HomeMy WebLinkAboutAPA1627HARZA-EBASCO
Susitna Joint Venture
Document Number
/t,dl
Please Return To
DOCUMENT CONTROL
.
'
PRELIMINARY ASSESSMENT OF
COOK INLET TIDAL POWER
PHASE I REPORT
VOLUME I
[i]
STATE OF ALASKA
OFF! CE OF THE GOVERNOR .
PRELIMINARY ASSESSMENT OF
COOK INLET TIDAL POWER
PHASE I REPORT
VOLUr-£ I
SEPTEMBER 1981
ARLIS
Alaska Resources
Library & Informauon Scrvtces
Anchorage, Alaska
Acres American Incorporated
Suite 329
The Clark Building
Columbia, Maryland 21044
Telephone (301) 992-5300
TABLE OF CONTENTS
Page
FOREWORD ........................•..•..•.•.•••............•.••...•.•.• 1
SECTION 1 -INTRODUCTION •••••.•••••••••••••••••••••••••.••.•••.•.• 1
1.1 -Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 -The Nature of Tidal Power ••.•••••••••••..••••••••.•.••• 1
1. 3 -Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 -Acknowledgements •• . • . . • . • • . • • • • • • . . • . . • • • • • • • • . • . . . . • . 5
1.5 -Previous Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.6 -Terms of Reference .••••••••••.••.•.••••••••••.•.••.•.. 6
1. 7 -Report Structure • • • • • • • • • • • • • • • . • • • • • • • . . • . • • • • • . . • • • . 7
SECTION 2 -SUMMARY OF FINDINGS •••.•.••.•••••••..••••••••.•••..•.. 8
2.1 -Technical Ev al uat ion • • • . . • • • • • . • • • • • • . . . . . • • • • • . • • • • • • 8
2. 2 -Project Costs and Schedules • • . . • • • • • • • . . • • . • • . . • • • . . . . 9
2.3 -Environmental Assessment ••••.•.•..••••••...•.••••..... 10
2.4 -Socioeconomic Assessment •••••••..•••••••••...••....... 10
2.5 -Regulatory Evaluation •...••.••••••••.••..••••..•...•.. 11
2. 6 -Economic Evaluation •..•.••••..•..........••••.••.••... 11
2. 7 -Constraints and Uncertainties ••••••••.••••••••.•..••.•• 13
2. 8 -Preferred Site . . . • . • • . • • • . • • • • • • . • . • • • • . • • . • . . . . • . . • . . 14
2. 9 -Succeeding Phases •.•.•••••.••••••••••••.•....•...•••.. 16
2.10 -Recommendations .•.•.••..••••.••••••• • •.••.•..•.•...... 17
SECTION 3 -METHODOLOGY .•.•....••.••.••.•••••.•..•.••••••....•.•.. 18
3.1 -Introduction •.••.•.•••••••. ~ •••••.••.••...•.••..••.•.• 18
3.2 -Task 1-Preliminary Field Reconnaissance ••.•••...•... 18
3. 3 -Task 2 -Comparative Evaluation ••••.•...•••••••••••••. 20
SECTION 4 -SITE SELECTION • • • • . • • • • • • • • • • • • • . • . . • . . • . • . . • • . . . • . . • • 24
4.1 -Introduction and Purpose ..•••.••••.•.••.•••••••••••.•. 24
4.2 -Existing Conditions ••••••..•.•••••.•••••••.•..•.•.••.. 24
4.3 -Concept Selection •..•••••.••.•.••••••••.••..••..•..... 25
4.4 -Site Selection •..•••.•.•.••.••••...••••.•.•••......... 28
SECTION 5 -TECHNICAL EVALUATION .•..•...•••.•..••.•........•...... 35
5.1 -Paraneter Selection •.•••••••••.••••...•..•....•......• 35
5.2 -Turbine-Generator Equipment Design .•..•.•••••......... 36
5. 3 -Tidal Power Plant Energy Study •.•••••...•.••••••.....• 38
5.4 -Closure of the Tidal Basin ...•..•••••••.••............ 45
5.5 -Civil Design •.........•.•.••.•.••....••••••.••.•..•... 45
SECTION 6 -COST ESTIMATES AND SCHEDULES ...••..................... 54
6.1 -Site-Speci fie Costs ..••..••.•.••••.•.••••.••..••...... 54
6 . 2 -Sc hed u 1 e s . . . . . . . . . • . • • . • . • • • • • . • • . • . • • . . . • . • . . . • . . . . . . 54
TABLE OF CONTENTS (Continued)
Page
SECTION 7 -PRELIMINARY ENVIRONMENTAL ASSESSMENT •••••••••..•••••.• 56
7.1 -Introduction .......................................... 56
7. 2 -Unique Effects .•••••••••••.•••••••••••..••.•••••.••••• 56
7. 3 -Short-Term and Local Effects •••.••••••••.•...••..••••• 57
7.4 -Environmental Constraints ••••••••••••••••.•••.•••••••• 58
SECTION 8 -SOCIOECONOMIC ASSESSMENT ••••••.•.••.••••••••.•..•••••• 60
8.1 -Introduction .......................................... 60
8. 2 -The Construction Period •...•.••••••••••.•••••••..••... 60
8.3 -The Operation Period •••••.•••••••••••••••••••••••••••• 61
SECTION 9 -REGULATORY EVALUATION •••••••••••••••••.••••••••••..•.. 62
SECTION 10-SYSTEM STUDY AND ECONOMIC EVALUATION •••••.••••.••.•••• 64
10.1 -Use of Raw Tidal Energy •.•••••••••••••••••.•••••.••••• 64
_10.2 -Energy Storage ........................................ 66
10.3 -Project Economics •••••.••••••••.•••••••••.••••••••••.. 68
10.4 -Constrained and Unconstrained Cases •••••••••••••••••.. 68
10.5 -Fuel Escalation ....................................... 69
10.6-Marketing and Financing •.•••••••••.•...••••••••.••••.• 69
SECTION 11-RISK ASSESSMENT ••••••.••.••.••••••••••••••••••••...••• 71
SECTION 12 -PHASES II AND III ••••••••••••••••••••••••••••.••••••.• 73
12.1 -Introduction .......................................... 73
12.2 -Phase II Studies •••••••••••••••••••••.•••••...•••••••• 73
12.3 -Phase II I Studies ••••••••..•••••••.•••••••.••• ~ ••••.•• 74
BIBLIOGRAPHY
MAP -Location of Selected Sites
APPENDICES -(Included in Volume II)
LIST OF TABLES
Number Title Page
4-1 Selected Parcmaters 33
5-1 Annual Energy and NlJTibers of Units at Selected Sites . . . . . . 44
6-1 Summary Cost Estimates (June 1981 Cost Levels) 55
7-1 Potential Interaction Between the Tidal Plant and
Elements of the Environment ..........•.................... 59
9-1 Cook Inlet Tidal Power Major Required Permits for
Project DeveloiJilent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
11-1 Proposed Investigation Prograns . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
LIST OF FIGURES
Number Title
1-1 The Origin of Ocean Tides
Page
2
1-2 Basic Concept (Details Eliminated for Clarity) ............ 4
3-1 Logic Diagram, Study ~thodology .....•...•................ 19
4-1 Selected Demand Forecasts ........................•........ 26
4-2 Water Levels and Energy Production During .a Typical Cycle . 27
4-3 Candidate Sites ........................................... 29
4-4 Summary of Selection Criteria Evaluations ................. 34
5-1 Horizontal Axial Flow Turbine Types ....................... 37
5-2 Effect of Varying Numbers of Turbines and Sluices ......... 40
5-3 Characteristic Optimization Curve ......................... 41
5-4 Eagle Bay Plant Optimization .............................. 42
5-5 Typical Example of Water Surface and Velocities Through
a Tide Cycle During Closure ............................... 46
5-6 Powerhouse Structure ...................................... 49
5-7 Access/Closure Dike Typical Cross Section ................. 50
5-8 Bridge and Causeway Crossing .............................. 52
10-1 Demand Curve for an ExC111ple Generating System ............. 65
10-2 The Effects of Coal Cost Escalation on Economics of
Alternative Eagle Bay DeveloJ'lllents .....•.................. 70
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
LIST OF APPENDICES*
Title
Task 1 Report (Submitted to the State of Alaska April 1981)
Visual Reconnaissance of Selected Sites (Submitted to the
State of Alaska April 1981)
Par illleter Se 1 ec t ion
Turbine Design
Electrical Equipment
Tidal Power Plant Energy Studies
Closure of the Tidal Basin
Tidal Power Facility Design and Construction Methods
Cost Estimates and Schedules
Preliminary Environmental Assessment
Socioeconomic Assessment
Regulatory Evaluation
System Study and Economic Evaluation
Marketing and Financing
Preliminary Risk Assessment
*Included in Volume II.
-----------------------
FORE \\ORO
This report was prepared by Peres Aneric an Incorporated in partial
fulfillment of a contract with the Office of the Governor, State of Alaska,
to conduct a study entitled "Preliminary Assessment of Cook Inlet Tidal
Power."
The \\Ork described herein constitutes the first phase of a planned three
phase study to determine the potentials and constraints of uti 1 i zing the
tides of Cook Inlet to produce useable energy. The three phases include:
( 1)
(2)
(3)
Phase I: Preliminary assessment of Cook Inlet tidal power potent-
ials and characteristics.
Phase I I: In-depth study of the potential industries or groups of
industries that appear to have a comparative advantage in association
with a Cook Inlet tidal power source.
Phase II I: Detailed engineering and environmental investigation of
site-specific configurations, as \Ell as the preparation of a concep-
tual developnent plan.
Conclusions and recommendations contained herein are based solely upon
Phase I study efforts. Results of later phases could lead to modifications
in the initial findings.
For the convenience of the reader, a fold-out map is provided as the last
page in this report. Kni k and Turnagain Arms at the upper end of Cook
In 1 et are shown thereon.
{i)
SECTION 1 -INTRODUCTION
1. 1 -Background
Of all the states, Alaska is most richly endowed with the potential for
vast energy resource development. It is literally a state of superlatives.
Oi 1, coal and natural gas developments in Alaska already contribute to the
satisfaction of national energy goals and the chances that undiscovered
fossil fuel resources exist there are strong. U1developed hydroelectric
resources are the greatest in the nation. feothermal, solar, and wind
energy potential are known to exist. Befitting its vast size, Alaska can
also boast of tidal ranges \'thich rank among the highest in the ~rld.
There is no question that Alaska can supply its own energy needs for cen-
turies, even as it makes significant contributions to national needs.
It is not enough, though, to know that development can occur. The more
difficult issue by far is that of \'thether or not itshould occur. No
development is without consequences.
To ensure that responsible and informed choices are made, Alaska has
embarked upon a program which will evaluate the relative advantages and
disadvantages of possible approaches to its energy future. A major feasi-
bility study of the Susitna Hydroelectric Project* began in January 1980.
More than six bi 11 ion ki 1 owatt hours of electric energy can be produced
annually from that project alone if it is constructed. Concurrent with the
'5usitna study is a study of Railbelt** Electric Power Alternatives ~ich
will address all viable means for providing electric energy to the most
populous region of the State. One .important alternative with relatively
1 arge energy potential is the prospect of harnessing the tides in Cook
Inlet. Because of the unique nature of this renewable resource, the State
commissioned a preliminary assessment of its potentials and charac-
teristics. This report provides such an assessment.
1.2 -The Nature of Tidal Power
The ebb and flow of t·he tides occur roughly twice daily in a predictable
way (see Figure 1-1). Energy is available from this natural process both
* This project ~uld consist of t\\U dans on the upper Susitna River ~ich
runs in a westerly direction through a canyon between Anchorage and
Fairbanks. The upper dan at Watana ~uld be rockfilled and a thin arch
concrete dam \\Uuld be installed at Devil Canyon, the lower site.
** The Railbelt is the area served by the Alaska Railroad. It includes
Anchorage and Fairbanks and is by far the most heavily populated region
in Alaska.
-1-
-2-
SPR~~G TIDES
FIGURE 1-1
THE ORIGIN OF
OCEAN TIDES .ii]
because tidal currents represent kinetic energy and because potential
energy is associated with maintaining differences between sea level and the
level of water in a basin which might be formed by the construction of one
or more artificial barriers (or "barrages").
Tapping the kinetic energy of tidal currents may have useful application
for communities whose energy needs are small and whose energy generating
options are limited. Unfortunately, the kinetic energy density of tidal
currents is relatively small and costs of extracting it are correspondingly
1 arge.
In those few places in the world where large tidal ranges exist, the tech-
nology to take advantage of the potential energy of the tides is already
well proven. This latter approach involves technologies which are akin to
those applied in the development of conventional hydroelectric power. This
report focuses upon the use of tidal potential energy to generate
electricity.
One tidal power station of commercial scale has already been successfully
operated for 15 years: The 240 MW facility at La Rance in France. A small
experimental plant has also been installed by Russia off the Arctic coast-
line at Kislaya Guba. In addition, construction work is now underway at
Annapolis Royal on the Bay of Fundy where a demonstration project to test a
single large straight flow turbine is to be installed by 1983 utilizing an
existing causeway. A number of very small tidal power facilities has also
been constructed on the coasts of China. Studies at other coastal loca-
tions around the world have been completed or are in progress.
The usual approach to tidal power development involves the creation of a
barrage which permits maintaining one or more basins at elevations lower
than high tide or higher than low tide. As soon as sufficient difference
in elevation between sea level and basin level has been obtained, water at
the higher level is allowed to flow through hydraulic turbines to the lower
level, thereby generating power. The sketch at Figure 1-2 illustrates the
process.
The energy produced by a tidal power plant occurs at predictable times and
is in phase with the lunar cycle. In the simplest single-basin tidal power
development, energy is produced in pulses several hours in duration,
between which are peri ads when no energy is produced. Further, because
significantly differe~t tidal ranges exist at neap and spring tides, the
amount of energy produced varies as the moon and sun cyclically and predi-
ctably change positions relative to the earth. This characteristic of
tidal energy must be accommodated either by the system into which the
energy is fed or by some method for storing or retiming tidal energy.
1. 3 -Purpose
It is the purpose of this preliminary assessment to
potentials and characteristics of Cook Inlet tidal power.
-3-
determine the
To accomplish
I
~
I
I) BASIN WAS FILLED DURING FLOOD
TIDE WHEN WATER FLOWED THROUGH
SLUICES WHICH WERE CLOSED AS
THE TIDE BEGAN TO FALL.
BASIN LEVEL
SEA LEVEL
21 THE DIFFERENCE BETWEEN BASIN
AND SEA LEVELS IS REFERRED TO
AS THE HEAD. IN GENERAL ,GREATER
HEADS PERMIT PRODUCTION OF
MORE ENERGY.
FIGURE 1-2
~
~ WATER FLOWS
THROUGH THE
HYDRAULIC TURBINE
AS SEA LEVEL
FALLS ON EBB TIDE.
BASIC CONCEPT
(DETAILS ELIMINATED
FOR CLARITY} iiJ
this overall objective, a progran involving four tasks, each of \tilich is
further divided into subtasks, has been followed. Succeeding sections sum-
marize the report, discuss the methodology \tilich was followed a1d describe
the results obtained.
1.4 -Acknowledgements
Significant contributions were made by others to this Phase I study. Par-
ticular participants include:
(1) Canadian Atlantic Power Group, Limited (CAPG}
Throughout the study period, CAPG representatives \\Orked closely with
the Acres tean. Having recently conducted major studies of tidal
power potential in the Bay of Fundy in Canada, CAPG brought a \'tealth
of knowledge to the project. The assistance of CAPG has been
important not only in terms of building upon Bay of Fundy data, but
also in analyzing the unique aspects of Cook Inlet itself. CAPG
representatives from the Canadian firms of SNC, FENCO and Acres
Consulting Services participated.
(2} The Anchorage Office of Hanscomb Associates (Hanscomb)
While the fact that tidal power facilities now operate elsewhere
clearly demonstrates technical feasibility of the concept,
determination of the economic viability of tidal power development in
Alaska requires cognizance of Alaska-specific costs. Hanscomb has
assisted Acres by providing important inputs for cost estimates and
schedules reported in later sections of this preliminary assessment.
(3} Mr. Robert H. Clark, P. Eng.
Mr. Clark had served as Chairman, Management Committee, Bay of Fundy
Tidal Power Review Board, during recent detailed studies in the Bay of
Fundy. His wise counsel as a consultant has been important,
particularly in terms of providing critical reviews and perceptive
suggestions as the \\Ork progressed.
1.5 -Previous Studies
A number of earlier studies have addressed the potential of harnessing Cook
Inlet tides:
( i) In 196 7, a paper pub 1 i shed by Wilson and Swa 1 es (Reference A. 4 in
Appendix 1) assessed conceptual developments and the costs and bene-
fits of tidal power. It was noted that energy demand forecasts did
not then warrant full-seale devel OJlllents at either Turnagain or Kni k
Arms.
-5-
(ii) R. Johnson's paper (Reference A.3 in Appendix .1) recommended a
two-basin Cook Inlet tidal power project with barrages across the
openings of Turnagain and Knik Arms. A structure connecting Fire
Is 1 and and Point Campbell would accommodate necessary turbines and
generators.
(iii) A paper published in 1976 by Behlke and Carlson (Reference A.1 in
Appendix 1) reviewed the hydraulic theory associated with tidal
power development and suggested an innovative scheme involving the
construction of small plants spaced along Cook Inlet to take
advantage of the time lag between high tide at one plant and the
next. Sequential generation was regarded as a means to perm.it
relatively continuous energy production without requiring separate
energy storage facilities. Behlke and Carlson also published a
paper in 1972 dealing with computer modeling of Cook Inlet tidal
phenomena (Reference A.4 in Appendix 1).
(iv) Stone and Webster Engineering Company completed a study in 1977
(Reference D.5 in Appendix 1) of tidal power development in the
United States. A major portion of this work was devoted to Cook
Inlet. The study concluded that on a life-cycle basis tidal power
would be economically competitive if alternative fuel costs
continued to escalate.
1.6 -Terms of Reference
The Division of Po)icy Development and Planning, Office of the Governor,
State of A 1 ask a, awarded a contract to Acres American Incorporated in
January 1981, to conduct this Phase I Preliminary Assessment of Cook Inlet
Tidal Power. The scope of work included in the contract is summarized in
Section 3, Methodology, in this report.
In addition to this final report, other significant contractual
requirements included:
(i) A report upon the completion of the initial site selection effort
(reproduced as Appendix I to this report).
(ii) A report on the visual reconnaissance of certain sites (reproduced
as Appendix II to this report).
(iii) An in-process review which was conducted in Juneau, Alaska, on
May 22, 1981.
The State of Alaska appointed Arthur Young and Company as Program Manager
for this Preliminary Assessment as well as for the Railbelt Alternatives
Study referenced in paragraph 1.1 above. Mr .. C. Sitkin fulfilled the
Program Manager role for Arthur Young and Company. Mr. Sitkin's advice,
assistance, interest and patience during the course of the work are
gratefully acknowledged.
-6-
1.7 -Report Structure
Should tidal po~r be developed in Cook Inlet, its effects will be widely
felt. It could contribute to relative stability in future electrical
energy costs, might offer an opportunity for shorter 1 and M:cess to the
Kenai Peninsula or to lands bordering Knik Arm ocross from Anchorage, and
it \\OUld most certainly cause environmental impacts \\hich deserve careful
and thoughtful consideration. It follows that even a preliminary assess-
ment of the exploitation of this renewable resource should be available to
and understood by all those ~o might eventually benefit from it--or by
those ~o might consider its consequences unacceptable. Thus, VolLme I of
this report has been structured to be responsive to the needs of the 1 a)111an
as ~11 as to provide the technical details necessary to substantiate its
findings. To the extent possible, Volume I presents the study process and
findings with a minimi.ITI of complex mathematical descriptions and technical
terminology. A series of appendices supports this report \\hich is included
in VollJTie II. It is in this latter set of doclJTients that more rigorous
analytical support may be found for the results obtained. A fold-out map
at the end of this report is provided for the convenience of the reader.
