GEOTHERMAL ENERGY Flashcards
Geo - Earth, Thermal - Heat
Natural Heat of the Earth
Source of Heat
?Heat flows outwar from Earth’s Interior
?the crust insulates us from the interior Hear
?Mantle is Semi Molten
?Outer Core is liquid and Inner Core is Solid
Regions where geothermal system is situated
Volcanic Regions
Heat source
Magma intruded to shallow levels (<6 KM) in the crust in the Recent Past (<100K years)
Reservoir Characteristics
?Fractured Rocks (3-10km)
?Permeable and Porous
?Needs water to sustain Convection and ?Produce Steam
Seal / Cap Rock
Impermeabl or Semi-Permeable
Elemets of a Geothermal System
1) Water - Sufficient to effect Convection needs recharge
2) Cap Rock - Impermeable Rock Formation
3) Reservoir - Permeable and Porous Rocks neutral kasi nagreact na sa wall rocks, if directly above the magma acidic
4) Heat Source - Shallow levels (<6km) in the recent (<100,000 yrs) past
Geysers
Alternating eruption and quiessence of Water due to heating and pressure
Silica Sinter Terrace
Form in neutral areas, deposits from the boiling water, mountains of silica terraces
Blue Water - Neutral
Fumaroles
Steam Vents
Hot Spring
Hot Boiling Waters
Thermal Area/ Steaming Ground
May usok lang
Mud Pool
bubbling of mud
Algal Mat
Emerald Green Waters due to algae with Gold at the side due to oxidation
Travertine
Form if limestone deposited by Mineral Springs
Edge of the reservoir
Hot pool
Blue water due to nuetrality
Solfatara
Steam Vents with significant Sulfur Deposition fumarole rich in Sulfur
Saffioni
Fumaroles with high Boric Acid
Kaipohan
Cold Gas emission w/ intense argillic alteration
?A place in Valencia Negros Oriental
?Trees are dead
Enthalpy
Total Heat content of a system
Critical Pt of Water
374 deg C
Classes of Geothermal Systems are based on
Entalphy (Heat Content) and
Pressure
Classes 1 -4
Low Entalphy
All Liquids
Class 5-6
Twophased
High Entalphy
Class
Reservoir Temp
Non Electrical Grade
<100 deg cel
Very Low Temp
100-150 deg cel
Low Temp
150-190 deg cel
Moderate Temp
190-230 ded cel
High Temp
230-300 deg cel
Very High Temp
> 300 deg cel
Steam Field
240 deg C
Usual Geothermal Fields in the Philippines
High Class 5
Highest Temp Geothermal observed
S.Vito (Campi Flegrei Campania) (400 deg)
Steam or Dry Geothermal
Larderello
M.Amiata (Italy)
Geysers California , Matsukawa Japan
Kawah Kamojan Indonesia
Very First Geothermal installed
Itality Larderello 1904
What pushed countries to use geothermal?
1973 Oil Crisis
As of 2017, how many countries use Geothermal?
24
Top 3 Countries in terms of installed capacity as of 2019
1) US
2) Indonesia
3) Philippines
1 Gigawat Country Club
1) US
2) Indonesia
3) Philippines
4) turkey
5) New Zealand
Largest Geothermal Fields
The Geysers, USA
Leyte/Tongonan PH
Cerro Prieto Mex
Larderello ITA
Mak-Ban Phi 458 Mw
Salak-Awibengkok INA
Darajat, INA
Salton Sea USA
Tiwi, PHI
Coso, USA
Wairakei, NZ
First Well in Tinglayan, Kalinga
Drilled by Apec
Father of Philippine Geothermal
Dr. Arturo P. Alacaraz
Date when a electric bulb was lit up by geothermal energy for the first time through a working model set up by Dr. Alcaraz
400 Feet into a ground
2.5 KW turbo Generator
April 12, 1967
Where is the first Geothermal PP discovered
Cale, Tiwi Albay
Philippine Geothermal Law
RA 5092 Geothermal Law (1967)
First commercial Geothermal production
1972
when was PNOC established?
1973
Tiwi and MakBan (first 110 MW)
1979
?Tonongonon Leyte,
?Palinpinon Valencia Negro OR
1983
BacMan Sorsogon
1993
Build Operate Transfer (BOT) Law
1990
Mahanagdong, Leyte
Mt.Apo
1996-1999
RA 9136 EPIRA Law
2001
Northern Negros (Decommisioned)
2006
reached 1,970 MW
2007
RA 9513 RE Law
2008
Maibarara, Sto.Tomas, Batangas
2014
Total Installed Capacity
1937.56 MW
MakBan, Laguna
458.53 MW
Maibarara, Sto.Tomas Batangas
32 MW
Tiwi, Albay
234 MW
BacMan, Sorsogon
140 MW
Leyte (Mahanagdong, Tongonan)
722.68 MW
Nasulo, Negros Oriental
49.37 MW
Palinpinon, Valencia, Negros Oriental
192.5 MW
Mt. Apo
108.48 MW
Govt Agency in charge of processing, evaluating, approving all RE Concession Areas
Issue RE Contracts
Department of Energy
REMB
Provisions of RE Contracts
?Term: 25 years renewable for another 25
?Major obligations:
1) Comply with the work program
2) Deliver Financial commitment such as Govt Share and Taxes
3) Comply with applicable laws affecting the stakeholders
RE Provides Fiscal and Non Fiscal Incentive
1) Processing support
2) Accesss to all sites/areas needed for exploration
3) Assistance in securing needed permits
4) Exclusive Rights to Conduct RE-related operation w/in the concession
Why is FTAA applicable to Geothermal?
