owt review

8/16/2019 OWT Review

1/63

FEASIBILITY STUDIES FOR

OFFSHORE WIND DEVELOPMENTIN INDIA


2/63

ACTIVITIESCommercial Viability Studies

Substructures for Oshore Wind Turbine Gravity based Foundation Monopile Foundation

Geotechnical Investiations

!esin of !ata Collection platformStudies for "are !iameter Monopiles #ile Soil interaction Studies Wave #ile Interaction Studies

Studies on Met$mast #latforms Free standin To%ers Guy %ired Met$mast

&


3/63

ASSESSMENT

'

!ays %ith Wind ( ) m*s !ays %ith Wind ( +m*s

, u m b e r o

f

! a y s

, u m b e r o

f

! a y s

.

Monthly climatoloy-s of Wind #o%er !ensity at+. m

W * m &

Sites Considered

Gu/arat01 2a3hau&1 ,avala3hi

Tamil ,adu01 4amesh%ara

m

&1 5anya3umari

6ased on Winds derived fromsatellite data

Wind Speeds for 0. years 70+$.8$0999 to 08$00$&..9:

One observation for each day at0.m above sea surface $ scaled to+.m

!ata validated usin ; moored

buoys 7


4/63

VARIOUS SITES

=

Wind speed distributionat +.m

. ; 0. 0; &. &;.

0...

&...'...

=...#o%er Curve

Wind Speed 7m*s:

#o%er 7

3W:

S1,o CompanyCapacity

7MW:

5anya3umari 4amesh%aram7#9.: 7#8;: 7#;.: 7#9.: 7#8;: 7#;.:

0 Su>lon &10 .1=' .1=; .1=8 .1'8 .1'+ .1=.& 4e #o%er '1& .1=. .1=& .1== .1'' .1'= .1')' 4e #o%er '1= .1;0 .1;' .1;; .1=' .1=; .1=)= 4e #o%er ;1. .1'9 .1=. .1=& .1'' .1'= .1';

; 4e #o%er )1& .1'0 .1'' .1'= .1'. .1'0 .1'&#lant "oad Factors after incorporatin losses in po%er production

Wind Uncertainties

Measurement?ncertainty

Future Wind 4esourceWind Shear

Power Production Losses

Turbine unavailability

Wake effects lossesElectrical losses


5/63

COMMERCIAL VIABILITY STUDIES

;

Item 4am 5anyaWater !epth 0. 0;!istance from coast ; ;

#ort @vailability08; 3m 0&;

3mCapital cost per Turbine 74sin Crs1:

;.1'; ;01)'

Item4am15anya

1?nit #rice of #o%er apart from incentives74s:

)1;= ;180

!ebt$Service Coverae 4atios 01' 01'#ro/ect Internal 4ate of 4eturnA I44

0'1+8

0'198

Revenue

Interest

6an3erInvestor

Capital Cost

Wind Turbine Operation andMaintenance

Insurance


6/63

SUB STRUCTURE CONCEPTS

)

Wind Tr!ine

4ated po%erA MW ;ub heihtA m +.

4otar diameterA m 0&)

To%er diameterA m )

M"n"#i$e

Water depthA m 0.

Monopile diameterA m )

Monopile thic3nessAm .1.)

Monopile lenthA m '.

Gra%it& Based F"ndati"n!iameterA m &.

eihtA m 0'

WeihtA tons 0&&) Gravity Based

Foundation

Monopile

Foundation


7/63

DESIGN METHODOLOGY

8


8/63

OVERVIEW Basi' L"ads

@erodynamic "oad on 4otor

• I


9/63

AERODYNAMIC LOADS ( FAST

9

B$ade E$ement M"mentmT)e"r&

Desi*n sitati"n

#o%er production

#o%er production and occurrence offault

,ormal shut do%n


10/63

LOAD CASES + ,-.//

Desi*n sitati"n Wind '"nditi"n

#o%er production

,TM Vin K Vhub K Vout

,WT Vhub

L Vdesin

,TM Vin K Vhub K Vout


11/63

AERODYNAMIC LOADS ( FAST

L"ad CaseF"r'e

01N2

Fre3en'&

0H42

DAF ESL 01N2

EOG R + 56/ 9&8 .108 018& 0;9=

EOG R 7 56/ 0.;. .10& 01=8 0'';