-7-
SECTION 2 -SUMMARY OF FINDINGS
2.1 -Technical Evaluation
Of sixteen tidal power sites (ranging in energy production capability from
117 GWh to 63,700 GWh) which would be capable of producing energy in Cook
Inlet, those at Rainbow on Turnagain Arm (2664 GWh), Point MacKenzie on
Knik Arm (3937 GWh), and above Eagle Bay on Knik Arm (4037 GWh), would
provide the best prospects for deve 1 opment. Energy production at any of
these sites is large compared to the estimated electrical energy
consumption in the Railbelt Region for 1980 of 2790 GWh. The construction
of a tidal power plant at any of these three sites is technically possible.
The use of 11 floated-in 11 caisson modules for the powerhouse and sluiceway
sections, for which foundation conditions at these sites have been assumed
to be suitable, would lead to lower capital costs than conventional in situ
construction behind temporary cofferdams.
A variety of development schemes for each site is available. The more
complex schemes offer the possibility of ascribing firm capacity and
continuous output to a tidal power plant. However, adding complexity leads
to increased costs. For purposes of a preliminary assessment, the simplest
operation mode was selected as the basis for determining whether tidal
energy has any viability from an economic standpoint. Therefore, all three
selected sites were evaluated as single basin, single effect, ebb tide
generation facilities.
In addition, development can be varied in terms of scale. A vastly
different level of capacity can be developed at each site with a minor cost
penalty as the size varies from the optimal development. This makes size
selection at the site very dependent on the market for project power. A
third developmental variable is the retiming of tidal project energy. This
need is also dependent on project power markets. It follows that the
planned study of potential users in Phase II could lead to later
modifications of the initial Phase I findings contained herein.
Suitable turbine-generating equipment and electrical equipment are
commercially available. Horizontal axial flow turbines, either bulb or
Straflo, are appropriate choices for consideration. Both are competitive
and the final selection should be made on the basis of an economic analysis
at the time that final design commences.
The unique characteristics of Cook Inlet tides can be simulated by computer
analysis. By taking into account the physical characteristics of a given
site and the operating characteristics of particular turbine-generating
equipment, it is possible to produce reasonably accurate estimates of
energy produced in selected time intervals over long periods of operation.
Simulation programs developed for use in this study can be used to optimize
energy values at any given site.
A tidal power plant can accommodate a vehicular crossing at a relatively
small cost increase and it is possible to arrange for uninterrupted traffic
flow without interference with tidal power plant operation.
-8-
CONCLUSION 1: It is technically possible to construct and operate a
tidal power plant at not less than three locations 1n Cook Inlet. Such a
plant could also provide a means for vehicular access to the far shore of
Knik Arm or of Turnagain Arm.
2.2 -Project Costs and Schedules
Estimates of the cost of tidal po\Er develollllent depend in part upon the
adequacy of data regarding actual site conditions. A major field investi-
gation program is required before firm cost estimates can be made. Within
the limits of 25 percent in either direction, the most likely capital costs
of tidal po\Er develollllent in January 1982 dollars for the three selected
sites to provide mimimum 11 at-site 11 production costs of energy are:
Cost in$ Million* (Jan '82)
Exclusive of Energy Dollars
Net Average Storage Costs per kW
Plant Annual Vehicle Excluding
Capacity Output Tidal Crossing Vehi c 1 e j
Size MW GWh Plant Increment Total Crossing**
Eagle Bay 1440 4037 3825 29 3854 $2656 !
I
Pt. MacKenzie 1260 3937 4131 42 4173 $3279 I
Rainbow 928 2664 2819 22 2841 $3038 I
'
The possibility of a lo\Er scale of develollllent was tested at the Eagle Bay
site because of its comparatively lo\Er cost for full scale development.
The results of this test are summarized in paragraph 2. 6.
Schedules for completion of a project at each of the selected sites must
allow for detailed engineering and environmental investigations, satis-
faction of regulatory .requirements, and the time necessary for detailed
final design and construction. For the selected sites, schedules are as
follows:
* Includes direct costs of all components, navigation facilities W'lere
appropriate, indirect costs of 12.5 percent, and contingency of 25
percent.
**Installed capacity costs only. No retiming costs are included.
-9-
Complete 1-I:KC
Feasibility License Project
Site Study By: Awarded By: Completion By:
Eagle Bay 1987 1989 2000
Point MacKenzie 1987 1989 2001
Rainbow 1987 1989 1997
CONCLUSION 2: Tidal power development wi 11 require significant capital
investments and long lead times before it can be implemented in Cook Inlet.
Some other means of electrical generation wi 11 have to be developed to
satisfy energy demand growth in the Railbelt until about the turn of the
century.
2.3 -Environmental Assessment
Tidal power develop11ent wi 11 lead to permanent changes behind tidal bar-
rages because some diminution in land areas ~ich are now alternately sub-
merged and drained will occur. Shoreline habitat will be altered. Natural
processes of erosion, sedimentation, ice formation and movement, salinity
distributions, currents and the like will change in complex ways. Although
areas selected for tidal power develop11ent are generally less productive
than those in the lower Cook Inlet, accommodations will have to be made to
ensure safe passage of migratory fish, to protect marine mammals, and to
mitigate habitat losses. Detailed environmental investigations should be
undertaken in parallel with technical feasibility studies.
CONCLUSION 3: The complex physical processes in Cook Inlet should be
thoroughly investigated, carefully modeled, and scientifically evaluated
before tidal plant construction conmences. A physical hydraulic model of
the Inlet may be necessary for this purpose. Major baseline environmental
data collection studies and rigorous analysis of their implications will be
required before a decision can be made as to the environmental accept-
ability of identified projects.
2.4 -Socioeconomic Assessment
Long periods for construction of tidal power plants and opportunities for
fabrication of caissons at or near the project site suggest that an in-
crease in labor force with relative stability for a period of years is
possible.
-10-
Addition of a vehicular crossing to a tidal power plant would facilitate
access to the Beluga area or to the Kenai Peninsula, depending upon which
site is selected for development. Some relief would be possible from the
pressures now felt in the Greater Anchorage area for lands suitable for
development. Improved access across either Arm would inevitably lead to
increased recreational usage in areas where some limitations are now posed
by distance and traffic problems {the Kenai Peninsula) or relative remote-
ness (Beluga area).
Based upon experience at La Rance tidal plant in France, a Cook Inlet tidal
power plant could become a major tourist attraction.
There is a potential for industrial growth as a result of the availability
of tidal energy at relatively stable, long-term rates. Investigation of
the applicability of tidal power development to industry is scheduled as a
Phase II study.
CONCLUSION 4: An average on-site employment level of 1900 to 2500
persons for periods of 7.5 to 11.5 years in the 1990's can be expected if
tidal power is developed at one of the selected sites in Cook Inlet. An
additional off-site labor force requirement of 300 to 400 persons would be
required during construction.
2.5 -Regulatory Evaluation
While a variety of federal, state and local regulatory requirements must be
satisfied, the most significant is the Federal Energy Regulatory Commission
{FERC) licensing requirement. Experience to date on major hydroelectric
projects has demonstrated that detailed engineering and environmental
investigations are necessary to support a license application. Depending
upon how much relevant data may otherwise have been collected for a parti-
cular project, periods of from three to five years may be necessary before
the application is submitted. Another period of some years (depending upon
the quality of the application and the extent to which the proposed project
is controversial) is involved in processing before a license is awarded.
CONCLUSION 5: In spite of the long lead times imposed by regulatory
requirements, there do not appear to be any regulatory constraints which
would preclude tidal power development in Cook Inlet •
•
2.6-Economic Evaluation
Tidal energy from a single-basin, single-effect plant is in phase with the
moon. Maximum energy output frequently coincides with minimum system
demand. Energy which cannot be absorbed by the electrical system is
-11-
"excess" unless it can be stored or otherwise used. Energy storage faci-
lities are within the state of the art, but a cost penalty must be assoc-
iated with providing storage to support a tidal power plant. Certain
industries can, however, accept "excess" energy on a cyclic basis without
intermediate storage.
There are several alternative methods of retiming available for use with a
tidal plant, including such methods as compressed air storage, hydroelec-
tric pumped storage, and hydrogen production. Although each method has
apparent advantages and disadvantages, detailed study is needed prior to
selection of the best method. Costs developed for retiming in this study
were selected as "generic 11 retiming costs, not for one specific method.
Phase III studies will address site-specific retiming after industrial
needs are defined in Phase II. ·
A preliminary economic analysis was undertaken to determine how the costs
of tidal energy might compare with those associated with a new coal fired
plant. Economic parameters \'Ere used (0 percent inflation, 3 percent
interest rate) and a differential escalation of coal prices at 1. 5 percent
per annum perpetually was allowed. The mid-range forecast was used because
it was considered most likely. The initial system evaluation of the three
tidal projects indicated that a smaller develollllent at the sites may be
more favorable economically. Although the unit production costs of energy
would be higher than for the optimal site develollllent, a savings to the
system v.ould occur with the ability to directly use (without retiming) a
higher percentage of the energy from the scaled-down project. For this
reason, a one half-size Eagle Bay devel Ollllent of 720 MW was tested econo-
mically in the system context. This smaller alternative was not developed
to the same level of detail (optimization, closure velocities, layout draw-
ings) as the three primary alternative sites, since it was considered to
check a preliminary conclusion of the system and economic study at a 1 ater
stage.
Energy Cost in Mi 11 s/kWh
( l) (2) (3) (4) (5!
if Energy C'A>st
Energy Energy all "Excess"
Cost Q>st Energy is
Production if if Retimed and
Costs of .. Excess 11 .. Excess" Causeway vaTue
Installed Raw Energy Energy is Subtr.acted
Capacity (Unretimed) Cannot is From Total
SITE MW Energy Be Used Retimed Capital Cost
Eagle Bay 1440 48 121 79 74
Eagle Bay 720 58 87 76 68
Point MacKenzie 1260 54 133 83 77
Rainbow 928 53 105 77 74
New Coal Plant 200 MW
(Level i zed-1995 Increments
First Year)
eAt 1. 5% esc. 44 44 44 44
eAt 3% esc. 53 53 53 53
-12-
It is important to note that tidal energy costs will remain relatively
stable after initial startup whereas the price of coal will probably con-
tinue to increase after 1995. It may be anticipated, then, that on a life
cycle basis, tidal energy costs will become increasingly more attractive
over the nominal 50-year life of the tidal plant.
After Phase II studies are accomplished, the extent to which unretimed (not
requiring storage) energy can be marketed to industry will be determined.
If some industry is attracted by the availability of unretimed tidal energy
at a relatively stable cost, the at-site energy values for a tidal plant
without vehicular crossing facilities will probably lie between those
listed in columns (2) and (4) in the above tabulation. It is important to
note that tidal plant capacity cannot be regarded as dependable capacity in
the conventional sense because it is intermittent. On the other hand, it
is entirely predictable and its energy output may be more valuable than
conventional secondary energy whose availability cannot be guaranteed.
CONCLUSION 6: The production costs of unretimed tidal energy are likely to
be reasonably competitive with those associated with a coal fired plant,
provided a market can be found for predictable but intermittent energy (see
Column (2) in the tabulation above). If the tidal plant provides a vehi-
cular crossing which is separately accounted for as a transportation bene-
fit, a tidal plant/energy storage facility with some firm capacity may also
be economically competitive on a life cycle basis with a conventional
coal-fired generating plant, depending upon the extent to which coal costs
escalate in future over general price inflation (see Column (5) in the
tabulation above).
2.7 -Constraints and Uncertainties
The potential market for Cook Inlet tidal power differs substantially from
that into which tidal energy from the existing La Rance tidal plant now
feeds. Cook Inlet marketing prospects also differ from those for tidal
power developments which have been studied at Passamaquoddy (a potential
joint U.S. -Canadian project) and in the Bay of Fundy in Canada.
Electrical systems associated with La Rance, Passamaquoddy and the Bay of
Fundy are large in comparison to the output of existing or potential tidal
power plants. Energy demand in the Railbelt in 2000 in the mid-range case
will be only about 50 percent greater than the amount of unretimed energy
which would be produced by the larger developments generating on the order
of 4000 GWh at either Eagle Bay or Point MacKenzie. For a lower level of
development at Eagle Bay (2300 GWh) or optimal development at Rainbow (2664
GWh), total Railbelt energy demand in 2000 in the mid-range forecast would
be little more than double the tidal power plant energy production
capability.
-13-
CONCLUSION 7: In the absence of unusual industrial expansion, smaller
scale and possibly staged developments at Rainbow (2664 GWh) and at Eagle
Bay (2300 GWH) would be consistent with demand growth in the Railbelt dur-
ing the first 10 years of operation. Because of the capital intensive
nature of a tidal power development, difficult financing problems will have
to be dealt with, particularly during the early years of operation--an
issue shared by such large projects as hydroelectric developments, nuclear
plants, and major pipelines.
Only limited site-specific data are available for the selected sites.
Professional judgements made on the basis of extrapolating this 1 imited
data must be verified before a final determination of feasibility can be
made. Depending upon the results of a field investigation program, estima-
ted capital costs could increase or decrease by as much as 25 percent in
real terms. In addition, at least 13 risk categories with potential major
impact on the feasibility of project develollllent have been identified.
Detailed studies based upon a rigorous field investigation program v.ould
permit elimination of or significant reductions in uncertainties which must
now be associated with data limitations.
Risks \\tlich could have major impacts on project viability and which gene-
rally demand further study and investigation at the feasibility study stage
include:
( 1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
( 9)
(10)
( 11)
(12)
Foundation condition uncertainties,
Seismic considerations,
Ice formation and movement behind tidal barriers,
Ability to construct 11 in the ~t 11 if subsurface conditions are found
to be unfavorable,
Availability of construction materials,
Length of periods during W'lich ~ather conditions will preclude
construction,
The potential for and effects of tsunamis,
Precise high water levels as determined by on-site gages,
Tidal current variations,
Environmental resource inventories and evaluations,
Compatability with the existing generation system, and
Economic and financial uncertainties.
CONCLUSION 8: The study results are sensitive to assumptions regarding
conditions for which precise on-site measurements have not been made. A
detailed feasibility study including a major field investigation program is
necessary to remove or reduce uncertainties stemning from limitations in
the current data base.
2.8 -Preferred Site
The site across Knik Arm north of Eagle Bay and Goose Bay v.ould be the
preferred candidate project for consideration in Phase II and III studies
for the following reasons:
-14-
(i) The production costs of unretimed energy for optimal development of
this site compare favorably with those associated with alternative
coal-fired generation and are lowest of the three sites
considered.
(ii) This site lends itself \Ell to staged development, permitting an
initial installation which would be consistent with projected
energy demand growth in the Railbelt or allowing for higher devel-
opment levels W'tich could support the energy needs associated with
industrial growth.
(iii) Seismic prob 1 ems are 1 ess 1 ike 1 y to be encountered at this site
than at Rainbow W'tich is nearest to an area of earth movement stem-
ming from the 1964 earthquake or at Point ·MacKenzie \\here possible
1 i quefaction of unfavorab 1 e materials lllder earthquake conditions
may cause concern in design of safe facilities.
( iv) No interference with operations at the Port of Jlilchorage or with
ocean shipping will occur.
(v) Important wildfowl habitat at Eagle Bay and Goose Bay W'tich would
be altered by construction at the Point MacKenzie site is less
1 ikely to be seriously impacted by construction above Eagle Bay.
Even so, some change in the Palmer Hayflats habitat resulting from
construction at the Eagle Bay site would be avoided at the Rainbow
site.
(vi) There is less likelihood at this site than at either Point
MacKenzie or Rainbow that interference with the natural movements
of Beluga whales and other marine mammals would occur.
(viii) This site is better situated to support through hydrogen production
the methanization of Beluga coals than the Rainbow site.
(ix) Closure velocity problems which may limit construction progress at
Point MacKenzie are not likely to be experienced at this site.
(x) If any site causes a change in normal tidal level variations (the
barrier effect), the smallest effect would be attributable to this
site.
(xi) In the event that Ph-ase II studies lead to the conclusion that
industrial development is not likely to be encouraged by tidal
power development, the at-site sales price of energy produced by
1 ess than full development at this site and ret imed as necessary
comes closest to being economically competitive with the costs of
energy produced by an alternative coal-fired generating plant.
CONCLUSION 9: The results of this preliminary assessment warrant proceed-
ing with Phase II and Phase III studies specifically oriented toward indus-
trial potential and conceptual plans for development of the site above
Eagle Bay on Knik Arm.
-15-
2.9 -Succeeding Phases
The recommended site at Eagle Bay can be developed in a manner vklich is
consistent with the projected energy demand in the Rail belt. Because
multiple turbine-generating units are involved, it \'tQUld be possible to
begin operation in the year 2000 at less than full capacity, adding capa-
city as demand increases over the next 7 or 8 years. The 10-year demand
growth between 2000 (the time at \'klich Eagle Bay could be completed) and
2010 is projected at 2500 GWh annually in the mid-range case. Install at ion
of 30 turbines and the use of energy storage \'tQUld permit the tidal
plant/storage system to contribute 2050 GWh of firm energy annually after
accounting for retiming losses. If a vehicle crossing is included in the
scheme, the tidal energy cost in this case \'tQuld be· economically favored
over the nominal energy cost for the coal alternative by 2020 if coal
prices escalate perpetually at 3 percent over the normal inflation rate and
by 2040 at a more modest escalation rate of 1.5 percent.
CONCLUSION 10: Tidal power development at Eagle Bay need not depend upon
the encouragement of industrial growth in the Railbelt Region. ·A viable
scheme for meeting most likely demand growth (the constrained case} is
available, if energy can be retimed economically.
As originally conceived, 11 Phase II is intended to look in depth at the
potential industries or groups of industries that appear to have a compar-
ative advantage in association with a Cook Inlet tidal power source ...
(Excerpt from letter, Office of the Governor, dated September 23, 1980,
seeking consulting services for the Preliminary Assessment of Cook Inlet
Tidal Power).
A higher level of develorxnent at Eagle Bay is possible (the unconstrained
case). Install at ion of 60 turbines ~uld permit an annual production level
of 4037 GWh. Up to 1600 GWh of unretimed energy annually could be directly
absorbed by the Railbelt system in this case, so that from 2437 GWh to 4037
GWh annually of unretimed tidal energy could be made available to industry
at 48 mills per kWh. If no retiming is required, this energy cost ~uld be
competitive with alternative energy costs from a coal fired plant at the
turn of the century; and, if coal prices continue to escalate, tidal energy
will become increasingly more attractive. In the event that retiming is
necessary, up to 3200 GWh annually could be made available at 74
mills/kWh--a cost \\ttich ~uld be favored over the coal alternative before
2025 if coal prices continue to escalate perpetually at 3 percent per annum
above the inflation rate and by 2050 at 1. 5 percent per annum.
It follows that if a decision is made by the State of Alaska to encourage
industrial development, it ~uld be possible to support such a decision
with a 60 powerhouse installation at Eagle Bay. Thus, the proposed Phase
II study ~uld include the following:
(1) Identify industries \\ttich ~uld be attracted by the anounts and costs
of energy available from full develorxnent of Eagle Bay site;
-16-
(2) Identify and address technical problems associated with transmission
and distribution of energy, either electrical energy or energy
converted to some other form (such as heat) or fuel (such as
hydrogen); and
(3) Determine how much and \\hat type of energy storage system is required
to meet industrial needs.
