Conference: East African Power Industry Convention
Location: Addis Ababa, Ethiopia
Presenter: Solomon Kebede
Abstract: Presented by Solomon Kebede at East African Power Industry Convention
Ethiopia launched a long term geothermal exploration undertaking in 1969. The study has revealed the existence of both low and high enthalpy geothermal resources in the Ethiopian Rift Valley and in the Afar depression, which are both part of the Great East African Rift System.
Over the years, a good inventory of the possible resource areas has been built up and a number of the more important sites have been explored. Of these areas, about sixteen geothermal prospect areas are judged to have potential for electricity generation. A much larger number are capable of being developed for applications in agriculture, agro-industry etc.
Exploration work peaked during the early to mid-1980s when exploration drilling was carried out at the Aluto-Langano geothermal field. Eight deep exploratory wells were drilled to a maximum depth of 2.5 km and temperature up to 350° C, of which four are potentially productive. During the early 1990s, exploration drilling was also carried out at Tendaho. Three deep (about 2100m) and three shallow (about 500m) wells were drilled at the Tendaho geothermal field, and proved the existence of high temperature and pressure fluid.
A new era of resource utilization started in 1998 by installing the constructing and installing Ethiopia’s first geothermal pilot power plant to generate electricity. This “Aluto-Langano Geothermal Pilot Power Plant” has a designed power output of 8.52 MWe (gross) and 7.28 MWe (Net). Initially, there was a disruption in power generation due to technical problems. These were studied and are currently being rectified. The plant is now achieving partial generation (3MWe).
In the Tendaho geothermal field, three deep (2100 m) and three shallow (500m) exploratory wells were drilled that encountered a temperature of over 270ºC. The techno-economic study indicates that four productive wells (out of six) of this geothermal field could supply a pilot power plant of about 5 MWe, and the potential of the deep reservoir is estimated about 20 MWe. At present, the Ethiopian Electric Power Corporation (EEPCo) and the Geological Survey of Ethiopia (GSE) are working on resource assessment of the Tendaho geothermal field within the framework of the Tendaho feasibility geothermal project, financed by the USTDA.
Other geothermal prospect areas in the Ethiopian Rift Valley are at various stages of exploration that vary from reconnaissance to detailed geoscientific studies including drilling of temperature gradient (TG) wells. These include: (i) Corbetti and Tulu-Moye: Detailed geoscientific studies including drilling of TG wells; (ii) Abaya, Fantale and Dofan: Detailed geoscientific studies; and (iii) Teo, Danab, Meteka, Kone and others: Reconnaissance investigations.