Geothermal Signatures in North Africa: Examples from Egypt and Algeria

This study presents an overview of the geothermal footprint of north Africa, with a focus on Algeria and Egypt which have medium-to-high geothermal potential. This study aims to calculate Curie depths, geothermal gradients, and heat flow maps for north Africa, in addition to estimating the stored geothermal power at three sites with high geothermal potential in Algeria and Egypt. Evaluation of terranes for geothermal energy potential makes use of key geothermal parameters. These include Curie depth, geothermal gradient, and heat flow. In this study, these parameters are estimated for north African countries using a variety of geophysical techniques. The Curie depth, calculated from power spectra of aeromagnetic data, ranges from 16 to 33 km. The present day temperature gradient varies between 18 to 34 °C/km and heat flow values lie between 54 and 102 mW/m2. A stochastic Monte Carlo simulation was performed to estimate the geothermal energy stored in the three North African geothermal fields (Hammam Faraun in Egypt and Hammam Bouhdjar and Maskhoutine in Algeria) for 25 years and 50 years. The geothermal electricity potential at Hammam Faraun is ~2.57 MWe and ~1.28 MWe for 25 and 50 years, respectively. The electricity potential for Hammam Bouhdjar is ~4.39 MWe for 25 years, and ~2.19 MWe for 50 years. The electricity potential for Hammam Maskhoutine is ~7.82 MWe for 25 years, and ~3.91 MWe for 50 years. Densely spaced geophysical surveys (e.g., magnetotelluric, gravity, magnetic) should be used to estimate the extent and thickness of geothermal reservoirs, and data from deep geothermal testing wells should be used to evaluate subsurface porosity and density to enhance estimates of geothermal power in the studied regions. Based on the estimates presented here, north African countries (especially northern Algeria and eastern Egypt) can benefit from the utilization of geothermal renewable energy sources.