"Phase I II waul d involve a detailed engineering ald environmental invest i-
gation of site-specific configurations, as well as the preparation of a
conceptual developnent plan" (Office of the Governor, September 23, 1980).
Whereas this report considers retiming in generic terms and evaluates
project economics on the basis of an expected cost penalty for energy stor-
age capacity, it will be possible after completion of Phase II to develop
site-specific details regarding the apparent optimal retiming needs for the
preferred tidal power devel opnents. This w:>rk w:>uld be accompli shed in
Phase III, which would have three major components:
(1) Developnent of site-specific characteristics and potentials of a pre-
ferred retiming facility (either to support the Railbelt System alone
in the case of tidal power developnent with a low level of installa-
tion or to support identified industries in the case of high levels of
install at ions);
{2) Preparation of a conceptual development plan to include layouts for
the tidal plant, storage system, transmission system, road network,
caisson prefabrication area, and ancillary facilities; and
(3) An environmental assessment of the proposed conceptual development
plan for the entire tidal plant/storage system/vehicular crossing
facility.
2.10 -Recommendations
It is recommended that:
(i) Information developed in this preliminary assessment be made avail-
ab 1 e for use in the ongoing study of Rai 1 belt Energy Alternatives,
(ii) A public meeting be conducted to inform the public of the results of
this preliminary assessment as well as to solicit comments and
recommendations for consideration in further tidal power investig-
ations, and
(iii) Phases II and III be undertaken as soon as practicable and that they
be carried out concurrently so that the tidal power alternative can
be properly assessed before the ongoing Railbelt Alternative Energy
Study is completed.
-17-
SECTION 3 -METHODOLOGY
3.1 -Introduction
The overall approach to the scope of ~rk set forth in the original terms
of reference (paragraph 1.6) involved the completion of four major tasks:
Task 1 -Preliminary Field Reconnaissance
Task 2 -Comparative Evaluation
Task 3 -Reports
Task 4 -Project Control and Administration
Each task was divided into a set of subtasks and, in one case, further
subdivided into individual ~rk packages. Figure 3-1 is a logic diagram
illustrating the sequence in \'klich certain subtasks \Ere undertaken.
3.2 -Task 1 -Preliminary Field Reconnaissance
The primary purpose of Task 1 was to identify three schemes for tidal power
plant configurations at specific sites so that succeeding, more detailed
evaluations could be focused upon actual local conditions. More \Eight was
given to identifying good representative sites with distinct differences
from one to another than to attempting to find the best possible site in
the Cook Inlet area. Indeed, the latter optimization process can only be
reasonably undertaken after a rigorous data collection program is conducted
to determine precise values for certain parameters \'ilich \Ere extrapolated
or based on professional judgement in the preliminary assessment stage.*
* The distinction between representative sites at the preliminary assess-
ment stage and optimum sites determined during a major feasibility study
is illustrated in the history of the Susitna Hydroelectric Project.
Early studies by the U.S. Bureau of Reclanation, Kaiser Engineering
Company, and the U.S. Army Corps of Engineers each settled upon dif-
ferent dam heights and locations. In spite of these marked differences,
all of the initial assessments \Ere sufficient to suggest that hydro-
electric develoJ:Xllent of the Susitna was probably technically, econo-
mically and environmentally justifiable.
-18-
I .......
\.0
I
DATA
COLLECTION ~
LOI
INITIAL
SCREENING ~
1.02
t
"ELO ~ RECON
1.05
t
VISUAL
RECONNAISSANCE
REPORT
.....
POWER
PLANT
CONFIGURATION
1.04
t
SITE RE8ULATORY
SELECTION EVALUATION
1.08 2.01
t ~
TASK I
REPORT
~ IW
SELECT TECHNICAL
PARAMETERS r----EVALUATION
2.01 2.02
ENVIRONMENTAL
ASSESSMENT
2.04
SYSTEM ... AND ~
ECONOMICS
2.01
+
COST
~ AND .._..
SCHEDULES
2.()5
f
--SOCIOECONOMIC
ASSESSMENT
1.08
'
FINAL
REPORT
~-
MARICETIN8
AND r---,
FINANCING
2.08
'
RISK PHASE
ASSESSMENT ..... n ANOM
PLAN
ILO. 2.10
'
r ~
FIGURE 3-1
LOGIC DIAGRAM, [iJ
STUDY METHODOLOGY Ill
(i) Subtask 1.01 -Data Collection
A major data collection effort marked the start of the assessment
process. The quantity and quality of information available to the
study team was surprisingly good, particularly in terms of the many
published references on existing and potential tidal power
developments. Less satisfactory, though not unexpected, was the
relative dearth of site specific data. Major uncertainties in
geotechnical information, oceanography, and the like were evident,
although several studies of Turnagain and Knik Arm crossings did
provide a basis upon which professional judgement and extrapolation
could be used to define probable values for parameters later needed
in the technical evaluation process.
(ii) Subtask 1.02-Initial Screening
Possible tidal power sites were located on a map of Cook Inlet and
initial parametric comparisons were made to determine relative
rankings in terms of theoretical energy production capabilities and
costs. Selection criteria were_ established and an initial list of
sixteen sites was reduced to seven. Particular cognizance was taken
of sites which had been considered in earlier reports on tidal power
potential in Cook Inlet.
(iii) Subtask 1.03-Field Reconnaissance
Each of the seven best sites remaining (after the initial screening
process) was visited and a visual examination of conditions was
made. Photographs were taken and a brief report was prepared on
each site (See Appendix 2).
(iv) Subtask 1.04 -Power Plant Configuration and Operation
A review of alternative concepts (including, for example, multiple
tidal basins, double effect operation) was made and an initial
estimate of the extent to which a barrage might itself affect tidal
ranges was formulated. Preliminary conceptual configurations were
considered at each of the seven sites and selection criteria were
further evaluated for each.
(v) Subtask 1.05 -Site Selection
Based upon the selection criteria which had been established in
Subtask 1.02, three sites were selected in this subtask for more
detailed evaluation in Task 2.
3.3 -Task 2 -Comparative Evaluation
The primary purpose of Task 2 was to evaluate each of the three earlier
selected sites in sufficient detail to determine characteristics, likely
costs and schedules, and constraints which might be associated with each.
-20-
htlereas much has been written about tidal power in general and \'klereas
exhaustive earlier studies of major tidal projects in the Bay of Fundy were
particularly useful, it is nonetheless true that certain trlique aspects in
Cook Inlet had to be specifically accounted for.
(i) Subtask 2.01 -Select Parameters
As the basis for preparing conceptual tidal plant 1 ayouts and
evaluating them, it was necessary to establish certain parameters.
Thus, for example, values had to be selected for design waves,
crest el ev at ions, found at ion conditions, tidal currents and the
like. To the extent that precise data had not been physically
measured, extrapolations were made from data \'klich did exist and
professional judgement was applied. Note was taken of uncertain-
ties at this point, for a later risk assessment and cost estimate
had to allow for the possibility that actual parameters to be
determined from instrumentation and dri 11 ing programs wi 11 vary
from assumed values.
(ii) Subtask 2.02 -Technical Evaluation
A major share of the project man-hours was devoted to completion of
this subtask. Because of its size, it was further subdivided into
work packages:
(a) Determination of Turbine-Generator Capacity and Energy Output
Although it had originally been planned to extrapolate results
of the 1976 -1977 Bay of Fundy studies to the tidal levels
and characteristics of Cook Inlet, simple extrapolation was
found to be less than satisfactory. Pacific tides evince
different characteristics than Atlantic tides. Thus, a spe-
cial computer program was modified to specifically model Cook
Inlet tides, basin levels, and energy outputs. Preliminary
cost estimates were prepared to permit initial optimization of
the number of sluiceways and turbines at each of the sites.
(This site optimization process is an iterative one. See hbrk
Package (i) below.)
(b) -Turbine-Generator Equipment Design
Contacts \\ere made with potential suppliers of equipment so
that it was possible to develop realistic values for operating
characteristics and costs in succeeding a1al yses.
(c) Sluiceway Design
(d) Closure of the Tidal Basin
A second computer program was developed to determine closure
velocities which increase during construction as the open
water gap narrows.
(e) Dike Design
-21-
(f) Construction Methods
(g) Electrical Equipment
As for turbine-generator equipment investigations, manufac-
turers provided useful data on electrical equipment character-
istics and costs.
(h) Preparation of Layout Configurations
(i) Optimization Procedure
It was noted in \\Ork package (a) that an initial optimization
of numbers of turbines and sluiceways was made based on very
preliminary cost estimates. As better cost estimates evolved
during the conduct of Subtask 2.03, further optimization runs
were made in order to produce the apparent best facility (from
an economic standpoint). Optimization was based only on the
1 east cost of raw energy without ret iming.
(iii) Subtask 2.03 -Cost Estimates and Schedules
Based upon 1 ayouts for the three selected sites and upon studies of
civil, mechanical and electrical features, cost estimates \\ere for-
mulated. Account was taken of unique construction costs and con-
straints in Alaska. Actual operating experience at La Rance and
the extensive Bay of Fundy studies and cost estimates were
reviewed. Percentages applied to account for engineering, manage-
ment, owner's costs and contingencies are generally consistent with
those used in the ongoing Susitna study.
(iv) Subtask 2.04-Preliminary Environmental Assessment
The literature was reviewed to identify probable environmental
impacts associated with construction at each site. This informa-
tion also was used to develop an initial overview of the nature of
extensive environmental data collection efforts Which will be
necessary if a major feasibility study is later conducted.
(v) Subtask 2.05 -Socioeconomic Assessment
An identification, on a regional basis, of the significant socio-
economic issues related to tidal power development was made in this
subtask. Account was also taken of the possibility that a tidal
power develoJlllent could provide causeway access across Turnagain or
Kni k Arms.
(vi) Subtask 2.06-Regulatory Evaluation
Federal, state and local institutional considerations--including
1 icensi ng, 1 eg al and regulatory requirements--were reviewed. Work
accompli shed on this subtask also provided useful information inso-
far as determining the expected duration of essential activities
which must be successfully accomplished before construction can
commence.
-22-
(vii) Subtask 2.07-System Study and Economic Evaluation
A review of the nature of the Railbelt System and the probable
energy and load demands at the time that tidal power might come on
1 ine was conducted. Estimates were made of the amount of tidal
energy which might be absorbed by the then extant system. "Excess"
energy quantities were estimated as the basis for determining the
extent to which energy storage may be necessary.
An examination of energy storage possibilities was made as the
basis for evaluating the approximate costs of converting "excess"
energy to a form more readily acceptable to utilities or to indus-
try. A preliminary economic assessment of the selected facilities
followed.
(viii) Subtask 2.08 -Marketing and Financing
A summary of marketing and financing constraints was prepared in
this subtask.
(ix) Subtask 2.09-Preliminary Risk Assessment
Major uncertainties associated with tidal power development in Cook
Inlet were identified and consequences were assessed. Of parti-
cular note here is that some of the "risks" carried at the prelimi-
nary assessment stage can be reduced or eliminated during later
feasibility studies where more precise data are collected.
(x) Subtask 2.10-Preparation of Phase II, III Plans
A preliminary statement of work was drawn up for activities which
should be accomplished to conduct a study of industry which might
use tidal energy (Phase II) and to carry forward engineering and
environmental studies into a more detailed conceptual development
plan (Phase III).
-23-
SECTION 4 -SITE SELECTION
4.1 -Introduction and Purpose
Cook Inlet is a major tidal estuary. With width as great as 80 miles and
length in excess of 180 miles, literally hundreds of potential tidal power
sites and a variety of types of development could be located within it. It
follows that a rational process for identifying and screening candidate
sites and types of development was essential before selection and technical
evaluation of particularly good representative sites was possible. The
identification and screening exercise is described in detail in Appendix I.
This section summarizes the selection process.
4.2 -Existing Conditions
4.2.1 -Physical Setting
Cook Inlet lies in a large structural depression between the Alaska
Range to the west and the Kenai and Chugach Ranges to the east.
Tertiary sedimentary formations were the foundation for later glacial
activity which at one time occupied its entire length, developing the
broad trough-like characteristic of the basin. The many glacial fed
tributary waters have carried enormous quantities of sediment into
the Inlet, forming mud flats exposed at low tides especially in the
Knik and Turnagain Arms and the Susitna River Delta.
Human activities in Cook Inlet are relatively extensive in comparison
to other parts of the State. The predominant activities that share
the Inlet waters include a broad based fishing industry, increasing
exploration of energy and mineral resources, as well as cargo and
passenger traffic to and from the ports of Anchorage, Kenai, Homer,
and Seldovia.
The tides in Cook Inlet are significantly higher than those prevail-
ing in the nearby open ocean. For example, the mean tidal ranges
recorded in the National Ocean Survey tide tables vary from 6.6 feet
at Kodiak Harbor to 11.4 feet at the Barren Islands up to 26.1 feet
at Anchorage. Because the gross potential energy available at a
given tidal power site varies directly as the square of the tidal
range, the upper portion of Cook Inlet is particularly attractive for
consideration of tidal power development.
4.2.2 -The Railbelt Electrical System
The electrical system which could benefit from tidal energy lies
within the Railbelt and includes the urban areas of Fairbanks,
-24-
Anchorage, Homer, Seward and a nlJTlber of other smaller c011111unities.
Projections of electrical energy demand in the Railbelt ~re recently
made by the Institute for Social and Economic Research (ISER),
University of Alaska. Figure 4-1 illustrates the mid-range (most
1 i kel y) and high forecasts through 2010 as derived from the ISER
forecasts.
Planning for potential Cook Inlet tidal power plants considers two
cases: (1) A constrained case, consistent with the most likely
forecast, and (2) An unconstrained case, resulting from encourage-
ment of industrial growth if the State of Alaska chose to (Kjopt such
a pol icy and if tidal energy were found to be sufficiently economic
to attract energy-consumptive industry. Since it is unlikely that
tidal power could be brought on line much before 1995 to 2000, the
10-year increase in average annual energy demand of 2500 GWh* between
2000 and 2010 in the most likely forecast was selected as an indi-
cator of the required energy production capabi 1 ity for plants to be
considered in the constrained case. By the same reasoning, the high
forecast (which itself assumes increased industrial development)
would range between 4000 GWh to 15,000 GWh in 2010 for the uncon-
strained case. The most attractive tidal power development v.ould be
one that developed either continuous power or sufficient dependable
peak energy production to contribute capacity to the power system as
we 11 as energy.
4.3 -Concept Selection
In the simplest concept for tidal power development, water flows from a
high pool through a hydraulic turbine to a low pool as illustrated earlier
in Figure 1-1. Three basic components are necessary: (1) Powerhouses
equipped with turbines and generators, (2) Sluiceways to permit rapid
filling of a basin, and (3) A barrage (or dike) to contain water within the
basin. A plot of typical variations in basin and sea levels and corres-
ponding energy production is provided as Figure 4-2. This basic scheme is
referred to as 11 Single basin, single effect, ebb tide operation ... As noted,
the production from such a scheme is in pulses of energy in phase with the
moon rather than the sun. This means the energy is out of phase with
normal human activity .. It also means that continuous power is not avail-
able without retiming the energy.
Double effect (operation on both ebb and flow tides) is possible if revers-
ible turbines are used. Multiple basins linked hydraulically or electri-
cally--or even operated independently on ebb and flow tidal cycles--are
possible. The primary advantage of the more complex schemes is that energy
generation can be made to occur for longer periods or continuously and
* A range between 1000 and 4000 GWh bracketing this amount was selected
for identifying constrained case candidates.
-25-
16000 ----
1&000
14000
13000
RANGE FOR
UNCONSTRAINED
12000 CASE IS
4000 TO
15000 GWh
11000
10000
.c 9000 ---~ -r--(!)
RANGE FOR 0 J.... GROWTH UNCONSTRAINED z 8000 "' 2000 TO 2010 c( CASE IS ~ J IS I"W 2500 GWh 1000 TO L&J ~ _l __ 4000 GWh 0 7000 4..0 > (!) ~ 0::
L&J 6000 ~ z
L&J
&000
4000
3000
2000
1000
IHO 1890 2000 2010
NOTE: BASED UPON ISER FORECASTS
FIGURE 4-1
SELECTED DEMAND FORECASTS
-26-
t
WATER
SURFACE
ELEVATION
t
ENERGY
Gwh
FILLING
MAXIMUM HEAD
DURING THIS
8ENERATIN8
CYCLE
TURBINING
TIME ...
TIME ~
FIGURE 4-2
WATER LEVELS AND
ENERGY PRODUCTION
DURING A TYPICAL
CYCLE.
-27-
J~llll', .,
li1
some dependab 1 e peaking capacity can be achieved. Q, the other hand,
significant cost penalties have to be paid without greatly changing total
energy generated.
For purposes of the preliminary assessment, it was reasoned that a single
basin, single effect concept providing raw tidal energy at a minimum cost
would provide the best basis for determining if such energy can be produced
economically.
4.4 -Site Selection
4.4.1 -Selection Criteria
Based upon reviews of earlier studies and the physical nature of Cook
Inlet, sixteen potential tidal power sites ~re initially selected as
indicated on Figure 4-3. A set of selection criteria was devised as
the basis for comparing one site with another. The criteria, togeth-
er with brief descriptions of how they ~re applied, are as follows:
(i) Relative Cost
It is, of course, not possible to produce reasonable cost
estimates at any particular site unti 1 site-specific con-
figurations are first developed. Even so, relative costs
(which suggest the probable order in ~ich potential sites
can be cost-ranked) can be evaluated. Pil appropriate para-
meter for this purpose is the ratio of annual energy produced
to a value ~ich is proportional to the volume of a potential
tidal barrier. Approximate annual energy was estimated based
on gross energy potential calculated with Bernshtein' s
Formula* using factors from previous studies to predict
optimum net annual energy production and installed
capacities.
Since actual costs tend to depend heavily upon the total
volume of materials placed, the ratio of energy to approxi-
mate volume is in effect providing a measure of the kilowatt
hours per dollar on a relative basis. High values, of
course, indicate economically favored sites. Table 4.1
provides parametric values for each site under the heading
II AE/LH2. II
It will be seen from this tabulation that the three sites
ultimately selected (Numbers 12, 14, 15) had high values for
the cost parameter.
* Gross Potential Energy-0.475 AR2 X 106 kWh/year ~ere
A = Area of the basin at mean tide range in square miles
R = Mean tidal range in feet
(Reference Source 0.2--See Appendix I)
-28-
I
N
1.0
I
61
154. 153.
DRIFT
152.
I._
~
~ ' & cJ
brf'
·~··
6
NINILCHIK
0~
0 10 20 30
SITE LIST
I . PORT GRAHAM
2. KACHEMAK BAY (I)
3. KACHEMAK BAY (2)
4. ILIAMNA lAY
~ . CHINITNA BAY
6. TUXEONI BAY
7. ANCHOR PT
8. FORELAND EAST/WEST
9. FORELAND NORTH
10. FIRE ISLANO/KNIK
II . FIRE ISLAND/ TURNAGAIN
12 . POINT MACKENZIE
13. CAIRN POINT
14. EAGLE BAY
I~ RAINBOW
16. SUNRISE
OFFICE OF THE GOVERNOR
~~~(I~ STATE OF ALASKA :=J
MIU COOK INLET TIDAL POWER
CANDIDATE SITES
FIGURE 4-3
ACRES AMERICAN INCOfiPOilATED
(ii) Closure Criteria
Even under natural conditions, tidal velocities are highest
in locations \\tlere the width of the Inlet is narrow. When a
tidal power facility is constructed by floating in
prefabricated units or by construction behind cofferdams, the
remaining open water at any particular site is gradually
reduced and maximum tidal velocities at the partially
completed faci 1 ity increase correspondingly. Because there
is a limiting velocity beyond \tklich marine equipment cannot
be operated safely, closure criteria may force a decision to
develop less than the theoretical optimum capacity at a
particular site. Indeed, as will be seen in later sections
of this report, one of the sites selected for ITDre detailed
technical evaluation in Task 2 was found to be constrained in
this way.
