Energy, Exergy, Economic, and Environmental (4E) analysis of a hybrid geothermal-solar energy system for energy cogeneration via ORC: Case study, Algeria

Abstract

In this study, the geothermal source of Hammam Debagh (north-east) in Algeria, was taken as a case study for modelling of a power and heat production system based on the use of an Organic Rankine Cycle (ORC) power plant. The ORC geothermal power plant is combined with a solar Fresnel Lens Reflector and parabolic Trough collector (FLR-PTC) system to form a hybrid geothermal solar ORC system (called HGS-ORC) and connected with a heating application system for district heating and drying. A thermodynamic (energy and exergy) analysis was carried out for different possible configurations of the HGS-ORC system. The configurations that were studied are basic HGS-ORC, two HGS-ORC configurations without recuperator with and without a mass flow control system of the working fluid, and two other HGS-ORC configurations equipped with a recuperator with and without a mass flow control system. An economic and environmental study of the different system configurations was made based on design data, local and global economic and environmental factors. The results show that the HGS-ORC configuration equipped with recuperator and control system has the best energy, exergy, economic and environmental (4E) performances. The estimated annual production of this configuration is about 10 GWh of electricity and more than 76 GWh of heat available for heating and drying. Based on a conventional power plant working with coal fired as heat source, the avoided CO2 emission by this configuration is about 12.84 t CO2/h.