ETHIOPIAN ELECTRIC POWER CORPORATION

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ETHIOPIAN ELECTRIC POWER CORPORATION

• REHABILTATION WORK PROGRESS AND EEPCOS FUTURE
  PLAN IN GEOTHERMAL DEVELOPMENT

Geothermal resource council 2007 Annual meeting
Reno, Nevada , USA September 30- OCT 03, 2007
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General Description of the Aluto Langano steam
fields

• The Aluto Langano Geothermal field is located in
  the Main Ethiopian rift valley at Lakes District
  between Lakes Langano and Ziway (Fig1)
• The proven productive area at Aluto is about 8km2
• Eight wells drilled in the early 1980s, out of
  which only four wells are successfully for
  production
• The two Wells drilled along the Wonji fault are
  high pressure wells (LA-3 and LA-6) , where as
  Wells drilled on the outflow zone are medium
  pressure wells (LA-4 LA-8)

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MAIN ETHIOPIAN RIFT WITH GEOTHERMAL PROSPECTS
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Aluto Langano Steam Field
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Power plant design and operation

• A combined steam and binary cycle unit rated at
  7.28 MW(net) was constructed and began operation
  in May1998.
• However, due to numerous issues with the power
  plant , gathering system, and production wells
  the plant failed operation in 2002

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Tendering and Contracting

• In 2004 a competitive tender was offered to
  evaluate the entire project by the Ethiopian
  Electric Power Company.
• In June 2005 a contract awarded to the Geothermal
  Development Associates to evaluate the condition
  of the geothermal resource and to refurbish and
  restart the power plant

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Tests and measurements of the Steam field

• Refurbishment of the wellhead and side valves
  that are stacked and was none functional
• By Running caliper logging proved that the two
  high pressure production wells are in good
  condition
• One of the medium pressure well (LA-4) is largely
  blocked by carbonate, and the second well (LA-8)
  is also blocked but still has a good flow rate.
• Tests with digital temperature and pressure logs
  proved the older test results of the mechanical
  logs

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The OEC unit Heat exchanger failure and Analysis

• The heat exchanger is a 316L stainless steel tube
  
• The heat exchanger is a counter-flow design with
  steam on the tube side and liquid on the
  shell-side
• Tubes failed on the steam discharge end
• Pitting occurs on the internal diameter of the
  tubing
• X-ray analysis shows that silica sulphr
  depositions with minor traces of K,Na, Cl Al
• Brine carryover is suspected to be the cause for
  the failure

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Chemistry and scale deposition Analysis

• The PH of the steam field is alkaline at about
  8.5-9.0.
• However, weak acids form when CO2 and H2s
• is condensed from the coexisting steam
• Condensation would be most sever at the discharge
  end of the condenser tubes, where cooling greater
  and thus pitting is most sever.

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Operating the GCCU unit

• The GCCU Rotor refurbished and de-rated to lower
  the design steam inlet pressure. This helped to
  overcome the pressure drop of the production
  wells.
• On June 07,207 the first startup of the GCCU unit
  after a six year silent time.
• Currently the unit has operating with full
  capacity

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TENDAHO GEOTHERMAL FIELD

• Extensive aerial and surface investigations
  carried out 1970 80
• Three deep (up to 2100m) and three shallow (up to
  500m) wells drilled 1993-98
• Four wells productive with reservoir
  temperatures up to 270ºC.
• Through Energy market group Geothermal
  Development Associates has studied resources
  confirmation
• Follow up geochemical and reservoir engineering
  studies being conducted by GSE

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EEPCOS future plan in geothermal power
development

• Development of 30 MW expansion at Aluto Langano
• Development of 3-5 MW pilot plant at Tendaho
  steam field for EEPCO has submitted letter of
  commitment on the final project proposal to ARGeo
• Resource assessment and power plant development
  at other prospects (Corbetti, Tulu- Moye, Abaya,
  Gedemsa, Dofan, fantale, etc.)

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GOVERNMENT RATIONALE FOR GEOTHERMAL EXPLORATION

• Build infrastructure, improved access to
  electricity for social services
• Accelerate development of indigenous energy
• Encourage private investment in IPP mode and
  suppliers credit in electricity generation,
  distribution
• Increase electricity generation capacity of
  800MW of which 90 is hydro, 10 from other
  sources
• Balance energy mix, decrease dependence on
  drought-prone hydro
• Exploit reliable base load character of
  geothermal energy
• Access resources from the UNEP/GEF ARGeo Regional
  Geothermal Program

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ELECTRICITY LEGISLATION, LICENSING

• Electricity Proclamation N0.86/1997 seeks to
  promote domestic, foreign private investment in
  power generation from all sources
• Independent power producers (IPPs) may generate,
  sell electric power to EEPCo or establish
  independent distribution systems in areas not
  served by grid
• Generation licenses available for life of project
  up to 40 years
• Transmission, distribution, power sale licenses
  available up to 50 years
• Power import, export licenses up to 10 years
• Projects require authorization of Ethiopia
  Environmental Protection Authority (EPA) before
  implementation

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Opportunities for Private Sector Participation

• Tendaho Plant Construction
• Aluto 30 MW Expansion
• Training of EEPCO and GSE Personnel

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EEPCO Geothermal Contact Information

• Merga Tassew, Geothermal Program Coordinator
• DEGAULLE SQUARE, P.O. BOX 1233
• ADDIS ABABA, ETHIOPIA
• Fax [phone]
• Tel. [phone]
• pso.dept_at_telecom.net.et
• mergatassew_at_yahoo.com

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THANK YOU FOR ATTENTION

• AND WISH YOU HAPPY ETHIOPIAN MILLINIUM!!