Search

This paper presents a techno-economic assessment of a hybrid solar-geothermal power plant that is modelled taking into account the available geothermal and solar energy resources at the Tendaho-1 (Dubti) geothermal field in Ethiopia. The hybrid power plant combines a single-flash geothermal power plant with a parabolic trough solar thermal plant to increase the energy level of geothermal steam. The geothermal fluid from one of the production wells at the geothermal site and the direct normal solar irradiance prevailing in the area offer the primary sources of energy used in the modelling. A thermodynamic analysis based on the principles of mass and energy conservation and a figure of merit analysis that allows evaluating the energy and economic performance of the hybrid power plant were performed. The technical and economic efficiency assessment was performed by comparing the performances of the hybrid power plant with a power system consisting of stand-alone geothermal and solar power plants. Results of the techno-economic assessment showed that for the same amount of energy inputs, depending on the available thermal energy storage capacity, a hybrid power plant generates up to 10.4% more electricity than a power system of two stand-alone power plants while generating a higher net present value at a lower cost of generation. In addition, the hybrid power plants with and without thermal storage system exhibit an economic figure of merit values of 2.62 and 3.42, i.e. the cost of solar resource per kWh of electricity in the hybrid energy system is reduced by 70.5% and 61.5%, respectively.

An evaluation on the technoeconomic assessment of a hybrid solar-geothermal power plant is performed taking into account the geothermal and solar energy resources available at Tendaho -1 (Dubti) geothermal site in Ethiopia. A hybrid power plant in which a single-flash geothermal power plant integrated with a parabolic trough concentrated solar power system is used as a base for the technoeconomic analysis. The technoeconomic performance of the hybrid system was compared with a power generation system composed of stand-alone solar and geothermal power plants. Results showed that the that by combining the solar and geothermal energies, in hybrid power system it is possible to generate 10.4% more electricity than it would be generated by two-stand-alone power plants. Moreover, the economic figure of merit values is found to be 3.42 and 2.62 for the hybrid power plant with and without TES respectively. This mean that the specific cost of utilizing the solar energy in the hybrid power system is lower by 70.5% and 61.5% than the specific cost of utilizing the solar energy in stand-alone solar power plant.