The relative degree to which closure limitations may apply is
found by evaluating the ratio between the length required to
accommodate powerhouses and the total length of the gap.
Extremely high values are undesirable since major closure
problems are then likely. Very low values are also not
favored since they indicate that major investments in dike
construction will have to be made to achieve relatively small
energy production.
Table 4.1 provides values for the closure parameter (LP/L)
for each site. Of the three sites ultimately selected, the
one with the highest closure parameter (Site 12) actually was
constrained by closure problems in the technical evaluation.
It is important to understand that the closure velocity
problem applies primarily to the floated-in construction
technique. An alternative construction approach wherein
units are built in place behind protective cofferdams is
possible. Based on earlier studies in the Bay of Fundy and
the particular nature of bottom conditions assumed in Cook
Inlet, floated-in units were considered to be the least-cost
approach.
(iii) Causeway Potential
Anchorage is by far the most heavily populated city in
Alaska. Land available for commercial and residential
development is presently limited. A tidal power faci 1 ity
astride Knik Arm could also serve as a causeway and would
make valuable lands more accessible west of Anchorage. Also,
it could slightly reduce the driving distance between
Anchorage and points north.
Causeway access to the Kenai peninsula would significantly
reduce the driving distance to populated areas and
recreational attractions southwest of Anchorage.
-30-
Thus it was reasoned that, where potential tidal power sites
could also serve as a causeway, such sites could be more
economically attractive. That is to say that some of the
high capital investment required to develop a site can be
partially offset by the value of a causeway.
( i v) Access
If access to any particular site was found to be relatively
easy, such a site was favored. Not only is the development
of access routes to a remote site costly, but also such
development inevitably leads to environmental impacts which
could be significant in some cases.
(v) Environmental Issues
Whereas a more detailed environmental assessment was prepared
later for selected sites, an attempt was made in the initial
screening process to identify major sensitivities which might
limit developments. In this regard, for example:
t Sites through which major anadromous fish runs must pass
were regarded as environmentally more sensitive.
• Sites at the 1 ower end of Cook In 1 et tended to be in
areas of higher biological productivity than those in the
silt-laden waters in the upper Inlet. Thus, Knik Arm and
Turnagain Arm were considered less environmentally sensi-
tive on this point.
• Where tidal power development had the potential of
producing major changes in known wildfowl resting areas
or habitat, such sites were considered more sensitive.
• Highly productive areas such as Kachemak Bay were
regarded as particularly sensitive.
(vi) Probable Foundations
Only limited data are available on foundation conditions
under Cook Inlet. Even so, a combination of this information
and professional judgement led to preliminary conclusions as
to probable preferred locations for facility construction.
(vii) Navigation Issues
Sites lying astride major ocean shipping channels or heavily
used routes for commercial and private vessels will require
navigation locks and could lead to some shipping delays. On
the other hand, average basin levels above tidal barrages
would remain higher than under natural conditions and could
facilitate movement of deep draft vessels. Navigation issues
were not regarded as limiting tidal power development, but
the need for lockage represented an increase in relative
costs.
-31-
{viii) Transmission Tie
Sites which required lengthy transmission lines and/or long
undersea cables were regarded as less favorable than those
situated near existing transmission corridors.
(ix) Energy Ranges for Constrained and Unconstrained Cases
Section 4.2 noted energy ranges which had been selected as
appropriate for constrained and unconstrained cases. Sites
whose apparent energy potential was within the selected
ranges were favored. Multiple small sites were also consid-
ered to be possible solutions to the unconstrained case,
although very low values for the cost· parameter (see Table
4.1) ultimately ruled them out. Table 4.1 provides initial
estimates of net energy for each site.
(x) Seismicity
Seismic risk is associated with all potential sites. Even
so, those lying near known major faults were considered least
desirable.
Figure 4-4 provides a summary of selection criteria evaluations.
More detail is presented in Appendix 1.
4.4.2 -Selected Sites
In addition to the criteria described above, consideration was also
given to the fact that the value of a preliminary assessment would be
enhanced if each of the three sites to be selected evinced a reason-
able degree of difference from another. In this regard, for example,
both the Rainbow and Sunrise sites in Turnagain Arm fared well in
terms of the criteria. Only one was selected, however, because the
location and characteristics of each are similar.
The three sites selected for further analysis (see Figure 4-3 for
location) are:
(i) For the constrained case,
• Rainbow (Site 15) on Turnagain Arm
• Above Eagle Bay/Goose Bay {Site 14) on the Knik Arm
(ii) For the unconstrained case,
• Point MacKenzie -Point Woronzof (Site 12) on the Knik
Arm.
-32-
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Site --
Port Graham
Kachemak Bay (1)
Kachemak Bay (2)
Iliamna Bay
Chinitna Bay
Tuxedni Bay/Snug
Harbor
Anchor Point
Foreland East/West
North Forelands
Knik/Fire Island
TABLE 4-1
SELECTED PARAMETERS
Initial
Tidal Estimate of
Range Net Energy
(ft) (kWh x 10 6 )
14.4 117
15.5 3,730
15.5 2,230
12.3 120
13.0 408
13.2 484
14.5 63,700
17.5 39,500
19.0 32,800
24.4 7,400
Turnagain/Fire Island 25.0 16,600
Point MacKenzie 25.7 6,000
Cairn Point 26.3 5,500
Above Eagle Bay/
Goose Bay 27.6 3,500
Rainbow 2 7. 5 3,000
Sunrise 30.3 1,900
* See Paragraph 4.4.1 (i) for explanation
** See Paragraph 4.4.1 (ii) for explanation
-33-
Cost
Parameter L /L ** p B
AE*
IH2 Closure
(kWh/ft 3) Parameter
0.98 .04
0.39 .16
0.53 .16
4.3 0.17
5.4 0.17
0.64 0.08
3.3 >1
11.2 >1
11.5 .74
15.7 .31
13.0 .57
27.4 .53
14.5 .82
46.1 .21
29.1 .13
28.7 .11
I w
~
I
RELATIVE COST
CLOSURE CRITERIA
CAUSEWAY POTENTIAL
ACCESS
ENVIRONMENTAL ISSUES
PROBABLE FOUNDATIONS
NAVIGATION ISSUES
TRANSMISSION TIE
ENERGY (CONSTRAINED)
1soo -4ooo a
ENERGY (UNCONSTRAINED)
40oo-8ooo a
SEISMICITY
LEGEND:
• MAJOR CONSTRAINTS
WI MINOR CONSTRAINTS
0 FAVORABLE CONDITIONS
2 3 4 5 8 7 8 8 10 II 12 13 14 1!5 18
H ~ ..,: z ~ 0
~ ~ Q. 0 0 c c c z z ~ J! J! ~ z z AI: c c:z: 0 Ill Ill ... 0 _, .... ... ... :z: :z: :z: J! .., :z: .... z ..,AI: A::C u u c % )( u c, co OA:: c c _, :I z f.., ~z Q.C!) ~ ~ u ... c
• • • • • • • WI WI
• 0 0 • • • • • (;I
• • • • • • • • •
t;i 0 0 • • • 0 0 0
tiJ • • ~ tiJ • • • •
0 0 • tiJ tiJ [i • til •
" ~ ~ " 0 ~ • • •
~ 0 0 • • • tJ ~ 0
•• • • I 0 0 • • • I • • tiJ ~ • • • • • 0
• til ~ • • • [;I til til
*MULTIPLE SMALL SITES COULD
MEET UNCONSTRAINED CASE LIMITS.
c _,
!!
~~~~ c--Z II.~
~
0
0
til
~
• •
0
• •
~
z .c (I)(!) -c
wz cAl:
-:I ~~... ...
~
~
~
0
IJ
•
0
0
• •
til
L__ ____
Ill ,.: ~
!i'! Q. Ill • ..,
0 ., .., z Ill ~ _, Ill i: 1111: z ,.:~ c (!) c z c :I IL.J! u Ill & .,
0 1;1 Cl 0 0
~ • 0 0 D
0 [] ~ ~ ~
0 0 0 0 0
(;I IJ 0 0 0
IJ D (J ~ IJ
• 0 0 0 0
D D 0 0 0
• I 0 D 0
0 D tiJ [;I •
tiil· [;il tJ [;i ~
~--
FIGURE 4-4
SUMMARY OF
SELECTION CRITERIA
EVALUATIONS (ii
SECTION 5 -TECHNICAL EVALUATION
5.1 -Parameter Selection
As the basis for detailed energy evaluation and conceptual design of a
tidal power facility, site specific physical parameters must be identified
and quantified wherever possible. It is important to know, for example,
what sort of waves must be withstood under the most extreme conditions.
But wave heights and frequencies depend in turn upon expected wind speeds
and directions, fetch (the length of open water over which winds will blow)
and the bathymetry near the site.
A number of important components is associated with a tidal power plant.
The parameter selection effort considered unique characteristics of each.
Particular components include:
(i) Powerhouses and Turbine Generators
Development of any one of the selected sites will require the
installation of thirty or more large turbine-generator units.
Powerhouse modules or caissons, each containing two turbine-
generators, were considered appropriate for application in Cook
Inlet.
( i i) S 1 uiceways
After any single generating cycle, it is necessary to fill the basin
rapidly so that sufficient head is available for the next generating
cycle. Sluiceways permit rapid filling. The small amount of
reverse flow through the turbines is relatively inconsequential.
Sluiceways consisting of large water passages which can be opened or
closed as necessary are contained in modules. These modules accom-
modate two s 1 ui ceways each and their exterior dimensions are such
that they match with powerhouse modules to form a regular and
functional structure.
(iii) Access Dikes
In cases where tidal current velocities are not likely to exceed
safe limits for'floating in modules, an access dike is constructed
from one abutment out to a point where sufficient depth and bearing
capacity will permit placement of the first module. As powerhouses
and sluiceways are successively placed, the access dike facilitates
movement of equipment and personne 1 across the partially completed
facility. Where high currents represent a constraint, a temporary
bridge may be used to gain access to the first caisson after it is
placed.
-35-
(iv) Closure Dike
After placement of the last module, the remaining gap in the barrage
is closed by a closure dike. Construction techniques similar to
those commonly used for breakwater construction are applicable.
Unlike a conventional dam, some leakage through the dike is toler-
able and the dike core is designed accordingly.
(v) Electrical Equipment and Controls
A system is necessary to take energy at the operating voltage from
the various generators to a point where it is then converted for
transmission to external points. A computer controlled supervisory
system for the whole tidal power plant will be required.
A description of selected parameters and the basis upon which they were
chosen is provided as Appendix 3.
5.2 -Turbine-Generator Equipment Design
Selection of the type of hydraulic turbine for any particular site depends
primarily upon the operating head at that site. For example, vertical
shaft turbines have generally proven cost-effective for conventional hydro-
electric power installations over a wide range of heads. In the particular
case of tidal power development, operating heads are low. In this case,
modern experience has shown that horizontal shaft units are most effective,
particularly when relatively long structures in the direction of flow are
otherwise required. For the foundation conditions in Cook Inlet, power-
house stability required that the total length of a powerhouse unit meas-
ured in the direction of flow be large, so that horizontal axis turbines
are attractive.
Three principal types of horizontal axial flow units are available and the
location and type of generator is decidedly different for each. Figure 5-l
provides a sketch of each type.
Up to the present time the most popular unit for large diameter low head
installations has been the bulb turbine. The generator is located within a
bulb shaped watertight enclosure upstream from the turbine runner. Large
bulb units are operating effectively in low head hydroelectric installa-
tions around the world.
A second type of horizontal unit involves a tube arrangement. In this
case, the genera tor is outside the water pass age and is connected to the
turbine by a long shaft. Tube units have not generally proven effective
for runner diameters as large as those which will be required in Cook
Inlet. Thus, tube units were not given further consideration in this
study.
A third arrangement is the Straflo in which the generator is mounted around
the outside of the turbine runner. The generator rotor rotates outside the
-36-
FLOW ...,
FLOW I.....,
FLOW ...,_
TURBINE
RUNNER
GENERATOR
TURBINE RUNNER
I. BULB UNIT
GENERATOR
2. TUBE UNIT
GENERATOR
3. STRAFLO UNIT
-37-
FIGURE 5-I
HORIZONTAL AXIAL
FLOW TURBINE TYPES [i]
water passage, but it is connected to the turbine runner in much the same
way that the rim of a wheel (the generator) is attached by spokes to the
hub (the turbine runner). Special seals are required to keep the generator
dry. In the absence of any other governing requirements, the length of the
water passage for a Straflo unit can be shorter than for a comparable bulb
unit. The first large Straflo unit (runner diameter 25 feet, rated at 17.8
MW at 18 feet net head) is now under construction for the tidal power
demonstration project at Annapolis on the Bay of Fundy.
Both bulb units and Straflo units are viable candidates for application in
Cook Inlet. For purposes of a preliminary assessment, energy calculations
and conceptual layouts have been based on bulb units in this study, primar-
ily because of the much greater experience data av.ailable for them. Large
fixed blade units with runner diameters on the order of 28 feet and capa-
cities ranging from 21 to 24 MW were considered. In the event that a later
detailed feasibility study is undertaken, both bulb and Straflo units
should be considered. Final selection will probably depend upon an econo-
mic analysis based on actual performance data.
Because of space limitations within the bulb, there are some constraints on
generator design. For heads greater than the rated head (i.e., for periods
when tidal heads are extreme) the continuous maximum rating (CMR) of the
generator limits the turbine power output. This limitation was accounted
for in the energy generation simulations (see paragraph 5.3 below).
A large number of powerhouse units is required at each of the three
selected sites. To minimize costs as well as to permit reliable operation,
turbine generator units would be connected into the electrical system in
blocks of four units each.
Appendix 4, Turbine Generator Equipment Design, and Appendix 5, Electrical
Equipment Design, provide further details.
5.3 -Tidal Power Plant Energy Study
5.3.1 -Base Case Analysis
It was noted in Section 4 that initial site screening efforts depend-
ed upon preliminary annual energy estimates related to volume of
barrier. In that assessment, mean tidal ranges were used. More
accurate ca 1 cu 1 at ions of energy production depend upon summation of
continuously varying energy production derived from operating heads
that change with both sea and basin levels, and upon specific opera-
ting characteristics of the turbine-generator equipment. As will be
seen from Figure 4-2, the operating head varies continuously during
any single generating cycle.
About 6 feet of head between basin and sea levels is required before
turbining commences.
-38-
A special computer model was developed to simulate the operation of
the tidal power plant for single basin, single effect schemes at
se 1 ected sites in Cook In 1 et. Without this mode 1, accurate repre-
sentations of the tidal levels would have been extremely difficult
and estimates of energy production would have suffered accordingly.
In this regard, it is worth noting that the shape of the tide curve
and other tidal characteristics for Cook Inlet are quite different
from those studied exhaustively for the Bay of Fundy and at La Rance.
Details of the simulation model and sample outputs are provided in
Appendix 6.
The objective of the model is to produce estimates of energy produc-
tion at a selected site for use in optimization studies. By estima-
ting the energy for several combinations of turbine numbers and
sluiceway capacities and applying costs, it is possible to select the
installation that produces the most economical energy at site. In
simple terms, it can be imagined that if only a small number of
turbines is used for one way, ebb-tide generation, only a small
amount of water is released from the basin and the basin water level
remains relatively high. As the number of turbines is increased,
more water is released and the basin level falls off more rapidly.
Figure 5-2 illustrates the point.
To ensure rapid filling of the basin as the tide rises, the sluices
must be opened. Some water will also pass through turbine water
passages in the filling process. Too few sluices will lead to a low
basin level at the start of the next generating cycle, resulting in a
loss in head and less energy. More sluices permit attaining higher
starting levels for generation, but each sluice represents a cost.
Too many sluices cause cost increases with little gain in energy
production.
A characteristic optimization curve is illustrated and annotated on
Figure 5-3.
Figure 5-4 is the actual optimization curve developed for the Eagle
Bay site. In this case, it was determined that the minimum cost of
unretimed energy corresponded to a facility containing 60 turbines
and 36 s 1 u ices. With this 1 eve 1 of deve 1 opment, 4037 GWh wou 1 d be
generated annually. The 11 cost of energy .. in mills per kWh recorded
on Figure 5-4 differs from energy costs used in the economic analysis
because interest during construction was not included in the optimi-
zation program.
Optimization is an iterative process. An initial rough estimate of
costs was necessary to find the preliminary optimum number of units.
Once more detailed cost estimates were prepared, a new energy value
was determined. This in turn led to further optimization of the
number of units. The process was repeated to obtain the curve of
Figure 5-4.
It is interesting to note that the at-site optimization curve tends
to be relatively flat across a broad range of possible energy
outputs. That is to say that variations of as much as 50 percent
-39-
FILLING GENERATING
t
WATER
LEVEL
NOTES:
TIME •
IF THE OPTIMUM NUMBER OF TURBINES CAUSES BASIN
LEVEL VARIATION (i), FEWER TURBINES PRODUCE BASIN
LEVEL @ 1 AND MORE TURBINES PRODUCE @.
SIMILARLY, IF THE OPTIMUM NUMBER OF SLUICES
CAUSES THE BASIN LEVEL TO RISE AS IN G),
FEWER SLUICES WILL CAUSE SLOWER FILLING @.
INCREASING NUMBE.J!.. OF SLUICES PRODUCES
FASTER FILLING (1).
-40-
FIGURE 5-2
EFFECT OF VARYING
NUMBERS OF
TURBINES AND
SLUICES.
t
COSTIN
MILLS
PER
KWh
INCREASING
NUMBER OF
TURBINES
NUMBER OF SLUICES
OPTIMUM NUMBER OF
TURBINES AND SLUICES
IS FOUND AT THIS POINT
ENERGY(GWh) ._
-41-
FIGURE 5-3
CHARACTERISTIC
OPTIMIZATION CURVE [i]
I
~
N
I
51 3' 50 ~"' 49 '"' -----:t: ' ~ 48 ~ X
...... ""' (I) 47 _,
"' _,
40/!4
~ 46 ...
·~ ~
: 45 II....
~ ~0 l&J z ~ TZ 36
""44 ~ ~ it"
&1.. ~ I()~ /IIJ/42-
0 43
.... 60/36
(I)
0 42
0
41
40
2200 2400 2600 2800 3000 3200 3400 !600 3800 4000 4200 4400
ANHUAL ENERGY GENERATED(GWH)
lilt
OFFICE OF THE GOVERNOR
STATE OF ALASkA
COOK INLET TIDAL POWER LEGEND I
I
60/36 TYPICALLY DENOTES EAGLE BAY
11 60 TURBINES I 36 SLUICES" PLANT OPTIMIZATION
*EXCLUDING INTEREST
DURING CONSTRUCTION FIGURE 5-4
'AC'REs AMERtCAN iNcoRPORATED
from optimum energy output may change energy values by only 20
percent or so. In the particular case of Eagle Bay, Figure 5-4 shows
that a 10 percent increase in annual energy is possible with an
increase in energy cost of only one mill/kWh. Thus, it is possible
that other factors may govern the final selection of plant capacity.
In the case of the Point MacKenzie site, closure velocity constraints
could require a reduction from an apparent optimum of 80 units to
only 60 units if the construction program were unable to accept the
restriction without cost penalty. Since this item was not investi-
gated in detail, the number of units was restricted to 60 to provide
a conservative estimate for the purposes of this preliminary study.
