Geothermal exploration in Eritrea - status report discussion

Abstract

Eritrea is entirely reliant on imported refined petroleum products for its electricity generation. In 2017, 50 MW were added, raising the total installed power capacity to 195 MW. As of the end of this year (2019), 13.5 MW will be generated from solar in the off-grid system. The installed capacity is not sufficient, as development mainly in mining, agriculture and industry sectors is planned to increase. Therefore, harnessing the geothermal potential of Eritrea can have a significant impact on the economic development of the country. The impact can be viewed as greater stability in the electricity price and lesser strain on the environment. Therefore, geothermal energy will have an important input in alleviating expenditure on foreign currency while safeguarding the environment. This year, 24 professionals have undertaken basic training in surface exploration studies in Asmara with the sponsorship of UNEP/ICEIDA. The tectonic setting and geological makeup of the Danakil region of Eritrea are favourable for harbouring geothermal resources with the potential for being developed, mainly for electricity generation and geothermal utilization. Alid, NabroDubbi and Jalua fields are the notable places with ample geothermal manifestations. The 2011 eruption in Nabro-Dubbi signifies that the area is still an active magmatic zone. The old surface manifestation has covered by basaltic flows and ashes. It is to be noted that other high geothermal manifestation also occur in Jalua volcanic complex but needs exploration study

There is considerable potential for the utilization of low-temperature thermal springs for recreation spas, health and mineral water bottling etc., around the AsmaraMassawa highway, close to Gulf of Zula and within the Danakil Depression, which mostly do not show any immediate association with recent magmatism. The completion of some of the surface studies on Alid prompts concentration on recent work. The hydrogeological assessment performed regionally indicates that the recharge area is mainly from three catchments, with input mainly from the highland area. Thorough assessments of Rose diagram and fault and fracture (FFD) analyses have been performed to know areas of up-flow zone. A reservoir temperature of more than 225°C was estimated in the Alid geothermal prospect using gas geothermometers. The resistivity survey that was conducted recently has availed an interesting anomaly at the rift floor and opened a wider perspective in exploration. Gravity and microseismic studies, and soil-gas surveys in Alid were planned for completion in 2019, but were postponed until next year.