geothermal potential of the kenya rift: energy estimates ... p. omenda geothermal potenti… ·...
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Peter Omenda and Silas SimiyuKenGen
Geothermal Potential of the Geothermal Potential of the Kenya Rift: energy estimates Kenya Rift: energy estimates
based on new databased on new data
2
• Kenya relies on three major sources of energy in the electricity sub sector: – Hydropower (57 %) – Fossil based thermal (32 %) – Geothermal (12 %).
IntroductionIntroduction
Hydro57%
Thermal32%
Geothermal12%
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Olkaria DomesField
Olkaria NortheastFieldOlkaria Central
Field
Olkaria WestField
Olkaria NorthwestField
Olkaria SoutheastField
Olkaria EastsField
Olkaria I
Olkaria III
Olkaria II
Greenhouses
Oserian power plant
Legend WellPlant location
Olkaria DomesField
Olkaria NortheastFieldOlkaria Central
Field
Olkaria WestField
Olkaria NorthwestField
Olkaria SoutheastField
Olkaria EastsField
Olkaria I
Olkaria III
Olkaria II
Greenhouses
Oserian power plant
Legend WellPlant location
Olkaria Fields
4
Geothermal InstallationsGeothermal Installations
• Four Power plants have been installed at Olkaria, namely:
Current– Olkaria I 45 MW– Olkaria II 70 MW– Olkaria III 13 MW– Oserian 2 MWTotal 130 MW
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Immediate additional Installations Immediate additional Installations (By 2010)(By 2010)
• Olkaria II Extension 35 MW• Olkaria III Expansion 24 MW• Olkaria IV Development 70 MW• Eburru Development 2.5 MW• Oserian II 2 MW
Total 133.5 MW
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Geothermal Occurrence in KenyaGeothermal Occurrence in Kenya
• Geothermal areas are located within the Kenya Rift
• Rift has been magmatically active since 25 Ma.
• Last magmatic activity occurred few hundred years ago
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High Temp Geothermal AreasHigh Temp Geothermal Areas• 14 high temp
geothermal areas identified in the rift
• 130 MW at Olkaria• Exploration drilling has
been done at Eburru• Detailed surface studies
done on 7 others
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Resource assessmentResource assessment• Mainly volcano (caldera) hosted
systems• Based on Olkaria experience
– 30-35 MW/km2
– Centralized heat sources– Similar permeability/hydrological structure
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Heat SourcesHeat Sources
• Shallow magma bodies:– magma chambers (5-
10km)– Dike swarms
• High geothermal gradient:– Thin crust (20-30km)– Upwelling mantle (50
km)
As imaged by gravity, seismics and geological models
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Suswa volcanoSuswa volcano• Late Pleistocene
caldera volcano• Geothermometry
temp >300oC
Suswa caldera
Island blockOuter caldera
Inner caldera
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Suswa volcanoSuswa volcano• Low resistivity
anomaly (15-20 ohm-m) within the caldera
• Power potential is estimated to be over 2-400 MW
Outer caldera
Inner caldera
Island block
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Longonot volcanoLongonot volcano• Large caldera
volcano and a summit crater
• Youngest activity less than 300 yr BP
Summit craterOuter caldera
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Longonot volcanoLongonot volcano
• Reservoir temp (>300oC) from geothermometry
• Estimated potential is more than 700 MWe based on >30km2 potential area
210 215 220Eastings (km)
9890
9895
9900
9905
210000 215000 220000
0579111213141517182021232731343944474955606687107
2004 MT
2006 MT
MT at 2000 mbsl
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Eburru Volcano• Pleistocene
caldera volcano • 6 exploration wells
drilled• Maximum
temperature is 285oC
Geological map of Eburru
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GeophysicsGeophysics--MTMT
• Heat source under the eastern volcano
• Resource Potential: >60 MW
• Pilot 2.5MW plant planned for 2007/8
191 192 193 194 195 196 197 198 199
Easting (km)
9926
9927
9928
9929
9930
9931
9932
9933
Nor
thoi
ngs
(km
)
EW-01EW-02
EW-03
EW-04
EW-05 EW-06
06791012152022232425262729
3341455065100150242289360451579
Cedar Hill
Lion Hill
Eburru FarmEburruPeak
- m
LegendMT sounding Volcanic centre
Geothermal wellCrater
Road Fault
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Menengai VolcanoMenengai Volcano• A large caldera volcano
on the rift floor (>70km2)• Low resistivity (<15
Ohm-m) at 2000 mbsl
MT Resistivity at 2000 mb s.l and proposed well site locations.
