7/21/2019 geothermal proposal by uges(unisel) http://slidepdf.com/reader/full/geothermal-proposal-by-ugesunisel 1/17 EXECUTIVE SUMMARY Topic : Proposal to build a geothermal plant Tawau in Sabah in NW Borneo Location: Tawau in Sabah in NW Borneo 95 acres. Objectie: to build a power plant to !acilitate the demand power consumption re"uirement Financial requirement: Non power generated# Power generating : Securit$ : Total # Energy prouction capacity: %W & month Time !rame !or con"truction o! plant: $ears #ro!it:
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'eothermal energ$ is thermal energ$ generated and stored in the (arth. Thermal energ$
is the energ$ that determines the temperature o! matter. The geothermal energ$ o! the
(arth)s crust originates !rom the original !ormation o! the planet and !rom radioactie deca$ o! materials *in currentl$ uncertain but possibl$ roughl$ e"ual proportions+. The geothermal
gradient, which is the di!!erence in temperature between the core o! the planet and its sur!ace,
dries a continuous conduction o! thermal energ$ in the !orm o! heat !rom the core to the
sur!ace. The adjectie geothermal originates !rom the 'ree- roots / *ge+, meaning earth,
and 01234 *thermos+, meaning hot.
(arth)s internal heat is thermal energ$ generated !rom radioactie deca$ and continual heat loss
!rom (arth)s !ormation.Temperatures at the core6mantle boundar$ ma$ reach oer 7888
*;,<88 =+.>7? The high temperature and pressure in (arth)s interior cause some roc- to melt and
solid mantle to behae plasticall$, resulting in portions o! mantle conecting upward since it is
lighter than the surrounding roc-. @oc- and water is heated in the crust, sometimes up to A;8
*;88 =+.
=rom hot springs, geothermal energ$ has been used !or bathing since Paleolithic times and
!or space heating since ancient @oman times, but it is now better -nown !or electricit$
generation. Worldwide, ,;88 megawatts *%W+ o! geothermal power is online in <8A.>C? Dn
additional <E gigawatts o! direct geothermal heatingcapacit$ is installed !or district heating,
space heating, spas, industrial processes, desalination and agricultural applications in <88.
'eothermal power is cost e!!ectie, reliable, sustainable, and enironmentall$ !riendl$,>E? but
has historicall$ been limited to areas near tectonic plate boundaries. @ecent technological
adances hae dramaticall$ eFpanded the range and siGe o! iable resources, especiall$ !or applications such as home heating, opening a potential !or widespread eFploitation. 'eothermal
wells release greenhouse gases trapped deep within the earth, but these emissions are much
lower per energ$ unit than those o! !ossil !uels. Ds a result, geothermal power has the potential to
help mitigate global warming i! widel$ deplo$ed in place o! !ossil !uels.
The (arth)s geothermal resources are theoreticall$ more than ade"uate to suppl$ humanit$)s
energ$ needs, but onl$ a er$ small !raction ma$ be pro!itabl$ eFploited. Hrilling and
eFploration !or deep resources is er$ eFpensie. =orecasts !or the !uture o! geothermal power
depend on assumptions about technolog$, energ$ prices, subsidies, and interest rates. Pilot
programs li-e (W(B)s customer opt in 'reen Power Program >9? show that customers would be
willing to pa$ a little more !or a renewable energ$ source li-e geothermal. But as a result o! goernment assisted research and industr$ eFperience, the cost o! generating geothermal power
has decreased b$ <5I oer the past two decades.>8? Jn <88, geothermal energ$ cost between
The Tawau 'eothermal Project is located in North (ast %ala$sia *Borneo+, =igure . The
!ield is being eFplored !or geothermal power deelopment b$ Tawau 'reen (nerg$ *T'(+, a
%ala$sian based renewable energ$ compan$. The !ield eidence is !or a moderate siGed olcanicgeothermal !ield with medium grade temperature. Dlthough the sur!ace geothermal mani!estation
and potential o! the area !or geothermal deelopment hae been -nown since the earl$ siFties
*Lir- 9C<+, the !ield has been largel$ oerloo-ed !or deelopment because o! the indications !or
medium grade temperature which would produce onl$ a small steam !lash i! deeloped as a
conentional !lashed steam power deelopment. Moweer, wor- b$ T'( oer the past two $ears
has changed this perception and it is now recogniGed that the !ield is prime !or deelopment with
an organic @an-ine c$cle power plant operating at a geothermal resource temperature o! around
<88o and probabl$ with pumped production wells The project is currentl$ being prepared !or a
two well eFploration drilling program eFpected to commence in ul$ <87 and it is eFpected that
the results o! drilling will be aailable at the time o! presentation o! this paper in april <85.*Peter @,<87+
the area. The $oungest olcanic roc-s are oliine basalts erupted in the late Pleistocene time at
Quoin Mill to the east o! %t %aria and %t Bombalai to the west, which appear to be late stage
erupties located on the rim o! a late stage circular collapse !eature deeloped about %t %aria
Thermoluminescence dating studies o! the Tawau olcanic roc-s hae been reported b$
Ta-ashima et al *<885+. O! < samples dated, the $oungest was !ound to be 8.89%a !rom a
monogenetic cinder cone. Dges o! dacitic olcanic roc-s !rom the !oot o! %t %aria ranged !rom8.A7 to 8.75 %a with the ages o! underl$ing andesitic laas ranging !rom 8.<; to 8.5< %a. Dges
!or the occurrence o! h$drothermal alteration in the project area were also determined with
samples !rom the Kpper Tawau Mot Springs *=igure 5+ being 8.5 to 8.9%a. Other ages were
widel$ scattered !rom 8.<; to 8.CC%a.
