Performance evaluation of a geothermal and solar-based multigeneration system and comparison with alternative case studies: Energy, exergy, and exergoeconomic aspects

This study modeled and analyzed the performance evaluation of a geothermal and solar-based multigeneration system and comparison with alternative case studies. For this purpose, three different models have been developed. In Model 1, a parabolic trough collector is used to transfer the energy in one stage. In Model 2, a parabolic trough collector transfers the heat in two stages. In Model 3, a system performs heat transfer with flat plate collectors in two stages. In addition, a hydrogen production system integrated into these models is also considered to store excess energy. These models are investigated for an existing region using geothermal and solar actual data from Afyonkarahisar in Turkey. The geothermal source is at a temperature of 130 °C and a flow rate of 85 kg/s. The solar incident varies between 400 and 1000 W/m2, with an average of 600 W/m2. The residual heat from the systems is used for residential heating. An electrolyzer and a fuel cell are integrated into the models. The costs of hydrogen and the conversion of electricity from hydrogen are investigated. When the exergy efficiencies are analyzed, they are 32.1%, 32.4%, and 30.6%. Hydrogen production costs of the models are calculated as 1.585 $/kg, 1.551 $/kg, and 1.585 $/kg. The conversion electricity costs of fuel cells are calculated as 0.0792, 0.0781, and 0.0792 $/kW, respectively.