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Menengai volcanoMenengai volcano• Geothermometry
indicate temp (>300oC)
• Estimated power potential is over 1,000 MWe based on >48km2 potential area
Conceptual model of Menengai prospect
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Arus & Lake BogoriaArus & Lake Bogoria• Plio-Pleistocene flood
lava field• Has hot springs,
spouting springs, fumaroles hot grounds
• Manifestations are structurally controlled
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Bogoria/Arus areaBogoria/Arus area
• High heat flow covers large areas of Arus-Bogoria and Baringo areas
160 170 180Eastings (km)
-30
-20
-10
0
10
20
30
40
50
60
70
80
Nor
thin
gs +
10,
000
(km
)
15
25
35
45
55
65
75
85
Menengai crater
MenengaiOlbanitablock
Arus &L. Bogoriablock
L. Baringoblock
The Equator
°C
Arus
L. Baringo
L. Bogoria
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Lake BaringoLake Baringo• No central volcano• >200oC reservoir is
present in the western region
• Heat source is due to dike swarms and plutonic intrusions
165000 170000 175000 180000 18500056000
61000
66000
71000
76000
81000
BarMT01
BarMT03
BarMT04
BarMT05
BarMT06
BarMT07
BarMT08
BarMT09
BarMT10
BarMT11
BarMT12
BarMT13
BarMT14
BarMT15
BarMT17
BarMT24
Chepkoiyo well
056810131415171819212325293341454790151200242289360451579
m
Endao
Loruk
RUGUS
KECHI
LORUK
Ngambo
Napiyet
Lemuyet
Salabani
Nosuguro
Komolion
KOKWOMOW
Loiminange
NAKURATABEM
KOKWA ISLAND
Lesukut Island
Lekoros Island
Rongena Island
Parmalok Island
KAMPI YA SAMAKI
Longicharo Island
Lake Baringo
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Korosi volcanic complex• Korosi is a Pleistocene
volcanic complex• Geothermometry
indicates temperatures of more than 250oC
Korosi
22
Korosi volcano
• Main heat source is located northern part of the volcano
• Potential is more than 200 MW
164 166 168 170 172 174 176 178 180 182 184 186 188 190 192 194
Eastings (Km)
78
80
82
84
86
88
90
92
94
96
98
100
Nor
thin
gs (K
m)
KorMT01
korMT02
KorMT03
KorMT04
KorMT05
KorMT06
KorMT07
KorMT08
KorMT09
KorMT10
KorMT11
KorMT12
KorMT13
KorMT14
KorMT15
KorMT16
KorMT17
KorMT18
KorMT19
KorMT20
KorMT21
KorMT22
KorMT23
KorMT24
KorMT25
KorMT27
KorMT26
KorMT28
KorMT29
KORMT32
KORMT33
KorMT35KorMT36
KorMT31
Legend
MT location
0122.533.253.3753.545678912143035405070120
Kinyach Crat er
LORUK CENTRE
CHESIRIMION
CHEPKO KECH
TUWA
KOKORE ADO MEYO N
NAGORETEI
SERONI
TANGULBEI
-m
L. Baringo
L. Tilam
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PakaPaka volcanovolcano• Detailed surface
investigations is currently being undertaken
• Last magmatic activity was <200 yrs
• High potential is expected due to high T fumaroles and other manifestations
Paka caldera
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Silali• Large caldera volcano• Has the largest hot springs in
the Kenya rift – 1,000l/s at 45-60oC discharge
• Planned for detailed investigations in 2007
• Large generation capacity is highly anticipated (>1,000MW?)
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Emuruangogolak and Barrier volcanoes
• Emuruagogolak and Barrier are large caldera volcanoes north of Silali
• Youngest volcanic activity in the rift occurred at Barrier
• Large potential is expected of more than 1,200MW between the two
Emuruagogolak caldera
Barrier volcanic complex
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Other prospects• Lake Magadi in the
south• Elmenteita near Eburru• Ol Banita north of
Menengai• Akira area south of
Longonot
Shombolevolcano
L Magadi
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ConclusionsConclusions• Current estimates suggests that
over 5,000MWe can be generated from the known resources in the rift
• Deep exploratory drilling is urgently required to prove the reservoirs
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