Preliminary Feasibility Analysis on the Direct Use of Geothermal Energy in Rwanda: : Case Study Gisenyi Hot Spring

Abstract: The energy sector is a motor to speed up the economy development but is also a major pollutant. Rwanda, having about 60% of its total electricity production from imported fossil fuel (diesel generators), has adopted a strategy of energy diversification especially from renewable energy sources. Geothermal energy utilization in Rwanda is at the beginning stage and its development is ongoing, all efforts are made for electrical generation from geothermal energy in order to increase the installed capacity in Rwanda and to achieve the Millennium Development Goals objectives. Apart from electrical generation, geothermal energy can be used directly in thermal applications for various industrial or recreational purposes.   This study focuses on geothermal direct use in Rwanda. It is understandable that space heating is not an option in Rwanda because of the predominantly warm climate conditions, however, there are still many direct heating applications that can successfully be served by the existing geothermal fields. The current status of energy situation in Rwanda and the geothermal potential in the region have been examined. Many hot springs and volcanic areas having a feasible geothermal potential for direct applications are spread over the Northern province of Rwanda. Several possible geothermal energy projects are shortly discussed in the report, targeting mostly various drying processes. The specific focus of investigation has been the Gisenyi hot spring site, where temperature measurements were taken as well as the flow rate was evaluated in order to assess the applicability of a fish drying facility in Rubavu district near lake Kivu. Thermal calculations have been performed to estimate the heating energy required to dry 25 tons of fish per month from 80% down to 10% moisture content. The result shows that the available temperature and flow rate of the Gisenyi spring can easily cover the demand for fish drying even if the fishing industry doubles the production in the future. In addition, the parameters of the required heat exchanger were preliminary evaluated. A simplified economy analysis was attempted as well, resulting in an expected feedback period of 2.25 years.