+ + + + + + + + + +

+ + + + + + + + + +


12/63

WIND 8 HYDRODYNAMIC LOAD ONTOWER AND SUBSTRUCTURE IS 9:; Part ( <

6asic Wind Speed 7Survival:A Vb L '9 m*s 6asic Wind Speed 7Operational:A Vb L 9 m*s

H&dr"d&nami' L"ads

Eart)3a1e L"ads IS 0+9' N &..& 74esponse Spectrum Method:

one FactorA L .10 7one II: 4eduction FactorA 4 L &1. 7Steel Chimney: Importance Factor A I L 01; 7Steel Chimney: #ercentae of dampin L & D

0&

Parameter

En%ir"nment

N"rm

a$

E=tre

meWave eiht

7S:& m = m

Wave period7T#:

8 s 0& s

Time #eriod 7T#:

Water!epth

Wave eiht7s:

0 1 2 3 0

0!"

1

1!"

Time Period #s$

Accleration #m%s2$


13/63

PILE SOIL INTERACTION

0'

DEPT

H (m)

Internal

FrictionΦo

Skin

Friction(KPa)

Ti

!esistance(Pa)

1!" 32 1!&& 0!113 33 3!&& 0!22

!" 33 !'& 0!1&

' 3( (!&& 0!3

(!" 3& &!&& 0!"

& 33 &!3& 0!3&

10!" 3 10!&' 0!"

12 2!1& 2!1'

13!" 31 1!0& 0!")

1" 1 2!) 2!1'

1'!" 1 2(!32 2!3)

1) 2 2&!)1 2!"&

1&!" 3 2"!&( 1!0

21 3" 2(!&( 1!"130 3 32!0 2!00


14/63

CHEC>ING

0=


15/63

EIGEN VALUE ANALYSIS

0;

Mode No

Gravity Based Foundation

Frequency

(Hz)

Period

(s)1 & 2 0.326 3.065

3 & 4 2.617 0.382

Mode No

Monopile

Frequency(Hz)

Period(s)

1 & 2 0.308 3.244

3 & 4 2.385 0.419

*eflection at t+e to, of t+e nacelle for -ravity based foundation and mono,ile due to for

eart+.uake load combination /as )3!(" cm and

&!& cm res,ectively!

tiliation factor for critical members for -

and mono,ile are 0!( and 0!1( res,ectively.

GRAVITY BASED FOUNDATION


16/63

GRAVITY BASED FOUNDATION +RAMESHWARAM

0).1..

&1..

=1..

)1..

+1..

0.1..

0&1..

Pitch RAO

Pitch (rad!)

. 0 & ' = ; ) 8 + 9 0..1..

.1=.

.1+.

01&.

01).

&1..

Heave RAO

"i!e Period (s)

Heave (!!)

Stabilit !"#S$Slidin% 22

#ver urnin% 31

'earin% 3.0

INSTALLATION METHODOLOGY FOR A


17/63

INSTALLATION METHODOLOGY FOR AMONOPILE

08

1$ Trans,ortin4 to location 2$ 5iftin4 and 5aunc+in4 3$ Positionin4

$ *rivin4 by +ammer "$ 6emovin4 of 7ammer after drivin4 '$ Placin4 Transition ,ieceon mono,ile


18/63

MONOPILE MANUFACTURING YARD

0+

M"n"#i$e

Transiti"nPie'e

H&dra$i' ?a'1+#


19/63


20/63

&.

Estimati"n @"r Insta$$ati"n "@ M"n"#i$e

S"#$ Item Units Unit Price %t&'ost

(in 'rore)

1 Structural Steel tons 10000 11 "!("

2 Plane Cement Concrete for 4routin4 m3 '000 100 0!0'

3ar4e for drivin4 :ono,ile /it+mobiliation; *emobiliation and PortC+ar4es

,er unit 20000000 1 2

Total cost "*

Estimati"n @"r Insta$$ati"n "@ Gra%it& Based F"ndati"n

S"#$ Item Units Unit Price %t&'ost(in

'rore)

1 Structural Steel tons 10000 1( 2!0'

2 : 0 -rade for 6CC m3 12000 "33 0!'