The project areas has a strongl$ deeloped pattern o! transcurrent !aulting on a NWS( trend
with subordinate NS and N(6SW trending !aults *see =igure 7+ *T'( <8Aa+ . This is consistent
with the structural !ramewor- and regional stress regime o! the Borneo region showing stri-e slip
!aulting and transpressional tectonics !rom the late Pliocene to the present da$ which probabl$
caused most structural deelopment *Belagaru and Mall, <889+.
Oerall the Tawau geothermal prospect is considered to be well situated with respect to plate
tectonics, has a long histor$ o! magamatism and recent olcanism and has a welldeeloped
structural !abric with good potential !or high structural permeabilit$.
,E%C0EMISTRY
T'( has completed a thorough reeFamination and resampling o! all -nown springs. hemical
anal$ses o! the springs are gien in Table and computed chemical geothermometers are gien
in Table <. Sur!ace thermal actiit$ at Dpas Liri consist mainl$ o! warm and hot springs ranging
up to ;Eo and these hae arbitraril$ been diided into 7 groups based on spatial and chemicalconsiderations *see =igure 5+. These include: DBloc- *Dpas Liri hot spring, o! Nal t$pe water
with a maFimum temperature o! ;Eo and 788 mg&-g l+, BBloc- *Balung hot springs,
maFimum 5Co, is a aSO7 water with slightl$ acidic pM o! C.8 to C.7, about 888mg&-g SO7,
mg&-g l and some Sul!ur deposition+, T Bloc- *Tawau cit$ hot spring, a miFed anion t$pe
water with l at A5A mg&-g+ and T<Bloc- *Tawau Mill conseration area hot springs+ maFimum
A7o, is a aSO7 water with acidic pM o! 7.8 to 7.7 and A<7 to 79 mg&-g SO7 , E mg&-g l
and some Sul!ur deposition+ *see =igure 5+. There are no !umarole mani!estations in the area.
Table < lists a set o! standard chemical geothermometr$ applied to the 7 bloc-s described aboe.
Jn relation to this tabulation
*'eotherm(F <87+ notes:
• chemical geothermometers donRt appl$ to the waters o! T< Bloc- and B Bloc- because
the$ are shallow and would not hae e"uilibrated at high temperatures
• The T< Bloc- hot spring isnRt listed but presents eidence o! a s$stem maFimum o! about
88 to 5o• Two !orms o! the Na&L geothermometer are listed. One is calibrated b$ =ournier and the
other is a relatiel$ new calibration b$ Santo$o and HiaG'onGales *<88+
• Table < does not list the commonl$ cited Na&L and L%g temperatures o! 'iggenbach
*9EE+ because the$ produce higher temperature estimates than do other calibrationsthereb$ increasing the ris- to the project o! oer estimating the resource
• Table < also lists the sul!atewater oF$gen isotope temperature using the data aailable in
oino et al *<88+ and the anh$drite *aSO7+ geothermometer calculated b$
'eotherm(F *<87+ using the Watch <7 computer code !or geochemical thermod$namic
speciation applied to a set o! representatie samples.