A plant which has been optimized to produce the least cost raw
(unretimed) energy is not necessarily the optimal plant for the Rail-
belt Electrical System. Of 2300 GWh produced by a 30-turbine instal-
lation at Eagle Bay (see Figure 5-4), about 1540 GWh* can be absorbed
without retiming in the Railbelt System. On the other hand, only
about 1600 GWh* of the 4037 GWh for a 60-turbine installation can be
absorbed without retiming. When energy costs are adjusted to account
for the addition of energy storage, the new mill rate for the smaller
30-turbine installation is actually less than that for the larger
60-turbine installation.
Tot a 1 system opt imi zat ion should be accomp 1 i shed during Phase I II
studies when site-specific retiming costs are known.
Table 5-1 provides information on selected numbers of units and
annual energies for each site. It will be seen from the tabulation
that while the preliminary estimates give a useful screening tool and
give the correct coarse ranking of sites, they are not accurate
enough for final concept evaluation. Variations of 10 percent to 20
percent occurred between the preliminary estimate and more precise
simulation values.
5.3.2 -Studies With Variable-Blade Turbine Characteristics
The power plant energy studies in the base case assumed that fixed
blade bulb turbines would be used. By varying the blade angle,
greater power and energy outputs can be achieved at low tides. A
limited number of simulations were performed for variable-blade
turbines. Tot a 1 annua 1 energy increases on the order of 5 to 10
percent were found to be possible with reductions in raw energy costs
of from 2.6 to 4.6 mills per kWh. It follows that equipment improve-
ments offer the potential for enhancing the economic attractiveness
of selected sites. After industrial needs for retiming are studied
in Phase II, further analysis of variable-blade units is warranted in
succeeding studies.
* See Appendix 10 for the basis upon which these values were
computed.
-43-
Rainbow
Eagle Bay
TABLE 5-1
ANNUAL ENERGY AND NUMBERS OF UNITS AT SELECTED SITES
(Based Upon At-site Optimization of Raw Energy Values)
Variation
Preliminary of
Computed Gross Computed
Annual Estimate Estimate
Number of Number of Energy of Annual From
Turbines Sluices {GWh) I. Energy (GWh) Preliminary
40 24 2664 3000 -12.6%
60 36 4037 3500 + 12.3%
Point MacKenzie 80* 60* 5000* 6000* -20.0%
* The installation at Point MacKenzie was reduced to 60 turbines as a
contingency in case higher closure velocities caused restriction in the
construction program leading to higher costs. With 60 turbines and 46
sluices, annual energy at Point MacKenzie is reduced to 3937 GWh.
-44-
5.4 -Closure of the Tidal Basin
Preliminary considerations favoring floated-in caissons indicate that for
the site conditions in Cook Inlet the most appropriate type of closure
structure is a dike constructed with a core of heavy rocks or blocks that
can resist closure velocities. It was noted in paragraph 5.3 above that
closure velocities impose some restrictions on construction operations at
sites where closure gap widths are relatively narrow. The magnitude of
tidal currents which must be dealt with is determined by such factors as
tide range, closure width, barrage height, basin storage area and the
number of operating sluices contained within the partially completed
structure.
A special computer model was developed to predict closure velocities. This
model was useful for several purposes:
(i) It permitted determination of velocities under varying conditions as
powerhouses and sluice units are floated into place; and
(ii) It provided information necessary for the size and type of materials
which must be placed in the dike closure operation.
A typical example of water surface levels and velocities at Point MacKenzie
appears as Figure 5-5. For the illustrated tidal range of 40 feet, place-
ment of floated-in caissons would not be possible since flow velocities
will exceed the limit of 13 feet per second which was set by construction
requirements. The next placement of a floated-in caisson would be delayed
in this case until four consecutive tidal ranges of 25 feet occurred.
Appendix 7 offers further details on closure calculations.
5.5 -Civil Design
5.5.1 -Concept
A tidal power installation can also accommodate a vehicle crossing
facility. Design approach depends upon whether or not land access is
of paramount importance.
Given that the primary objective of this study is to conduct a pre-
liminary assessment of Cook Inlet Tidal Power, the initial conceptual
design effort was oriented toward producing a facility whose sole
purpose is to generate electricity economically. Once that concep-
tual design had been completed, it was then possible to analyze those
particular modifications which would be necessary in order to accom-
modate traffic safely. Thus, both the engineering design efforts and
the cost and schedule work treat causeway potential as an increment
which could be added to a facility optimized for tidal power.
-45-
z
<[
Wl2
~
0
.... 8
liJ >
j4
l1J
0::
.... 0
l1J
l1J
lL
z-4
z
~-8 ....
<[ >
&a1
...J -12
l1J
0::
Ul_l6 .... • -16
2
0 116
POINT MACKENZIE TIDE RANGE = 40 FT
V3
TIME
I i-
V2
BARRAGE HEIGHT= 20 FT (MTL l
CLOSURE LENGTH = 5000 FT
EQUIVALENT NO Clf SLUICEWAYS =00
l
/i ----i---··--
;I
2/3 5/6
0
~
(.)
l1J
f/)
0::
Ul
Q..
e ....
tti
lL
4 z
>-....
(.)
0
...J
l1J >
N FRACTIONS OF A TIDE C'fCLE
iiJ OFFICE OF THE GOVERNOR
10 STATE OF ALASKA
1----------1
COOK INLET TIOAL POWER
TYPICAL EXAMPLE OF WATER
SURFACE a VELOCITIES THROUGH
A TIDE CYCLE DURING Q..OSURE
FIGURE 5-5
-46-
Civil desiqn focused upon key elements as follows:
(i) Powerhouse structure and layouts
(ii) Sluiceway design concept
(iii) Dike design (closure and access)
(iv) Development of site profiles including caisson positions.
There are two fundamental approaches to construction of a tidal power
facility: (1) Construction in place 11 in the dry11 oehind temporary
cofferdams, or (2) Prefabrication of modules away from the site and
construction 11 in the wet .. by floating these modules into position and
sinking them on prepared foundations. Each approach offers part i-
cular advantages and poses certain problems.
The use of temporary cofferdams is common in marine construction.
Because construction work-forces and equipment must work within an
area which has been pumped out and is protected from flooding by the
cofferdams, safety considerations are important. The La Rance tidal
power development employed dry construction techniques.
Floated-in caissons have also been successfully employed elsewhere.
A major extension of the harbor breakwater at Baie Comeau, Quebec,
adopted caisson construction in the 1960's. The Kislaya Guba experi-
mental tidal power development in Russia employed wet construction
techniques. The closure of tidal estuaries on the coast of the
Netherlands also employs this technique.
The choice between wet and dry construction is governed primarily by
economic considerations. The same final result is achieved with
either approach. To a great extent, cost differences between wet and
dry construction depend upon the particular nature of the bottom
conditions. As has been noted elsewhere, however, only limited
information was available for site-specific conditions in Cook
In 1 et.
Even so, the most likely bottom conditions at each of the selected
sites are such that wet construction would be the more economical
approach. In the event that future detailed field investigations
demonstrate that actual conditions favor dry construction, that
method can be adopted in the detailed feasibility study. In short,
for purposes of this preliminary assessment, wet construction was
chosen. If tidal energy is competitive under this selection and if
later data collection leads to a more economical approach, it follows
that tidal energy could become even more competitive.
By way of comparison, cost estimates prepared for both wet and dry
construction at preferred sites in the Bay of Fundy led to the
conclusion that dry construction would increase the costs of that
portion of the work by between 33 percent and 100 percent, depending
upon the site being considered.
-47-
Details of the civil design considerations are presented in
Appendix 8.
5.5.2 -Powerhouses and Sluiceways
A number of factors must be considered in selecting appropriate
dimensions for a powerhouse unit. A major consideration is, of
course, the need to fit in all of the necessary mechanical and elec-
trical equipment. For example, the minimum length of water passage
for selected bulb turbines must be accommodated. Calculations must
be made to ensure integrity of the structure against seepage, slid-
ing, overturning and settlement.
Assumed foundation conditions led to the conclusion that the maximum
length of the structure is governed by the required factor of safety
against sliding and overturning and the allowable bearing capacity of
the material upon which the plant is placed.
Other factors such as ice, wind, waves, salt water attack, tempera-
ture extremes, and expected seismic conditions were also considered.
A typical layout for the powerhouse is illustrated on Figure 5-6.
Site profiles, sluiceway layouts, and other technical drawings appear
in Appendix 8. Throughout the conceptual design process, account was
taken of constructability aspects. Only construction techniques and
equipment within the state of the art were considered.
5.5.3 -Dike Design
Dikes are necessary for both access and closure sections. Signifi-
cant design requirements in the dike sections are that they can be
constructed under the extreme tidal conditions in Cook Inlet and that
seepage through the section be controlled within limits imposed by
safety and the necessity to maintain basin levels higher than sea
level for periods of eight hours or so. A typical dike cross section
is illustrated in Figure 5-7.
During construction operations, the first sections placed will be the
sea side of the rockfill zone (appearing on Figure 5-7 as zone (4))
and portions of the transition zone (appearing as zone (2) in Figure
5-7). Consistent with techniques commonly found in construction of
conventional breakwaters, zone (4) materials will provide a measure
of protection as succeeding zones are placed. The material sizes
will include boulders up to 5 feet in diameter because of high tidal
velocities which will be encountered during closure operations.
Complete closure is achieved before additional transition zone mater-
ials are placed on the basin side of the rockfill slope.
It will be noted on Figure 5-7 that the access dike also accommodates
a tunnel for the electrical conductors (SF6 bus) which carry energy
from the generators to a switchyard.
-48-
I
~
1.0
I
A
:•; r:.ii.' t
MAlf f'!_!!L
"' ·-
'$'fWII]1~ lMIOu' ~
flOW -
...
L.....:J~-~~L.:.:.....J~~~~r::::;:::J
f a
---~~
--1
A
j
j
b
~
-......._CAl, ..... "" . .._ ..... ..
_fi.M_
'---{::~..:=--:-..
IJ'.g" H"·!:._
CI!IIT IL till TMLlt
~
;-""-
II __ ,....,___
n."llll ,...,,
~--+-·---!~ !!:.:£.!..~.
£J3""'"1'-'i..,--"-i"!'!_ ~-......{_,.~.,.~=-=~=~=~=-==~==:=:~=-=-=-=-:-==-::=:==;.J,.......,j
'--f'LL W.TII
U:MI~Tl
' •!•·-o• -----·----·-·-· ---
SECTION A-A '-~~~u
. "'"""
1oUC1 'LL-i
SECTION 1-1
·" 1•• ..... 1-. ..... 1 -·1 .... "'_,_, .... ....,, .. ... _ ..
• ta.•-IIT111111 .,_ .TU * , ... -,.,... .... •n•
..
• ..
NOTES
I AI..L IU~f"** aM lltfl .. IIClD TO Mtt•
nt:vATIDN o MID .utt • nn
2 .IIVtCI" a&Y WILL. ,_,.,1.0 AT l¥Eit'l
.... f'QW[ ....... l ... IT
POWERHOUSE STRUCTURE
F'IGUR! 5-6
I
()1
0
I
ij
s:!
' .. v
.... 10
tu
bJ 60 ....
! so
~ 40
I-
~ 30
ld
.;: 20
J 10
"' z 0
2
0
z -10
(j)
17)
()
<')
•
•
(l)
•
BASIN SIQE
MAX BASIN ---
LEGEND IIAX
SITE NAME BASil
CORE ZONE (SANO a IRMEU
TRANSITION ZON£ (CRUSHED ROCil
OR E~ENTI PT. MACKENZIE 18.1
ROC1( Fill ZONE (QUARRY RUN) EAGLE BAY ,._,
ROell Fill ZONE I BOULDERS UP TO
5-ft DIAMETER) RAINBOW 52.1
!ARMOR BEDDINI ZONE: BASIII SIDE
ARMOR ZONE: BASIN SIDE
ARMOR BEDDING ZONE: SEA SIDE '
' '
ARMOR ZONE: SEA SIDE
l OF DIKE AND ROAD
~EA ~IDE
Q)
FOUNDATION SURFACE
II IN ...... IILLW CREST EL OF CREST El. OF
IAIHI ClOSUfiE OIIC E ACCESS DICE
(FEET) (FEET)
18.5 28.8 0 45 sa
14.8 ao.a 0 45 150
12.8 H.1 0 49 a•
10 ....
tu
bJ 60 ....
50 ~
40 z
~
IIHHW I-
30 "' >
tu -20 J ..,
10 J
lll.LW "' z 0 2! ---0
-10 z
NOTES:
I.PROPOSED DtiCE SECTION ASSUMES A
COMPETENT FOUNDATION SURFACE
t.AN INVERTED F'll TER Will BE RE'
UNOER THf: ROCIC FILL TO CONTROL
....... Wlt(RE THE DIICE FOONOATION IS
COMPOSED OF FIN£ SEDIMENTS.
3.PLACEMENT OF THE BACKFILL WILL
BE BY THE VERTICAL CLOSURE
METHOD.
4. Pf'OPCJSf:D Sft BUS TUNNEL FROM
POWERHOUSE TO SWITCHYARO IN ACCESS
DIKE ONLY.
~ 0 ~ •
OFFICE OF THE CIOV!IItiOit
Ill STAT! 01' Al.... I
COOK IIIU T nDAl f'OWI:It
ACCESS/ CLOSURE DIKE
TYPICAL CROSS SECTION
II l:-------~=1 FIGURE 5-7 I I
5.5.4 -Bridge and Causeway Crossing
The tidal power facility can provide vehicular access across the
barrage if a bridge section is used over the powerhouses and sluice-
ways and if a roadway is built atop a widened and raised dike
section. As may be seen from the typical cross section of the dike
in Figure 5-7, only a 40-foot roadway is provided to serve operation
and maintenance needs for a tidal plant. If general public access is
to be allowed, the dike would be raised and the roadway would be
widened to permit 44-foot clearance for one lane of traffic in each
direction. Details of the bridge and causeway crossing are provided
as Figure 5-8.
It is clear that a combined tidal power facility/causeway could be
constructed for significantly less than two separate facilities. It
is also clear, however, that while a tidal power plant can accom-
modate vehicular traffic at a small cost increase, the addition of a
tidal power plant to an initial vehicular crossing offers less poten-
tial for cost savings unless provisions are made at the outset for a
future tidal power installation. Important scheduling impacts and
extreme financing problems apply in this latter case.
5.5.5 -Construction Methods
An overview
Appendix 9.
of applicable construction methods is provided
The general construction sequence is as follows:
(i) Construct the access dike and dry dock facilities.
as
The access dike for the Rainbow and Eagle Bay sites will be
constructed at the outset. Because of closure velocity limi-
tations, a temporary bridge will provide access to powerhouse
units at the Point MacKenzie site. Concrete crib structures
filled with rock retain the access dike at the point where the
first powerhouse caisson will be placed. Concurrent with
access dike construction is the construction of dry docks and
wharf facilities. It is from the dry docks that caissons will
be floated to the point where they are placed in the structure
or to a wharf for temporary storage when conditions do not
favor immediate placement.
(ii) Dredge a channel and prepare the foundation base.
Because of shallows near the shore at each of the three sites,
a channel must be dredged from the dry dock and wharf location
to deeper waters where caissons will be placed. Major dredg-
ing requirements also exist to ensure removal of unsuitable
materials.
(iii) Construct prefabricated powerhouse and sluiceway units and
float into position.
-51-
I
(J'1
N
I
CLOSURE DIKE
PLAN
IPPMJACM llAIIP
PROFILE
STIIUCT\IItfS
. l.A
--STRUCTURE
IIPPIIOM:M
IIAIIP
S!,.UICEWAY
OUTLINE
BRIDG£ E~ EASTRUCTURE
[)W
I
' I
I
I
I
I
I
I
/44'.0" Z-LAMt:, 2-DIIIf:CTIOMAL
I
SECTION A-A
tRD&OWlY
POWt:IIHOUSE
OUTLINE
r U'-0" CLIAit 4
,_CAST
'
111-0IICED COMCIIUI II(CII
T ...... ..._ ..
ITIIU<:TUIIE
BRIDGE SUPERSTRUCTURE
OFFICI IJI' TME 80IIEIIIICJII
5flnl OF ALAIIIA
CIOOK .LET TIDAL I'OW£11
BRIDGE AND CAUSE WAY
CROSSING
FIGURE 5-8
Special forms and a number of modern, time saving construction
methods (e.g., steam curing, quick stripping) permit fabrica-
tion of caissons under factory conditions using mass produc-
tion methods. As units are completed, the dry dock is flooded
and completed caissons are floated to the holding area at the
wharf or directly into place.
(iv) Complete construction of powerhouse and sluiceway units and
install equipment.
As may be seen from Figure 5-6, caissons are honeycombed with
individual cells to facilitate floatation. These interior
cells will be filled with lean concrete or sand when the unit
is moved into position. Sluiceways will be kept open as
construction proceeds to permit some reduction in high closure
velocities which wiJl otherwise be experienced. Staged devel-
opment at any of the three selected sites can be accommodated
by placing all powerhouse caissons initially, installing mech-
anical and electrical equipment only in an initial group of
powerhouses.
(v) Construct the closure dike.
Self-propelled bottom-dump vessels will place the rockfill
zone of the dike section in horizontal levels until insuffi-
cient draft for the vessel is reached. Succeeding layers will
be placed from a walking platform on which a large crane
operates. Final layers of the closure dike can be placed by
end dumping after the crest rises above expected high tide
levels. Transition zones, other materials on the basin side,
and armoring of slopes will be placed after complete closure
is achieved with the rockfill section.
-53-
SECTION 6 -COST ESTIMATES AND SCHEDULES
6.1 -Site-Specific Costs
Based upon analysis of comprehensive Bay of Fundy estimates, quantity
takeoffs from conceptual designs, and information obtained from major
manufacturers and dredging firms, base case cost estimates were developed
for each site. These estimates are suiTITlarized in Table 6-1 and are
presented in more detail in Appendix 9. All prices reflect cost levels as
of June 1981 and January 1982 in the Anchorage area.
Reasonably conservative judgements were made where· data gaps existed,
particularly with respect to geotechnical conditions at each site. In
1 ight of the fact that much more field data has been collected for the
Susitna Project than for Cook Inlet Tidal Power, a contingency allowance
was set at 25 percent of the total estimate (as compared to 20 percent for
Susitna). While the values presented in Table 6-1 are considered to be the
most likely costs for each site, deviations up to 25 percent in either
direction* are considered possible. A major feasibility study including a
detailed field investigation program would be necessary to improve
estimating precision.
6.2 -Schedules
Although partial operation of a tidal power plant may be possible even
while additional turbine generator equipment is being installed, the
earliest expected final completion dates for full development of optimized
plants are 1997 for Rainbow (928 MW), 2000 for Eagle Bay (1440 MW), and
2001 for Point MacKenzie (1260 MW). A significant portion of the schedule
in each case is devoted to satisfaction of regulatory requirements.
Indeed, it is not anticipated that a license will be awarded by the Federal
Energy Regulatory Commission (FERC) until late in 1989.
There is a possibility that staged development at any of the sites could
permit earlier dates for initial 11 power on line.11 Even so, operation
earlier than 1995 is not considered likely in any case.
* Potential cost savings relate to possible equi prnent improvements (see
paragraph 5.3.2); marine disposal of dredged materials in lieu of
containment (see paragraph 7.3); conservative assumptions as to
found at ion conditions (see Sect ion 11); useful ness of dredged materials
(see paragraph 7.3); and other considerations.