3 Steel for 6CC tons )0000 (&!&" 0!'

Sand for illin4 Inside oundation m3 "00 303 0!1"

" To/in4 oundation for 100 km ,er unit 3000000 1 0!30

' *red4in4 for 1!"m and 5evelin4 t+e -round m3 "00 (3' 0!0

(

*red4in4 is+in4 7arbor to re.uired draft of m

and for ot+er infrastructure ,er unit "000000 1 0!"0

) Total 'ost +",,


21/63

GEOTECHNICAL INVESTIGATIONS ?A>HAU AND NAVLA>HI GU?ARAT

L"'ati"n

C"+Ordinates

2a3hau &'o 81=.=P,Q )+o &81+P<

,avla3hi

&&o ;01);P,Q 8.o 0=18&P<

Suitable foundation isessential for theeective performanceof oshore structure%hich reEuires3no%lede on Soil#roBle1

GEOTECHNICAL INVESTIGATION


22/63

GEOTECHNICAL INVESTIGATION+METHODOLOGY

!rillin ri

2ac3$up 6are

Casin pipe

Geotechnical investiations%ere carried out by

mobili>in a /ac3 up bareof suitable le lenthinstalled belo% the sea bedlevelS#e'i'ati"n Dimensi"ns

Len*t) &= m

Breadt) 0& m

De#t) & m

Dra@t 0 m

Le* $en*t) '. m

Le* Diameter .1); m

The drillin ri placed inside

the /ac3up bare %as used forcollectin soil and roc3samples1

The methodoloy involvesinstallation of 0;. mm

diameter casin pipe %ith 01;m to &1. m depth belo% sea

?a'1 # !ar*e

Dri$$in* ri*


23/63

SOIL EPLORATION PROCEDURE @fter the installation of casin

pipeA drillin operation %as

initiated inside the boreholeusin drillin rods %hichconnected to the drillin ri forsample collection1

For proBlin soil strataAStandard penetration test hasbeen performed insideborehole as per IS &0'0 atevery 01;m intervals or atevery identiBable chane ofstrataA %hichever is met

earlier1 6oth disturbed and

?ndisturbed samples %erecollected durin drillin forlaboratory investiations to

evaluate the enineerin andh sical ro erties of sub

Distur-ed

soil samle

Undistur-ed soil

samle

S#$it S#""n Sam#$er @"rsam#$e '"$$e'ti"n

C"$$e'ted S"i$ Sam#$es

BORE LOG DATA FOR ?A>HAU


24/63

BORE LOG DATA FOR ?A>HAULOCATION

The top 0& m of startin from seabed level consists of Very Soft

Marine Clay %ith S#T value 0havin hih natural %ater content1

Silty clay %ith considerable sandportion up to a depth of 0)1; m %asobserved beyond 0& m depth1 Theobserved S#T numbers at 0'1; mA 0;

m and 0)1; m eJceeds ;. countssuestin that the soil is in densestate condition1

From 0)1; m to &;1; m the soilchanes from silty clay to densesand %ith S#T value reater than ;.suestin that the soil is in densestate condition1

The soil belo% &;1; m %as hard siltalon %ith clay portion havin S#Tvalue reater than ;.1 The soil is

reddish in colour %ith siniBcantbearin capacity characteristicsB"re+$"* data

DIFFICULTIES FACED AT ?A>HAU


25/63

DIFFICULTIES FACED AT ?A>HAULOCATION

#resence of soft marine clay resulted in instability to the /ac3

up les1 Fails to recover soil samples because of its hih %ater

content1

More Sample disturbance due to instability in /ac3 up les

Presen'e "@ Marine '$a& 'asin*insta!i$it& t" ?a'1+# !ar*e

O!tained S"i$ sam#$eit) m"re sam#$e

distr!an'e

0a2 0!2

0'2

BORE LOG DATA FOR NAVLA>HI


26/63

The top 01; m from sea bed level the soilconsists of very soft marine clay

deposit %ith S#T value less than 0 %ithhih %ater content %ith poor strenthcharacteristics1

From 01; m to ) m depthA the subsoilchanes from marine clay to blackishdense sand %ith S#T more than ;.1

The dense sand deposit continues from )m to 9 m depth %ith S#T values reaterthan ;.1

#resence of rocky stratum %as observedbeyond 9 m depth1 4otary drillin %asinitiated for obtainin roc3 samples1 The

obtained roc3 core samples %ere testedfor its Core recovery ratio 7C44: and 4oc3Euality desination to eJamine the Eualityand freshness of the roc31

