GEOTHERMAL EXPLORATION AND DEVELOPMENT IN ETHIOPIA: COUNTRY
UPDATE Solomon Kebede
Nov 28, 2019
Sustainable Development Goals Short Course IV on Geothermal Resources Exploration and Development
Director, Geothermal resources ExplorationGeological Survey of Ethiopia
PRESENTATION OUTLINE
IntroductionStatus of electricity productionGeothermal resources in Ethiopia
Geological set upLevel of explorationSurface explorationDeep drillingGeothermal utilization
Geothermal development planChallenges and way forward
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Status of Geothermal Exploration and Development in Ethiopia
• Horn of Africa• Area > 1.1 million Sq. Km • 6 Neighbors• Physiography• Population• Agricultural led economy
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Status of Geothermal Exploration and Development in Ethiopia
Introduction
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
STATUS OF ELECTRICITY PRODUCTION
No Source of generation
Installed capacity (MW)
%
1 Hydropower 4077 90.1
2 Other renewables
349 7.7
3 Geothermal 7. 3 0.2
4 Thermal 89 2
Total 4522.3 100
Status of Geothermal Exploration and Development in EthiopiaIntroduction
ERS Part of the EARS, ERS runs from SW to NE part, divided: MER and Afar dep Latest actvity along the AxisSilicic volcanism dominate in MER, basaltic in AfarRegional heat flow anomaly + volcanic systems abnormally forming local areas of high thermal gradient
Status of Geothermal Exploration and Development in EthiopiaIntroduction
Geological Setup
Level of Exploration
Areas at reconnaissance level ( geology and geochemistry, no geophysics ( 5/25
GEOTHERMAL RESOURCES
Areas where detail surface exploration has been completed (geology, geochemistry, geophysics, conceptual modelling (20/.25)
From the 20 in two areas drilling has been conducted and 1 area has pilot plant 7.3 MW
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Status of Geothermal Exploration and Development in Ethiopia
25 high temp areas identified
Inferred Reservoir
Reservoir Area
Reservoir thicknessReservoir AverageTemperatureRecovery factorEnergy Efficiency(Flash type)Rock Porosity
Rock densityRock volumetricspecific heatFluid densityFluid volumetricspecific heatPlantfactor/availability
At an initial stage, the details not known Formula is used to calulate (volumetric method)
Estimated electrical potential 10 800 MW
GEOTHERMAL RESOURCESEstimation of potential
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Status of Geothermal Exploration and Development in Ethiopia
Monte Carlo Probability
Direct Use potential not yet being made
Detail Surface Explorations ( Case example Aluto)Detail: (Geological, Geochemical, Geophysical ( Resistivity, Gravity and Microseismic)
Geological : (litho logical, structural, alteration )
Findings ImplicationsDifferentiated products/caldera/large volume
Shallow magmatic chamber/ large magma
> 65 craters , extensive manifeatations
Persistence of heat source
3 Major fault zones with manifestations
Potential targets, 3 flow paths
E-W progressive downfaulting
Depth to reservoir, thickness of units
Impermeable altered clay zones with underneath fractured rocks
Existence of cap rocks and reservoir rocks
9x8 Km caldera Size of anomaly approx 80 km 2
Status of Geothermal Exploration and Development in Ethiopia
WE
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Geochemical : (fluid and gas, isotopic, radon and Co2 flux)
Areas of radon anomaly and high CO2fluxes are situated: (i) along the Jawe faultzone and (ii) at Bobessa
Geothermometers > above 300°CNCG of 2-3 % in weight of the total fluidRecharge from rift escarpmentsPossible scaling phenomena, Calcite lower
temp wells, Silica (below 160 to 190 °C inthe hottest wells)
Eestimated pH values >> no corrosionSr 86 /Sr 87 ratios indicated Bobesa fumaroles
are not outflows
Status of Geothermal Exploration and Development in EthiopiaDetail Surface Explorations ( Case example Aluto)
The fluids are of Na-HCO3-Cl Main results
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
West‐east 2D resistivity profiles
Over 100 stations monitored
Status of Geothermal Exploration and Development in EthiopiaDetail Surface Explorations ( Case example Aluto)Geophysical : (MT) subsurface electrical conductivity is inferred from
measurements of natural geomagnetic and geoelectric field variation
Results
Clay cap of 1- 10 ohm in 2 areas
Underneath higher resistivity> high temp alteration > top of the reservoir
Active geothermal systems Model
used to provide information on subsurfacestructures and intrusive bodies
Status of Geothermal Exploration and Development in EthiopiaDetail Surface Explorations ( Case example Aluto)Geophysical : (Gravity)
Over 200 stations
Negative anomalies >>pyroclastics and infillings Positive anomaly P1, extends in the eastern part of the caldera
horizontal derivatives shows curvilinear /linear features L1, L2 and L3, trending NNE-SSW and basement structures
to monitor areas of current natural seismictremors which may correspond to anupflow center
Frequency is high to the east
Structural high to the east (depth of hypocenters, the point of origin of earthquakes about 4km, interpolation curve)
Status of Geothermal Exploration and Development in EthiopiaDetail Surface Explorations ( Case example Aluto)Geophysical : (Microseismic):
9 Stations
the eastern part in correspondence of a structural high better potential target of exploration drilling
Interpolation curve
Two reservoirs and the areal extent of the reservoir is inferred on the base of the geoelectrical anomaly ( about 5 sq km in the east and 6 sq km in the center)
Top of reservoir is expected at shallow depth 600m in the east and deeper in the central
Thickness of the reservoir is estimated to be to 1,200 m.
