Addressing Essential Hydrogeological and Environmental Constraints for Geothermal Development in East Africa

Abstract

Geothermal energy is vastly under-utilized and represents an exciting means of addressing energy challenges, alleviating poverty, and promoting economic development in the nations of the East African Rift System (EARS). The countries that straddle the rift system are home to a combined population of more than 400 million, a significant proportion of whom do not have access to power or safe drinking water resources. These coexisting water and energy issues have traditionally been tackled as separate challenges. The Combined Power and Freshwater Generation (Combi-Gen) project aims to initiate a disruptive shift in the approach to the twin challenges of energy shortage and water-scarcity through development of a novel thermal chimney driven air-cooled condenser that will capture a substantial portion of the post-flash and reaction turbine geothermal vapour and convert it into potable water, without creating a parasitic power load. In order to enhance the design of such systems, a robust understanding of the geothermal resource and the wider hydrogeological systematics must be obtained. This is essential for assessment of fluid composition, analysis of scaling and corrosive species, flow rate and pressure control, and ultimately optimization of engineering performance. In addition, it is also imperative to gauge the wider hydrological connectivity of geothermal ground waters in order to establish potential impacts on the environment and existing essential water resources.