-54-
TABLE 6-1
SUMMARY COST ESTIMATES
(June 1981 Cost Levels,$ M1llion)
Rainbow Eagle Bay Point MacKenzie
Item {40 Turbines} (60 Turbines} {60 Turbines}
1. Lands 20 20 20
2. Site Preparation 18 32 29
3. Access Dike 10 17 123
4. Units
Powerhouses 1,016 1,470 1,480
Sluices 261 383 517
5. Sluice Extension, Fishways 25 25 25
6. Closure Dike 283 312 82
7. Transmission 120 120 101
8. Locks --- ---
191
9. Subtotal 1,753 2,379 2,568
10. Contractor Facilities 228 309 334
11. Total Direct Costs 1,981 2,688 2,902
12. Engineering, Management 248 336 363
Owner's Costs at 12.5%
13. Contingency at 25% 495 672 726 --
CAPITAL COST TOTAL, $2,724 $3,696 $3,991
JUNE 1981
CAPITAL COST TOTAL, $2,819 $3,825 $4,131
JANUARY 1982
CAPACITY (MW) 928 1,440 1,260
CAPITAL COST PER $2,935 $2,567 $3,167
INSTALLED KW, JUNE 1981
CAPITAL COST PER $3,037 $2,656 $3,279
INSTALLED KW, JANUARY 1982
-55-
SECTION 7 -PRELIMINARY ENVIRONMENTAL ASSESSMENT
7.1 -Introduction
Construction of a tidal power plant anywhere in Cook Inlet will inevitably
lead to change in the physical setting and will in turn impact environ-
mental resources there. A major environmental field data collection and
analysis program is necessary in order to define these impacts with reason-
able precision. Such a program should be included in a detailed feasibi-
lity study in the event that the State of Alaska later chooses to proceed
with tidal power development.
A preliminary environmental assessment was conducted.to
(i) Gain a macroscopic understanding of physical processes in Cook
Inlet;
(ii) Identify sensitive and important components of the natural environ-
ment;
(iii) Forecast the change in the natural environment which might result
from construction of a tidal plant; and
(iv) Identify requirements for further more detailed environmental
study.
The preliminary environmental assessment is presented in Appendix 10 to
this report.
7.2 -Unique Effects
Many of the effects of tidal power development are essentially the same as
those which would be experienced by construction of any major marine
project. Dredge and fill, access and traffic and disruptions during
construction all fall into this category. In addition, however, a tidal
power facility would produce unique and important changes stemming from the
nature of its operation.
Lands bordering the Inlet are alternately inunctated and exposed as the
tides rise and fall. Closest to the extreme low tide level are lands which
only occasionally are exposed and drained. By the same token, areas
extending away from the shores of the Inlet may be only rarely submerged
during periods of highest high tides. Operation of a tidal power plant
would permanently alter this natural condition because (1) the basin level
upstream of a tidal power barrage would normally not fall as low nor rise
as high as under natural conditions and (2) the average basin le~el wpuld
be maintained above mean tide level.
-56-
Hydraulic characteristics would also be altered. Currents, erosion proces-
ses, sedimentation deposition, ice formation and movement are examples.
Under ebb tide generation, mud flats bordering proposed basin areas could
diminish and marshland vegetation could encroach seaward. It follows that
habitat for waterfowl, shore birds and miscellaneous species will change.
Evaluation of expected change and determination of resulting beneficial or
deleterious impacts will depend upon rigorous field studies. Furthermore,
because of the complex nature of physical processes now occurring in Cook
Inlet, there is much to be said for developing a hydraulic and/or a mathe-
matical model in much the same way as has been accomplished elsewhere for
other important estuaries (e.g., the Chesapeake Bay, San Francisco Bay).
Consideration must be given in the design of tidal power plants to the need
for safe passage of migratory fish runs as well as for protection of marine
mammals which normally frequent areas selected for tidal power develop-
ment.
Table 7-1 summarizes the potential interaction between a tidal plant and
elements of the environment.
7.3-Short-Term and Local Effects
In addition to unique long-term impacts summarized in the preceding para-
graph, construction activities will introduce important short-term effects
which can be reduced by careful construction management.
Dredging, particularly at the Eagle Bay and Rainbow sites, will require the
removal of about 30 million cubic yards of sediments. It is not antici-
pated that most of this material will have any useful value as a construc-
tion material.* A major disposal effort is required. Although organic and
chemical pollutants are not likely to be present, studies will have to be
made of the effects of marine dumping on bottom organisms. Three disposal
methods were considered in this study: (1) marine dumping, (2) enclosed
landfill areas, and (3) use of suitable materials for construction. For
estimating purposes, a disposal area contained by dikes or cellular coffer-
dams was tentatively located near the dredging site.
Site development will 'require access from both land and sea for heavy
equipment. Careful selection of access routes will be necessary to avoid
sensitive areas.
* The assumption as to lack of value is taken in the interest of conser-
vatism. It is worth noting that when the U.S. Army Corps of Engineers
dredged a shoal southwest of Anchorage in Cook Inlet in 1976, surpris-
ingly large quantities of cobbles and clean, well-graded granular
materials were found.
-57-
Good environmental practices during construction should include noise
reduction measures, erosion control, proper disposal of wastes and lands-
caping of borrow and quarry areas.
7.4-Environmental Constraints
No environmental impacts have been identified which would be so severe as
to preclude development of tidal power at Eagle Bay, Point MacKenzie, or
Rainbow. On the other hand, it would be premature to assert that tidal
power development wi 11 be environmentally acceptable. Detailed environ-
mental studies in parallel with technical feasibility studies are consider-
ed necessary and appropriate before a decision is made to construct a tidal
power facility in Cook Inlet.
-58-
TABLE 7-1 -POTENTIAL INTERACTION BETWEEN THE TIDAL PLANT
AND ELEMENTS OF THE ENVIRONMENT
TIDAL PLANT FACILITIES
AND CONSTRUCTION
ACTIVITIES
CONSTRUCTION ACTIVITIES
SITE DEVELOPMENT-LAND BASED
CLEARING, 5RADING, SURFACE EXCAVATION,
etJILDING STRUCTURES, MATERIAL STORAGE
ROAD, RAIL SPUR CONSTRUCTION
EXCAVATION f'OR AIUTTMEIITI
MATERIAL I'LACEMENT
OPERATE LAND lASED MARINE EQUIPMENT
WORICER FACILITIU AND USE
SITE DEVELOPMENT-MARINE
PILE DRIVIIIIG
INTERTIDAL COIIISTRUCTIOIII ZONE
DltEDGIIIIG
MATTitESI/OikE I'LACEMENT
TUG AND lARGE OPERATION
CAISSON STORAGE AND TRANSPORT
CAISSON INSTALLATION
STATIOHAitY MAitiNf: EOUIPMENf
MECHANICAL I ELECTitiCAL EOUIPMENT
INSTALLATION
SITE ACCESSIBILITY
ltOAD,RAIL TRANIPOitT OF PERSONNEL,
MATERLALSLQit EQUIPMIUIT
MARINE TRANSI"'RT OF PERSONNEl, MATERIALS. OR EQUIPMENT
REMOTE CONSTRUCTION FACILITIES
CONSTRUCTION MATEit IAL SOURCE AREAS
DREDGE DISPOSAL -Sifts--uJI(ANO
OREDGE DISI"'SAL SITES • MARINE
OPERATION OF ftERMANENT FACILITIES
ACCESS AND CLOSURE DIKE !I'RUENCll
PHYSICAL ESTUARY IARRII!It
POWERHOUSE AND SLUICEWAY !PRI!IENCII
TURBIN£ Ol'lltATION
ILUICEW4Y OI'IR4TION
POWER FACILITIES (PRUENCEI
SWI TCHYAitD OI'IRATION
ORYDOCK AND DOCK FACILITIES tPitiSEIICEI
LONG-TERM OPERATION
IMPOUNDMENT (PRESENCE)
WATER LEVEL 'LUCTUATION
LOCKS (PRESENCE)
OPERA'I'ION
SITE ACCESS I PRESENCE!
ROAD, RAIL SPUR UIE
MARINE USE
WORKER FACILITIES !PRESENCE!
USE OF WORICERI
~
II: ...
Ill ... ,.. ..,
z: u
... II: c ::)
~a ,.. Ill
% II:
~ ....
II: ~ ! Ill &. z
0 -... .
• • • • • •
• • • • • • • L•
ELEMENTS OF THE ENVIRONMENT
' i
Ill
!
::) II: Ill
• Ill II • !c i
)1: Ill
I ~ ~ ""I! g ~ -J II: -i a CD 1-
Ill u :
a: ~ • ~ f 0 z ; ..,
-~ a •
JE!$EE
: 0 !! s
... u -. u
... 0 ~ .... Ill J_,•~u .... c Ill -:l!lac!c ~J!i:5ii a..f···
~ = > Iii .... u j: !: ~ r ~.!1 • ••foiz~ ul! i=w2 i=t-~~!c.., !.,..,..,::! ... ~
~ Ill -Ill _, .,I..,>::!CDa ,.. c8~ iii'W::! t-
• Ill i >. ::::; z a a w c -u2zzaat-::» !c%~:5:5~~=0 a: ... .., ............ _a: OZt-IIILL-'-iJII~ iii'::»::)UC
~ CD
~
0 a:
Q
~
%
•le • • •• • •• • • e1 1e
• • • • • • • •I• • • • • • • • .,~ • •• re •• • I• • r• re r• • I• le •• • r• • • • . .,. • •I• • • • • ., . •
• r.-r.-T • Ia • • flf • •T• • • • • • • • • • • • • • ••• • • • • • •• • • • •J• • • • • • •• • • • • r• • • • • • •• •• • • •• • • • • • • • • • • • • • • •• • • ----'
•I I I I I I I I I I I I I 1•1--;n;l•
I • • •I 1•1•1•1 I lll•J•J
I•I•Ielele I 1 I I I I I I I le e1 leJel I
I• •• •I • el • • I •r I I I I I 1•1•1•1•1•1•1•1 I I I LJ JJi
•• J•l• • I • • r• 18 • • r• • I• • • ,. I ••
•J J l J•J• •• • • • • • • •• • •i• • • • • • •
rer-t"""l • .,. re • • r• IItle
•I• • • r• • L• •..1•
•I I I• •• • •
•I I I• •• • • • •• • •• • • • •• •I I 1•1•1•1•1•1•1• • • • • • • • •I•
•l J•J•J•J ·J~ •1•1• • • •• • •J• • • • • •• • •
•I I 1el I I I •• • • • le
• • • • • • • • • • • •1•
•I I I• • • •
el I I • I I le
t INDICATES POTENTIAL FOR INTERACTION BETWEEN ENVIRONMENTAL
ELEMENT AND PLANT COMPONEN~
-59-
SECTION 8 -SOCIOECONOMIC ASSESSMENT
8.1 -Introduction
Development of tidal power at any of the three selected sites would be
characterized by three distinct ~tages, each of which would lead to certain
socioeconomic impacts:
(i) An initial pre-construction period of about nine years during \\ttich
detailed investigations would be accomplished. Total labor force
involvement during this stage would consist largely of professional
engineers and scientists and would peak at 200 to 300 persons. No
significant adverse socioeconomic impacts on the community are
likely to be felt during this period.
(ii) Intense construction, manufacturing and support activities would
take place for a period of 7 to 12 years, involving large direct and
indirect work forces.
(iii) Tidal plant operation following construction would involve only a
small direct labor force. On the other hand, long-term
socioeconomic impacts would result from the avai 1 ability of energy
at relatively stable prices, the potential for industrial growth,
improved access to the far shore across Knik or Turnagain Arm, and
changes in recreation and tourism in the area.
A socioeconomic assessment dealing primarily with stages (ii) and (iii) is
provided as Appendix 11. Results are summarized in this section.
8.2 -The Construction Period
A preliminary estimate of work force requirements indicates that an average
of 1875 man-years per year would be the direct on-site labor requirement at
Rainbow for a period of 7.5 years. Corresponding figures for full
development of Eagle Bay are 2000 man-years and 10.5 years; and for Point
MacKenzie, 2500 man-years and 11.5 years. Indirect labor for the supply of
raw materials would employ 300 to 400 persons per year for any of the three
sites.
These requirements correspond to about 3 percent of the total labor force
and about 50 percent of the construction labor force as it existed in the
Anchorage-Matsu region in March 1981.
Raw materials such as aggregate and rock will be quarried and crushed
locally. Steel products, cement and lumber will probably be supplied from
outside sources. It is assumed that turbines, generators and other
equipment will be manufactured elsewhere in North America or in Europe.
-60-
Even so, an opportunity to consider the potential for manufacturing
hydroelectric equipment in Alaska is available since a tidal plant alone
may require as many as 60 large turbines and a large potential for other
hydroelectric development also exists in Alaska. No study of in-State
manufacture was conducted, however.
8.3 -The Operation Period
A tidal power plant can also serve as a causeway either across Turnagain
Arm (the Rainbow site) or across Knik Arm (Point MacKenzie or Eagle Bay
sites). Perceived advantages for better land access to the Kenai Peninsula
or to the Beluga area have been addressed in earlier studies of potential
vehicular crossings. The Knik Arm sites in particular would provide a
stimulus for rapid land development on the west shore. Mineral
development, industrial development and increased recreational pressures
would be likely consequences of a Knik Arm crossing.
Based on experience at the La Rance tidal power plant in France, a tidal
power plant within easy driving distance of Anchorage would probably become
a major tourist attraction.
The extent to which industrial growth is a necessary consequence of tidal
power deve 1 opment depends upon the deve 1 opment leve 1 se 1 ected at a given
site. The Rainbow site and a reduced scale development at the Eagle Bay
site are constrained cases which meet expected energy demands without
u n u sua 1 i nd u s t r i a 1 i z at i on .
-61-
SECTION 9 -REGULATORY EVALUATION
A variety of federal, state and local licenses and permits must be obtained
before construction of a tidal power plant can commence (see Table 9.1).
Insofar as a major 1 icense from the Federal Energy Regulatory Commission
(FERC) is concerned, develojlllent of tidal power is most analogous to devel-
Ojlllent of a large low-head hydroelectric plant on a major river.
Because FERC has jurisdiction, a major feasibility study will be needed as
the basis for preparing an acceptable license application. Detailed envi-
ronmental investigations and rigorous technical evaluations wi 11 neces-
sarily be required. Based upon recent major project filings with FERC, it
is likely that three to four years will be requireo to conduct the neces-
sary feasibility study and file an application. Pl1 additional 30 months
will probably be needed for processing.
A number of additional permits and certifications must be secured from
federal, state, and local agencies. While information and documentation
requirements are in some cases significant, none of these CK:Iditional regu-
1 atory efforts is expected to occupy the critical path. Appendix 12
provides details on applicable regulatory matters.
It was earlier mentioned that the potential for combining a tidal power
plant with a causeway offers opportunity for cost savings. If the most
immediate needs of the State 'ltOuld be best served by providing a vehicular
crossing in advance of tidal power develojlllent, regulatory requirements
would require varying lead times depending upon the selected approach:
(i) A vehicular crossing could be built as a causeway incorporating anpty
caissons \\hich could later be used for install at ion of turbines and
sluices. While some cost savings may accrue if tidal power is ulti-
mately developed, it is probable that a license from FERC will be
needed because of the ultimate project purpose. Thus, long lead
times as discussed above 'ltOuld apply.
(ii) A vehicular crossing could be built independently of tidal po\\er
develojlllent. No FERC license \'«luld be required, but it is likely
that another Federal Agency (possibly the Corps of Engineers) would
take the lead insofar as preparation of an environmental impact
statement is concerned. Detailed field studies \'tOUld be required,
but it might be possible to satisfy regulatory requirements a year or
t\'tO sooner than in case ( i) above. Furthermore, construction could
probably be completed more rapidly. The disadvantage, of course, is
that 1 ittle or no cost sharing between a 1 ater tidal power develop-
ment and the crossing 'ltOUld be possible.
-62-
TABLE 9-1
COOK INLET TIDAL POWER
MAJOR REQUIRED PERMITS FOR PROJECT DEVELOPMENT
FEDERAL
STATE
FERC License
Corps of Engineers
Department of Commerce
Coastal Zone Certificate of Compliance
Department of Environmental Conservation
Water Quality Certification
Department of Natural Resources
Water Rights
Water Quality Certification
Tideland Submerged Land Use
Right-of-Way or Easement
Dam Safety
Department of Transportation and Public Facilities
Encroachment with Highway Right-of-Way
Department of Fish and Game
Anadromous Fish Protection
Critical Habitat*
Fishwarp*
Department of Public Safety
Building Plan Check
* May not be needed at some sites.
-63-
SECTION 10 -SYSTEM STUDY AND ECONOMIC EVALUATION
10.1 -Use of Raw Tidal Energy
Although relatively large values of annual energy production are possible
from each of the three sites considered in this study, the nature of tidal
energy is such that it is cyclic in nature. Periods of high energy produc-
tion are interspersed twice daily with somewhat longer periods when no
energy is produced. It is frequently true that more energy can be generat-
ed at a site than the existing system can absorb at that particular time.
A number of alternatives exist for dealing with this situation. These are
discussed briefly below and are presented in more detail in Appendix 13.
Before addressing the question of what can or should be done with 11 excess 11
tidal energy, it is useful to review the basis upon which certain portions
of energy produced can be absorbed.
In a typical electrical system, the electrical load is not constant during
a given day. Demand is usually low during the hours following midnight and
it gradually rises to a peak in the late afternoon or early evening. The
electrical system itself consists of various types of generating units.
Some of these units operate most efficiently when they generate on a rela-
tively uniform and steady basis (baseload generation). Others can be cycled
to varying degrees to meet peak loads as they come. Coal-fired steam
plants are typical baseload units. Only a few such units operate in the
Railbelt. Gas turbines frequently are maintained for peaking. Because of
the relatively low costs of Cook Inlet natural gas, much of the electrical
energy in the Anchorage area is produced by gas turbines.
A sketch of a stylized demand curve for an example electrical system
appears as Figure 10-1. Tidal energy production from a single-basin,
single-effect plant is also superimposed on the demand curve. More tidal
energy is produced in the morning hours than can be absorbed by the example
system, resulting in a significant amount of 11 excess 11 energy. The remain-
ing tidal energy is absorbed by the system because cycling units are turned
on and off as necessary.
Real electrical systems are not normally as simplistic as the example
implies. The Railbelt is no exception. Some units which can be cycled
were not designed originally for as many rapid starts and stops as would be
required in the example. Other units which can be easily cycled from a
technical standpoint are subject to environmental constraints (e.g., hydro-
electric plants lend themselves well to rapid load-following but the neces-
sity to maintain certain minimum or maximum flows downstream of the site
for fisheries or recreation can restrict usage of hydro for peaking).
-64-
SYSTEM
ENERGY
DEMAND
MIDNIGHT
-l.l(,
~ c.;
~ ~·
~:
~·
~ ~ If/
CYCLING
GENERATION
BASE LOAD GENERATION
PEAK ENERGY
DEMAND
NOON MIDNIGHT
TIME OF DAY
-65-
FIGURE 10-1
DEMAND CURVE
FOR AN EXAMPLE
GENERATING SYSTEM [i]
Based upon the configuration of the Railbelt system as it is expected to
exist in the late 1990's, estimates were made of the maximum amount of
tidal energy which could be absorbed in its raw form and of the "excess"
energy which may be available for other purposes.
10.2 -Energy Storage
If a system could be devised for storing "excess" energy for use at later
times when system demand is higher, then the "excess" could be converted to
usable energy. Fortunately, a variety of schemes exists for this purpose.