From 9 m to 09 mA roc3 samples %erecollected for every 0 m depth interval1

Weathered basalt roc3 %as observed

BORE LOG DATA FOR NAVLA>HILOCATION

B"re+$"* data

SUMMARY OF LABORATORY TEST


27/63

. Undistr!ed sam#$es and -, Distr!ed sam#$es ere '"$$e'ted@"r $a!"rat"r& testin*

SUMMARY OF LABORATORY TESTRESULTS ?A>HAU

SUMMARY OF LABORATORY TEST


28/63

SUMMARY OF LABORATORY TESTRESULTS NAVLA>HI

#$%

. Distr!ed sam#$es ere '"$$e'ted @"r $a!"rat"r& testin* at t"# m

• R"'1 Pr"#erties @r"m m t" - m de#t)


29/63

SUBSTRUCTURE DESIGN FOR WIND

DATA COLLECTION PLATFORM

&9


30/63

OFFSHORE WIND

RNati"na$ "s)"re ind ener*& #"$i'&+5/-;

by MNRE

The main ob/ective of the oshore %ind enerypolicy is to promote research and development

activities in Oshore %ind enery sector1

It allo%s various overnment and interestedprivate parties to enae in data collection at

potential sites1

ence Su>lon and ,IW< alon %ith FOWI,! hasapproached ,IOT in desin of substructure foroshore data collection platform1

'.


31/63

PLATFORM

'0

To obtain ban3able %ind data and chec3 commercial viabilityof oshore %ind pro/ect1

To obtain Oceanoraphic data li3e WavesA Tides and Currentsfor desin of Substructure for Oshore Wind1

Instruments for collectin various #arameters

#arameters Instrument

Wind VelocityA !irection "idarWave !irectionA eiht and#eriods

Wave 4ider 6uoy

Current VelocityA !irection @!C#A 4CM

Tide 4TGA @TG

#A Salinity TSS Water Uuality buoy

TemperatureA #ressureAumidity

@utomatic %eatherStation

LIDAR

Automatic&eather 'tation

Solar panels

Batteries


32/63

LOCATION OF PLATFORM

G$@ "@ >t')

2a3hau "atitude &'.8&=1=&X,

"onitude )+&8=+1&=X<

Water depth $0;m 0)1'3m from shore

G$@ "@ >am!)at

#ipavav 6andar "atitude &.=0P'.X,

"onitude 80'&P;.X<

Water depth $0;m &'3m from shore


33/63

STRUCTURAL PROPERTIES

M"n"#i$e Pr"#erties #ile !iameter$01& m #ile Thic3ness$.1.&; m #ile "enth$&; m

P$at@"rm Pr"#erties!iameter of platform$;m #lat thic3ness N .1.&mMild Steel

''


34/63

ENVIRONMENTAL CONDITION AND LOADING

Wa%e ( Wind C"nditi"ns

#arameter


35/63

STRUCTURAL ARRANGEMENT OFPLATFORM

#latform arranement %itheEuipment

Main bea

Secondary6eam

4iid beam

ST@@! Model

Final Member #roperties

S1,O

Member Section

0 4iid beam & ISMC 0;.

& Main beam & ISMC 0;.

' Secondary 6eam IS@ 8;

!esin #arameters

S1,O

#arameter Value

0 Grade of steel Fe&;.

& !esinStandards

IS +.. &..8

' Method "imit StateMethod

Total Weiht 7Includin "ive load: N 0= tons

';


36/63

@nalysis

!eYection at platform $ .1.9 m 7allo%able "*0;. of.1&0m:1

@nalysis 7Theoretical Method in Tomlinson: !eYection at platform $ 7.1..; H .1.80 H.1.=):

$ .10&& mFree Vibration @nalysis

4eular %ave FreEuency $ ; N '. s ,o 4esonance due to %aves

ETREME SEA STATE 0STROM2

Free Vibration @nalysisMode ,o Frequency (Hz)Period (s)

0 & 0.69 1.44

' = 8.33 0.12

; 33.33 0.03

')


37/63

EARTH UA>E ANALYSIS

!eYection at the top of the platform $ .10& m 7allo%able "*0;.:1


38/63

MEMBER CAPACITY

Member ?tili>ation

Member

"oad Combination

Strom


39/63

COMPARISON OF SACS PLAIS

.0$.9$&.0;Ocean Structures Group '9

Soil is modeled as a three

nonlinear sprins and it hasbeen validated %ith plaJisfor #$ curves

118 ()63 ()

$& $0 . 0 & ' = ;

$0)

$0=

$0&

$0.

