steam plant were built, then
the price of coal would most likely drop markedly. For
instance, Arctic Slope Engineering's current analysis
indicates that an FOB Bethel coal cost might be $127 per ton
at 13,000 BTU per pound.
There is a lack of definitive information and commitment at
this time to the use of coal. A long term goal for the Bethel
Region might be to determine the cost and availability of coal
and the viability of such a plan. Since there is no
established infrastructure for the delivery of coal to the
Bethel Region, its viability as an economic option for energy
generation is highly speculative. Harza's analysis of present
worth for space heating supply showed a 30 percent reduction
from the base case through the immediate conversion to direct
coal combustion. This assumed a residential furnace
replacement cost of $1200 per household, several hundred
dollars per year for O&M and a delivered cost of $140/ton at
10,000 BTU per pound nominal values. Financing options were
not addressed in the report.
If an intertie system were in place, the utilization of coal
for electrical generation would promote greater advantage of
economies of scale than the diesel/intertie alternative with
only coal-fired space heating.
1916/485(18)
Kisarall*k
Hydroelectric
Potential Analysis
Bethel — Section III
Bethel - Section in
APAIVE
111. ELECTRIC ENERGY RESO:U:RCEI
I
TI-Os section presents an analy'sis of exis;t;ing energy resources in
the Bethel area,, J>a5et on available information, Published reports,
U565 maps:, ffeld investigations and other available Ifteratur-e as
listeP
d in the hibliagra hies, uith oac, part, as :well as; communication
with people in the area, have been utilized to complete knawledge
on resourcts that can t>e deVeloped with known technology within the
next twenty years.
RtAOUtces have been analyzed in regard to economic and environ-mental
feasibility, Except tor the potential oil and gas discoveries,
'which would require a very large scale develaMent and are not
addressed in; this report, the development of the Golden Gate
hYdY'Oelec:t,ric Site aRpears to be the best prospect to pr&vide tbt-
required electrical energy in the future, Small communities without
access to hydroelectric or geothermal energy Vill have to rely on.
diesel , coal/Wood gigneration, transmissiom interties or implement
wind and solat Power on a small scale. Unfortunately neither coal/
wood generation or win:d And solar power appear,tIq be economically
advantageous at this time. ,
StOre restralAts ;on devel6paent of most potential resour"ce s are
created by the present land statu$ uncertainties, Fievelopeable
potential resourCes are however, ment4janed and economically
evaluated on a�n approxim'a'te basis in tbis study regardless of the
Potential land usage conflicts.
The following potential energy resources will be discussed:
I. *4r1electric Potential
Z, Coal/Wood Entergy Con'versllon
3. Geothermal: Potential
A-, Wind Power Potential
5Transmission Intertiec-
6, Conservation
The available energy resources will be 4valuated in regaM tt, their
potential to replata� or sopplement the pr:es:en:t ;jse of petr*114;eum
f Uels.
Bethel - SectionIII
AP1/
The present state of the art in vi'nd and solar energy conversions
idered to: be uneconomical on a "'utility" scale due to
either high cost or questionable
both these energyconversion technologiesbe pursued on a
demonstration - or private individual level -in the near; future.
Overall energy needs, however, most be filled by means of proven
technology and economically feasible developments. Emphasis has
been placed on reftewable, resources. This does riot imply that other
resources have been overlooked but rather attempts to put then in
perspective in regard to possi.ble development and costs.
1.!:!&2)pctric Potential
!! i
The Golden Hydro, on the Kisaralik River has the
potentialEsupplythe,entire future needsof the Bethel
projectarea through the year 2000, ,The energy from;,;the Golden
Gate hy4ro can! ! - ! by c t
numerous small village!s surro'unding Bethel to d centralized
power distribution point located in Bethel, whic:h is in
turn suppliedvia a>.milelongtransission line from
the Golden Gate Wdro project. This concept: is showin in
Figure 111-1. It is estimated that 1986 would prove to
bethe earliestpossibledatefor e project
permitsassuming all necessary ' z acquired.
This completion ! date is, however,ouestiooable
present1future landstatus+uncertain.
projectThe _ i...E.iE....#"YukonDelta" National
Wildlife Refuge created by the Federal Land Policy
Management Act ;of November 16, 1978, Emergency Order 204E.
The following pages address the preliminary geologic
investigation, construction, construction cost, envirort-
mental impact and energy potential of the Golden Gate
Project.
