An integrated bifacial photovoltaic and supercritical geothermal driven copper-chlorine thermochemical cycle for multigeneration

Abstract

This study thermodynamically investigates a newly developed supercritical geothermal and solar-based integrated energy system and applies to a local community which is near Kakkonda, WD-1a geothermal plant in Shinozaki, Japan. The proposed system produces useful outputs, such as electricity, heat for space heating and freshwater for self-consumption in the community and the auxiliary systems and hydrogen for commercial purposes. Thermochemical copper-chlorine cycle, bifacial photovoltaic plant, Rankine cycle, heat pump, and multi-effect water desalination subsystems are integrated into this unique system to employ solar, geothermal, and sea sources to produce useful outputs. The overall system and its components are analyzed thermodynamically using both energetic and exergetic approaches. The parametric studies and dynamic time-dependent simulations are carried out for performance assessment. The economic comparison methods are applied to determine feasibilities. According to the calculations, 2,144.45 tons of hydrogen is produced annually. A total of 204 households is considered to consume 1235 MWh electricity, 851 MWh thermal energy and 5,314.75 tons of freshwater annually. The overall energy and exergy efficiencies are 22.7% and 18.2%, respectively, for the average ambient conditions. The unit costs of useful commodities are found to be 2.73$/kg for the hydrogen, 0.023$/kWh for the electricity, 0.015$/kWh for the thermal energy, 0.47$/m3 for the freshwater. The overall system shows 5.15 years payback period with a 22% internal rate of return. The proposed subsystems and overall system possess environmentally benign, sustainable and reliable electricity, space heating, fresh water and hydrogen production system.