Hi!!erent geothermometr$ computations can $ield er$ di!!erent results o! di!!erent responses to
cooling !rom highest temperature conditions at depth. The general se"uence o! response rate
*most resistant to least resistant+ is sul!atewater E8 isotope Na&L NaaL "uartG *NaLa%g, L%g, Dnh$drite, halcedon$+ 'eotherm(F, <87+. The isotope geothermometer in
particular ta-es a long time to e"uilibrate, estimated at E $ears at <88o. Other processes such
as miFing oFidation and precipitation can also a!!ect results.
These geochemical data are interpreted as !ollows the h$drothermal s$stem that !eeds the Dpas
Liri Mot springs appears to rise !rom a deep upwelling under %t %aria at about E8 to <<88,
resides !or a long time at about the same temperature and then cools to about <8o in an
out!low to the south and south east be!ore discharging at the Dpas Liri hot springs. There is a
large OE shi!t that is displa$ed b$ the hot springs that implies a long residence time that in turn
implies time !or complete e"uilibration o! the isotope temperature.
POWER PLANTS
The basic t$pes o! geothermal power plants in use toda$ are steam condensing turbines
and binar$ c$cle units. Steam condensing turbines can be used in !lash or dr$steam plants
operating at sites with intermediate and hightemperature resources *58+. The power plant
Technolog$ deelopments during the 9E8s hae adanced lower temperature geothermal
electricit$ production. These plants, -nown as Ubinar$V geothermal plants, toda$ ma-e use o!
resource temperatures as low as C5o=, or ;7o *assuming certain parameters are in place+ and
as high as A58o= *;;o+. DpproFimatel$ 5 percent o! all geothermal power plants utiliGe
binar$ conersion technolog$.
Jn the binar$ process, the geothermal !luid, which can be either hot water, steam, or a miFture o!
the two, heats another li"uid such as isopentane or isobutane *-nown as the Uwor-ing !luidV+,
that boils at a lower temperature than water. The two li"uids are -ept completel$ separate
through the use o! a heat eFchanger used to trans!er heat energ$ !rom the geothermal water to the
wor-ing !luid. When heated, the wor-ing !luid aporiGes into gas and *li-e steam+ the !orce o!
the eFpanding gas turns the turbines that power the generators.
'eothermal !luids neer ma-e contact with the atmosphere be!ore the$ are pumped bac- into the
underground geothermal reseroir. Because the geothermal water neer !lashes in aircooled
binar$ plants, 88 percent can be injected bac- into the s$stem through a closed loop. This seres
the duel purpose o! reducing alread$ low emissions to near Gero, and also maintaining reseroir
pressure, thereb$ eFtending project li!etime. =or lower pressure steam, a two phase binar$ c$cle
is sometimes used. Twophase s$stems are similar to traditional binar$ c$cles, eFcept the steam!low enters the aporiGer&heateFchanger, while the geothermal li"uid is used to preheat the
organic motie !luid. The steam condensate either !lows into the preheater or is combined in the
geothermal li"uid a!ter the preheater. Since the steam pressure in the aporiGer&heateFchanger
remains aboe atmospheric pressure, the non condensable gases *N'+ can be reinjected
together with cooledgeothermal !luid or simpl$ ented without the need !or a power consuming
acuum pump. =igure 7 shows Binar$ Power plant schematics.
owners o! power plants with a rated capacit$ o! A8 6 ,888 -W shall submit technical details o!
the plant to the National (nerg$ Duthorit$. Dlso, the National (nerg$ Duthorit$ shall be
in!ormed annuall$ o! the total generation o! power plants with a rated capacit$ o! oer 88 -W.
The National (nerg$ Duthorit$ is responsible !or monitoring mineral prospecting or eFtraction areas and geothermal areas, as well as to regulate the compliance o! companies
operating under issued licenses. The National (nerg$ Duthorit$ will report to the %inister o!
Jndustr$, (nerg$ and Tourism on the conduct o! eFploration, prospecting, and eFtraction in
accordance with !urther instructions issued b$ the %inister. The protection and monitoring o!
prospecting and eFtraction areas is also subject to the Nature onseration Dct.
7.A The ariet$ o! JcelandRs geothermal
Jceland is well -nown to be a world leader in the use o! geothermal district heating. D!ter
the Second World War, Or-usto!nun carried out research and deelopment, which has led to the
use o! geothermal resources !or heating o! households. Toda$, about 9&8 households are heated
with geothermal energ$.
Space heating is the largest component in the direct use o! geothermal energ$ in Jceland.
The !igure 7.A below gies a brea-down o! the utiliGation o! geothermal energ$ !or <8A. Jn the
$ear <8A, the total use o! geothermal was high, with space heating accounting !or 75I.
Figure 4.3: The distribution of geothermal energy 2013