KiSaraliK River originates in the ilbuck Mountains
and flows west-northwest approximately 110 miles where it
empties into the K;skokwim River near the village of
Akia . The proposed dam site is located in a narrow
meandering gorge at approximate river mile 67 and $3.5
airline miles east-southeast of the City of Bethel, This
site is in section 17, T , 2Wr Seward Meridian and
identified as ""Lower Falls"" on the U.S. .S. Bethel - )
quadrangle although theta are no falls at the location.
Where are no .significant falls anywhere along this section
of river where a substantial head could be utilized,
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K
Drainage Area Normal Maximum ater Surface (msl EI,
Minimum Water Surface, El.
Tailwater El.
Surface Area - Normal Max. W.S.
Live Storage (70 ft. drawdown)
Regulation
Type
Height
Crest Elevation (nsl)
Volume
SPILLWAY
Type
Crest Elevation
Width
Design Discharge
POWER TUNNEL
Length:
Finished Dia-meter
POWER PLANT'
Type
Capacity
MAxinum Gross Head
Type of Turbines
TRAtiWSSION LINE
Vo I tage
Length
Conduc toTze
,r $*
544 sq,
mi. (1409
L110 ft.
(338
1060 ft.
(323
805 ft.
(245 m):
6700 Ac.
(2680 a)
32-0,750
acft. (395.7 MCM)
to cfs
(22. 7 cms)
Rockf i 11
ft. (96 M)
ft. (343 a)
2,500,000 CY.
(1,911,500
Asphaltic Concreto
Ungated Side Channel
375 ft. (114 m)
87,000,cfs (2,464 cms)
925 ft' (282 m)
16 ft.6.9 m) modified
horseshaeconcrete lined
Undergtound
3000WW (2 units)
Ve,rti"cal Fr�kis
,138 V
-69 mi. (111 W
796.5 KCM� AC-$R
Bethel Section IJI
4PA15/E
The selected
site
offers several advantages,
over other
possible dam
sites
on the Kisaralik River.
These are:
(1) The topograpby is such that the volume of material
t�, construct a. dam of sufficient height to providei"
suitable storage and head for low winter flows is
less than at the other sites.
(2) The U-shaped bend in the river provides for a"very
short over tunnel; a feature not evident at:the
.`,.-
other sites.
(3) More favorable geologic conditions.
(4) A natural bench at an appropriate height for the
excavation of a side channel spillway.
Several 'dam heights were investigated with respect to
available prime power and :the of of dam vs. cost of
power. Preliminary studiu. indicate a Jreservoir with
normal maximum water surface at tl;evation 1110 will
Orovid# the greatest ben4flt to cost ratio when using a
regulated flow of., 800 cfs. All head and sUrage is
developed with a rockfill dam 325 feet high with a crest
at elevation U25 and a 90on 1110.,
This will create a reservoir having a capacity of
716,000 acre-feet of A usable storage of 320,750:
acre feet is provided with a drawdovn of 70 feet. F i gure
111-2shows the'extent of the reservoir.
Jhis chapteY�.9`ives a description of the Noject, tho
Preliminary design of the major project elemeots,.;the
schedule for the construction of the project and the
est imate&osts.
C ProJect Armaement,
The Kisaralik River Project would consist of the fol:lowing
principal elements.,
(1) A rockfill dam across the river, founded on rock,
with a side channel spillway lhav:ing a crest at
elev,ation 1110 on the north abutment..,,_,The up , k,
slope of the dam would be 1.7 horizontal' to"I veritic`a
The 'downstream slopoul,d ble�1.5 horizontal
vertical." Ove-r"s,(ze rock would be placed against the
downstream face for eart�hquake stability. T he d am
would have a crest of 550 feet in length and 20 feet
Bethel Section III.
in width, An impervious membrane of asphaltic
concrete on the upstreamface and a concrete grout
Cap 8 longthe upstream toe would be Provided..
concrete intake structure with Invert at elevation
820 is provided with a trashrack bars the right abutment
of the river.
reinforced concrete lined tunnel feet in
length with a finished diameter of 16 feet.
underground powerhouse containing the turbines,
venerators and electrical switchgear.
5 surface switchyard adjacent to the powerhouse adit
containing the transformers, switches., etc. and
transmission take -off structures..
Other facilities, including a 50 mile winter
construction access road from near Wa , and
transmission line.
The powerplant would contain two generators rated at
kv kW each, powered by vertical Francis turbines of
23,000 Hp each. The - protect would produce 1,31,400 ld
per year.
The not operating head would be in the order of 265 feet
average flow is $00 cfs.
The generating waits would have a overload rating of
above their na pl Este rating.