The reservoir is expected to be two-phase in the upflow zone and liquid dominatedin the peripheral one
Deep wells are proposed in both areas
Status of Geothermal Exploration and Development in EthiopiaDetail Surface Explorations ( Case example Aluto)
Conceptual model
ALUTO
6 wells drilled (mid 1990)3 are productive (temp 250 deg C and out put 5 MW)
10 wells drilled (mid 1980, 2014)6 are productive (4 connected to power plant 7.3 MW, 2 wells for well head turbine)
Status of Geothermal Exploration and Development in EthiopiaDeep drilling
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
• A binary plant installed in 1998• Capacity 7.3 MW• Currently Under
Maintenance
Status of Geothermal Exploration and Development in EthiopiaGeothermal Utilization (Electrical)
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
FILWIHA SODERE
WONDO GENET
Status of Geothermal Exploration and Development in EthiopiaGeothermal Utilization (Direct Use: utilizing the heat from hot water/steam for various purposes)
Limited to swimming pools and medical purposes
Capacity (MWt) = Max. flow rate (kg/s)[inlet temp. (oC) - outlet temp. (oC)] x 0.004184
Energy use (TJ/yr) = Ave. flow rate (kg/s) x [inlet temp. (oC) - outlet temp. (oC)] x 0.1319
Capacity and energy use not yet determined
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Temperature in deg C
Potential Applications in Ethiopia
20
40
60
80
100
120
140
160
180
200
Processing in pulp/paper factories
Sugar refining in factories
Drying and curing of cement in factories Drying of agricultural products
Swimming poolsFish farming
Heating of green houses
Status of Geothermal Exploration and Development in EthiopiaGeothermal Utilization (Direct Use, Future potential)
Vegetabledrying
Fish farming
Green house heating
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Public Sector
Surface expl (GSE)Direct Use Feasibility (GSE)Aluto drilling of 22 wells (EEP)(Two rigs purchased, chinese/kengen areinvolving)Tendaho drilling of wells in 3 target areas(WB, AFD, JICA) (EEP, GSE))Aluto well head plant (JICA)
Private Sector
Many IPPS (Corbetti, Tulu Moye, Ormat, RG,Cluff) have completed detail surfaceexploration in multiple prospects and aremoving to the next stage (EEA)
Status of Geothermal Exploration and Development in EthiopiaCurrent Geothermal Projects
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Geothermal Development Plan By 2030
No Locality Developer Current status (MWe)1 Aluto Langano Public (EEP) implementation 70
2 Alalobad Public (EEP) implementation 25
3 Corbetti Private (CorbettiGeothermal)PPA negotiation 520
4Tulu Moye
Private ( Tulu Moye Geothermal)
implementation 520
5 Wendo Genet, Dofan,Boku, Dugna Fano
Private (Ormat Plc) PPA negotiation 450
6 Fentale Private (CluffGeothermal)PPA negotiation 150
Total 1735
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Status of Geothermal Exploration and Development in Ethiopia
• Recent studies indicated model C is preferable
• All IPPs are currently operating under model A
• The public sector is currently operating under Model D
• Inpractice combination of models is being implemented
Pre-
Surv
eySu
rface
Expl
orat
ion
Test
Dril
ling
F/S
Plan
ning
Pow
er P
lant
C
onst
ruct
ion
Ope
ratio
n &
Mai
nten
ance
APrivatePublic
Public Private B
Public Private C
Public Private
D
Development Model
Several models considered
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Status of Geothermal Exploration and Development in Ethiopia
Challenges of Geothermal Devt in Ethiopia
Challenge Yes or NoResource No
Energy ploicy Yes
Availability of finance
No
Instutional yes
Local capacity Yes
Awareness Yes
Kenyan Geothermal Ethiopian Geothermal
> 10 000 MW pot> 10 000 MW pot
Status of Geothermal Exploration and Development in Ethiopia
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Establish better institutional set up and system ofproject implementation
Establish better coordination among stake holders Facilitate negotiations with IPPs and give timely
decisions and create more enabling environments tothe private sector
Create awareness at federal and regional level Build local capacity in human power and technology Coordinate individual geothermal and related
professionals efforts through geothermal association
Way Forward
Status of Geothermal Exploration and Development in Ethiopia
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Ethiopian Geothermal Association established and legalized on Sept 3,2019
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
Advise the countries energy sector in geothermal issues
Promote and support geothermal professionals in research and development
Establish standards in geothermal exploration and development activities
Enhance the geothermal knowledge of its members through discussions and workshops
Develop strategies to attract professionals in geothermal field of studies
Collaborate with other civil associations (local, regional, international) and private developers in the implementation of joint seminars, researches, symposiums and workshops
Promote the versatile use of geothermal energy in the country
Main Objectives of EGA
SDG short course IV on Exploration and Development of Geothermal Resources Organized by UNU‐GTP and KenGen ( Lake Bogoria and Lake Naivasha/ Nov 13‐Dec3,2019)