$+

$)

$=

$&

.

ateral displace!ent o pile

plaxi

*

*election (!!)

*epth (!)


40/63

ST!U'TU!.L D!.WI#/ 0 '$##E'TI$#

DET.ILS

.0$.9$&.0;Ocean Structures Group =.

ENVIRONMENTAL IMPACT ASSESSMENT


41/63

ENVIRONMENTAL IMPACT ASSESSMENT

=0

T#< IM#@CT

@ir


42/63

MONOPILES + EVOLUTION

=&

8.D of the Oshore %ind turbines are supported on

Monopiles

LARGE MONOPILES ( PILE SOIL


43/63

LARGE MONOPILES PILE SOILINTERACTION #ile soil system is conventionally considerin as

' non linear orthoonal sprins at reular

intervals alon the depth of the pile1 "ateral sprin P+& 'r%es

Vertical sprin T+4 'r%es +4 'r%es "imitations of @#I Method based #$y curves

The eect of pile diameter is not consideredfor estimatin initial stiness 3P1

The eect of pile tip rotation and hori>ontaldisplacement for lare diameter piles is notconsideredA %hich causes additional forcesto the pileA hence more resistance in soil1

4otation of lare diameter monopiles causesadditional vertical stresses resultin in moreresistance of soil1

The interaction bet%een various soil layersis not considered1

='

PILE SOIL INTERACTION+FEM


44/63

PILE SOIL INTERACTION FEMMETHOD #ile alon %ith soil is modelled usin Finite ?$

*omain crosssection

1 10 10 300 "m @ "m

2 20 10 1100 10m @ 10m

3 30 10 2200 1"m @ 1"m

0 10 '00 20m @ 20m

" "0 10 10000 2"m @ 2"m

' '0 10 13000 30m @ 30m

( (0 10 2'000 3"m @ 3"mPla=is model

FEM METHOD + RESULT


45/63

FEM METHOD RESULTETRACTION

=;E.uilibrium c+eck for 1m diameter of ,ile

S1,O

"oad7 3,: 4esistance7 3,: D oferror

0 '. $.&918= .1+)& ). $.;919' .108

' 9. $.9.1)' .18.= 0&. $0&01&. .19+; 0;. $0;01'+ .19&) 0+. $0+01&0 .1)88 &0. $&0.1). .1&++ &=. $&=.10; .1.)9 &8. $&)919. .1.'

0. '.. $&991'& .1&'

The results from #laJis '! arein ' components 7stress points:

The eective normal stress7[Pn:

The ori>ontal shear stress7\J>:

The vertical shear stress 7\y:

,ormal hori>ontal stressesare resolved in direction offorce to et total stress in eachelement

Final force in each element 7Soil4esistance #: L @ J Total stress1

Similar eJtraction is carried outfor all the interface elements atevery 0m depth and forces areinterated to obtain total

T"ta$ stress J Kn0)"ri4"nta$ '"m#6 7

-0H"ri4"nta$ '"m#62

+CURVES


46/63

CURVES0@#I F


47/63

USAGE OF P Y CURVES ETRACTEDFROM FEM METHOD To evaluate p$y curves a =m diameter monopile is modelled

in F


48/63

FORCES

=+

Solver

Continuity eEuation

Momentum eEuations

Study the ydrodynamic Forces on lare diameter monopiles usin,umerical TechniEues1 Construct Finite Volume based ,umerical Model for Monopiles1

Validate %ith published laboratory results1 Compare %ith analytic forces from Morisons


49/63

VOLUME OF FLUID METHOD

=9

,date t+e interface ,rofile usin4 reconstructin4 met+ods!

It is an interface ca,turin4 met+od in an Eulerian frame /ork for simulatin4

multi,+ase flo/s!

