ISESCO JOURNAL of Science and Technology
The Official Journal of ISESCO Centre for Promotion of Scientific Research


In this paper, a geothermal-based tri-generation energy system with three useful outputs is proposed, namely electricity generation, water heating and hydrogen production. For this purpose, the three following parts are considered: Organic Rankine Cycle (ORC), Domestic water heater and Proton Exchange Membrane (PEM) electrolysis. To have a better view of the system’s performance, parametric studies of the effects of geofluid mass flow rate, turbine inlet temperature and pressure on the system’s energy and exergy are undertaken. The related energy and exergy efficiencies of the overall system are calculated around 35% and 59%, respectively, while these efficiencies with electricity generation and hot water production (combined heat and power) amount to 34% and 54%. These amounts for electricity generation only are 13% and 21%, respectively. The amounts of net electricity generation, hydrogen production and domestic hot water production in specific design parameter values are estimated to be around 60.84 kW, 0.026 mol/s and 1.023 kg/s, respectively.

Keywords: Geothermal, Tri-Generation, Organic Rankine Cycle, PEME