Appendix 13 reviews energy storage possibilities and.provides estimates of
cost penalties which would be incurred if a storage system were construct-
ed. One example involves hydroelectric pumped storage. In simple terms, a
high reservoir (perhaps on a mountain) and a low reservoir (possibly Cook
Inlet itself) are linked by a hydraulic passage.* When excess energy is
available from the system, water is pumped up to the higher reservoir.
When energy is required, water flows through hydraulic turbines into the
lower reservoir. In practice, the turbines are reversible and alternate
between pumping and turbining modes.
The penalty which must be paid for energy storage is relatively high in
terms of dollars per installed kilowatt. Thus, economies will be achieved
if storage requirements are reduced. A number of possibilities exist in
this regard:
(i) The tidal power plant could begin initial operation at less than
optimal capacity. (Recall that the optimization process described
in Section 5 and in Appendix 6 shows a relatively flat energy cost
over a wide range of possible energy output.) As demand grows in
future years, additional turbines could be installed accord-
ingly--provided, of course, that provision has been made in the
barrage to accommodate such expansion.
(ii) Industries may be identified which can operate effectively on inter-
mittent but regular pulses of energy. (For example, hydrogen
production is possible by electrolysis. The hydrogen can then be
stored for industry use as appropriate.) Proposed Phase II studies
should examine potential industrial users and the compatability of
their requirements with tidal energy production.
(iii) A large multi-reservoir hydroelectric project could be operated
effectively in the same system as a tidal power plant. In a two dam
system, for example, the powerhouse at the lower dam generates
energy and releases water in accordance with downstream flow
* While technically possible, environmental constraints may preclude the
storage of saline waters in natural or man-made reservoirs on mountains
near Cook Inlet.
-66-
regulations established in concert with resource agencies. The
powerhouse at the upper dam could operate during periods when no
t ida 1 energy is produced and be turned off when t ida 1 energy is
being fed into the system. The proposed Susitna Hydroelectric
Project could serve well in this role. Definition of appropriate
capacities at Watana (the upper dam in the Susitna Project) and net
benefits associated with combined operations can be accomplished by
merging tidal energy production programs developed in this study
with hydroelectric energy generation programs used on Susitna.
(Note that in this Phase I study of Cook Inlet tidal power, it was
not assumed that the Susitna Project would exist in the late 1990's.
Tidal power was evaluated as an alternative whose benefits would be
measured against the conventional generation system which would
probably evolve in the Railbelt in the absence of the Susitna
Project--corresponding to the "without Susitna" case in the Susitna
studies.)
(iv) In addition to identifying industries which can absorb intermittent
energy (see (ii) above), it is also true that encouragement of
electrical energy-intensive industries in general would result in
increased demand (corresponding to the high ISER forecast or
higher). In the sample system illustrated in Figure 10-1, the net
effect would be to raise the energy demand curve and possibly reduce
the "excess" tidal energy.
(v) Depending upon the extent of industrial growth, it is possible to
contemplate an unconstrained case wherein the Rainbow site on Turn-
again Arm and the Eagle Bay site on Knik Arm are operated on alter-
nate tides (one turbining on ebb tide and one on flood tide). The
resultant total tidal energy generation would be such that cyclic
"pulses" of energy from one would occur roughly at times when the
other is not producing energy. Even so, some periods of no energy
production would remain. Double-effect operation is also possible
and may offer advantages in the unconstrained case over the two
single-effect basins. The value to potential industrial users
should be tested during Phase II industrial studies.
A subtle but important issue insofar as energy storage is concerned is the
fact that variations from spring to neap tides occur over much longer
periods than conventional storage systems are normally equipped to accom-
modate. That is, the excess energy which may have been available during a
period of high tidal range must be held for a week or more to offset later
lower tidal ranges.
* These values are consistent with those specified by the Alaska Power
Authority for economic evaluation of potential hydroelectric
developments.
-67-
10.3 -Project Economics
Preliminary estimates were made of the way in which tidal energy costs
compare with those associated with more conventional generating plants. An
economic analysis in 1981 dollars (0 percent inflation, 3 percent real cost
of capital) suggests that in the absence of retiming (energy storage) tidal
energy costs would likely be competitive with thermal generation costs in
the late 199o•s.
A 11 worst case .. analysis suggests that if a tidal plant were developed to
its optimal capacity by about 2000, if the mid-range forecast were follow-
ed, and if all of the calculated 11 excess 11 energy must be retimed, tidal
energy may be initially about 50 percent to 75 percent more expensive than
energy generated by more conventional means. Based on the alternatives for
reducing energy storage requirements cited in the preceding paragraph, this
11 Worst case 11 is not likely to be realized. Phase II studies of industrial
users would assist in defining the extent to which retiming costs might be
avoided or reduced. Phase III engineering studies could then include a
more precise site specific retiming facility (if required) together with
associated costs.
10.4 -Constrained and Unconstrained Cases
It was noted in Section 4 that during the site selection process, Rainbow
and Eagle Bay were chosen as likely candidates to meet Railbelt System
demand without major industrial growth {the constrained case). Point
MacKenzie was selected because it had the potential for supporting indus-
trial energy needs over and above those assumed in ISER•s 11 most likely11
forecast (the unconstrained case). As the analysis proceeded, however,
certain important changes occurred:
(i) The potential requirement to accommodate closure velocity limitations
at Point MacKenzie resulted in a reduction from the original gross
estimate of 6000 GWh annual energy to 3937 GWh, putting Point
MacKenzie near the arbitrary 4000 GWh borderline which had been
selected to divide constrained from unconstrained cases. Even if the
closure constraint were removed (possibly by stacking two turbines
vertically where depths permit), the at-site optimum energy would
only be about 5000 GWh at Point MacKenzie.
(ii) The favorable nature of the site conditions at Eagle Bay is such that
the initial gross estimate of 3500 GWh was increased in the simula-
tion runs to 4037 GWh.
Eagle Bay is favored over Point MacKenzie for consideration as the uncon-
strained case. It would have lower energy costs, would not require naviga-
tion locks to support ocean traffic, would be further removed from areas
sometimes frequented by Beluga whales and would not impose major changes on
important habitat at Eagle Bay and Goose Bay.
-68-
Insofar as the constrained case is concerned, Rainbow at 2664 GWh lies
within the expected forecast range. On the other hand, the installed
capacity at Eagle Bay can be reduced below the apparent optimum if less
energy is needed.
A reduced capacity project at Eagle Bay was considered. A 30 powerhouse
project there would have a total capital cost of $2,803,000,000 and would
produce 2300 GWh annual energy. Mill rates for the reduced capacity Eagle
Bay are competitive with an optimally developed Rainbow project if the need
for some retiming is found in succeeding phases.
10.5 -Fuel Escalation
If the price of coal continues to escalate after 1995, a variety of
possible Eagle Bay developments will become increasingly more attractive
from an economic standpoint. The attractiveness is dependent upon the rate
of real escalation. At a real rate of 1.5 percent, suggested in the
Battelle Energy Alternative Study, coal costs are at or below tidal power
costs for project life. At double this rate or 3 percent, the tidal plant
has some advantage in later years of project life. Figure 10-2 compares
energy costs of the coal alternative (including fuel escalation) to Eagle
Bay energy costs for 50 years of project life, and for fuel escalation
which continues perpetually. (Note that the levelized coal energy costs
appearing in tables in Section 2 were based on an assumption of zero
escalation after 2005.)
10.6 -Marketing and Financing
A review of the existing La Rance tidal power plant and of proposed instal-
lations at Passamaquoddy and in the Bay of Fundy resulted in the identifi-
cation of important finance and marketing issues. Results of this effort
are provided in Appendix 15.
Perhaps the most important considerations have to do with the high
front-end loading of a capital intensive project. Simply stated, major
investments have to be made well in advance of project revenues and high
debt services will impact the costs of power. Long-term stability in tidal
energy costs is possible, but costs in the early years of operation are
likely to exceed the costs of alternative energy generation.
The State· has recognized this problem and has established a program of
financial assistance for power projects. Further analysis of financial
issues should be closely coordinated with the State.
-69-
I .....
0
I
130
110
100
80
ENERGY
COST
MILLS 80
PER
KWh
(1982 ., 70
60
40
30
20
10
IH5 2000
COAL ALTERNATIVE WITH
CONTINUING FUEL ESCALATION
AT 3% PER ANNUM---,
COAL ALTERNATIVE WITH
CONTiNUING FUEL ESCALATION
AT 1.5% PER ANNUM
COAL ALTERNATIVE WITH NO
ESCALATION-CONSTANT 1982 PRICE LEVEL
2010 2020 2030 2040 2050
YEAR
MILL JtO. I CAUSEWAY
RATE TURIIJtES IEJtEfiT IRETIMIJte
78 10 JtO
71 30 JtO
74 10 YES
68 30 YES
58 30 JtO
52 30 YES
48 ~ I
43 I I s
FIGURE 10-2
THE EFFECTS OF COAL
COST ESCALATION ON
YES
YES
YES
YES
JtO
JtO
JtO
JtO
ECONOMICS OF ALTERNATIVE IIIII
EAGLE BAY DEVELOPMENTS
SECTION 11 -RISK ASSESSMENT
Because field investigations specifically oriented toward tidal power
production have not yet been made, much of the technical evaluation in this
study relied upon extrapolations from available data and upon rational
assumptions. While a conscious effort was made to maintain a degree of
conservatism in the selection of preliminary design criteria, it is
nonetheless true that uncertainty as to actual conditions must be reduced
significantly before construction of a tidal plant is ever started.
One example of the importance of reducing uncertainties may be found in
assumptions regarding the depth at \tttlich competent foundations will be
found. The total direct costs of dredging at the Rainbow site anount to
nearly $190 million. When this figure is adjusted for contractor costs and
indirect costs, it becomes about $290 million--more than 10 percent of the
total capital cost at the site. Subsurface exploration is essential to
verify the validity of assumed quantities and costs. Results obtained from
a drilling program have the potential for introducing significant changes
in project economics--in either direction.
Risks in this preliminary assessment stage are viewed primarily in terms of
uncertainties in data and assumptions. During a later feasibility study, it
would be possible to assess total project risks.
Appendix 16 provides a preliminary risk assessment as the basis for
identifying certain investigation programs \tttlich should be undertaken if a
detailed feasibility study is conducted. Table 11-1 lists proposed
investigation programs which are expected to be required in future.
-71-
TABLE 11-1
PROPOSED INVESTIGATION PROGRAMS
Proposed Investigation
1. Investigation of Regulatory
Licensing Requirements
2. Subsurface Exploration
3. Seismological Investigation
4. Probability Analysis
5. Investigation of Construction
Approach
6. Hydraulic Survey
7. Hydraulic Model Studies
Description of Items to be Investigated
-Continued updating of the preliminary
app 1 i cation
-Preparation of required backup reports
- Geological conditions
-Geotechnical conditions
-Foundation physical parameters
-Fault system
-Seismic activity
-Maximum and minimum tides
-Maximum wave height
-Seismic event frequency and magnitude
-Tsunami wave occurrence and magnitude
-Site conditions
-Material sources and availability
-Construction methods
-Tidal variations
-Tide mode shape
-Storm surge
-Wave height
- Shoaling and refraction
-Water temperatures
-Barrier effect and impact on tides
-Tidal current
-Sedimentation
-Erosion
8. Chemical and Biological Testing -Identification of harmful chemical
composition of existing material when
moved to new areas
9. Energy Storage Study
10. System Model Study
-Determine presence and identify types
of biological organisms
-Determine presence or absence of
endangered species
-Storage sites
-Storage type
-Capital cost
-Interest rate
-Escalation rates
-Operation requirements
-Electrical energy growth rates
-72-
SECTION 12 -PHASES II AND III
12.1 -Introduction
When the Office of the Governor, State of Alaska, requested proposals on
September 23, 1980, to conduct a Phase I Preliminary Assessment of Cook _
Inlet Tidal Power, it was noted that t\\U additional phases \'«>Uld be
considered for future award as follows:
( i) 11 Phase II is intended to look in depth at the potential industries
that appear to have a comparative advantage in association with a
Cook Inlet tidal power source, .. and
( ii) 11 Phase III would involve a detailed engineering and environmental
investigation of site-specific configurations, as well as the
preparation of a conceptual development plan .11
It was in 1 ight of these succeeding phases that a concept for the study of
.. constrai ned 11 and 11 unconstrained" cases was formulated (see paragraph
10.4). Briefly stated, it was envisaged at the start that tidal power
develollllent in the constrained case might be possible simply as an alterna-
tive means of satisfying most likely energy demand growth--without provid-
ing any unusual impetus for further industrialization in the Rai 1 belt. On
the other hand, if the State should choose to encourage industrial growth,
some greater level of tidal power development in the unconstrained case
might be possible.
As a result of the Phase I study, it has been concluded that tidal power
develollllent need not depend upon accelerated industrialization (Conclusion
7, Section 2). A low level development at the Eagle Bay site could be
readily matched with anticipated system needs.
12.2 -Phase II Studies
An "in-depth look at potential industries that appear to have a comparative
advantage" necessarily implies that an identification process is neces-
sary--in effect, a screening to determine ~ich industries might best use
tidal energy in the anounts and at the costs determined in Phase I. Possi-
bi 1 ities include aluminum production ~ich may require on the order of
3000 GWh annually and up to 350 MW of power at nearly 100 percent capacity
factor for a single modern plant. Industrial users may also be attracted
by the possibility that hydrogen production from unretimed excess energy
could be accommodated.
Once candidate industries are identified, there is a need to focus more
directly upon their specific energy needs and to assess technical problems
associated with energy distribution and conversion. Simply stated, there
is some cost at which energy in the form acceptable to a particular
-73-
industry becomes attractive. The costs and the technica 1 difficulties of
getting from raw (unretimed) tidal energy to the precise needs of selected
industries become crucial considerations.
After initial screening and in-depth consideration of viable candidate
industries, the next step in the Phase II studies would be selection of one
or more preferred users. This selection would set the stage for choice of
the most appropriate tidal plant energy production (which may be more or
less than the apparent optimal raw energy of 4037 GWh, depending upon
retiming needs, energy costs acceptable to the selected industry, and the
like). It would also pennit the selection of an appropriate capacity and
storage time for an energy storage system if one is required.
This proposed Phase II work provides an important link between Phases I and
III. The generic descriptions of energy storage in Phase I should be made
site-specific in Phase III. Phase II is necessary as the basis for
defining how much storage and what major features are sought.
12.3 -Phase III Studies
Studies proposed for Phase III have three major components:
(i) Development of conceptual site-specific characteristics and
potentials of a retiming facility \\tlich neets the needs detennined
in Phase II or \tilich neets the needs of the Railbelt system in the
event that Alaska elects not to encourage industrial growth.
(ii) Preparation of a conceptual development plan which includes layouts
and descriptions for the tidal plant, storage system, transmission
system, road network, caisson prefabrication area, and ancillary
f ac i1 it i es .
(iii) An environmental assessment of the proposed conceptual development
plan for the entire tidal plant/retiming facility/vehicular crossing
system.
Phase III can commence concurrently with Phase II since major portions of
components (ii) and (iii) above can be developed in advance of the retiming
plant {component (i)). Assuming an early concurrent start, Phases II and
III could be completed before March 1, 1982.
-74-
AHdVHOOI1BI8
BIBLIOGRAPHY
A -Tidal Power in Cook Inlet
B -Bay of Fundy Tidal Power Developments
C -La Rance Tidal Power Project, France
D -Other Tidal Power Studies
E -Cook Inlet Engineering and Technical Studies
F -Cook Inlet Scientific Data: Geology and Seismic Data
G -Cook Inlet Scientific Data: Water Quality and Environment
H -Cook Inlet Scientific Data: Sediment at ion
I -Cook Inlet Scientific Data: Tidal Data
J -Cook Inlet Scientific Data: Climatic Data
K -Cook Inlet Scientific Data: Socioeconomics
L -Construction Methods and Design Manuals
M-Economics, Licensing and Risk
B-1
BIBLIOGRAPHY
SECTION A. TIDAL POWER IN COOK INLET
A.1 Behlke, C. E. and R. F. Carlson. 1976. An Investigation of Small
Tidal Power Plant Possibilities on Cook Inlet, Alaska. lkliv. of
Alaska, Fairbanks.
A.2 Carlson, R. F. and C. E. Behlke. 1972. A Computer Model of the
Tidal Phenomena in Cook Inlet, Alaska. Institute of Water Resources,
Pub. fib. IWR-17, Uiiv. of Alaska, Fairbanks.
A.3 Johnson, Roy W. 1975. "Harnessing Cook Inlet's Tidal ktivity,"
presented to the Construction Specifications Institute Regional
Convention, Anchorage.
A.4 Stone and Webster Engineering. 1977. Tidal Power Study for the U.S.
Energy and Research Development Administration, Vols. I and II.
Boston.
A.5 Wilson, E. M. and M. C. Swales. 1976. An Assessment of the Tidal
Power Potential of Cook Inlet, Alaska.
SECTION B. BAY OF FUNDY TIDAL POWER DEVELOPMENTS
B.1 Acres Consulting Services, Ltd. 1971. Tidal Power on the Bay of
Fundy, A Technical and Economic Appraisal for WOod Gundy Ltd., N. M.
Rothschild and Sons, and Bank of NOva SCotia.
B.2 Acres Consulting Services, Ltd.
Development in the Bay of Fundy.
Board.
1974. Feasibility of Tidal Power
Bay of Fundy Tidal Power Review
B.3 Bay of Fundy Tidal Power Review Board and Management Committee.
1977. Reassessment of Fundy Tidal Power. Thorn Press, Ltd.
B.4 Beak Consultants. 1976. Summary of Environmental Implications. Bay
of Fundy Tidal Review Board.
8.5 Canadian Atlantic Power Group. 1976-1977.
Study-1975, Phase I, Vols. I and II.
Review BOard.
Bay of Fundy Tidal Power
Bay of Fundy Tidal Power
8.6 Clark, R. H. 1977. Review of Organization and Plans: Workshop on
the Environmental Implications of the Bay of Fundy Tidal Power. Bay
of Fundy Tidal Review BOard.
B-2
B.7 Douma, A. and G. D. Stewart. 11 Annapolis Straflo Turbine Will
Demonstrate Bay of Fundy Tidal Power Concept, 11 Modern Power Systems.
January 1981.
B.8 Dyment, Robert. 11 Hydro Fundy, .. Public Works in Canada, Vol. 9, No.
4, April 1961.
B.9 11 Fundy Tidal Power and the Environment, .. Proceedings of a Workshop on
the Environmental Implications of Fundy Tidal Power. 1977. Ed. by
G. R. Daborn, Acadia Univ. Institute, Wolfville, Nova Scotia.
B.lO Korea Ocean Research and Development Institute. 1978. International
Symposium on Korea Tidal Power. Seoul, Korea.
B.ll Leonard & Partners, Ltd.
Socioeconomic Component.
1976. Presentation on the Scope of the
Bay of Fundy Tidal Power Review Board.
8.12 Moyse, C. M. 1978. 11 Bay of Fundy Environmental and Tidal Power
Bibliography, .. in Fisheries and Marine Services Technical Report
#822, Government of Canada; jointly issued by Biological Station, St.
Andrews and Atlantic Bedford Institute of Oceanography, Dartmouth.
B.13 Seoni, Raj M. 1977. 11 Electrical Equipment Proposed for Tidal Power
Plants in the Bay of Fundy, 11 presented at IEEE Power Engineering
Society Summer Meeting, Mexico City. Canadian Atlantic Power Group.
8.14 Sykes, A. · 1979. Bay of Fundy Tidal Power Project; Some Suggestions
for Improving the Chances for an Early and Successful Launch.
London.
B.15 Tidal Power Consultants, Ltd. 1972. Technical Opinion of the
Development of Tidal Power in the Bay of Fundy.
