Feasibility design of an integrated single-flash binary pilot power plant in NW-Rwanda

Abstract

Having 60% of its total electricity production dependent on diesel generators, Rwanda has adopted a strategy to produce its energy from other sources, especially from renewable ones. Geothermal energy is one of the most promising resources and its development is ongoing. The purpose of this report is to pre-design a pilot geothermal power plant intended to be used in the country. In this study, an integrated single-flash binary power plant has been proposed and the modelling was done using the Engineering Equation Solver (EES) software. The results show that a back-pressure turbine for the pilot power plant is best option, both economically and with regard to technical aspects. About 23 kJ per 1 kg of geothermal fluid can be produced, and later an Organic Rankine Cycle (ORC) can be added to reach about 86 kJ per 1 kg of fluid. At this stage, the overall first law of utilisation efficiency will be 10.4% and the second law efficiency will be about 47.5% which is good compared with other geothermal plant cycles.