Multi-mode performance assessment of an innovative heat design structure for a geothermal plant using efficient heat recovery, producing power, cooling, hydrogen and freshwater

This work presents a novel method for using geothermal energy in a polygeneration system to produce electricity, chilled and hot water, fresh water, and hydrogen simultaneously. This solution has undergone extensive analysis, including evaluations from energy, exergy, economic, and environmental perspectives. The proposed process consists of Kalina cycle, ammonia Rankine cycle, desalination unit, transcritical carbon dioxide (CO2) cycle, and Proton exchange membrane (PEM) electrolyzer. An environmental assessment was conducted to determine the parameters related to oil fuel storage and to calculate the reduction in CO2 emissions compared to systems based on biomass, gaseous fuel, and shale gas. According to the economic assessment, two key parameters—total cost rate and total cost of exergy unit (TCEU)—were determined. For the scenario 1, the best findings for TCEU and energy efficiency values were 16.84 $/GJ and 29.55 %, correspondingly. In the scenario 2, the best findings for TCEU and exergy efficiency values were 12.25 $/GJ and 53.53 %, respectively. Ultimately, the best outcome for efficiencies of energy and exergy were 29.68 % and 59.86 %, respectively.