B.16 Tidal Power Consultants, Ltd. and Systems Control, Inc., Steve Lee
(SCI). 1976. Market and System Analysis, Alternative Supplies and
Transmission. Bay of Fundy Tidal Power Review Board.
SECTION C. LA RANCE TIDAL POWER PROJECT, FRANCE
C.1 Caquot, Albert. 1966. 11 The Definitive Cut-off Project, La Rance ...
Revue Francaise de ~·energie. L'Academie des Sciences, France.
C.2 Cotillon, Johannes. 1974. 11 La Rance: Six Years of Operating a Tidal
Power Plant in France, .. Water Power. October, 1974, pp. 314-322.
C.3 Cotillon, Johannes. 1978. 11 La Rance Tidal Power Station Review and
Comments, 11 Tidal Power and Estuary Management. Colston Research
Papers, University of Bristol.
8-3
C.4 Call iez, H. and M. Farel. 1966. 11 General Description of the Tidal
Generating Station and Its Electromechanical Equipment 11
• Revue
Francaise de L'energie. L'Academie des Sciences, France.
C.5 Gibrat, Robert. 1966. 11 Scientific Aspects of the Use of Tidal Power 11
Revue Francaise de L'energie. L'Academie des Sciences, France.
C.6 Gibrat, Robert. 1980. Tidal Power in 1980. La Rance, France.
C.7 Glasser, G. and F. Avroy. 1966. 11 Research into the Development of the
Bulb Unit... Revue Francaise de L'energie. L'Academie des Sciences,
France.
C.8 Olivier-Martin, D., P. Le Bailly, M. Banal. 1966. 11 The Studies of
Methods for Barring the Rance ... Revue Francaise de L'energie.
L'Academie des Sciences, France.
SECTION D. OTHER TIDAL POWER STUDIES
D.1 Bernshtein, L. H. 1965. Tidal Energy for Electric Power Plants.
U.S. Department of Commerce. Tr. from Russian.
D.2 Bernstein, Lev B. 11 Russian Tidal Power Station is Precast Offsite,
Floated Into Place,.. Civil Engineering. ASCE, April 1974,
pp. 46-49.
0.3 Bernstein, Lev B. 11 Kislogubsk: A Small Station Generating Great
Expect at ions, 11 Water Power. May 1974, pp. 172-177.
D.4 BHRA Fluid Engineering. 1978. International Symposium on Wave and
Tidal Energy. Univ. of Kent, Canterbury, England.
D.5 British Columbia Hydro & Power Authority. 1977. Tidal Power Study:
Memorandum No. 1, Preliminary Site Selection.
D.6 Clark, R. H. and R. L. Walker. 1976. 11 Progress of Feasibility
Reassessment of Exploiting Tidal Energy, .. presented to 90th E. I.C.
Congress, Halifax, Canada, 1976.
0.7 Co 1 stan Research Society. 1978. 11 Tidal Power and Estuary
Management, .. Proceedings of its Thirtieth Symposium. Ed. by Severn,
et al. Univ. of Bristol.
0.8 Gurevich, E. S., et al. 11 Protection of Structures from Corrosion and
Overgrowth of the Kislogubsk Tidal Electric Station, .. Gidro-
tekhnicheskoe Stroitel 'stvo. No. 2, Feb. 1971, pp. 26-28. Tr. from
Russian.
0.9 Haydock, J. L. and J. G. Warnock. 1974. 11 Tidal Power and Energy
Storage, .. presented at IEEE Ocean Energy Symposium, Halifax, N.S.
B-4
D.lO Todd, M. B. 11 Soviets Make Big Tidal Power Plans, .. Water World,
August 1980.
D.11 U.S. Department of Interior. 1963. The International Passamaquoddy
Tidal Power Project and Upper St. John River Hydroelectric Power
Development.
D.12 Witherall, R. G. and J. G. Warnock. 1978. 11 Selection of Turbines
and Generator Equipment for Tidal Power Plants, .. presented at the
International Symposium on Korea Tidal Power, Seoul, Korea.
D.13 Zhebrovskaya, V. D. 11 Laboratory and Field Investigations of the
Artificial Base of the Kislogubsk Tidal Electric Station, .. Gidro-
tekhnicheskoe Stroitel•stvo. No.2, Feb. 1971, pp. 28-30. Tr. from
Russian.
SECTION E. COOK INLET ENGINEERING AND TECHNICAL STUDIES
E.1. Alaska Department of Highways.
Turnagain Arm Crossing: Phase I
Anchorage.
1963. . Feasibility Study for
-Research of Existing Data.
E.2 Alaska Department of Highways. 1964. Feasibility Study of Turnagain
Arm Crossing: Phase II -Alternative Crossing Study. Prepared by
Porter, o•Brien & Armstrong, and Tryck, Nyman & Associates.
E.3 Alaska Department of Highways. 1965. Turnagain Arm Crossing -Route
Study. Anchorage.
E.4 Alaska Department of Highways. 1968. Turnagain Arm Crossing -
Financing Studies. Prepared by Armstrong & Associates. Anchorage.
E.5 Alaska Department of Highways. 1969. Turnagain Arm Crossing -
Causeway Studies. Prepared by Armstrong & Associates. Anchorage.
E.6 Alaska Department of Highways. 1972. Knik Arm Hishway Crossing:
Basic Research, Analysis, and Exploratory Investigat1ons. Prepared
by Howard, Needles, Tamen & Bergendoff. Anchorage.
E.7 Alaska Department of Public Works. 1975. Phase I Feasibility Study
-Proposed Knik Arm Crossing Utilizing a Ferry System. Prepared by
Tippets-Abbett-McCarthy-Stratton. Anchorage.
E.8 Dames and Moore. 1970. Report of Seismic Reflection Survey,
Proposed Monorail Crossing, Seward•s Success, Alaska. Great Northern
Corp. No. 9207-00l-20, Anchorage.
E.9 Robert W. Retherford, Assoc. 1971. Route Selection Report -
Submarine Cable Crossing of Knik Arm 138 kV Transmission Line, Beluga
Project. Chugach Electric, Assoc. Anchorage.
B-5
E.10 Todd, M. B. and Marathon Oil Co. 11 Cook Inlet Platfonn Design
Perfonns Well in Operation, .. The Oil and Gas Journal, July 7, 1969.
E.ll U.S. C£ological Survey, Water Resources Division. 1965. Hydraulic
Investigations in Knik Arm of Cook Inlet.
SECTION F. COOK INLET SCIENTIFIC DATA: GEOLOGY AND SEISMIC DATA
F .1 Alaska Department of Highways, Engineering Geology Section. 1971.
Engineering Geology and Foundation Report: Report of Preliminary
Field and Laboratory Soils Data, Knik Arm. Project NO. Xl2750.
F.2 Alaska Department of Highways, Engineering Geol-ogy Section.
Field and Laboratory Soils Data -Turnagain Arm Crossing.
#F-021-2110, Anchorage.
1969.
Project
F.3 Miller, Robert D. and E. lhbrovolny. 1959. Surficial Geology of
Anchorage and Vicinity. U.S. C£ological Survey Bulletin 1093, U.S.
GOvernment Printing Office, Washington, D.C.
F.4 U.S. Army Corps of Engineers, Alaska District, and Municipality of
Anchorage. 1979. Anchorage Area Soil Survey, Metropolitan Anchorage
Urban Study, Vol. 7. Anchorage.
F. 5 U.S. Department of Agriculture. 1980. Soil Survey, South Anchorage
Area, Alaska.
F.6 U.S. Geological Survey. 11 The Alaska Earthquake, March 27, 1964.11
U.S.G.S. Professional Papers, Nos. 542, 543, and 544.
SECTION G. COOK INLET SCIENTIFIC DATA: WATER QUALITY AND ENVIRONMENT
G.1 Alaska Department of Fish and Game. Waterbird Use of and Management
Considerations for Cook Inlet State Game Refuges. (Draft Report)
Anchorage.
G.2 Alaska Department of Fish and Game. Waterfowl Recreation and
Subsistence Use. (Draft Report) Anchorage.
G.3 Alaska Department of Fish and Game. Narrative Statement: Potter
Point State Game Refuge. (Unpublished Report}
G.4 Alaska Oil and Gas Association. 1971. Bibliography of the
Oceanography and Biology of the Northern Gulf of Alaska. Institute
of Marine SCiences, Pub. No. IMS Rll-21, Lniv. of Alaska, Fairbanks.
G.5 Clausen, Debra. 1979. Uses of State Concern and Special Habitats in
the Cook Inlet Region. Alaska Dept. of Fish and Game, Marine COastal
Habitat Management. Anchorage.
B-6
G.6 Kinney, P. J., et al. 1970. Cook Inlet Environmental Data, RV
Acona Cruise 065 -May 21-28, 1968. Institute of Marine Sciences
Report No. R70-2. Univ. of Alaska, Fairbanks.
G.7 Murphy, R. S., et al. 1972. Effect of Waste Discharges Into a
Silt-Laden Estuary, A Case Study of Cook Inlet, Alaska. Insitute of
Water Resources Pub. No. IWR-26. Univ. of Alaska, Fairbanks.
G.8 Rosenberg, D. H., et al. 1967. Oceanography of Cook Inlet with
S~ecial Reference to the Effluent from the Collier Carbon and
C emical Plant. Institute of Marine Science, Pub. No. IMS-67-3.
Univ. of Alaska, Fairbanks.
G.9 Seguin, Randolph J. 1976. Portage Wildlife Habitat Inventory and
Analysis, 1976. U.S. Bureau of Land Management, Anchorage District
Office. Anchorage, Alaska.
G.10 Seguin, Randolph J. 1977. Portage Wildlife Habitat Inventory and
Analysis, 1977. U.S. Bureau of Land Management, Anchorage District
Office. Anchorage, Alaska.
G.ll Shaw, T. L., ed. 1980. An Environmental ~praisal of Tidal Power
Stations: With Particular Reference to theevern Barrage. Pittman
Publishing Ltd., London.
G.12 U.S. Army Corps of Engineers, Alaska District. 1978. Wetlands of
Potter Marsh, Point Campbell to Potter. Anchorage.
G.13 U.S. Department of Commerce, National Oceanic and Atmospheric
Administration. 1980. The Relationship Between the Upper Limits of
Coastal Wetlands and Tidal Datums Along the Pacific Coast. National
Ocean Survey, Rockville, Maryland.
G.14 Wright, F. F. 1972. Primer of Estuarine OceanograehX. Institute of
Marine Sciences Report No. 72-11, Preliminary Ed1t1on. Univ. of
Alaska, Fairbanks.
SECTION H. COOK INLET SCIENTIFIC DATA: SEDIMENTATION
H.1 CH2M-Hill. 1979, Oceanographic and Dredging Data. Anchorage
Harbor, Alaska.
H.2 Everts, C. H. 1976. Shoaling Rates Prediction Using a Sedimentation
Tank. U.S. Army Corps of Engineers, Alaska District. Anchorage.
H.3 Everts, C. H. and Moore, ___ . 1976. Shoaling Rates and Related Data
from Knik Arm Near Anchorane. Technical Paper No. 76-1. u.s. Army
Corps of Engineers, Alaska istrict. Anchorage.
H.4 U.S. Army Corps of Engineers, Alaska District. 1979. Anchorage
Harbor Shoaling Study.
B-7
H.5 U.S. Army Corps of Engineers, Alaska District. 1970. Bottom and
Sub-bottom Survey of Areas A and A1, Cook Inlet Shoal. Ancnorage.
H.6 U.S. Army Corps of Engineers, Alaska District. 1971. Cook Inlet
Sedimentation Report. Alaska Coastal Research Program. Anchorage.
H.7 U.S. Army Corps of Engineers, Alaska District. 1978. Cook Inlet
Shoal, Alaska Feasibility Report: Channel Improvement for
Navigation. Anchorage.
H.8 U.S. Army Corps of Engineers, Alaska District. 1970. Report on Cook
Inlet Sedimentation Research Program. Alaska Coastal Engineering
Research Program. Anchorage.
H.9 U.S. Army Corps of Engineers, Alaska District. 1972. Sedimentation
Rates Taken at Anchorage Dock. Anchorage.
SECTION I. COOK INLET SCIENTIFIC DATA: TIDAL DATA
I.l Bri tch, Robert P. 1976. Tidal Currents in Knik Arm, Cook Inlet,
Alaska. (Unpublished Dissertation) University of Alaska,
Fairbanks.
I.2 Marmer, H. A. 1951. Tidal Datum Planes. U.S. Department of
Commerce, Coast & Geodetic Survey, Special Publication No. 135.
!.3 Mungall, J. C. 1973. Cook Inlet Tidal Stream Atlas. Institute of
Marine Sciences, Sea Grant Report 73-17. University of Alaska,
Anchorage.
I.4 U.S. Department of Commerce, Coast & Geodetic Survey. 1940. Manual
of Harmonic Analysis and Prediction of Tides. Special Pub. No. 98.
I.5 U.S. Department of Commerce, Coast & Geodetic Survey. 1952. Manual
of Harmonic Aoalysis Constant Reductions. Special Pub. No. 260.
I.6 U.S. Department of Commerce, National Oceanic and Atmospheric
Administration (NOAA), National Ocean Survey (NOS). 1973-75. NOS
Oceanoraphic Circulatory Survey Report No. 4, Cook Inlet. (Draft
Report
I. 7 U.S. Department of Commerce, NOAA, NOS. 1981. Supplemental Tide
Predictions, Anchorage, Nikishka, Seldovia and Valdez, Alaska.
I.8 U.S. Department of Commerce, NOAA, NOS. 1980. Tidal Current Tables
1981, Pacific Coast of North America and Asia.
!.9 U.S. Department of Commerce, NOAA, Tides: Harmonic Constant
Reductions for Anchorage, Coast & Geodetic Survey Form No. 180
(3-12-56), from Marine Predictions Branch, NOS, Rockville, Maryland.
B-8
I.10 U.S. Department of Commerce, NOAA, NOS. 1980. West Coast of North
and South America, Tide Tables 1981.
I.ll U.S. Department of Commerce, NOAA, NOS. Unpublished Tide Data for
Cook Inlet, from current files and archives of Tidal Datums Branch
and Marine Prediction Branch, Rockville, Maryland.
I.12 U.S. Geological Survey, Water Resources Division. 1970. Current
Velocity Profiles. Anchorage.
1.13 U.S. Geological Survey, Water Resources Division. 1980. Current
Velocity Data for Knik Arm in the Vicinity of Anchorage, Alaska.
Anchorage.
SECTION J. COOK INLET SCIENTIFIC DATA: CLIMATIC DATA
J.1 Battelle Memorial Institute, Pacific Northwest Laboratories. 1980.
Wind Resources Data for Alaska.
J.2 U.S. Department of Commerce, Environment Science Services
Admi ni strati on. 1969. Coastal Weather and Marine Data Summary for
the Gulf of Alaska, Cape Spencer Westward to Kodiak Island.
Environmental Data Service Pub. No. EDSTM-8, Silver Spring, Maryland.
J.3 U.S. Department of Commerce, National Oceanic and Atmospheric
Administration. 1973. "Monthly Normals of Temperature, Precipitation
and Heating and Cooling Degree Days, 1941-1970," Climatography of the
U.S., No. 81 {Alaska), National Climatic Center, Ashville, N.C.
J.4 U.S. Department of Commerce, National Oceanic and Atmospheric
Administration, Environmental Data & Information Service. 1976, 1977,
1978, 1979. Climatolotical Data for Alaska. National Climatic
Center, Ashville, North arolina.
J.S U.S. Department of Commerce, National Oceanic and Atmospheric
Administration. 1980. Comparative Climatic Data for the United
States Through 1979. National Climatic Center, Ashville, N.C.
SECTION K. COOK INLET SCIENTIFIC DATA: SOCIOECONOMICS
K.1 Alaska OCS Socioeconomic Studies Program. 1980. Lower Cook Inlet
Petroleum Develo~ment Scenarios -Conmercial Fishing Industrt
Analysis. Techn1cal Report #44. Sponsor: U.S. Department o
Interior, Bureau of Land Management, Alaska Outer Continental Shelf
Office, Anchorage.
K.2 Alaska OCS Socioeconomic Studies Program. 1980. Lower Cook Inlet
Petroleum Development Scenarios -Transportation Systems Analysis.
Technical Report #45. Sponsor: U.S. Department of Interior, Bureau
of Land Management, Alaska Outer Continental Shelf Office, Anchorage.
B-9
K.3 Alaska OCS Socioeconomic Studies Program. 1980. Lower Cook Inlet
Petroleum Development Scenarios -Anchorage Socioeconomic & Physical
Baseline. Technical Report #48, Voltme I. Sponsor: U.s. ~partment
of Interior, Bureau of Land Management, Alaska Outer Continental Shelf
Office, Anchorage.
K.4 Alaska. Department of Labor, Research and Analysis Section. Alaska
Economic Trends {Periodical), May 1981, Juneau.
K.5 U.S. Public Road Administration. 1945. Preliminary Report on
Turnagain Arm Crossing.
SECTION L. CONSTRUCTION METHODS AND DESIGN MANUALS
L.1 Abu-Wafa, T. and A. H. Labib. 11 Aswan High Dam and Rockfill Built
Under Water,11 Civil Enfineering, JlJ.Jgust, 1971. Ministry of High Aswan
Dam, lhited Arab Repub ic.
L.2 Brown, R. E. and A. J. Glenn. 11 Vibroflotation and Terra-Probe
Comparison, .. ASCE Journal of the Geotechnical Engineering Division,
GT 10, October 1976, pp. 1059-1071.
L. 3 Gerwick, Ben C. 11 Preparation of Foundations for Concrete Caisson Sea
Structures, 11 from Rocky M:>untain Regional Meeting of Society of
Petroleum Engineers of AIME, Billings, Montana, May 1974.
L.4 Richard Costain, Ltd.
Units at Hong Kong, n
1971.
11 Unique Plant for Laying Immersed Tube Tunnel
Construction Progress, London, No. 16, Nov.
L.5 Sparks, C. P. 11 The Size of North Sea Platfonns Calls for a Secure
Footing on Seafloor, .. Offshore, Sept. 1976, pp. 138-152.
L.6 Torum, Alf, et al. Offshore Concrete Structures -Hydraulic Aspects.
Prepared for Offshore Technology COnference of Alierican Institute of
Mining, Metallurgical and Petroleum Engineers, Inc., Houston, May
1974.
L. 7 U.S. Army Corps of Engineers. 1977. Shore Protection Manu a 1 • Vo 1 s.
I, II, and III. Coastal Engineering Research tenter, Ft. Belvoir,
Virginia.
L.8 U.S. Army Corps of Engineers, 197-. Hydraulic Design Criteria. Vols.
I and II. Waterways Experiment Station, Vicksburg, Mississippi.
B-10
SECTION M. ECONOMICS, LICENSING AND RISK
M.1 Alaska Administrative Code, Vols. I, II, and III. 1973-Present.
pub. by Office of Lieutenant Governor, State of Alaska, Juneau.
M.2
M. 3 Alaska Power Authority, Susitna Hydroelectric Project. 1981. ~
Limit Capital Cost and Associated Economic Analysis. (Draft Report)
Prepared by Peres Alierican Incorporated.
M.4 Chapman, C. B. "Large Engineering Project Risk Analysis," IEEE
Transactions on Engineering Management, Vol. EM-26, No. 3, Aug. 19~
B-11
S3~1S 03~~31::19 .:10 NO I~ V~01
0 5
SCALE 1": 4 MILES
10 MILES
SELECTED SITES
COOK
IN UPPER
INLET AREA
PAINTED BY CHIP DEBELIUS