Because RA 9513 defines Geothermal as Mienral Resources
Prospects AREAS for Low Enthalphy Geothermal
1) Banton Is, Romblon
2) Balut Is,Davao del Sur
3) Maricaban Is., Batangas
Coal
44.50%
Nat Gas
22.90%
Geothermal
13.40%
Hydro
10.50%
Oil
7.10%
Wind
0.90%
Biomass
0.40%
Solar
0.20%
Stages
- Surface Reconnaissance
- Exploration Drilling
- Production Drilling
- SAGS+Pplant
- Operation + Maintenance
Upstream
Resource Development
Downstream
Plant Construction/Operations
Risk
Decraeasing as Project Progresses
Cost
Increasing Cost and Bankability
Surface Studies
?Gathering Local Knowledhe
?Lithology, structures
?Locating Known Active Geothermal Surface features
?Overall Surface geology
Geochemical Surfveung
?Geothermometry
?Electrical Conductivity
?pH
?Flow rate of fluids from active features
?Soil Sampling
Geophysical Surveying
?Gravity
?Electrical Resistiviy
?Magnetotellurics
?Temp gradient Drilling Borehole
?2D and 3D Seismics
Alterations in a Geothermal Field from top to bottom
Unaltered
Zeolite-Smectite Zone
Argillic Zone (Clayey)
Propylitic Zone
Size
~10 kg of Steam to produce 1 unit (Kwh)
Great Volumes of Fluid at hight tempures or a reservoir that can be recharged with fluids that are heated by contact with water
Host Rocks
Limestone-Shale
Volcanic Rocks-Granite
Volcanic Rocs-mot common single rock type in which reservoirs occur
High Heat Flow
Fracturing must exist and presernce of high heat flow ( geothermal gradients in usual tectonically active regions) have greater weight in consideration than the type of host rock
Depth
1-3km economically viable
Well spacing
wells are spaced
Temp
<100 not electric grade
Commercially viable systems starts at 190 deg C
Geothermal Resrouce Layers
1) Resistive Shallow Layer (Near Surfcae)
2) Conductive Clay Cap
3) Reservoir (should be fractured)
4) Hear Source
Mienralgy
Smectite Zeolite
Smectite (Arigillic) Clay Cap
Smectite - Illite Transition Zone
Illite-Chlorite Porpylitic
Resitivity signature of Clay Cap
below 10 ohmeter thus conductive since low ang reisitivity
Alteration zones
Smectite Zone or Clay Cap
pH of the Reservoir is
Neutral to
Moderately Alkaline (8.5) - Mod Acidic (5.5)
Acidic Minerals
Kaoliniteand Pyrophyllite
Neutral
Pyrite
Smectite
Chlore-Smecitie
Illite
Chlorite
Epidote
Actinolite
Basic
Calcite
Prehnite
Laumontite
Wairakite
Drilling
Conductd to verify presence of commercially acceptable temp (PT Survey)
To sensure presnce of permeable zones
Obtain Core samples
Feed Zone
typically found in permeable layers characterized by Total or partial mud loss circulation
Blank Liners
Covers anything above the top of the reservoir to avoid cold water intrusion
Perforated Liners
Used in the production Area
High NCG (Non Condensible Gasses)
Tripping of plants due to lowering of condenser vaccums
Scaling
causes well diamter to decrease
Corrosion
Results to pitting, thinning, and casing wear (Cracks or Holes) of wells
Cold Water intrusion
Cooling of reservoir
Three major classes of Geothermal Scales (Bara)
1) Silica and Silicates
2) Carbonate of Calcium and Fe
3) Sulfides of Iron and Heavy Metals
Separator (Brine From Steam)
Brine is injected Back to to the reservoir
Steam goes though the scrubber to again be purified from condensate water
Condensate is injected Back to the reservoir
Geothermal and Environment
Has less impact on the evnironment
?Less emission than FF fire plant ~5% of Coal
?Closed loop production kaya walag discharge of chmical pollutants and waste
?Land use is small compared to other fuels ~10% of Solar (Solar kumakain ng field)
?Readily coexist with natural habitat and agriculture
?Relaiable base load of renewable power