The head at which the outs would be required to operate,
30feet, is in the range normally covered by reaction
(Francis) turbines. Vertical units were selected to
minimize the horizontal dimensions of an underground
powerhouse,
minimum of two units should be installed so that the
project, t which would be the major source of energy to the
system, ould operate with one unit out of service.,
The installation of more than to units would require a
larger powerhouse excavation and three 10 MW units with
appurtenances would cost considerably more than t
nits. if two 10 w units were installed initially with
Rothe) - Sortion T')
APAIS/E
provisions for a future unit, all of the necessary excava-
tion for the unit, in the powerhouse, tailrace and supply
line would have to be done initially. The cost of
installing three 10 MW units would be considerably higher
than two 15 MW units in a one stage development and the
cost of installing two 10 MW units with provisions for a
.uture unit would cost approximately the same as installing
two 15 MW units, The cost of mobilizing and providing
camp facilities in this remote location is extremely
high; therefore, stage development is not recommended.
The installation of three or more units has the advantages
of being able to operate the machines at a higher rate of
efficiency and providing a greater peaking capacity with
one unit down. During the early years of surplus energy,
operation at a higher efficiency would result in spilling
more water over the spillway. As, energy requirements
approach the prime capacity of the plaint, the units would
operate within a reasonable range of efficiency. With
the long transmission line being the most vulnerable
portion of the Project and hydruelectric units being very
reliable, two 15 MW units have been selected for the
purpose of this report.
e. GeologyFoundation and ConstrAtionMaterials:
The geo' ' ogy of the Bethel quandrangle was published in
1959 by Hoare and Coonrad (Map 1-285); there has been
little `addition to this work since then. According to
their classification., the bed"ck in the Lower Falls area
is pert of the undifferentiated Gemuk group (KCg), of
probable late Paleozoic and ftsozoic age. The unit is
comprised of chiefly massive arcs thin -bedded, fine-grained
siliceous rocks, some volcanic rocks, calcareous silt tone,
and I imestone.
At the damsite, the rocks are siliceous metasiltstones or
argillites a ' nd'zcherts. The rocks are generally massive,
displaying little evidence of former bedding planes.
However, parting and outcrop patterns indicate a N20W
strike for the original structure. Overprinting this
texture are several zones of cherty, more resistant rock
that trend roughly northwest and east -west, and at least
two main joint sets (40EMON and NMMIE).
While the structure of the unit is somewhat complex on a
local scale, It appears to present-=, special probless
for construction of a am. Bedrock ou'.crop on the hillsides
above tine river is generally frost -riven and fractured,
but fresher exposures adjacent to the scouring action of
the river are more uniformly coMetent.
A zone of especially Iresistant, cherty material cuts
across the river in an east -west direction near the Lower
Falls area. The zone is subParalltlproposed axis
Of d.emajor portionr
ckfM
structure ;From numerous; outtrops or. both sides
midstream,channel and
feet of alluvium would r to be removed
bottom
x'a_♦ €r r
r r ae •
r of r were observed,: and there 's no
indn of such from the regional ZOPPIng of 'Hoare and
Coonrad. Tho mountainsides of the gorge area appear to
have been Stable_ of majora
'Construction s be r from
crosscuttingeither abutment. The a
equidimentionaldebris
one foot in rr. ta
from the gorge
one-half miles downstream Contain well -graded sandy
Geologically,
constroctioA
Joiner sets.
the dmsite is favorable, The most importa
wouldProblem be adequate grojtinaOf I
The watershed above' the proposed damsite was detervin
to be r r,
r � r
r � r
r r
Bethel - Section III
APA15/E
The 544 square miles or 348,160 acres with 20 inches of
runoff (1-67 feet) calcUlattg to 680,270 acte-fott of
rwnoff per year. The total runoff of 580,270 acre-feet
per year equates to an average annual flow of 800 cfs,
It is believed that $00 cfs average would flow during the
driest year and the power available used in this study
would be firm with annual regulation. With a net head of
265 feet, the project would develop 15,000 continuous
or 131,400 Wh of f I re energy per year. (See Appendix A -A),
It is strongly recommended that a stream gage be installed
near the proposed dansita at the earliest possible date.
If the average annual flow is much greater than used iii
this study, the dam shoU14 be designed for futvre raising,
the power tunnel diameter increased, and the powerhouse'
designed fot future expansion, if feasibility - level
studies so indicate,
9, Description of Project Facilities:
Dam: The da-m would be a non -overflow tockfill type
Mounded on bedrock. The rockfill would have a
maximum, height of 308 feet from elevation 810 to
1118. The crest would be 550 feet in length and
20 feet in width with a 7-foot high concrete coping
wall on the upstream edge to elevation 1125 The
rockfill iR the dam. with 'upstream slope of L7h-V
and downstream slope of 1.5h;IV, will be zoned and
compacted in the lifts with vibratory compactors. A
concrete grout ca ' p will be placed along the, upstream
toe to grout the rock joint sets. The dam would be
sealed between the grout cap and the coping wall
with asphaltic concrete pavement on the upstream
face with an average thickness of 12 inches.