• Bolume fraction2

• Trans,ort e.uation2

• 5ocal material

,ro,erties2

Fluid 0

Interface

Fluid &

• Bolumeoffluid

function

0$!# =∇+∂

∂α

α U

t


50/63

NUMERICAL MODELLING


51/63

NUMERICAL MODELLING

;0

Open FOAM: ,umerical simulations1 snappyHexMesh: Geometrical modellin1

HFOAM: Wave eneration and absorption1

InletSeabed %all

Sides patch

Monopile WallOutlet

6oundary Conditions

*=

y)*

0* 2"*

!omain

WAVE GENERATION AND MESHING


52/63

WAVE GENERATION AND MESHING

;&

Waves are enerated usin code developedand published by #1 iuera et al1 7Coastale thereby reducin thecomputational time and eort1

:es+in4 around t+e ,ile Close vie/ from to,

7%)

:es+ Siin4

VALIDATION


53/63

VALIDATION

;'

The numerical model is validated %ith the results

published by "1F1 Chen et al1 R,umerical

investiation of %aveNstructure interaction usin

OpenFO@M]A Ocean


54/63

DETAILED STUDIES

;=

!*" .1.; .1.0 .10; .1&

"inear

*"L.1..;7*d L .1.&):

L.1&)

!L&1'&

L.1&)

!L=1)=

L.1&)

!L)19)

L.1&)

!L91'.

Wea3ly nonlinear

*"L.1.'

7*d L .108:

L018.

!L&1'&

L018.

!L=1)=

L018.

!L)19)

L018.

!L91'.

Fully nonlinear

*" L.1.8

7*d L .1':

L'1'.

!L&1'&

L'1'.

!L=1)=

L'1'.

!L)19)

L'1'.

!L91'.

Water depthA h 0.m Time #eriodA T ;1+'s

OFFSHORE MET+MAST ( TAMIL NADU


55/63

OFFSHORE MET MAST TAMIL NADU

OFFSHORE MET+MAST ( TAMIL NADU


56/63

6asic loadsWind Guest factor Force Coe_cient Method

Wave loads Morison


57/63

T)ird

F"rt)

First Se'"nd

m"des 0-6, s2

Stati' Ana$&sis

OFFSHORE MET MAST


58/63

GUY WIRE ( SUCTION PILES

Methodoloy for application of "oads and load Combinations

%ill be eJactly similar to that of Free standin to%er1

STRUCTURAL ANALYSIS


59/63

Mode 07;1.0 s:

Mode &7;1.0 s:

Mode '701== s:

Mode =

7.1)9 s:

Mode ;

7.1)9 s:

ontal Members N.1;=Vertical members N

.190

?tili>ation Factor

EARTH UA>E ANALYSIS


60/63

Time$istoryMethod

4esponseSpectrum Method

*ia4onal racin4 0!21

7oriontal :embers 0!0)

Bertical members 0!2

?tili>ation

Factor

6ase Shear Vs Time

@ccleration Vs Time

+.//

+


61/63

PUSH OVER ANALYSIS #ush over analysis has been done to chec3 the ultimate

capacity of the structure 74eserve Strenth:1

The load is increased in speciBed time steps and the loadstep at %hich the collapse occurs is identiBed1

6eserve Stren4t+ D 2!2

efore Colla,se

Plasticity 2"

After Colla,sePlasticity 100

SUCTION PILE ANALYSIS


62/63

The dimensions of the piles areA Guy %ire support

"enth &1+ mA !iameter 0 m1 Monopole support "enth =1+ mA !iameter &1; m1

Det7Dri3in8Force(K#)

SkinFriction

(K#)

Sel6enetration

9 )'!1&3 0 FES

9"+ )&!01& 1!1 FES

9" &1!)" !"' FES*": &!'(1 10!2( FES

*"; &(!&( 1)!2' FES

: 100!323 2)!" FES

:"+ 103!1& 1!10 FES

:" 10"!&(" ""! FES

Det7Dri3in8Force(K#)

Skin6riction(K#)

Sel6enetratio

n

9 "0!3 0 FES

9"< (2!( !" FES

* &!"" 1(!)3 FES

: "3)!(0 (1!3" FES

, ")2!)' 1'0!"" FES

,"< '0!& 21)!"2 FES

+ '2(!01 2)"!2 FES

+"< '&!0& 3'1!2 FES

Suction Anc+or for -uyWire Suction Anc+or for :ono,ole

SUMMARY AND CONCLUSIONS


63/63

SUMMARY AND CONCLUSIONS Commercial viability studies indicate I44 of 0= D %ith a

"eveli>ed Cost Of

owt review

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