Building a geospatial model to identify potential geothermal sites in Ayrobera: Afar depression, NE Ethiopia

Abstract

Ethiopia has a long-term plan to maximize its power generation to support its growing economy by diversifying its energy sources. Geothermal is an important alternative energy source as the country has a vast potential within the Ethiopian Rift. Several high-temperature geothermal sites that can be utilized for power generation have been identified in the Main Ethiopian Rift and the Afar Depression, using geoscientific investigations at different times. Locating a potential site for geothermal development is a complex process involving decision-making and is prone to human error. Various geospatial datasets can be integrated using geographic information systems to identify potential areas for geothermal development. This technique would facilitate informed decision-making, thus lowering the risk of drilling unsuccessful wells. In this paper, we have used geospatial modeling for potential site identification in the Ayrobera geothermal field, located in the Afar Depression in NE Ethiopia. Weighted Overlay Analysis using the Analytical Hierarchy Process was performed using geospatial datasets as the inputs, including geological, temperature, and geophysical data layers, to determine the most suitable potential geothermal sites. This process yielded a final suitability map, showing the Highly Suitable, Suitable, Less Suitable, and Unsuitable zones. The Highly Suitable and Suitable areas were located near the faults and fumaroles. The Less Suitable and Unsuitable regions were located in the central and northern portions of the study area, far away from surface manifestations and faults.