Thermodynamic Analysis and Multi-Objective Optimization of Binary Geothermal Power Plant Using CO_2 as Working Fluid with Genetic Algorithm Principles

The future of geothermal energy is increasingly linked to the development of Enhanced Geothermal Systems (EGS) technology, which promises to become a substantial renewable energy source. However, low heat recovery factors and water constraints hinder its widespread adoption. A promising solution to overcome water limitations is the utilization of CO2 as a working fluid in binary geothermal power plants, leveraging its lower boiling point to improve energy extraction efficiency. This research explores using CO2 to address these challenges as a working fluid in binary geothermal power plants to avoid water constraints, leveraging its lower boiling point to enhance energy extraction efficiency. A comprehensive thermodynamic and thermoeconomic analysis was conducted, focusing on the impact of temperature, pressure, and mass flow rate on the plant's exergetic efficiency, which represents the ability of the system to convert heat to valuable work and exergoeconomic performance that represents the economic consideration from energy produced with the parameter needs. Genetic algorithms are employed to optimize these parameters, a computational method inspired by natural selection that helps identify optimal solutions across a Pareto front, highlighting trade-offs between goals from multi-objective parameters. The Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS) was then used to determine the most favorable operating conditions. The results indicate that optimal conditions for CO2 are 140°C, 19,950 kPa, and 100.95 kg/s, achieving an energy efficiency of 30% and an exergoeconomic value of 0.14 $/s. These findings significantly advance the field by enhancing both the performance and economic viability of geothermal power plants, providing valuable insights for promoting sustainable energy solutions and mitigating environmental impacts. These research outcomes guide the optimal parameters to achieve the most optimal energy produced on the geothermal power plant by using CO2 as the working fluid.