A 20-foot high cofferdam placed upstream from the
grout cap would divert the power water through the
power tunnel during dam construction. The cofferdam
would not 6e removed.
A typical dam -section Is shown on Figure 111-7. An
area -capacity curve for the reservoir is included in
Figure I 11- 3,
(2) SP-111WOY: The probable maximum flood for the Kisaralik
ViverYas not been determined for this study. For
estimating purposes, a spi,11way at elevatJon 1110
with a channel width of 375 feet and a slope of 5%
Bethel, - Section 111
APAIVE
Bethel - Section III
APA15/E
Each leg :of the trifurcation would contain a sph rical
valve for positive closure of each waterway,
The turbines and generators wll be connected by a
vertical drive shaft. Each generator would have a
continuous overload rating of 15 per ceht,
Tunnel & Powerhouse are shown on Figure 111-6.
(5) Transmission Lines: A substation at the powerhouse
would trans -form the generated voltage of IM kV to
the transmission voltage of 138 kV. Utilization of
138 kV nominal voltage anda 795 KCM conductor wo6ld
as:sure ade:quate voltage levels in Bethel, Energy
losses would be low due to the relatively large
conductor chosen. An ;overhead line would strike
northwest for approximately 56 miles turning sharply
northward near Xwethluk and cross the Kuskokwim
River. The I ine would -then turn southeast and
terminate in a substation near Bethel. The total
length of the transmission line woUld be approxi-
mately 69 miles.
(6) Access Roads-, There, are no access roads to; the si.
�t the ''0 nt time. A winter access road approxi
mately �50 miles in length from ;the village of -Aki
to the project site would provide :the means of
construction mobzation and demobzation. I
A permanent road approximately 2 miles in length
would be constructed downstream from the powerhouse
to the concrete aggregate borrow area. A gravel
strip would be constructed, at the end :of the pemanent
road for project access with fixed wing aircraft.
h - , Environmental and Other Concerns.
Preliminary investigations indicate that caribou, moose,
wolf, wolverine, grizzly bear, and b1ack bear habitats,
and numerous raptor nesting sites along the Kisaralik
River would probably be lost.
There are no known archaeological sites in the area that
would be inundated. However, to be certain that no sites
,,Are disturbed an archaeological survey should -be conducted
prior to constrtictfbh.
Bethel - Sect i on 1 l
ApAIS/
The Kisara ik river impoundment would require further
study to accurately assess the fishery in the river.
Chums, king and silver salmon are known to spawn in the
K saral'ik River an4-its tributaries .above the Golden Gate
Falls (See Appendix Q-1).
The transmission corridors would crass several small
streams.. As there is a possibility that the transmission
line construction could introduce sediment into these
streams, A -study should be conducted daring the detailed
environmental assessment, to determine the optimum methods
of insuring that anadromeus fish streams are protected.
Use of single wire ground return transmission system.
wherever possible, would minimize visual impact.
i.. Land Status -
The powder-davelbp emt site is presently, located within
the proposed Yukon Delta Wildlife 'Refuge (Federal Land
Policy 14anaget t Act of Rovenber 16, 1978, Emergency
Order 204E). The: 2114E withdrawal is valid for 3 gears.
The Kisaralik River is also considered under Emergency
Order 104t, which has not been invoked yet. This order
would withdraw the river and ;a 2-4 mile corridor along
each bank for a pare of Zg years and be more restrictive
than the 204E order. If bills HR39 or S9 pass, the
Kisaralik might also be included in the "Vild & Scenic
i ver" system.
j- Projett Construction;
The project construction would be carried out by separate
supp1 and. civil worts construction contracts. single
general contractor would build the project.
The contractor would be required to provide access to the
site by constructing necessary barge facilities on the
Kuskokwim River for unloading tonstnttion equipment,
materials, supplies, etc.'as necessary to construct the
project. The contractor wood construct the winter
access road, air trip, permanent road, construction camp, -
etc. as well as the other pmJect features and equipment
installation.
Overburd6 containing organic natter and decomposed rock
removed from requiredexcavations would be used as fill
material in the operator housing area on the left abutment
of the river downstream of the powerhouse tailrace. ,